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 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  libata-core.c - helper library for ATA
  *
  *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
  *  Copyright 2003-2004 Jeff Garzik
  *
  *  libata documentation is available via 'make {ps|pdf}docs',
  *  as Documentation/driver-api/libata.rst
  *
  *  Hardware documentation available from http://www.t13.org/ and
  *  http://www.sata-io.org/
  *
  *  Standards documents from:
  *  http://www.t13.org (ATA standards, PCI DMA IDE spec)
  *  http://www.t10.org (SCSI MMC - for ATAPI MMC)
  *  http://www.sata-io.org (SATA)
  *  http://www.compactflash.org (CF)
  *  http://www.qic.org (QIC157 - Tape and DSC)
  *  http://www.ce-ata.org (CE-ATA: not supported)
  *
  * libata is essentially a library of internal helper functions for
  * low-level ATA host controller drivers.  As such, the API/ABI is
  * likely to change as new drivers are added and updated.
  * Do not depend on ABI/API stability.
  */
 
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/mm.h>
 #include <linux/spinlock.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
 #include <linux/timer.h>
 #include <linux/time.h>
 #include <linux/interrupt.h>
 #include <linux/completion.h>
 #include <linux/suspend.h>
 #include <linux/workqueue.h>
 #include <linux/scatterlist.h>
 #include <linux/io.h>
 #include <linux/log2.h>
 #include <linux/slab.h>
 #include <linux/glob.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_host.h>
 #include <linux/libata.h>
 #include <asm/byteorder.h>
 #include <asm/unaligned.h>
 #include <linux/cdrom.h>
 #include <linux/ratelimit.h>
 #include <linux/leds.h>
 #include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 #include <asm/setup.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/libata.h>
 
 #include "libata.h"
 #include "libata-transport.h"
 
 const struct ata_port_operations ata_base_port_ops = {
     .prereset       = ata_std_prereset,
     .postreset      = ata_std_postreset,
     .error_handler      = ata_std_error_handler,
     .sched_eh       = ata_std_sched_eh,
     .end_eh         = ata_std_end_eh,
 };
 
 const struct ata_port_operations sata_port_ops = {
     .inherits       = &ata_base_port_ops,
 
     .qc_defer       = ata_std_qc_defer,
     .hardreset      = sata_std_hardreset,
 };
 EXPORT_SYMBOL_GPL(sata_port_ops);
 
 static unsigned int ata_dev_init_params(struct ata_device *dev,
                     u16 heads, u16 sectors);
 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
 static void ata_dev_xfermask(struct ata_device *dev);
 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
 
 atomic_t ata_print_id = ATOMIC_INIT(0);
 
 #ifdef CONFIG_ATA_FORCE
 struct ata_force_param {
     const char  *name;
     u8      cbl;
     u8      spd_limit;
     unsigned int    xfer_mask;
     unsigned int    horkage_on;
     unsigned int    horkage_off;
     u16     lflags_on;
     u16     lflags_off;
 };
 
 struct ata_force_ent {
     int         port;
     int         device;
     struct ata_force_param  param;
 };
 
 static struct ata_force_ent *ata_force_tbl;
 static int ata_force_tbl_size;
 
 static char ata_force_param_buf[COMMAND_LINE_SIZE] __initdata;
 /* param_buf is thrown away after initialization, disallow read */
 module_param_string(force, ata_force_param_buf, sizeof(ata_force_param_buf), 0);
 MODULE_PARM_DESC(force, "Force ATA configurations including cable type, link speed and transfer mode (see Documentation/admin-guide/kernel-parameters.rst for details)");
 #endif
 
 static int atapi_enabled = 1;
 module_param(atapi_enabled, int, 0444);
 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on [default])");
 
 static int atapi_dmadir = 0;
 module_param(atapi_dmadir, int, 0444);
 MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off [default], 1=on)");
 
 int atapi_passthru16 = 1;
 module_param(atapi_passthru16, int, 0444);
 MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
 
 int libata_fua = 0;
 module_param_named(fua, libata_fua, int, 0444);
 MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
 
 static int ata_ignore_hpa;
 module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);
 MODULE_PARM_DESC(ignore_hpa, "Ignore HPA limit (0=keep BIOS limits, 1=ignore limits, using full disk)");
 
 static int libata_dma_mask = ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CFA;
 module_param_named(dma, libata_dma_mask, int, 0444);
 MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");
 
 static int ata_probe_timeout;
 module_param(ata_probe_timeout, int, 0444);
 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
 
 int libata_noacpi = 0;
 module_param_named(noacpi, libata_noacpi, int, 0444);
 MODULE_PARM_DESC(noacpi, "Disable the use of ACPI in probe/suspend/resume (0=off [default], 1=on)");
 
 int libata_allow_tpm = 0;
 module_param_named(allow_tpm, libata_allow_tpm, int, 0444);
 MODULE_PARM_DESC(allow_tpm, "Permit the use of TPM commands (0=off [default], 1=on)");
 
 static int atapi_an;
 module_param(atapi_an, int, 0444);
 MODULE_PARM_DESC(atapi_an, "Enable ATAPI AN media presence notification (0=0ff [default], 1=on)");
 
 MODULE_AUTHOR("Jeff Garzik");
 MODULE_DESCRIPTION("Library module for ATA devices");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
 
 static inline bool ata_dev_print_info(struct ata_device *dev)
 {
     struct ata_eh_context *ehc = &dev->link->eh_context;
 
     return ehc->i.flags & ATA_EHI_PRINTINFO;
 }
 
 static bool ata_sstatus_online(u32 sstatus)
 {
     return (sstatus & 0xf) == 0x3;
 }
 
 /**
  *  ata_link_next - link iteration helper
  *  @link: the previous link, NULL to start
  *  @ap: ATA port containing links to iterate
  *  @mode: iteration mode, one of ATA_LITER_*
  *
  *  LOCKING:
  *  Host lock or EH context.
  *
  *  RETURNS:
  *  Pointer to the next link.
  */
 struct ata_link *ata_link_next(struct ata_link *link, struct ata_port *ap,
                    enum ata_link_iter_mode mode)
 {
     BUG_ON(mode != ATA_LITER_EDGE &&
            mode != ATA_LITER_PMP_FIRST && mode != ATA_LITER_HOST_FIRST);
 
     /* NULL link indicates start of iteration */
     if (!link)
         switch (mode) {
         case ATA_LITER_EDGE:
         case ATA_LITER_PMP_FIRST:
             if (sata_pmp_attached(ap))
                 return ap->pmp_link;
             fallthrough;
         case ATA_LITER_HOST_FIRST:
             return &ap->link;
         }
 
     /* we just iterated over the host link, what's next? */
     if (link == &ap->link)
         switch (mode) {
         case ATA_LITER_HOST_FIRST:
             if (sata_pmp_attached(ap))
                 return ap->pmp_link;
             fallthrough;
         case ATA_LITER_PMP_FIRST:
             if (unlikely(ap->slave_link))
                 return ap->slave_link;
             fallthrough;
         case ATA_LITER_EDGE:
             return NULL;
         }
 
     /* slave_link excludes PMP */
     if (unlikely(link == ap->slave_link))
         return NULL;
 
     /* we were over a PMP link */
     if (++link < ap->pmp_link + ap->nr_pmp_links)
         return link;
 
     if (mode == ATA_LITER_PMP_FIRST)
         return &ap->link;
 
     return NULL;
 }
 EXPORT_SYMBOL_GPL(ata_link_next);
 
 /**
  *  ata_dev_next - device iteration helper
  *  @dev: the previous device, NULL to start
  *  @link: ATA link containing devices to iterate
  *  @mode: iteration mode, one of ATA_DITER_*
  *
  *  LOCKING:
  *  Host lock or EH context.
  *
  *  RETURNS:
  *  Pointer to the next device.
  */
 struct ata_device *ata_dev_next(struct ata_device *dev, struct ata_link *link,
                 enum ata_dev_iter_mode mode)
 {
     BUG_ON(mode != ATA_DITER_ENABLED && mode != ATA_DITER_ENABLED_REVERSE &&
            mode != ATA_DITER_ALL && mode != ATA_DITER_ALL_REVERSE);
 
     /* NULL dev indicates start of iteration */
     if (!dev)
         switch (mode) {
         case ATA_DITER_ENABLED:
         case ATA_DITER_ALL:
             dev = link->device;
             goto check;
         case ATA_DITER_ENABLED_REVERSE:
         case ATA_DITER_ALL_REVERSE:
             dev = link->device + ata_link_max_devices(link) - 1;
             goto check;
         }
 
  next:
     /* move to the next one */
     switch (mode) {
     case ATA_DITER_ENABLED:
     case ATA_DITER_ALL:
         if (++dev < link->device + ata_link_max_devices(link))
             goto check;
         return NULL;
     case ATA_DITER_ENABLED_REVERSE:
     case ATA_DITER_ALL_REVERSE:
         if (--dev >= link->device)
             goto check;
         return NULL;
     }
 
  check:
     if ((mode == ATA_DITER_ENABLED || mode == ATA_DITER_ENABLED_REVERSE) &&
         !ata_dev_enabled(dev))
         goto next;
     return dev;
 }
 EXPORT_SYMBOL_GPL(ata_dev_next);
 
 /**
  *  ata_dev_phys_link - find physical link for a device
  *  @dev: ATA device to look up physical link for
  *
  *  Look up physical link which @dev is attached to.  Note that
  *  this is different from @dev->link only when @dev is on slave
  *  link.  For all other cases, it's the same as @dev->link.
  *
  *  LOCKING:
  *  Don't care.
  *
  *  RETURNS:
  *  Pointer to the found physical link.
  */
 struct ata_link *ata_dev_phys_link(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
 
     if (!ap->slave_link)
         return dev->link;
     if (!dev->devno)
         return &ap->link;
     return ap->slave_link;
 }
 
 #ifdef CONFIG_ATA_FORCE
 /**
  *  ata_force_cbl - force cable type according to libata.force
  *  @ap: ATA port of interest
  *
  *  Force cable type according to libata.force and whine about it.
  *  The last entry which has matching port number is used, so it
  *  can be specified as part of device force parameters.  For
  *  example, both "a:40c,1.00:udma4" and "1.00:40c,udma4" have the
  *  same effect.
  *
  *  LOCKING:
  *  EH context.
  */
 void ata_force_cbl(struct ata_port *ap)
 {
     int i;
 
     for (i = ata_force_tbl_size - 1; i >= 0; i--) {
         const struct ata_force_ent *fe = &ata_force_tbl[i];
 
         if (fe->port != -1 && fe->port != ap->print_id)
             continue;
 
         if (fe->param.cbl == ATA_CBL_NONE)
             continue;
 
         ap->cbl = fe->param.cbl;
         ata_port_notice(ap, "FORCE: cable set to %s\n", fe->param.name);
         return;
     }
 }
 
 /**
  *  ata_force_link_limits - force link limits according to libata.force
  *  @link: ATA link of interest
  *
  *  Force link flags and SATA spd limit according to libata.force
  *  and whine about it.  When only the port part is specified
  *  (e.g. 1:), the limit applies to all links connected to both
  *  the host link and all fan-out ports connected via PMP.  If the
  *  device part is specified as 0 (e.g. 1.00:), it specifies the
  *  first fan-out link not the host link.  Device number 15 always
  *  points to the host link whether PMP is attached or not.  If the
  *  controller has slave link, device number 16 points to it.
  *
  *  LOCKING:
  *  EH context.
  */
 static void ata_force_link_limits(struct ata_link *link)
 {
     bool did_spd = false;
     int linkno = link->pmp;
     int i;
 
     if (ata_is_host_link(link))
         linkno += 15;
 
     for (i = ata_force_tbl_size - 1; i >= 0; i--) {
         const struct ata_force_ent *fe = &ata_force_tbl[i];
 
         if (fe->port != -1 && fe->port != link->ap->print_id)
             continue;
 
         if (fe->device != -1 && fe->device != linkno)
             continue;
 
         /* only honor the first spd limit */
         if (!did_spd && fe->param.spd_limit) {
             link->hw_sata_spd_limit = (1 << fe->param.spd_limit) - 1;
             ata_link_notice(link, "FORCE: PHY spd limit set to %s\n",
                     fe->param.name);
             did_spd = true;
         }
 
         /* let lflags stack */
         if (fe->param.lflags_on) {
             link->flags |= fe->param.lflags_on;
             ata_link_notice(link,
                     "FORCE: link flag 0x%x forced -> 0x%x\n",
                     fe->param.lflags_on, link->flags);
         }
         if (fe->param.lflags_off) {
             link->flags &= ~fe->param.lflags_off;
             ata_link_notice(link,
                 "FORCE: link flag 0x%x cleared -> 0x%x\n",
                 fe->param.lflags_off, link->flags);
         }
     }
 }
 
 /**
  *  ata_force_xfermask - force xfermask according to libata.force
  *  @dev: ATA device of interest
  *
  *  Force xfer_mask according to libata.force and whine about it.
  *  For consistency with link selection, device number 15 selects
  *  the first device connected to the host link.
  *
  *  LOCKING:
  *  EH context.
  */
 static void ata_force_xfermask(struct ata_device *dev)
 {
     int devno = dev->link->pmp + dev->devno;
     int alt_devno = devno;
     int i;
 
     /* allow n.15/16 for devices attached to host port */
     if (ata_is_host_link(dev->link))
         alt_devno += 15;
 
     for (i = ata_force_tbl_size - 1; i >= 0; i--) {
         const struct ata_force_ent *fe = &ata_force_tbl[i];
         unsigned int pio_mask, mwdma_mask, udma_mask;
 
         if (fe->port != -1 && fe->port != dev->link->ap->print_id)
             continue;
 
         if (fe->device != -1 && fe->device != devno &&
             fe->device != alt_devno)
             continue;
 
         if (!fe->param.xfer_mask)
             continue;
 
         ata_unpack_xfermask(fe->param.xfer_mask,
                     &pio_mask, &mwdma_mask, &udma_mask);
         if (udma_mask)
             dev->udma_mask = udma_mask;
         else if (mwdma_mask) {
             dev->udma_mask = 0;
             dev->mwdma_mask = mwdma_mask;
         } else {
             dev->udma_mask = 0;
             dev->mwdma_mask = 0;
             dev->pio_mask = pio_mask;
         }
 
         ata_dev_notice(dev, "FORCE: xfer_mask set to %s\n",
                    fe->param.name);
         return;
     }
 }
 
 /**
  *  ata_force_horkage - force horkage according to libata.force
  *  @dev: ATA device of interest
  *
  *  Force horkage according to libata.force and whine about it.
  *  For consistency with link selection, device number 15 selects
  *  the first device connected to the host link.
  *
  *  LOCKING:
  *  EH context.
  */
 static void ata_force_horkage(struct ata_device *dev)
 {
     int devno = dev->link->pmp + dev->devno;
     int alt_devno = devno;
     int i;
 
     /* allow n.15/16 for devices attached to host port */
     if (ata_is_host_link(dev->link))
         alt_devno += 15;
 
     for (i = 0; i < ata_force_tbl_size; i++) {
         const struct ata_force_ent *fe = &ata_force_tbl[i];
 
         if (fe->port != -1 && fe->port != dev->link->ap->print_id)
             continue;
 
         if (fe->device != -1 && fe->device != devno &&
             fe->device != alt_devno)
             continue;
 
         if (!(~dev->horkage & fe->param.horkage_on) &&
             !(dev->horkage & fe->param.horkage_off))
             continue;
 
         dev->horkage |= fe->param.horkage_on;
         dev->horkage &= ~fe->param.horkage_off;
 
         ata_dev_notice(dev, "FORCE: horkage modified (%s)\n",
                    fe->param.name);
     }
 }
 #else
 static inline void ata_force_link_limits(struct ata_link *link) { }
 static inline void ata_force_xfermask(struct ata_device *dev) { }
 static inline void ata_force_horkage(struct ata_device *dev) { }
 #endif
 
 /**
  *  atapi_cmd_type - Determine ATAPI command type from SCSI opcode
  *  @opcode: SCSI opcode
  *
  *  Determine ATAPI command type from @opcode.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  ATAPI_{READ|WRITE|READ_CD|PASS_THRU|MISC}
  */
 int atapi_cmd_type(u8 opcode)
 {
     switch (opcode) {
     case GPCMD_READ_10:
     case GPCMD_READ_12:
         return ATAPI_READ;
 
     case GPCMD_WRITE_10:
     case GPCMD_WRITE_12:
     case GPCMD_WRITE_AND_VERIFY_10:
         return ATAPI_WRITE;
 
     case GPCMD_READ_CD:
     case GPCMD_READ_CD_MSF:
         return ATAPI_READ_CD;
 
     case ATA_16:
     case ATA_12:
         if (atapi_passthru16)
             return ATAPI_PASS_THRU;
         fallthrough;
     default:
         return ATAPI_MISC;
     }
 }
 EXPORT_SYMBOL_GPL(atapi_cmd_type);
 
 static const u8 ata_rw_cmds[] = {
     /* pio multi */
     ATA_CMD_READ_MULTI,
     ATA_CMD_WRITE_MULTI,
     ATA_CMD_READ_MULTI_EXT,
     ATA_CMD_WRITE_MULTI_EXT,
     0,
     0,
     0,
     ATA_CMD_WRITE_MULTI_FUA_EXT,
     /* pio */
     ATA_CMD_PIO_READ,
     ATA_CMD_PIO_WRITE,
     ATA_CMD_PIO_READ_EXT,
     ATA_CMD_PIO_WRITE_EXT,
     0,
     0,
     0,
     0,
     /* dma */
     ATA_CMD_READ,
     ATA_CMD_WRITE,
     ATA_CMD_READ_EXT,
     ATA_CMD_WRITE_EXT,
     0,
     0,
     0,
     ATA_CMD_WRITE_FUA_EXT
 };
 
 /**
  *  ata_rwcmd_protocol - set taskfile r/w commands and protocol
  *  @tf: command to examine and configure
  *  @dev: device tf belongs to
  *
  *  Examine the device configuration and tf->flags to calculate
  *  the proper read/write commands and protocol to use.
  *
  *  LOCKING:
  *  caller.
  */
 static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
 {
     u8 cmd;
 
     int index, fua, lba48, write;
 
     fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
     lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
     write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
 
     if (dev->flags & ATA_DFLAG_PIO) {
         tf->protocol = ATA_PROT_PIO;
         index = dev->multi_count ? 0 : 8;
     } else if (lba48 && (dev->link->ap->flags & ATA_FLAG_PIO_LBA48)) {
         /* Unable to use DMA due to host limitation */
         tf->protocol = ATA_PROT_PIO;
         index = dev->multi_count ? 0 : 8;
     } else {
         tf->protocol = ATA_PROT_DMA;
         index = 16;
     }
 
     cmd = ata_rw_cmds[index + fua + lba48 + write];
     if (cmd) {
         tf->command = cmd;
         return 0;
     }
     return -1;
 }
 
 /**
  *  ata_tf_read_block - Read block address from ATA taskfile
  *  @tf: ATA taskfile of interest
  *  @dev: ATA device @tf belongs to
  *
  *  LOCKING:
  *  None.
  *
  *  Read block address from @tf.  This function can handle all
  *  three address formats - LBA, LBA48 and CHS.  tf->protocol and
  *  flags select the address format to use.
  *
  *  RETURNS:
  *  Block address read from @tf.
  */
 u64 ata_tf_read_block(const struct ata_taskfile *tf, struct ata_device *dev)
 {
     u64 block = 0;
 
     if (tf->flags & ATA_TFLAG_LBA) {
         if (tf->flags & ATA_TFLAG_LBA48) {
             block |= (u64)tf->hob_lbah << 40;
             block |= (u64)tf->hob_lbam << 32;
             block |= (u64)tf->hob_lbal << 24;
         } else
             block |= (tf->device & 0xf) << 24;
 
         block |= tf->lbah << 16;
         block |= tf->lbam << 8;
         block |= tf->lbal;
     } else {
         u32 cyl, head, sect;
 
         cyl = tf->lbam | (tf->lbah << 8);
         head = tf->device & 0xf;
         sect = tf->lbal;
 
         if (!sect) {
             ata_dev_warn(dev,
                      "device reported invalid CHS sector 0\n");
             return U64_MAX;
         }
 
         block = (cyl * dev->heads + head) * dev->sectors + sect - 1;
     }
 
     return block;
 }
 
 /**
  *  ata_build_rw_tf - Build ATA taskfile for given read/write request
  *  @tf: Target ATA taskfile
  *  @dev: ATA device @tf belongs to
  *  @block: Block address
  *  @n_block: Number of blocks
  *  @tf_flags: RW/FUA etc...
  *  @tag: tag
  *  @class: IO priority class
  *
  *  LOCKING:
  *  None.
  *
  *  Build ATA taskfile @tf for read/write request described by
  *  @block, @n_block, @tf_flags and @tag on @dev.
  *
  *  RETURNS:
  *
  *  0 on success, -ERANGE if the request is too large for @dev,
  *  -EINVAL if the request is invalid.
  */
 int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
             u64 block, u32 n_block, unsigned int tf_flags,
             unsigned int tag, int class)
 {
     tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
     tf->flags |= tf_flags;
 
     if (ata_ncq_enabled(dev) && !ata_tag_internal(tag)) {
         /* yay, NCQ */
         if (!lba_48_ok(block, n_block))
             return -ERANGE;
 
         tf->protocol = ATA_PROT_NCQ;
         tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
 
         if (tf->flags & ATA_TFLAG_WRITE)
             tf->command = ATA_CMD_FPDMA_WRITE;
         else
             tf->command = ATA_CMD_FPDMA_READ;
 
         tf->nsect = tag << 3;
         tf->hob_feature = (n_block >> 8) & 0xff;
         tf->feature = n_block & 0xff;
 
         tf->hob_lbah = (block >> 40) & 0xff;
         tf->hob_lbam = (block >> 32) & 0xff;
         tf->hob_lbal = (block >> 24) & 0xff;
         tf->lbah = (block >> 16) & 0xff;
         tf->lbam = (block >> 8) & 0xff;
         tf->lbal = block & 0xff;
 
         tf->device = ATA_LBA;
         if (tf->flags & ATA_TFLAG_FUA)
             tf->device |= 1 << 7;
 
         if (dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLE &&
             class == IOPRIO_CLASS_RT)
             tf->hob_nsect |= ATA_PRIO_HIGH << ATA_SHIFT_PRIO;
     } else if (dev->flags & ATA_DFLAG_LBA) {
         tf->flags |= ATA_TFLAG_LBA;
 
         if (lba_28_ok(block, n_block)) {
             /* use LBA28 */
             tf->device |= (block >> 24) & 0xf;
         } else if (lba_48_ok(block, n_block)) {
             if (!(dev->flags & ATA_DFLAG_LBA48))
                 return -ERANGE;
 
             /* use LBA48 */
             tf->flags |= ATA_TFLAG_LBA48;
 
             tf->hob_nsect = (n_block >> 8) & 0xff;
 
             tf->hob_lbah = (block >> 40) & 0xff;
             tf->hob_lbam = (block >> 32) & 0xff;
             tf->hob_lbal = (block >> 24) & 0xff;
         } else
             /* request too large even for LBA48 */
             return -ERANGE;
 
         if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
             return -EINVAL;
 
         tf->nsect = n_block & 0xff;
 
         tf->lbah = (block >> 16) & 0xff;
         tf->lbam = (block >> 8) & 0xff;
         tf->lbal = block & 0xff;
 
         tf->device |= ATA_LBA;
     } else {
         /* CHS */
         u32 sect, head, cyl, track;
 
         /* The request -may- be too large for CHS addressing. */
         if (!lba_28_ok(block, n_block))
             return -ERANGE;
 
         if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
             return -EINVAL;
 
         /* Convert LBA to CHS */
         track = (u32)block / dev->sectors;
         cyl   = track / dev->heads;
         head  = track % dev->heads;
         sect  = (u32)block % dev->sectors + 1;
 
         /* Check whether the converted CHS can fit.
            Cylinder: 0-65535
            Head: 0-15
            Sector: 1-255*/
         if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
             return -ERANGE;
 
         tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
         tf->lbal = sect;
         tf->lbam = cyl;
         tf->lbah = cyl >> 8;
         tf->device |= head;
     }
 
     return 0;
 }
 
 /**
  *  ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
  *  @pio_mask: pio_mask
  *  @mwdma_mask: mwdma_mask
  *  @udma_mask: udma_mask
  *
  *  Pack @pio_mask, @mwdma_mask and @udma_mask into a single
  *  unsigned int xfer_mask.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  Packed xfer_mask.
  */
 unsigned int ata_pack_xfermask(unsigned int pio_mask,
                    unsigned int mwdma_mask,
                    unsigned int udma_mask)
 {
     return  ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
         ((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
         ((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
 }
 EXPORT_SYMBOL_GPL(ata_pack_xfermask);
 
 /**
  *  ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
  *  @xfer_mask: xfer_mask to unpack
  *  @pio_mask: resulting pio_mask
  *  @mwdma_mask: resulting mwdma_mask
  *  @udma_mask: resulting udma_mask
  *
  *  Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
  *  Any NULL destination masks will be ignored.
  */
 void ata_unpack_xfermask(unsigned int xfer_mask, unsigned int *pio_mask,
              unsigned int *mwdma_mask, unsigned int *udma_mask)
 {
     if (pio_mask)
         *pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
     if (mwdma_mask)
         *mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
     if (udma_mask)
         *udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
 }
 
 static const struct ata_xfer_ent {
     int shift, bits;
     u8 base;
 } ata_xfer_tbl[] = {
     { ATA_SHIFT_PIO, ATA_NR_PIO_MODES, XFER_PIO_0 },
     { ATA_SHIFT_MWDMA, ATA_NR_MWDMA_MODES, XFER_MW_DMA_0 },
     { ATA_SHIFT_UDMA, ATA_NR_UDMA_MODES, XFER_UDMA_0 },
     { -1, },
 };
 
 /**
  *  ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
  *  @xfer_mask: xfer_mask of interest
  *
  *  Return matching XFER_* value for @xfer_mask.  Only the highest
  *  bit of @xfer_mask is considered.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  Matching XFER_* value, 0xff if no match found.
  */
 u8 ata_xfer_mask2mode(unsigned int xfer_mask)
 {
     int highbit = fls(xfer_mask) - 1;
     const struct ata_xfer_ent *ent;
 
     for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
         if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
             return ent->base + highbit - ent->shift;
     return 0xff;
 }
 EXPORT_SYMBOL_GPL(ata_xfer_mask2mode);
 
 /**
  *  ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
  *  @xfer_mode: XFER_* of interest
  *
  *  Return matching xfer_mask for @xfer_mode.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  Matching xfer_mask, 0 if no match found.
  */
 unsigned int ata_xfer_mode2mask(u8 xfer_mode)
 {
     const struct ata_xfer_ent *ent;
 
     for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
         if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
             return ((2 << (ent->shift + xfer_mode - ent->base)) - 1)
                 & ~((1 << ent->shift) - 1);
     return 0;
 }
 EXPORT_SYMBOL_GPL(ata_xfer_mode2mask);
 
 /**
  *  ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
  *  @xfer_mode: XFER_* of interest
  *
  *  Return matching xfer_shift for @xfer_mode.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  Matching xfer_shift, -1 if no match found.
  */
 int ata_xfer_mode2shift(u8 xfer_mode)
 {
     const struct ata_xfer_ent *ent;
 
     for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
         if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
             return ent->shift;
     return -1;
 }
 EXPORT_SYMBOL_GPL(ata_xfer_mode2shift);
 
 /**
  *  ata_mode_string - convert xfer_mask to string
  *  @xfer_mask: mask of bits supported; only highest bit counts.
  *
  *  Determine string which represents the highest speed
  *  (highest bit in @modemask).
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  Constant C string representing highest speed listed in
  *  @mode_mask, or the constant C string "<n/a>".
  */
 const char *ata_mode_string(unsigned int xfer_mask)
 {
     static const char * const xfer_mode_str[] = {
         "PIO0",
         "PIO1",
         "PIO2",
         "PIO3",
         "PIO4",
         "PIO5",
         "PIO6",
         "MWDMA0",
         "MWDMA1",
         "MWDMA2",
         "MWDMA3",
         "MWDMA4",
         "UDMA/16",
         "UDMA/25",
         "UDMA/33",
         "UDMA/44",
         "UDMA/66",
         "UDMA/100",
         "UDMA/133",
         "UDMA7",
     };
     int highbit;
 
     highbit = fls(xfer_mask) - 1;
     if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
         return xfer_mode_str[highbit];
     return "<n/a>";
 }
 EXPORT_SYMBOL_GPL(ata_mode_string);
 
 const char *sata_spd_string(unsigned int spd)
 {
     static const char * const spd_str[] = {
         "1.5 Gbps",
         "3.0 Gbps",
         "6.0 Gbps",
     };
 
     if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
         return "<unknown>";
     return spd_str[spd - 1];
 }
 
 /**
  *  ata_dev_classify - determine device type based on ATA-spec signature
  *  @tf: ATA taskfile register set for device to be identified
  *
  *  Determine from taskfile register contents whether a device is
  *  ATA or ATAPI, as per "Signature and persistence" section
  *  of ATA/PI spec (volume 1, sect 5.14).
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP,
  *  %ATA_DEV_ZAC, or %ATA_DEV_UNKNOWN the event of failure.
  */
 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
 {
     /* Apple's open source Darwin code hints that some devices only
      * put a proper signature into the LBA mid/high registers,
      * So, we only check those.  It's sufficient for uniqueness.
      *
      * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
      * signatures for ATA and ATAPI devices attached on SerialATA,
      * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
      * spec has never mentioned about using different signatures
      * for ATA/ATAPI devices.  Then, Serial ATA II: Port
      * Multiplier specification began to use 0x69/0x96 to identify
      * port multpliers and 0x3c/0xc3 to identify SEMB device.
      * ATA/ATAPI-7 dropped descriptions about 0x3c/0xc3 and
      * 0x69/0x96 shortly and described them as reserved for
      * SerialATA.
      *
      * We follow the current spec and consider that 0x69/0x96
      * identifies a port multiplier and 0x3c/0xc3 a SEMB device.
      * Unfortunately, WDC WD1600JS-62MHB5 (a hard drive) reports
      * SEMB signature.  This is worked around in
      * ata_dev_read_id().
      */
     if (tf->lbam == 0 && tf->lbah == 0)
         return ATA_DEV_ATA;
 
     if (tf->lbam == 0x14 && tf->lbah == 0xeb)
         return ATA_DEV_ATAPI;
 
     if (tf->lbam == 0x69 && tf->lbah == 0x96)
         return ATA_DEV_PMP;
 
     if (tf->lbam == 0x3c && tf->lbah == 0xc3)
         return ATA_DEV_SEMB;
 
     if (tf->lbam == 0xcd && tf->lbah == 0xab)
         return ATA_DEV_ZAC;
 
     return ATA_DEV_UNKNOWN;
 }
 EXPORT_SYMBOL_GPL(ata_dev_classify);
 
 /**
  *  ata_id_string - Convert IDENTIFY DEVICE page into string
  *  @id: IDENTIFY DEVICE results we will examine
  *  @s: string into which data is output
  *  @ofs: offset into identify device page
  *  @len: length of string to return. must be an even number.
  *
  *  The strings in the IDENTIFY DEVICE page are broken up into
  *  16-bit chunks.  Run through the string, and output each
  *  8-bit chunk linearly, regardless of platform.
  *
  *  LOCKING:
  *  caller.
  */
 
 void ata_id_string(const u16 *id, unsigned char *s,
            unsigned int ofs, unsigned int len)
 {
     unsigned int c;
 
     BUG_ON(len & 1);
 
     while (len > 0) {
         c = id[ofs] >> 8;
         *s = c;
         s++;
 
         c = id[ofs] & 0xff;
         *s = c;
         s++;
 
         ofs++;
         len -= 2;
     }
 }
 EXPORT_SYMBOL_GPL(ata_id_string);
 
 /**
  *  ata_id_c_string - Convert IDENTIFY DEVICE page into C string
  *  @id: IDENTIFY DEVICE results we will examine
  *  @s: string into which data is output
  *  @ofs: offset into identify device page
  *  @len: length of string to return. must be an odd number.
  *
  *  This function is identical to ata_id_string except that it
  *  trims trailing spaces and terminates the resulting string with
  *  null.  @len must be actual maximum length (even number) + 1.
  *
  *  LOCKING:
  *  caller.
  */
 void ata_id_c_string(const u16 *id, unsigned char *s,
              unsigned int ofs, unsigned int len)
 {
     unsigned char *p;
 
     ata_id_string(id, s, ofs, len - 1);
 
     p = s + strnlen(s, len - 1);
     while (p > s && p[-1] == ' ')
         p--;
     *p = '\0';
 }
 EXPORT_SYMBOL_GPL(ata_id_c_string);
 
 static u64 ata_id_n_sectors(const u16 *id)
 {
     if (ata_id_has_lba(id)) {
         if (ata_id_has_lba48(id))
             return ata_id_u64(id, ATA_ID_LBA_CAPACITY_2);
 
         return ata_id_u32(id, ATA_ID_LBA_CAPACITY);
     }
 
     if (ata_id_current_chs_valid(id))
         return (u32)id[ATA_ID_CUR_CYLS] * (u32)id[ATA_ID_CUR_HEADS] *
                (u32)id[ATA_ID_CUR_SECTORS];
 
     return (u32)id[ATA_ID_CYLS] * (u32)id[ATA_ID_HEADS] *
            (u32)id[ATA_ID_SECTORS];
 }
 
 u64 ata_tf_to_lba48(const struct ata_taskfile *tf)
 {
     u64 sectors = 0;
 
     sectors |= ((u64)(tf->hob_lbah & 0xff)) << 40;
     sectors |= ((u64)(tf->hob_lbam & 0xff)) << 32;
     sectors |= ((u64)(tf->hob_lbal & 0xff)) << 24;
     sectors |= (tf->lbah & 0xff) << 16;
     sectors |= (tf->lbam & 0xff) << 8;
     sectors |= (tf->lbal & 0xff);
 
     return sectors;
 }
 
 u64 ata_tf_to_lba(const struct ata_taskfile *tf)
 {
     u64 sectors = 0;
 
     sectors |= (tf->device & 0x0f) << 24;
     sectors |= (tf->lbah & 0xff) << 16;
     sectors |= (tf->lbam & 0xff) << 8;
     sectors |= (tf->lbal & 0xff);
 
     return sectors;
 }
 
 /**
  *  ata_read_native_max_address - Read native max address
  *  @dev: target device
  *  @max_sectors: out parameter for the result native max address
  *
  *  Perform an LBA48 or LBA28 native size query upon the device in
  *  question.
  *
  *  RETURNS:
  *  0 on success, -EACCES if command is aborted by the drive.
  *  -EIO on other errors.
  */
 static int ata_read_native_max_address(struct ata_device *dev, u64 *max_sectors)
 {
     unsigned int err_mask;
     struct ata_taskfile tf;
     int lba48 = ata_id_has_lba48(dev->id);
 
     ata_tf_init(dev, &tf);
 
     /* always clear all address registers */
     tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
 
     if (lba48) {
         tf.command = ATA_CMD_READ_NATIVE_MAX_EXT;
         tf.flags |= ATA_TFLAG_LBA48;
     } else
         tf.command = ATA_CMD_READ_NATIVE_MAX;
 
     tf.protocol = ATA_PROT_NODATA;
     tf.device |= ATA_LBA;
 
     err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
     if (err_mask) {
         ata_dev_warn(dev,
                  "failed to read native max address (err_mask=0x%x)\n",
                  err_mask);
         if (err_mask == AC_ERR_DEV && (tf.error & ATA_ABORTED))
             return -EACCES;
         return -EIO;
     }
 
     if (lba48)
         *max_sectors = ata_tf_to_lba48(&tf) + 1;
     else
         *max_sectors = ata_tf_to_lba(&tf) + 1;
     if (dev->horkage & ATA_HORKAGE_HPA_SIZE)
         (*max_sectors)--;
     return 0;
 }
 
 /**
  *  ata_set_max_sectors - Set max sectors
  *  @dev: target device
  *  @new_sectors: new max sectors value to set for the device
  *
  *  Set max sectors of @dev to @new_sectors.
  *
  *  RETURNS:
  *  0 on success, -EACCES if command is aborted or denied (due to
  *  previous non-volatile SET_MAX) by the drive.  -EIO on other
  *  errors.
  */
 static int ata_set_max_sectors(struct ata_device *dev, u64 new_sectors)
 {
     unsigned int err_mask;
     struct ata_taskfile tf;
     int lba48 = ata_id_has_lba48(dev->id);
 
     new_sectors--;
 
     ata_tf_init(dev, &tf);
 
     tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
 
     if (lba48) {
         tf.command = ATA_CMD_SET_MAX_EXT;
         tf.flags |= ATA_TFLAG_LBA48;
 
         tf.hob_lbal = (new_sectors >> 24) & 0xff;
         tf.hob_lbam = (new_sectors >> 32) & 0xff;
         tf.hob_lbah = (new_sectors >> 40) & 0xff;
     } else {
         tf.command = ATA_CMD_SET_MAX;
 
         tf.device |= (new_sectors >> 24) & 0xf;
     }
 
     tf.protocol = ATA_PROT_NODATA;
     tf.device |= ATA_LBA;
 
     tf.lbal = (new_sectors >> 0) & 0xff;
     tf.lbam = (new_sectors >> 8) & 0xff;
     tf.lbah = (new_sectors >> 16) & 0xff;
 
     err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
     if (err_mask) {
         ata_dev_warn(dev,
                  "failed to set max address (err_mask=0x%x)\n",
                  err_mask);
         if (err_mask == AC_ERR_DEV &&
             (tf.error & (ATA_ABORTED | ATA_IDNF)))
             return -EACCES;
         return -EIO;
     }
 
     return 0;
 }
 
 /**
  *  ata_hpa_resize      -   Resize a device with an HPA set
  *  @dev: Device to resize
  *
  *  Read the size of an LBA28 or LBA48 disk with HPA features and resize
  *  it if required to the full size of the media. The caller must check
  *  the drive has the HPA feature set enabled.
  *
  *  RETURNS:
  *  0 on success, -errno on failure.
  */
 static int ata_hpa_resize(struct ata_device *dev)
 {
     bool print_info = ata_dev_print_info(dev);
     bool unlock_hpa = ata_ignore_hpa || dev->flags & ATA_DFLAG_UNLOCK_HPA;
     u64 sectors = ata_id_n_sectors(dev->id);
     u64 native_sectors;
     int rc;
 
     /* do we need to do it? */
     if ((dev->class != ATA_DEV_ATA && dev->class != ATA_DEV_ZAC) ||
         !ata_id_has_lba(dev->id) || !ata_id_hpa_enabled(dev->id) ||
         (dev->horkage & ATA_HORKAGE_BROKEN_HPA))
         return 0;
 
     /* read native max address */
     rc = ata_read_native_max_address(dev, &native_sectors);
     if (rc) {
         /* If device aborted the command or HPA isn't going to
          * be unlocked, skip HPA resizing.
          */
         if (rc == -EACCES || !unlock_hpa) {
             ata_dev_warn(dev,
                      "HPA support seems broken, skipping HPA handling\n");
             dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
 
             /* we can continue if device aborted the command */
             if (rc == -EACCES)
                 rc = 0;
         }
 
         return rc;
     }
     dev->n_native_sectors = native_sectors;
 
     /* nothing to do? */
     if (native_sectors <= sectors || !unlock_hpa) {
         if (!print_info || native_sectors == sectors)
             return 0;
 
         if (native_sectors > sectors)
             ata_dev_info(dev,
                 "HPA detected: current %llu, native %llu\n",
                 (unsigned long long)sectors,
                 (unsigned long long)native_sectors);
         else if (native_sectors < sectors)
             ata_dev_warn(dev,
                 "native sectors (%llu) is smaller than sectors (%llu)\n",
                 (unsigned long long)native_sectors,
                 (unsigned long long)sectors);
         return 0;
     }
 
     /* let's unlock HPA */
     rc = ata_set_max_sectors(dev, native_sectors);
     if (rc == -EACCES) {
         /* if device aborted the command, skip HPA resizing */
         ata_dev_warn(dev,
                  "device aborted resize (%llu -> %llu), skipping HPA handling\n",
                  (unsigned long long)sectors,
                  (unsigned long long)native_sectors);
         dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
         return 0;
     } else if (rc)
         return rc;
 
     /* re-read IDENTIFY data */
     rc = ata_dev_reread_id(dev, 0);
     if (rc) {
         ata_dev_err(dev,
                 "failed to re-read IDENTIFY data after HPA resizing\n");
         return rc;
     }
 
     if (print_info) {
         u64 new_sectors = ata_id_n_sectors(dev->id);
         ata_dev_info(dev,
             "HPA unlocked: %llu -> %llu, native %llu\n",
             (unsigned long long)sectors,
             (unsigned long long)new_sectors,
             (unsigned long long)native_sectors);
     }
 
     return 0;
 }
 
 /**
  *  ata_dump_id - IDENTIFY DEVICE info debugging output
  *  @dev: device from which the information is fetched
  *  @id: IDENTIFY DEVICE page to dump
  *
  *  Dump selected 16-bit words from the given IDENTIFY DEVICE
  *  page.
  *
  *  LOCKING:
  *  caller.
  */
 
 static inline void ata_dump_id(struct ata_device *dev, const u16 *id)
 {
     ata_dev_dbg(dev,
         "49==0x%04x  53==0x%04x  63==0x%04x  64==0x%04x  75==0x%04x\n"
         "80==0x%04x  81==0x%04x  82==0x%04x  83==0x%04x  84==0x%04x\n"
         "88==0x%04x  93==0x%04x\n",
         id[49], id[53], id[63], id[64], id[75], id[80],
         id[81], id[82], id[83], id[84], id[88], id[93]);
 }
 
 /**
  *  ata_id_xfermask - Compute xfermask from the given IDENTIFY data
  *  @id: IDENTIFY data to compute xfer mask from
  *
  *  Compute the xfermask for this device. This is not as trivial
  *  as it seems if we must consider early devices correctly.
  *
  *  FIXME: pre IDE drive timing (do we care ?).
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  Computed xfermask
  */
 unsigned int ata_id_xfermask(const u16 *id)
 {
     unsigned int pio_mask, mwdma_mask, udma_mask;
 
     /* Usual case. Word 53 indicates word 64 is valid */
     if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
         pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
         pio_mask <<= 3;
         pio_mask |= 0x7;
     } else {
         /* If word 64 isn't valid then Word 51 high byte holds
          * the PIO timing number for the maximum. Turn it into
          * a mask.
          */
         u8 mode = (id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF;
         if (mode < 5)   /* Valid PIO range */
             pio_mask = (2 << mode) - 1;
         else
             pio_mask = 1;
 
         /* But wait.. there's more. Design your standards by
          * committee and you too can get a free iordy field to
          * process. However it is the speeds not the modes that
          * are supported... Note drivers using the timing API
          * will get this right anyway
          */
     }
 
     mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;
 
     if (ata_id_is_cfa(id)) {
         /*
          *  Process compact flash extended modes
          */
         int pio = (id[ATA_ID_CFA_MODES] >> 0) & 0x7;
         int dma = (id[ATA_ID_CFA_MODES] >> 3) & 0x7;
 
         if (pio)
             pio_mask |= (1 << 5);
         if (pio > 1)
             pio_mask |= (1 << 6);
         if (dma)
             mwdma_mask |= (1 << 3);
         if (dma > 1)
             mwdma_mask |= (1 << 4);
     }
 
     udma_mask = 0;
     if (id[ATA_ID_FIELD_VALID] & (1 << 2))
         udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;
 
     return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
 }
 EXPORT_SYMBOL_GPL(ata_id_xfermask);
 
 static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
 {
     struct completion *waiting = qc->private_data;
 
     complete(waiting);
 }
 
 /**
  *  ata_exec_internal_sg - execute libata internal command
  *  @dev: Device to which the command is sent
  *  @tf: Taskfile registers for the command and the result
  *  @cdb: CDB for packet command
  *  @dma_dir: Data transfer direction of the command
  *  @sgl: sg list for the data buffer of the command
  *  @n_elem: Number of sg entries
  *  @timeout: Timeout in msecs (0 for default)
  *
  *  Executes libata internal command with timeout.  @tf contains
  *  command on entry and result on return.  Timeout and error
  *  conditions are reported via return value.  No recovery action
  *  is taken after a command times out.  It's caller's duty to
  *  clean up after timeout.
  *
  *  LOCKING:
  *  None.  Should be called with kernel context, might sleep.
  *
  *  RETURNS:
  *  Zero on success, AC_ERR_* mask on failure
  */
 static unsigned ata_exec_internal_sg(struct ata_device *dev,
                      struct ata_taskfile *tf, const u8 *cdb,
                      int dma_dir, struct scatterlist *sgl,
                      unsigned int n_elem, unsigned int timeout)
 {
     struct ata_link *link = dev->link;
     struct ata_port *ap = link->ap;
     u8 command = tf->command;
     int auto_timeout = 0;
     struct ata_queued_cmd *qc;
     unsigned int preempted_tag;
     u32 preempted_sactive;
     u64 preempted_qc_active;
     int preempted_nr_active_links;
     DECLARE_COMPLETION_ONSTACK(wait);
     unsigned long flags;
     unsigned int err_mask;
     int rc;
 
     spin_lock_irqsave(ap->lock, flags);
 
     /* no internal command while frozen */
     if (ap->pflags & ATA_PFLAG_FROZEN) {
         spin_unlock_irqrestore(ap->lock, flags);
         return AC_ERR_SYSTEM;
     }
 
     /* initialize internal qc */
     qc = __ata_qc_from_tag(ap, ATA_TAG_INTERNAL);
 
     qc->tag = ATA_TAG_INTERNAL;
     qc->hw_tag = 0;
     qc->scsicmd = NULL;
     qc->ap = ap;
     qc->dev = dev;
     ata_qc_reinit(qc);
 
     preempted_tag = link->active_tag;
     preempted_sactive = link->sactive;
     preempted_qc_active = ap->qc_active;
     preempted_nr_active_links = ap->nr_active_links;
     link->active_tag = ATA_TAG_POISON;
     link->sactive = 0;
     ap->qc_active = 0;
     ap->nr_active_links = 0;
 
     /* prepare & issue qc */
     qc->tf = *tf;
     if (cdb)
         memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
 
     /* some SATA bridges need us to indicate data xfer direction */
     if (tf->protocol == ATAPI_PROT_DMA && (dev->flags & ATA_DFLAG_DMADIR) &&
         dma_dir == DMA_FROM_DEVICE)
         qc->tf.feature |= ATAPI_DMADIR;
 
     qc->flags |= ATA_QCFLAG_RESULT_TF;
     qc->dma_dir = dma_dir;
     if (dma_dir != DMA_NONE) {
         unsigned int i, buflen = 0;
         struct scatterlist *sg;
 
         for_each_sg(sgl, sg, n_elem, i)
             buflen += sg->length;
 
         ata_sg_init(qc, sgl, n_elem);
         qc->nbytes = buflen;
     }
 
     qc->private_data = &wait;
     qc->complete_fn = ata_qc_complete_internal;
 
     ata_qc_issue(qc);
 
     spin_unlock_irqrestore(ap->lock, flags);
 
     if (!timeout) {
         if (ata_probe_timeout)
             timeout = ata_probe_timeout * 1000;
         else {
             timeout = ata_internal_cmd_timeout(dev, command);
             auto_timeout = 1;
         }
     }
 
     if (ap->ops->error_handler)
         ata_eh_release(ap);
 
     rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));
 
     if (ap->ops->error_handler)
         ata_eh_acquire(ap);
 
     ata_sff_flush_pio_task(ap);
 
     if (!rc) {
         spin_lock_irqsave(ap->lock, flags);
 
         /* We're racing with irq here.  If we lose, the
          * following test prevents us from completing the qc
          * twice.  If we win, the port is frozen and will be
          * cleaned up by ->post_internal_cmd().
          */
         if (qc->flags & ATA_QCFLAG_ACTIVE) {
             qc->err_mask |= AC_ERR_TIMEOUT;
 
             if (ap->ops->error_handler)
                 ata_port_freeze(ap);
             else
                 ata_qc_complete(qc);
 
             ata_dev_warn(dev, "qc timeout (cmd 0x%x)\n",
                      command);
         }
 
         spin_unlock_irqrestore(ap->lock, flags);
     }
 
     /* do post_internal_cmd */
     if (ap->ops->post_internal_cmd)
         ap->ops->post_internal_cmd(qc);
 
     /* perform minimal error analysis */
     if (qc->flags & ATA_QCFLAG_FAILED) {
         if (qc->result_tf.status & (ATA_ERR | ATA_DF))
             qc->err_mask |= AC_ERR_DEV;
 
         if (!qc->err_mask)
             qc->err_mask |= AC_ERR_OTHER;
 
         if (qc->err_mask & ~AC_ERR_OTHER)
             qc->err_mask &= ~AC_ERR_OTHER;
     } else if (qc->tf.command == ATA_CMD_REQ_SENSE_DATA) {
         qc->result_tf.status |= ATA_SENSE;
     }
 
     /* finish up */
     spin_lock_irqsave(ap->lock, flags);
 
     *tf = qc->result_tf;
     err_mask = qc->err_mask;
 
     ata_qc_free(qc);
     link->active_tag = preempted_tag;
     link->sactive = preempted_sactive;
     ap->qc_active = preempted_qc_active;
     ap->nr_active_links = preempted_nr_active_links;
 
     spin_unlock_irqrestore(ap->lock, flags);
 
     if ((err_mask & AC_ERR_TIMEOUT) && auto_timeout)
         ata_internal_cmd_timed_out(dev, command);
 
     return err_mask;
 }
 
 /**
  *  ata_exec_internal - execute libata internal command
  *  @dev: Device to which the command is sent
  *  @tf: Taskfile registers for the command and the result
  *  @cdb: CDB for packet command
  *  @dma_dir: Data transfer direction of the command
  *  @buf: Data buffer of the command
  *  @buflen: Length of data buffer
  *  @timeout: Timeout in msecs (0 for default)
  *
  *  Wrapper around ata_exec_internal_sg() which takes simple
  *  buffer instead of sg list.
  *
  *  LOCKING:
  *  None.  Should be called with kernel context, might sleep.
  *
  *  RETURNS:
  *  Zero on success, AC_ERR_* mask on failure
  */
 unsigned ata_exec_internal(struct ata_device *dev,
                struct ata_taskfile *tf, const u8 *cdb,
                int dma_dir, void *buf, unsigned int buflen,
                unsigned int timeout)
 {
     struct scatterlist *psg = NULL, sg;
     unsigned int n_elem = 0;
 
     if (dma_dir != DMA_NONE) {
         WARN_ON(!buf);
         sg_init_one(&sg, buf, buflen);
         psg = &sg;
         n_elem++;
     }
 
     return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem,
                     timeout);
 }
 
 /**
  *  ata_pio_need_iordy  -   check if iordy needed
  *  @adev: ATA device
  *
  *  Check if the current speed of the device requires IORDY. Used
  *  by various controllers for chip configuration.
  */
 unsigned int ata_pio_need_iordy(const struct ata_device *adev)
 {
     /* Don't set IORDY if we're preparing for reset.  IORDY may
      * lead to controller lock up on certain controllers if the
      * port is not occupied.  See bko#11703 for details.
      */
     if (adev->link->ap->pflags & ATA_PFLAG_RESETTING)
         return 0;
     /* Controller doesn't support IORDY.  Probably a pointless
      * check as the caller should know this.
      */
     if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
         return 0;
     /* CF spec. r4.1 Table 22 says no iordy on PIO5 and PIO6.  */
     if (ata_id_is_cfa(adev->id)
         && (adev->pio_mode == XFER_PIO_5 || adev->pio_mode == XFER_PIO_6))
         return 0;
     /* PIO3 and higher it is mandatory */
     if (adev->pio_mode > XFER_PIO_2)
         return 1;
     /* We turn it on when possible */
     if (ata_id_has_iordy(adev->id))
         return 1;
     return 0;
 }
 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
 
 /**
  *  ata_pio_mask_no_iordy   -   Return the non IORDY mask
  *  @adev: ATA device
  *
  *  Compute the highest mode possible if we are not using iordy. Return
  *  -1 if no iordy mode is available.
  */
 static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
 {
     /* If we have no drive specific rule, then PIO 2 is non IORDY */
     if (adev->id[ATA_ID_FIELD_VALID] & 2) { /* EIDE */
         u16 pio = adev->id[ATA_ID_EIDE_PIO];
         /* Is the speed faster than the drive allows non IORDY ? */
         if (pio) {
             /* This is cycle times not frequency - watch the logic! */
             if (pio > 240)  /* PIO2 is 240nS per cycle */
                 return 3 << ATA_SHIFT_PIO;
             return 7 << ATA_SHIFT_PIO;
         }
     }
     return 3 << ATA_SHIFT_PIO;
 }
 
 /**
  *  ata_do_dev_read_id      -   default ID read method
  *  @dev: device
  *  @tf: proposed taskfile
  *  @id: data buffer
  *
  *  Issue the identify taskfile and hand back the buffer containing
  *  identify data. For some RAID controllers and for pre ATA devices
  *  this function is wrapped or replaced by the driver
  */
 unsigned int ata_do_dev_read_id(struct ata_device *dev,
                 struct ata_taskfile *tf, __le16 *id)
 {
     return ata_exec_internal(dev, tf, NULL, DMA_FROM_DEVICE,
                      id, sizeof(id[0]) * ATA_ID_WORDS, 0);
 }
 EXPORT_SYMBOL_GPL(ata_do_dev_read_id);
 
 /**
  *  ata_dev_read_id - Read ID data from the specified device
  *  @dev: target device
  *  @p_class: pointer to class of the target device (may be changed)
  *  @flags: ATA_READID_* flags
  *  @id: buffer to read IDENTIFY data into
  *
  *  Read ID data from the specified device.  ATA_CMD_ID_ATA is
  *  performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
  *  devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
  *  for pre-ATA4 drives.
  *
  *  FIXME: ATA_CMD_ID_ATA is optional for early drives and right
  *  now we abort if we hit that case.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  *
  *  RETURNS:
  *  0 on success, -errno otherwise.
  */
 int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
             unsigned int flags, u16 *id)
 {
     struct ata_port *ap = dev->link->ap;
     unsigned int class = *p_class;
     struct ata_taskfile tf;
     unsigned int err_mask = 0;
     const char *reason;
     bool is_semb = class == ATA_DEV_SEMB;
     int may_fallback = 1, tried_spinup = 0;
     int rc;
 
 retry:
     ata_tf_init(dev, &tf);
 
     switch (class) {
     case ATA_DEV_SEMB:
         class = ATA_DEV_ATA;    /* some hard drives report SEMB sig */
         fallthrough;
     case ATA_DEV_ATA:
     case ATA_DEV_ZAC:
         tf.command = ATA_CMD_ID_ATA;
         break;
     case ATA_DEV_ATAPI:
         tf.command = ATA_CMD_ID_ATAPI;
         break;
     default:
         rc = -ENODEV;
         reason = "unsupported class";
         goto err_out;
     }
 
     tf.protocol = ATA_PROT_PIO;
 
     /* Some devices choke if TF registers contain garbage.  Make
      * sure those are properly initialized.
      */
     tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
 
     /* Device presence detection is unreliable on some
      * controllers.  Always poll IDENTIFY if available.
      */
     tf.flags |= ATA_TFLAG_POLLING;
 
     if (ap->ops->read_id)
         err_mask = ap->ops->read_id(dev, &tf, (__le16 *)id);
     else
         err_mask = ata_do_dev_read_id(dev, &tf, (__le16 *)id);
 
     if (err_mask) {
         if (err_mask & AC_ERR_NODEV_HINT) {
             ata_dev_dbg(dev, "NODEV after polling detection\n");
             return -ENOENT;
         }
 
         if (is_semb) {
             ata_dev_info(dev,
              "IDENTIFY failed on device w/ SEMB sig, disabled\n");
             /* SEMB is not supported yet */
             *p_class = ATA_DEV_SEMB_UNSUP;
             return 0;
         }
 
         if ((err_mask == AC_ERR_DEV) && (tf.error & ATA_ABORTED)) {
             /* Device or controller might have reported
              * the wrong device class.  Give a shot at the
              * other IDENTIFY if the current one is
              * aborted by the device.
              */
             if (may_fallback) {
                 may_fallback = 0;
 
                 if (class == ATA_DEV_ATA)
                     class = ATA_DEV_ATAPI;
                 else
                     class = ATA_DEV_ATA;
                 goto retry;
             }
 
             /* Control reaches here iff the device aborted
              * both flavors of IDENTIFYs which happens
              * sometimes with phantom devices.
              */
             ata_dev_dbg(dev,
                     "both IDENTIFYs aborted, assuming NODEV\n");
             return -ENOENT;
         }
 
         rc = -EIO;
         reason = "I/O error";
         goto err_out;
     }
 
     if (dev->horkage & ATA_HORKAGE_DUMP_ID) {
         ata_dev_info(dev, "dumping IDENTIFY data, "
                 "class=%d may_fallback=%d tried_spinup=%d\n",
                 class, may_fallback, tried_spinup);
         print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET,
                    16, 2, id, ATA_ID_WORDS * sizeof(*id), true);
     }
 
     /* Falling back doesn't make sense if ID data was read
      * successfully at least once.
      */
     may_fallback = 0;
 
     swap_buf_le16(id, ATA_ID_WORDS);
 
     /* sanity check */
     rc = -EINVAL;
     reason = "device reports invalid type";
 
     if (class == ATA_DEV_ATA || class == ATA_DEV_ZAC) {
         if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
             goto err_out;
         if (ap->host->flags & ATA_HOST_IGNORE_ATA &&
                             ata_id_is_ata(id)) {
             ata_dev_dbg(dev,
                 "host indicates ignore ATA devices, ignored\n");
             return -ENOENT;
         }
     } else {
         if (ata_id_is_ata(id))
             goto err_out;
     }
 
     if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
         tried_spinup = 1;
         /*
          * Drive powered-up in standby mode, and requires a specific
          * SET_FEATURES spin-up subcommand before it will accept
          * anything other than the original IDENTIFY command.
          */
         err_mask = ata_dev_set_feature(dev, SETFEATURES_SPINUP, 0);
         if (err_mask && id[2] != 0x738c) {
             rc = -EIO;
             reason = "SPINUP failed";
             goto err_out;
         }
         /*
          * If the drive initially returned incomplete IDENTIFY info,
          * we now must reissue the IDENTIFY command.
          */
         if (id[2] == 0x37c8)
             goto retry;
     }
 
     if ((flags & ATA_READID_POSTRESET) &&
         (class == ATA_DEV_ATA || class == ATA_DEV_ZAC)) {
         /*
          * The exact sequence expected by certain pre-ATA4 drives is:
          * SRST RESET
          * IDENTIFY (optional in early ATA)
          * INITIALIZE DEVICE PARAMETERS (later IDE and ATA)
          * anything else..
          * Some drives were very specific about that exact sequence.
          *
          * Note that ATA4 says lba is mandatory so the second check
          * should never trigger.
          */
         if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
             err_mask = ata_dev_init_params(dev, id[3], id[6]);
             if (err_mask) {
                 rc = -EIO;
                 reason = "INIT_DEV_PARAMS failed";
                 goto err_out;
             }
 
             /* current CHS translation info (id[53-58]) might be
              * changed. reread the identify device info.
              */
             flags &= ~ATA_READID_POSTRESET;
             goto retry;
         }
     }
 
     *p_class = class;
 
     return 0;
 
  err_out:
     ata_dev_warn(dev, "failed to IDENTIFY (%s, err_mask=0x%x)\n",
              reason, err_mask);
     return rc;
 }
 
 /**
  *  ata_read_log_page - read a specific log page
  *  @dev: target device
  *  @log: log to read
  *  @page: page to read
  *  @buf: buffer to store read page
  *  @sectors: number of sectors to read
  *
  *  Read log page using READ_LOG_EXT command.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep).
  *
  *  RETURNS:
  *  0 on success, AC_ERR_* mask otherwise.
  */
 unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
                    u8 page, void *buf, unsigned int sectors)
 {
     unsigned long ap_flags = dev->link->ap->flags;
     struct ata_taskfile tf;
     unsigned int err_mask;
     bool dma = false;
 
     ata_dev_dbg(dev, "read log page - log 0x%x, page 0x%x\n", log, page);
 
     /*
      * Return error without actually issuing the command on controllers
      * which e.g. lockup on a read log page.
      */
     if (ap_flags & ATA_FLAG_NO_LOG_PAGE)
         return AC_ERR_DEV;
 
 retry:
     ata_tf_init(dev, &tf);
     if (ata_dma_enabled(dev) && ata_id_has_read_log_dma_ext(dev->id) &&
         !(dev->horkage & ATA_HORKAGE_NO_DMA_LOG)) {
         tf.command = ATA_CMD_READ_LOG_DMA_EXT;
         tf.protocol = ATA_PROT_DMA;
         dma = true;
     } else {
         tf.command = ATA_CMD_READ_LOG_EXT;
         tf.protocol = ATA_PROT_PIO;
         dma = false;
     }
     tf.lbal = log;
     tf.lbam = page;
     tf.nsect = sectors;
     tf.hob_nsect = sectors >> 8;
     tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_LBA48 | ATA_TFLAG_DEVICE;
 
     err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
                      buf, sectors * ATA_SECT_SIZE, 0);
 
     if (err_mask) {
         if (dma) {
             dev->horkage |= ATA_HORKAGE_NO_DMA_LOG;
             goto retry;
         }
         ata_dev_err(dev,
                 "Read log 0x%02x page 0x%02x failed, Emask 0x%x\n",
                 (unsigned int)log, (unsigned int)page, err_mask);
     }
 
     return err_mask;
 }
 
 static int ata_log_supported(struct ata_device *dev, u8 log)
 {
     struct ata_port *ap = dev->link->ap;
 
     if (dev->horkage & ATA_HORKAGE_NO_LOG_DIR)
         return 0;
 
     if (ata_read_log_page(dev, ATA_LOG_DIRECTORY, 0, ap->sector_buf, 1))
         return 0;
     return get_unaligned_le16(&ap->sector_buf[log * 2]);
 }
 
 static bool ata_identify_page_supported(struct ata_device *dev, u8 page)
 {
     struct ata_port *ap = dev->link->ap;
     unsigned int err, i;
 
     if (dev->horkage & ATA_HORKAGE_NO_ID_DEV_LOG)
         return false;
 
     if (!ata_log_supported(dev, ATA_LOG_IDENTIFY_DEVICE)) {
         /*
          * IDENTIFY DEVICE data log is defined as mandatory starting
          * with ACS-3 (ATA version 10). Warn about the missing log
          * for drives which implement this ATA level or above.
          */
         if (ata_id_major_version(dev->id) >= 10)
             ata_dev_warn(dev,
                 "ATA Identify Device Log not supported\n");
         dev->horkage |= ATA_HORKAGE_NO_ID_DEV_LOG;
         return false;
     }
 
     /*
      * Read IDENTIFY DEVICE data log, page 0, to figure out if the page is
      * supported.
      */
     err = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE, 0, ap->sector_buf,
                 1);
     if (err)
         return false;
 
     for (i = 0; i < ap->sector_buf[8]; i++) {
         if (ap->sector_buf[9 + i] == page)
             return true;
     }
 
     return false;
 }
 
 static int ata_do_link_spd_horkage(struct ata_device *dev)
 {
     struct ata_link *plink = ata_dev_phys_link(dev);
     u32 target, target_limit;
 
     if (!sata_scr_valid(plink))
         return 0;
 
     if (dev->horkage & ATA_HORKAGE_1_5_GBPS)
         target = 1;
     else
         return 0;
 
     target_limit = (1 << target) - 1;
 
     /* if already on stricter limit, no need to push further */
     if (plink->sata_spd_limit <= target_limit)
         return 0;
 
     plink->sata_spd_limit = target_limit;
 
     /* Request another EH round by returning -EAGAIN if link is
      * going faster than the target speed.  Forward progress is
      * guaranteed by setting sata_spd_limit to target_limit above.
      */
     if (plink->sata_spd > target) {
         ata_dev_info(dev, "applying link speed limit horkage to %s\n",
                  sata_spd_string(target));
         return -EAGAIN;
     }
     return 0;
 }
 
 static inline u8 ata_dev_knobble(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
 
     if (ata_dev_blacklisted(dev) & ATA_HORKAGE_BRIDGE_OK)
         return 0;
 
     return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
 }
 
 static void ata_dev_config_ncq_send_recv(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
     unsigned int err_mask;
 
     if (!ata_log_supported(dev, ATA_LOG_NCQ_SEND_RECV)) {
         ata_dev_warn(dev, "NCQ Send/Recv Log not supported\n");
         return;
     }
     err_mask = ata_read_log_page(dev, ATA_LOG_NCQ_SEND_RECV,
                      0, ap->sector_buf, 1);
     if (!err_mask) {
         u8 *cmds = dev->ncq_send_recv_cmds;
 
         dev->flags |= ATA_DFLAG_NCQ_SEND_RECV;
         memcpy(cmds, ap->sector_buf, ATA_LOG_NCQ_SEND_RECV_SIZE);
 
         if (dev->horkage & ATA_HORKAGE_NO_NCQ_TRIM) {
             ata_dev_dbg(dev, "disabling queued TRIM support\n");
             cmds[ATA_LOG_NCQ_SEND_RECV_DSM_OFFSET] &=
                 ~ATA_LOG_NCQ_SEND_RECV_DSM_TRIM;
         }
     }
 }
 
 static void ata_dev_config_ncq_non_data(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
     unsigned int err_mask;
 
     if (!ata_log_supported(dev, ATA_LOG_NCQ_NON_DATA)) {
         ata_dev_warn(dev,
                  "NCQ Send/Recv Log not supported\n");
         return;
     }
     err_mask = ata_read_log_page(dev, ATA_LOG_NCQ_NON_DATA,
                      0, ap->sector_buf, 1);
     if (!err_mask) {
         u8 *cmds = dev->ncq_non_data_cmds;
 
         memcpy(cmds, ap->sector_buf, ATA_LOG_NCQ_NON_DATA_SIZE);
     }
 }
 
 static void ata_dev_config_ncq_prio(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
     unsigned int err_mask;
 
     if (!ata_identify_page_supported(dev, ATA_LOG_SATA_SETTINGS))
         return;
 
     err_mask = ata_read_log_page(dev,
                      ATA_LOG_IDENTIFY_DEVICE,
                      ATA_LOG_SATA_SETTINGS,
                      ap->sector_buf,
                      1);
     if (err_mask)
         goto not_supported;
 
     if (!(ap->sector_buf[ATA_LOG_NCQ_PRIO_OFFSET] & BIT(3)))
         goto not_supported;
 
     dev->flags |= ATA_DFLAG_NCQ_PRIO;
 
     return;
 
 not_supported:
     dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;
     dev->flags &= ~ATA_DFLAG_NCQ_PRIO;
 }
 
 static bool ata_dev_check_adapter(struct ata_device *dev,
                   unsigned short vendor_id)
 {
     struct pci_dev *pcidev = NULL;
     struct device *parent_dev = NULL;
 
     for (parent_dev = dev->tdev.parent; parent_dev != NULL;
          parent_dev = parent_dev->parent) {
         if (dev_is_pci(parent_dev)) {
             pcidev = to_pci_dev(parent_dev);
             if (pcidev->vendor == vendor_id)
                 return true;
             break;
         }
     }
 
     return false;
 }
 
 static int ata_dev_config_ncq(struct ata_device *dev,
                    char *desc, size_t desc_sz)
 {
     struct ata_port *ap = dev->link->ap;
     int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
     unsigned int err_mask;
     char *aa_desc = "";
 
     if (!ata_id_has_ncq(dev->id)) {
         desc[0] = '\0';
         return 0;
     }
     if (!IS_ENABLED(CONFIG_SATA_HOST))
         return 0;
     if (dev->horkage & ATA_HORKAGE_NONCQ) {
         snprintf(desc, desc_sz, "NCQ (not used)");
         return 0;
     }
 
     if (dev->horkage & ATA_HORKAGE_NO_NCQ_ON_ATI &&
         ata_dev_check_adapter(dev, PCI_VENDOR_ID_ATI)) {
         snprintf(desc, desc_sz, "NCQ (not used)");
         return 0;
     }
 
     if (ap->flags & ATA_FLAG_NCQ) {
         hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE);
         dev->flags |= ATA_DFLAG_NCQ;
     }
 
     if (!(dev->horkage & ATA_HORKAGE_BROKEN_FPDMA_AA) &&
         (ap->flags & ATA_FLAG_FPDMA_AA) &&
         ata_id_has_fpdma_aa(dev->id)) {
         err_mask = ata_dev_set_feature(dev, SETFEATURES_SATA_ENABLE,
             SATA_FPDMA_AA);
         if (err_mask) {
             ata_dev_err(dev,
                     "failed to enable AA (error_mask=0x%x)\n",
                     err_mask);
             if (err_mask != AC_ERR_DEV) {
                 dev->horkage |= ATA_HORKAGE_BROKEN_FPDMA_AA;
                 return -EIO;
             }
         } else
             aa_desc = ", AA";
     }
 
     if (hdepth >= ddepth)
         snprintf(desc, desc_sz, "NCQ (depth %d)%s", ddepth, aa_desc);
     else
         snprintf(desc, desc_sz, "NCQ (depth %d/%d)%s", hdepth,
             ddepth, aa_desc);
 
     if ((ap->flags & ATA_FLAG_FPDMA_AUX)) {
         if (ata_id_has_ncq_send_and_recv(dev->id))
             ata_dev_config_ncq_send_recv(dev);
         if (ata_id_has_ncq_non_data(dev->id))
             ata_dev_config_ncq_non_data(dev);
         if (ata_id_has_ncq_prio(dev->id))
             ata_dev_config_ncq_prio(dev);
     }
 
     return 0;
 }
 
 static void ata_dev_config_sense_reporting(struct ata_device *dev)
 {
     unsigned int err_mask;
 
     if (!ata_id_has_sense_reporting(dev->id))
         return;
 
     if (ata_id_sense_reporting_enabled(dev->id))
         return;
 
     err_mask = ata_dev_set_feature(dev, SETFEATURE_SENSE_DATA, 0x1);
     if (err_mask) {
         ata_dev_dbg(dev,
                 "failed to enable Sense Data Reporting, Emask 0x%x\n",
                 err_mask);
     }
 }
 
 static void ata_dev_config_zac(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
     unsigned int err_mask;
     u8 *identify_buf = ap->sector_buf;
 
     dev->zac_zones_optimal_open = U32_MAX;
     dev->zac_zones_optimal_nonseq = U32_MAX;
     dev->zac_zones_max_open = U32_MAX;
 
     /*
      * Always set the 'ZAC' flag for Host-managed devices.
      */
     if (dev->class == ATA_DEV_ZAC)
         dev->flags |= ATA_DFLAG_ZAC;
     else if (ata_id_zoned_cap(dev->id) == 0x01)
         /*
          * Check for host-aware devices.
          */
         dev->flags |= ATA_DFLAG_ZAC;
 
     if (!(dev->flags & ATA_DFLAG_ZAC))
         return;
 
     if (!ata_identify_page_supported(dev, ATA_LOG_ZONED_INFORMATION)) {
         ata_dev_warn(dev,
                  "ATA Zoned Information Log not supported\n");
         return;
     }
 
     /*
      * Read IDENTIFY DEVICE data log, page 9 (Zoned-device information)
      */
     err_mask = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE,
                      ATA_LOG_ZONED_INFORMATION,
                      identify_buf, 1);
     if (!err_mask) {
         u64 zoned_cap, opt_open, opt_nonseq, max_open;
 
         zoned_cap = get_unaligned_le64(&identify_buf[8]);
         if ((zoned_cap >> 63))
             dev->zac_zoned_cap = (zoned_cap & 1);
         opt_open = get_unaligned_le64(&identify_buf[24]);
         if ((opt_open >> 63))
             dev->zac_zones_optimal_open = (u32)opt_open;
         opt_nonseq = get_unaligned_le64(&identify_buf[32]);
         if ((opt_nonseq >> 63))
             dev->zac_zones_optimal_nonseq = (u32)opt_nonseq;
         max_open = get_unaligned_le64(&identify_buf[40]);
         if ((max_open >> 63))
             dev->zac_zones_max_open = (u32)max_open;
     }
 }
 
 static void ata_dev_config_trusted(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
     u64 trusted_cap;
     unsigned int err;
 
     if (!ata_id_has_trusted(dev->id))
         return;
 
     if (!ata_identify_page_supported(dev, ATA_LOG_SECURITY)) {
         ata_dev_warn(dev,
                  "Security Log not supported\n");
         return;
     }
 
     err = ata_read_log_page(dev, ATA_LOG_IDENTIFY_DEVICE, ATA_LOG_SECURITY,
             ap->sector_buf, 1);
     if (err)
         return;
 
     trusted_cap = get_unaligned_le64(&ap->sector_buf[40]);
     if (!(trusted_cap & (1ULL << 63))) {
         ata_dev_dbg(dev,
                 "Trusted Computing capability qword not valid!\n");
         return;
     }
 
     if (trusted_cap & (1 << 0))
         dev->flags |= ATA_DFLAG_TRUSTED;
 }
 
 static int ata_dev_config_lba(struct ata_device *dev)
 {
     const u16 *id = dev->id;
     const char *lba_desc;
     char ncq_desc[24];
     int ret;
 
     dev->flags |= ATA_DFLAG_LBA;
 
     if (ata_id_has_lba48(id)) {
         lba_desc = "LBA48";
         dev->flags |= ATA_DFLAG_LBA48;
         if (dev->n_sectors >= (1UL << 28) &&
             ata_id_has_flush_ext(id))
             dev->flags |= ATA_DFLAG_FLUSH_EXT;
     } else {
         lba_desc = "LBA";
     }
 
     /* config NCQ */
     ret = ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
 
     /* print device info to dmesg */
     if (ata_dev_print_info(dev))
         ata_dev_info(dev,
                  "%llu sectors, multi %u: %s %s\n",
                  (unsigned long long)dev->n_sectors,
                  dev->multi_count, lba_desc, ncq_desc);
 
     return ret;
 }
 
 static void ata_dev_config_chs(struct ata_device *dev)
 {
     const u16 *id = dev->id;
 
     if (ata_id_current_chs_valid(id)) {
         /* Current CHS translation is valid. */
         dev->cylinders = id[54];
         dev->heads     = id[55];
         dev->sectors   = id[56];
     } else {
         /* Default translation */
         dev->cylinders  = id[1];
         dev->heads  = id[3];
         dev->sectors    = id[6];
     }
 
     /* print device info to dmesg */
     if (ata_dev_print_info(dev))
         ata_dev_info(dev,
                  "%llu sectors, multi %u, CHS %u/%u/%u\n",
                  (unsigned long long)dev->n_sectors,
                  dev->multi_count, dev->cylinders,
                  dev->heads, dev->sectors);
 }
 
 static void ata_dev_config_devslp(struct ata_device *dev)
 {
     u8 *sata_setting = dev->link->ap->sector_buf;
     unsigned int err_mask;
     int i, j;
 
     /*
      * Check device sleep capability. Get DevSlp timing variables
      * from SATA Settings page of Identify Device Data Log.
      */
     if (!ata_id_has_devslp(dev->id) ||
         !ata_identify_page_supported(dev, ATA_LOG_SATA_SETTINGS))
         return;
 
     err_mask = ata_read_log_page(dev,
                      ATA_LOG_IDENTIFY_DEVICE,
                      ATA_LOG_SATA_SETTINGS,
                      sata_setting, 1);
     if (err_mask)
         return;
 
     dev->flags |= ATA_DFLAG_DEVSLP;
     for (i = 0; i < ATA_LOG_DEVSLP_SIZE; i++) {
         j = ATA_LOG_DEVSLP_OFFSET + i;
         dev->devslp_timing[i] = sata_setting[j];
     }
 }
 
 static void ata_dev_config_cpr(struct ata_device *dev)
 {
     unsigned int err_mask;
     size_t buf_len;
     int i, nr_cpr = 0;
     struct ata_cpr_log *cpr_log = NULL;
     u8 *desc, *buf = NULL;
 
     if (ata_id_major_version(dev->id) < 11)
         goto out;
 
     buf_len = ata_log_supported(dev, ATA_LOG_CONCURRENT_POSITIONING_RANGES);
     if (buf_len == 0)
         goto out;
 
     /*
      * Read the concurrent positioning ranges log (0x47). We can have at
      * most 255 32B range descriptors plus a 64B header. This log varies in
      * size, so use the size reported in the GPL directory. Reading beyond
      * the supported length will result in an error.
      */
     buf_len <<= 9;
     buf = kzalloc(buf_len, GFP_KERNEL);
     if (!buf)
         goto out;
 
     err_mask = ata_read_log_page(dev, ATA_LOG_CONCURRENT_POSITIONING_RANGES,
                      0, buf, buf_len >> 9);
     if (err_mask)
         goto out;
 
     nr_cpr = buf[0];
     if (!nr_cpr)
         goto out;
 
     cpr_log = kzalloc(struct_size(cpr_log, cpr, nr_cpr), GFP_KERNEL);
     if (!cpr_log)
         goto out;
 
     cpr_log->nr_cpr = nr_cpr;
     desc = &buf[64];
     for (i = 0; i < nr_cpr; i++, desc += 32) {
         cpr_log->cpr[i].num = desc[0];
         cpr_log->cpr[i].num_storage_elements = desc[1];
         cpr_log->cpr[i].start_lba = get_unaligned_le64(&desc[8]);
         cpr_log->cpr[i].num_lbas = get_unaligned_le64(&desc[16]);
     }
 
 out:
     swap(dev->cpr_log, cpr_log);
     kfree(cpr_log);
     kfree(buf);
 }
 
 static void ata_dev_print_features(struct ata_device *dev)
 {
     if (!(dev->flags & ATA_DFLAG_FEATURES_MASK))
         return;
 
     ata_dev_info(dev,
              "Features:%s%s%s%s%s%s\n",
              dev->flags & ATA_DFLAG_TRUSTED ? " Trust" : "",
              dev->flags & ATA_DFLAG_DA ? " Dev-Attention" : "",
              dev->flags & ATA_DFLAG_DEVSLP ? " Dev-Sleep" : "",
              dev->flags & ATA_DFLAG_NCQ_SEND_RECV ? " NCQ-sndrcv" : "",
              dev->flags & ATA_DFLAG_NCQ_PRIO ? " NCQ-prio" : "",
              dev->cpr_log ? " CPR" : "");
 }
 
 /**
  *  ata_dev_configure - Configure the specified ATA/ATAPI device
  *  @dev: Target device to configure
  *
  *  Configure @dev according to @dev->id.  Generic and low-level
  *  driver specific fixups are also applied.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  *
  *  RETURNS:
  *  0 on success, -errno otherwise
  */
 int ata_dev_configure(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
     bool print_info = ata_dev_print_info(dev);
     const u16 *id = dev->id;
     unsigned int xfer_mask;
     unsigned int err_mask;
     char revbuf[7];     /* XYZ-99\0 */
     char fwrevbuf[ATA_ID_FW_REV_LEN+1];
     char modelbuf[ATA_ID_PROD_LEN+1];
     int rc;
 
     if (!ata_dev_enabled(dev)) {
         ata_dev_dbg(dev, "no device\n");
         return 0;
     }
 
     /* set horkage */
     dev->horkage |= ata_dev_blacklisted(dev);
     ata_force_horkage(dev);
 
     if (dev->horkage & ATA_HORKAGE_DISABLE) {
         ata_dev_info(dev, "unsupported device, disabling\n");
         ata_dev_disable(dev);
         return 0;
     }
 
     if ((!atapi_enabled || (ap->flags & ATA_FLAG_NO_ATAPI)) &&
         dev->class == ATA_DEV_ATAPI) {
         ata_dev_warn(dev, "WARNING: ATAPI is %s, device ignored\n",
                  atapi_enabled ? "not supported with this driver"
                  : "disabled");
         ata_dev_disable(dev);
         return 0;
     }
 
     rc = ata_do_link_spd_horkage(dev);
     if (rc)
         return rc;
 
     /* some WD SATA-1 drives have issues with LPM, turn on NOLPM for them */
     if ((dev->horkage & ATA_HORKAGE_WD_BROKEN_LPM) &&
         (id[ATA_ID_SATA_CAPABILITY] & 0xe) == 0x2)
         dev->horkage |= ATA_HORKAGE_NOLPM;
 
     if (ap->flags & ATA_FLAG_NO_LPM)
         dev->horkage |= ATA_HORKAGE_NOLPM;
 
     if (dev->horkage & ATA_HORKAGE_NOLPM) {
         ata_dev_warn(dev, "LPM support broken, forcing max_power\n");
         dev->link->ap->target_lpm_policy = ATA_LPM_MAX_POWER;
     }
 
     /* let ACPI work its magic */
     rc = ata_acpi_on_devcfg(dev);
     if (rc)
         return rc;
 
     /* massage HPA, do it early as it might change IDENTIFY data */
     rc = ata_hpa_resize(dev);
     if (rc)
         return rc;
 
     /* print device capabilities */
     ata_dev_dbg(dev,
             "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
             "85:%04x 86:%04x 87:%04x 88:%04x\n",
             __func__,
             id[49], id[82], id[83], id[84],
             id[85], id[86], id[87], id[88]);
 
     /* initialize to-be-configured parameters */
     dev->flags &= ~ATA_DFLAG_CFG_MASK;
     dev->max_sectors = 0;
     dev->cdb_len = 0;
     dev->n_sectors = 0;
     dev->cylinders = 0;
     dev->heads = 0;
     dev->sectors = 0;
     dev->multi_count = 0;
 
     /*
      * common ATA, ATAPI feature tests
      */
 
     /* find max transfer mode; for printk only */
     xfer_mask = ata_id_xfermask(id);
 
     ata_dump_id(dev, id);
 
     /* SCSI only uses 4-char revisions, dump full 8 chars from ATA */
     ata_id_c_string(dev->id, fwrevbuf, ATA_ID_FW_REV,
             sizeof(fwrevbuf));
 
     ata_id_c_string(dev->id, modelbuf, ATA_ID_PROD,
             sizeof(modelbuf));
 
     /* ATA-specific feature tests */
     if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
         if (ata_id_is_cfa(id)) {
             /* CPRM may make this media unusable */
             if (id[ATA_ID_CFA_KEY_MGMT] & 1)
                 ata_dev_warn(dev,
     "supports DRM functions and may not be fully accessible\n");
             snprintf(revbuf, 7, "CFA");
         } else {
             snprintf(revbuf, 7, "ATA-%d", ata_id_major_version(id));
             /* Warn the user if the device has TPM extensions */
             if (ata_id_has_tpm(id))
                 ata_dev_warn(dev,
     "supports DRM functions and may not be fully accessible\n");
         }
 
         dev->n_sectors = ata_id_n_sectors(id);
 
         /* get current R/W Multiple count setting */
         if ((dev->id[47] >> 8) == 0x80 && (dev->id[59] & 0x100)) {
             unsigned int max = dev->id[47] & 0xff;
             unsigned int cnt = dev->id[59] & 0xff;
             /* only recognize/allow powers of two here */
             if (is_power_of_2(max) && is_power_of_2(cnt))
                 if (cnt <= max)
                     dev->multi_count = cnt;
         }
 
         /* print device info to dmesg */
         if (print_info)
             ata_dev_info(dev, "%s: %s, %s, max %s\n",
                      revbuf, modelbuf, fwrevbuf,
                      ata_mode_string(xfer_mask));
 
         if (ata_id_has_lba(id)) {
             rc = ata_dev_config_lba(dev);
             if (rc)
                 return rc;
         } else {
             ata_dev_config_chs(dev);
         }
 
         ata_dev_config_devslp(dev);
         ata_dev_config_sense_reporting(dev);
         ata_dev_config_zac(dev);
         ata_dev_config_trusted(dev);
         ata_dev_config_cpr(dev);
         dev->cdb_len = 32;
 
         if (print_info)
             ata_dev_print_features(dev);
     }
 
     /* ATAPI-specific feature tests */
     else if (dev->class == ATA_DEV_ATAPI) {
         const char *cdb_intr_string = "";
         const char *atapi_an_string = "";
         const char *dma_dir_string = "";
         u32 sntf;
 
         rc = atapi_cdb_len(id);
         if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
             ata_dev_warn(dev, "unsupported CDB len %d\n", rc);
             rc = -EINVAL;
             goto err_out_nosup;
         }
         dev->cdb_len = (unsigned int) rc;
 
         /* Enable ATAPI AN if both the host and device have
          * the support.  If PMP is attached, SNTF is required
          * to enable ATAPI AN to discern between PHY status
          * changed notifications and ATAPI ANs.
          */
         if (atapi_an &&
             (ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
             (!sata_pmp_attached(ap) ||
              sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
             /* issue SET feature command to turn this on */
             err_mask = ata_dev_set_feature(dev,
                     SETFEATURES_SATA_ENABLE, SATA_AN);
             if (err_mask)
                 ata_dev_err(dev,
                         "failed to enable ATAPI AN (err_mask=0x%x)\n",
                         err_mask);
             else {
                 dev->flags |= ATA_DFLAG_AN;
                 atapi_an_string = ", ATAPI AN";
             }
         }
 
         if (ata_id_cdb_intr(dev->id)) {
             dev->flags |= ATA_DFLAG_CDB_INTR;
             cdb_intr_string = ", CDB intr";
         }
 
         if (atapi_dmadir || (dev->horkage & ATA_HORKAGE_ATAPI_DMADIR) || atapi_id_dmadir(dev->id)) {
             dev->flags |= ATA_DFLAG_DMADIR;
             dma_dir_string = ", DMADIR";
         }
 
         if (ata_id_has_da(dev->id)) {
             dev->flags |= ATA_DFLAG_DA;
             zpodd_init(dev);
         }
 
         /* print device info to dmesg */
         if (print_info)
             ata_dev_info(dev,
                      "ATAPI: %s, %s, max %s%s%s%s\n",
                      modelbuf, fwrevbuf,
                      ata_mode_string(xfer_mask),
                      cdb_intr_string, atapi_an_string,
                      dma_dir_string);
     }
 
     /* determine max_sectors */
     dev->max_sectors = ATA_MAX_SECTORS;
     if (dev->flags & ATA_DFLAG_LBA48)
         dev->max_sectors = ATA_MAX_SECTORS_LBA48;
 
     /* Limit PATA drive on SATA cable bridge transfers to udma5,
        200 sectors */
     if (ata_dev_knobble(dev)) {
         if (print_info)
             ata_dev_info(dev, "applying bridge limits\n");
         dev->udma_mask &= ATA_UDMA5;
         dev->max_sectors = ATA_MAX_SECTORS;
     }
 
     if ((dev->class == ATA_DEV_ATAPI) &&
         (atapi_command_packet_set(id) == TYPE_TAPE)) {
         dev->max_sectors = ATA_MAX_SECTORS_TAPE;
         dev->horkage |= ATA_HORKAGE_STUCK_ERR;
     }
 
     if (dev->horkage & ATA_HORKAGE_MAX_SEC_128)
         dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
                      dev->max_sectors);
 
     if (dev->horkage & ATA_HORKAGE_MAX_SEC_1024)
         dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_1024,
                      dev->max_sectors);
 
     if (dev->horkage & ATA_HORKAGE_MAX_SEC_LBA48)
         dev->max_sectors = ATA_MAX_SECTORS_LBA48;
 
     if (ap->ops->dev_config)
         ap->ops->dev_config(dev);
 
     if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
         /* Let the user know. We don't want to disallow opens for
            rescue purposes, or in case the vendor is just a blithering
            idiot. Do this after the dev_config call as some controllers
            with buggy firmware may want to avoid reporting false device
            bugs */
 
         if (print_info) {
             ata_dev_warn(dev,
 "Drive reports diagnostics failure. This may indicate a drive\n");
             ata_dev_warn(dev,
 "fault or invalid emulation. Contact drive vendor for information.\n");
         }
     }
 
     if ((dev->horkage & ATA_HORKAGE_FIRMWARE_WARN) && print_info) {
         ata_dev_warn(dev, "WARNING: device requires firmware update to be fully functional\n");
         ata_dev_warn(dev, "         contact the vendor or visit http://ata.wiki.kernel.org\n");
     }
 
     return 0;
 
 err_out_nosup:
     return rc;
 }
 
 /**
  *  ata_cable_40wire    -   return 40 wire cable type
  *  @ap: port
  *
  *  Helper method for drivers which want to hardwire 40 wire cable
  *  detection.
  */
 
 int ata_cable_40wire(struct ata_port *ap)
 {
     return ATA_CBL_PATA40;
 }
 EXPORT_SYMBOL_GPL(ata_cable_40wire);
 
 /**
  *  ata_cable_80wire    -   return 80 wire cable type
  *  @ap: port
  *
  *  Helper method for drivers which want to hardwire 80 wire cable
  *  detection.
  */
 
 int ata_cable_80wire(struct ata_port *ap)
 {
     return ATA_CBL_PATA80;
 }
 EXPORT_SYMBOL_GPL(ata_cable_80wire);
 
 /**
  *  ata_cable_unknown   -   return unknown PATA cable.
  *  @ap: port
  *
  *  Helper method for drivers which have no PATA cable detection.
  */
 
 int ata_cable_unknown(struct ata_port *ap)
 {
     return ATA_CBL_PATA_UNK;
 }
 EXPORT_SYMBOL_GPL(ata_cable_unknown);
 
 /**
  *  ata_cable_ignore    -   return ignored PATA cable.
  *  @ap: port
  *
  *  Helper method for drivers which don't use cable type to limit
  *  transfer mode.
  */
 int ata_cable_ignore(struct ata_port *ap)
 {
     return ATA_CBL_PATA_IGN;
 }
 EXPORT_SYMBOL_GPL(ata_cable_ignore);
 
 /**
  *  ata_cable_sata  -   return SATA cable type
  *  @ap: port
  *
  *  Helper method for drivers which have SATA cables
  */
 
 int ata_cable_sata(struct ata_port *ap)
 {
     return ATA_CBL_SATA;
 }
 EXPORT_SYMBOL_GPL(ata_cable_sata);
 
 /**
  *  ata_bus_probe - Reset and probe ATA bus
  *  @ap: Bus to probe
  *
  *  Master ATA bus probing function.  Initiates a hardware-dependent
  *  bus reset, then attempts to identify any devices found on
  *  the bus.
  *
  *  LOCKING:
  *  PCI/etc. bus probe sem.
  *
  *  RETURNS:
  *  Zero on success, negative errno otherwise.
  */
 
 int ata_bus_probe(struct ata_port *ap)
 {
     unsigned int classes[ATA_MAX_DEVICES];
     int tries[ATA_MAX_DEVICES];
     int rc;
     struct ata_device *dev;
 
     ata_for_each_dev(dev, &ap->link, ALL)
         tries[dev->devno] = ATA_PROBE_MAX_TRIES;
 
  retry:
     ata_for_each_dev(dev, &ap->link, ALL) {
         /* If we issue an SRST then an ATA drive (not ATAPI)
          * may change configuration and be in PIO0 timing. If
          * we do a hard reset (or are coming from power on)
          * this is true for ATA or ATAPI. Until we've set a
          * suitable controller mode we should not touch the
          * bus as we may be talking too fast.
          */
         dev->pio_mode = XFER_PIO_0;
         dev->dma_mode = 0xff;
 
         /* If the controller has a pio mode setup function
          * then use it to set the chipset to rights. Don't
          * touch the DMA setup as that will be dealt with when
          * configuring devices.
          */
         if (ap->ops->set_piomode)
             ap->ops->set_piomode(ap, dev);
     }
 
     /* reset and determine device classes */
     ap->ops->phy_reset(ap);
 
     ata_for_each_dev(dev, &ap->link, ALL) {
         if (dev->class != ATA_DEV_UNKNOWN)
             classes[dev->devno] = dev->class;
         else
             classes[dev->devno] = ATA_DEV_NONE;
 
         dev->class = ATA_DEV_UNKNOWN;
     }
 
     /* read IDENTIFY page and configure devices. We have to do the identify
        specific sequence bass-ackwards so that PDIAG- is released by
        the slave device */
 
     ata_for_each_dev(dev, &ap->link, ALL_REVERSE) {
         if (tries[dev->devno])
             dev->class = classes[dev->devno];
 
         if (!ata_dev_enabled(dev))
             continue;
 
         rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
                      dev->id);
         if (rc)
             goto fail;
     }
 
     /* Now ask for the cable type as PDIAG- should have been released */
     if (ap->ops->cable_detect)
         ap->cbl = ap->ops->cable_detect(ap);
 
     /* We may have SATA bridge glue hiding here irrespective of
      * the reported cable types and sensed types.  When SATA
      * drives indicate we have a bridge, we don't know which end
      * of the link the bridge is which is a problem.
      */
     ata_for_each_dev(dev, &ap->link, ENABLED)
         if (ata_id_is_sata(dev->id))
             ap->cbl = ATA_CBL_SATA;
 
     /* After the identify sequence we can now set up the devices. We do
        this in the normal order so that the user doesn't get confused */
 
     ata_for_each_dev(dev, &ap->link, ENABLED) {
         ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
         rc = ata_dev_configure(dev);
         ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
         if (rc)
             goto fail;
     }
 
     /* configure transfer mode */
     rc = ata_set_mode(&ap->link, &dev);
     if (rc)
         goto fail;
 
     ata_for_each_dev(dev, &ap->link, ENABLED)
         return 0;
 
     return -ENODEV;
 
  fail:
     tries[dev->devno]--;
 
     switch (rc) {
     case -EINVAL:
         /* eeek, something went very wrong, give up */
         tries[dev->devno] = 0;
         break;
 
     case -ENODEV:
         /* give it just one more chance */
         tries[dev->devno] = min(tries[dev->devno], 1);
         fallthrough;
     case -EIO:
         if (tries[dev->devno] == 1) {
             /* This is the last chance, better to slow
              * down than lose it.
              */
             sata_down_spd_limit(&ap->link, 0);
             ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
         }
     }
 
     if (!tries[dev->devno])
         ata_dev_disable(dev);
 
     goto retry;
 }
 
 /**
  *  sata_print_link_status - Print SATA link status
  *  @link: SATA link to printk link status about
  *
  *  This function prints link speed and status of a SATA link.
  *
  *  LOCKING:
  *  None.
  */
 static void sata_print_link_status(struct ata_link *link)
 {
     u32 sstatus, scontrol, tmp;
 
     if (sata_scr_read(link, SCR_STATUS, &sstatus))
         return;
     sata_scr_read(link, SCR_CONTROL, &scontrol);
 
     if (ata_phys_link_online(link)) {
         tmp = (sstatus >> 4) & 0xf;
         ata_link_info(link, "SATA link up %s (SStatus %X SControl %X)\n",
                   sata_spd_string(tmp), sstatus, scontrol);
     } else {
         ata_link_info(link, "SATA link down (SStatus %X SControl %X)\n",
                   sstatus, scontrol);
     }
 }
 
 /**
  *  ata_dev_pair        -   return other device on cable
  *  @adev: device
  *
  *  Obtain the other device on the same cable, or if none is
  *  present NULL is returned
  */
 
 struct ata_device *ata_dev_pair(struct ata_device *adev)
 {
     struct ata_link *link = adev->link;
     struct ata_device *pair = &link->device[1 - adev->devno];
     if (!ata_dev_enabled(pair))
         return NULL;
     return pair;
 }
 EXPORT_SYMBOL_GPL(ata_dev_pair);
 
 /**
  *  sata_down_spd_limit - adjust SATA spd limit downward
  *  @link: Link to adjust SATA spd limit for
  *  @spd_limit: Additional limit
  *
  *  Adjust SATA spd limit of @link downward.  Note that this
  *  function only adjusts the limit.  The change must be applied
  *  using sata_set_spd().
  *
  *  If @spd_limit is non-zero, the speed is limited to equal to or
  *  lower than @spd_limit if such speed is supported.  If
  *  @spd_limit is slower than any supported speed, only the lowest
  *  supported speed is allowed.
  *
  *  LOCKING:
  *  Inherited from caller.
  *
  *  RETURNS:
  *  0 on success, negative errno on failure
  */
 int sata_down_spd_limit(struct ata_link *link, u32 spd_limit)
 {
     u32 sstatus, spd, mask;
     int rc, bit;
 
     if (!sata_scr_valid(link))
         return -EOPNOTSUPP;
 
     /* If SCR can be read, use it to determine the current SPD.
      * If not, use cached value in link->sata_spd.
      */
     rc = sata_scr_read(link, SCR_STATUS, &sstatus);
     if (rc == 0 && ata_sstatus_online(sstatus))
         spd = (sstatus >> 4) & 0xf;
     else
         spd = link->sata_spd;
 
     mask = link->sata_spd_limit;
     if (mask <= 1)
         return -EINVAL;
 
     /* unconditionally mask off the highest bit */
     bit = fls(mask) - 1;
     mask &= ~(1 << bit);
 
     /*
      * Mask off all speeds higher than or equal to the current one.  At
      * this point, if current SPD is not available and we previously
      * recorded the link speed from SStatus, the driver has already
      * masked off the highest bit so mask should already be 1 or 0.
      * Otherwise, we should not force 1.5Gbps on a link where we have
      * not previously recorded speed from SStatus.  Just return in this
      * case.
      */
     if (spd > 1)
         mask &= (1 << (spd - 1)) - 1;
     else
         return -EINVAL;
 
     /* were we already at the bottom? */
     if (!mask)
         return -EINVAL;
 
     if (spd_limit) {
         if (mask & ((1 << spd_limit) - 1))
             mask &= (1 << spd_limit) - 1;
         else {
             bit = ffs(mask) - 1;
             mask = 1 << bit;
         }
     }
 
     link->sata_spd_limit = mask;
 
     ata_link_warn(link, "limiting SATA link speed to %s\n",
               sata_spd_string(fls(mask)));
 
     return 0;
 }
 
 #ifdef CONFIG_ATA_ACPI
 /**
  *  ata_timing_cycle2mode - find xfer mode for the specified cycle duration
  *  @xfer_shift: ATA_SHIFT_* value for transfer type to examine.
  *  @cycle: cycle duration in ns
  *
  *  Return matching xfer mode for @cycle.  The returned mode is of
  *  the transfer type specified by @xfer_shift.  If @cycle is too
  *  slow for @xfer_shift, 0xff is returned.  If @cycle is faster
  *  than the fastest known mode, the fasted mode is returned.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  Matching xfer_mode, 0xff if no match found.
  */
 u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle)
 {
     u8 base_mode = 0xff, last_mode = 0xff;
     const struct ata_xfer_ent *ent;
     const struct ata_timing *t;
 
     for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
         if (ent->shift == xfer_shift)
             base_mode = ent->base;
 
     for (t = ata_timing_find_mode(base_mode);
          t && ata_xfer_mode2shift(t->mode) == xfer_shift; t++) {
         unsigned short this_cycle;
 
         switch (xfer_shift) {
         case ATA_SHIFT_PIO:
         case ATA_SHIFT_MWDMA:
             this_cycle = t->cycle;
             break;
         case ATA_SHIFT_UDMA:
             this_cycle = t->udma;
             break;
         default:
             return 0xff;
         }
 
         if (cycle > this_cycle)
             break;
 
         last_mode = t->mode;
     }
 
     return last_mode;
 }
 #endif
 
 /**
  *  ata_down_xfermask_limit - adjust dev xfer masks downward
  *  @dev: Device to adjust xfer masks
  *  @sel: ATA_DNXFER_* selector
  *
  *  Adjust xfer masks of @dev downward.  Note that this function
  *  does not apply the change.  Invoking ata_set_mode() afterwards
  *  will apply the limit.
  *
  *  LOCKING:
  *  Inherited from caller.
  *
  *  RETURNS:
  *  0 on success, negative errno on failure
  */
 int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel)
 {
     char buf[32];
     unsigned int orig_mask, xfer_mask;
     unsigned int pio_mask, mwdma_mask, udma_mask;
     int quiet, highbit;
 
     quiet = !!(sel & ATA_DNXFER_QUIET);
     sel &= ~ATA_DNXFER_QUIET;
 
     xfer_mask = orig_mask = ata_pack_xfermask(dev->pio_mask,
                           dev->mwdma_mask,
                           dev->udma_mask);
     ata_unpack_xfermask(xfer_mask, &pio_mask, &mwdma_mask, &udma_mask);
 
     switch (sel) {
     case ATA_DNXFER_PIO:
         highbit = fls(pio_mask) - 1;
         pio_mask &= ~(1 << highbit);
         break;
 
     case ATA_DNXFER_DMA:
         if (udma_mask) {
             highbit = fls(udma_mask) - 1;
             udma_mask &= ~(1 << highbit);
             if (!udma_mask)
                 return -ENOENT;
         } else if (mwdma_mask) {
             highbit = fls(mwdma_mask) - 1;
             mwdma_mask &= ~(1 << highbit);
             if (!mwdma_mask)
                 return -ENOENT;
         }
         break;
 
     case ATA_DNXFER_40C:
         udma_mask &= ATA_UDMA_MASK_40C;
         break;
 
     case ATA_DNXFER_FORCE_PIO0:
         pio_mask &= 1;
         fallthrough;
     case ATA_DNXFER_FORCE_PIO:
         mwdma_mask = 0;
         udma_mask = 0;
         break;
 
     default:
         BUG();
     }
 
     xfer_mask &= ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
 
     if (!(xfer_mask & ATA_MASK_PIO) || xfer_mask == orig_mask)
         return -ENOENT;
 
     if (!quiet) {
         if (xfer_mask & (ATA_MASK_MWDMA | ATA_MASK_UDMA))
             snprintf(buf, sizeof(buf), "%s:%s",
                  ata_mode_string(xfer_mask),
                  ata_mode_string(xfer_mask & ATA_MASK_PIO));
         else
             snprintf(buf, sizeof(buf), "%s",
                  ata_mode_string(xfer_mask));
 
         ata_dev_warn(dev, "limiting speed to %s\n", buf);
     }
 
     ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
                 &dev->udma_mask);
 
     return 0;
 }
 
 static int ata_dev_set_mode(struct ata_device *dev)
 {
     struct ata_port *ap = dev->link->ap;
     struct ata_eh_context *ehc = &dev->link->eh_context;
     const bool nosetxfer = dev->horkage & ATA_HORKAGE_NOSETXFER;
     const char *dev_err_whine = "";
     int ign_dev_err = 0;
     unsigned int err_mask = 0;
     int rc;
 
     dev->flags &= ~ATA_DFLAG_PIO;
     if (dev->xfer_shift == ATA_SHIFT_PIO)
         dev->flags |= ATA_DFLAG_PIO;
 
     if (nosetxfer && ap->flags & ATA_FLAG_SATA && ata_id_is_sata(dev->id))
         dev_err_whine = " (SET_XFERMODE skipped)";
     else {
         if (nosetxfer)
             ata_dev_warn(dev,
                      "NOSETXFER but PATA detected - can't "
                      "skip SETXFER, might malfunction\n");
         err_mask = ata_dev_set_xfermode(dev);
     }
 
     if (err_mask & ~AC_ERR_DEV)
         goto fail;
 
     /* revalidate */
     ehc->i.flags |= ATA_EHI_POST_SETMODE;
     rc = ata_dev_revalidate(dev, ATA_DEV_UNKNOWN, 0);
     ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
     if (rc)
         return rc;
 
     if (dev->xfer_shift == ATA_SHIFT_PIO) {
         /* Old CFA may refuse this command, which is just fine */
         if (ata_id_is_cfa(dev->id))
             ign_dev_err = 1;
         /* Catch several broken garbage emulations plus some pre
            ATA devices */
         if (ata_id_major_version(dev->id) == 0 &&
                     dev->pio_mode <= XFER_PIO_2)
             ign_dev_err = 1;
         /* Some very old devices and some bad newer ones fail
            any kind of SET_XFERMODE request but support PIO0-2
            timings and no IORDY */
         if (!ata_id_has_iordy(dev->id) && dev->pio_mode <= XFER_PIO_2)
             ign_dev_err = 1;
     }
     /* Early MWDMA devices do DMA but don't allow DMA mode setting.
        Don't fail an MWDMA0 set IFF the device indicates it is in MWDMA0 */
     if (dev->xfer_shift == ATA_SHIFT_MWDMA &&
         dev->dma_mode == XFER_MW_DMA_0 &&
         (dev->id[63] >> 8) & 1)
         ign_dev_err = 1;
 
     /* if the device is actually configured correctly, ignore dev err */
     if (dev->xfer_mode == ata_xfer_mask2mode(ata_id_xfermask(dev->id)))
         ign_dev_err = 1;
 
     if (err_mask & AC_ERR_DEV) {
         if (!ign_dev_err)
             goto fail;
         else
             dev_err_whine = " (device error ignored)";
     }
 
     ata_dev_dbg(dev, "xfer_shift=%u, xfer_mode=0x%x\n",
             dev->xfer_shift, (int)dev->xfer_mode);
 
     if (!(ehc->i.flags & ATA_EHI_QUIET) ||
         ehc->i.flags & ATA_EHI_DID_HARDRESET)
         ata_dev_info(dev, "configured for %s%s\n",
                  ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)),
                  dev_err_whine);
 
     return 0;
 
  fail:
     ata_dev_err(dev, "failed to set xfermode (err_mask=0x%x)\n", err_mask);
     return -EIO;
 }
 
 /**
  *  ata_do_set_mode - Program timings and issue SET FEATURES - XFER
  *  @link: link on which timings will be programmed
  *  @r_failed_dev: out parameter for failed device
  *
  *  Standard implementation of the function used to tune and set
  *  ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
  *  ata_dev_set_mode() fails, pointer to the failing device is
  *  returned in @r_failed_dev.
  *
  *  LOCKING:
  *  PCI/etc. bus probe sem.
  *
  *  RETURNS:
  *  0 on success, negative errno otherwise
  */
 
 int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
 {
     struct ata_port *ap = link->ap;
     struct ata_device *dev;
     int rc = 0, used_dma = 0, found = 0;
 
     /* step 1: calculate xfer_mask */
     ata_for_each_dev(dev, link, ENABLED) {
         unsigned int pio_mask, dma_mask;
         unsigned int mode_mask;
 
         mode_mask = ATA_DMA_MASK_ATA;
         if (dev->class == ATA_DEV_ATAPI)
             mode_mask = ATA_DMA_MASK_ATAPI;
         else if (ata_id_is_cfa(dev->id))
             mode_mask = ATA_DMA_MASK_CFA;
 
         ata_dev_xfermask(dev);
         ata_force_xfermask(dev);
 
         pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
 
         if (libata_dma_mask & mode_mask)
             dma_mask = ata_pack_xfermask(0, dev->mwdma_mask,
                              dev->udma_mask);
         else
             dma_mask = 0;
 
         dev->pio_mode = ata_xfer_mask2mode(pio_mask);
         dev->dma_mode = ata_xfer_mask2mode(dma_mask);
 
         found = 1;
         if (ata_dma_enabled(dev))
             used_dma = 1;
     }
     if (!found)
         goto out;
 
     /* step 2: always set host PIO timings */
     ata_for_each_dev(dev, link, ENABLED) {
         if (dev->pio_mode == 0xff) {
             ata_dev_warn(dev, "no PIO support\n");
             rc = -EINVAL;
             goto out;
         }
 
         dev->xfer_mode = dev->pio_mode;
         dev->xfer_shift = ATA_SHIFT_PIO;
         if (ap->ops->set_piomode)
             ap->ops->set_piomode(ap, dev);
     }
 
     /* step 3: set host DMA timings */
     ata_for_each_dev(dev, link, ENABLED) {
         if (!ata_dma_enabled(dev))
             continue;
 
         dev->xfer_mode = dev->dma_mode;
         dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
         if (ap->ops->set_dmamode)
             ap->ops->set_dmamode(ap, dev);
     }
 
     /* step 4: update devices' xfer mode */
     ata_for_each_dev(dev, link, ENABLED) {
         rc = ata_dev_set_mode(dev);
         if (rc)
             goto out;
     }
 
     /* Record simplex status. If we selected DMA then the other
      * host channels are not permitted to do so.
      */
     if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
         ap->host->simplex_claimed = ap;
 
  out:
     if (rc)
         *r_failed_dev = dev;
     return rc;
 }
 EXPORT_SYMBOL_GPL(ata_do_set_mode);
 
 /**
  *  ata_wait_ready - wait for link to become ready
  *  @link: link to be waited on
  *  @deadline: deadline jiffies for the operation
  *  @check_ready: callback to check link readiness
  *
  *  Wait for @link to become ready.  @check_ready should return
  *  positive number if @link is ready, 0 if it isn't, -ENODEV if
  *  link doesn't seem to be occupied, other errno for other error
  *  conditions.
  *
  *  Transient -ENODEV conditions are allowed for
  *  ATA_TMOUT_FF_WAIT.
  *
  *  LOCKING:
  *  EH context.
  *
  *  RETURNS:
  *  0 if @link is ready before @deadline; otherwise, -errno.
  */
 int ata_wait_ready(struct ata_link *link, unsigned long deadline,
            int (*check_ready)(struct ata_link *link))
 {
     unsigned long start = jiffies;
     unsigned long nodev_deadline;
     int warned = 0;
 
     /* choose which 0xff timeout to use, read comment in libata.h */
     if (link->ap->host->flags & ATA_HOST_PARALLEL_SCAN)
         nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT_LONG);
     else
         nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT);
 
     /* Slave readiness can't be tested separately from master.  On
      * M/S emulation configuration, this function should be called
      * only on the master and it will handle both master and slave.
      */
     WARN_ON(link == link->ap->slave_link);
 
     if (time_after(nodev_deadline, deadline))
         nodev_deadline = deadline;
 
     while (1) {
         unsigned long now = jiffies;
         int ready, tmp;
 
         ready = tmp = check_ready(link);
         if (ready > 0)
             return 0;
 
         /*
          * -ENODEV could be transient.  Ignore -ENODEV if link
          * is online.  Also, some SATA devices take a long
          * time to clear 0xff after reset.  Wait for
          * ATA_TMOUT_FF_WAIT[_LONG] on -ENODEV if link isn't
          * offline.
          *
          * Note that some PATA controllers (pata_ali) explode
          * if status register is read more than once when
          * there's no device attached.
          */
         if (ready == -ENODEV) {
             if (ata_link_online(link))
                 ready = 0;
             else if ((link->ap->flags & ATA_FLAG_SATA) &&
                  !ata_link_offline(link) &&
                  time_before(now, nodev_deadline))
                 ready = 0;
         }
 
         if (ready)
             return ready;
         if (time_after(now, deadline))
             return -EBUSY;
 
         if (!warned && time_after(now, start + 5 * HZ) &&
             (deadline - now > 3 * HZ)) {
             ata_link_warn(link,
                 "link is slow to respond, please be patient "
                 "(ready=%d)\n", tmp);
             warned = 1;
         }
 
         ata_msleep(link->ap, 50);
     }
 }
 
 /**
  *  ata_wait_after_reset - wait for link to become ready after reset
  *  @link: link to be waited on
  *  @deadline: deadline jiffies for the operation
  *  @check_ready: callback to check link readiness
  *
  *  Wait for @link to become ready after reset.
  *
  *  LOCKING:
  *  EH context.
  *
  *  RETURNS:
  *  0 if @link is ready before @deadline; otherwise, -errno.
  */
 int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
                 int (*check_ready)(struct ata_link *link))
 {
     ata_msleep(link->ap, ATA_WAIT_AFTER_RESET);
 
     return ata_wait_ready(link, deadline, check_ready);
 }
 EXPORT_SYMBOL_GPL(ata_wait_after_reset);
 
 /**
  *  ata_std_prereset - prepare for reset
  *  @link: ATA link to be reset
  *  @deadline: deadline jiffies for the operation
  *
  *  @link is about to be reset.  Initialize it.  Failure from
  *  prereset makes libata abort whole reset sequence and give up
  *  that port, so prereset should be best-effort.  It does its
  *  best to prepare for reset sequence but if things go wrong, it
  *  should just whine, not fail.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  *
  *  RETURNS:
  *  Always 0.
  */
 int ata_std_prereset(struct ata_link *link, unsigned long deadline)
 {
     struct ata_port *ap = link->ap;
     struct ata_eh_context *ehc = &link->eh_context;
     const unsigned long *timing = sata_ehc_deb_timing(ehc);
     int rc;
 
     /* if we're about to do hardreset, nothing more to do */
     if (ehc->i.action & ATA_EH_HARDRESET)
         return 0;
 
     /* if SATA, resume link */
     if (ap->flags & ATA_FLAG_SATA) {
         rc = sata_link_resume(link, timing, deadline);
         /* whine about phy resume failure but proceed */
         if (rc && rc != -EOPNOTSUPP)
             ata_link_warn(link,
                       "failed to resume link for reset (errno=%d)\n",
                       rc);
     }
 
     /* no point in trying softreset on offline link */
     if (ata_phys_link_offline(link))
         ehc->i.action &= ~ATA_EH_SOFTRESET;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(ata_std_prereset);
 
 /**
  *  sata_std_hardreset - COMRESET w/o waiting or classification
  *  @link: link to reset
  *  @class: resulting class of attached device
  *  @deadline: deadline jiffies for the operation
  *
  *  Standard SATA COMRESET w/o waiting or classification.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  *
  *  RETURNS:
  *  0 if link offline, -EAGAIN if link online, -errno on errors.
  */
 int sata_std_hardreset(struct ata_link *link, unsigned int *class,
                unsigned long deadline)
 {
     const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
     bool online;
     int rc;
 
     /* do hardreset */
     rc = sata_link_hardreset(link, timing, deadline, &online, NULL);
     return online ? -EAGAIN : rc;
 }
 EXPORT_SYMBOL_GPL(sata_std_hardreset);
 
 /**
  *  ata_std_postreset - standard postreset callback
  *  @link: the target ata_link
  *  @classes: classes of attached devices
  *
  *  This function is invoked after a successful reset.  Note that
  *  the device might have been reset more than once using
  *  different reset methods before postreset is invoked.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  */
 void ata_std_postreset(struct ata_link *link, unsigned int *classes)
 {
     u32 serror;
 
     /* reset complete, clear SError */
     if (!sata_scr_read(link, SCR_ERROR, &serror))
         sata_scr_write(link, SCR_ERROR, serror);
 
     /* print link status */
     sata_print_link_status(link);
 }
 EXPORT_SYMBOL_GPL(ata_std_postreset);
 
 /**
  *  ata_dev_same_device - Determine whether new ID matches configured device
  *  @dev: device to compare against
  *  @new_class: class of the new device
  *  @new_id: IDENTIFY page of the new device
  *
  *  Compare @new_class and @new_id against @dev and determine
  *  whether @dev is the device indicated by @new_class and
  *  @new_id.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  1 if @dev matches @new_class and @new_id, 0 otherwise.
  */
 static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
                    const u16 *new_id)
 {
     const u16 *old_id = dev->id;
     unsigned char model[2][ATA_ID_PROD_LEN + 1];
     unsigned char serial[2][ATA_ID_SERNO_LEN + 1];
 
     if (dev->class != new_class) {
         ata_dev_info(dev, "class mismatch %d != %d\n",
                  dev->class, new_class);
         return 0;
     }
 
     ata_id_c_string(old_id, model[0], ATA_ID_PROD, sizeof(model[0]));
     ata_id_c_string(new_id, model[1], ATA_ID_PROD, sizeof(model[1]));
     ata_id_c_string(old_id, serial[0], ATA_ID_SERNO, sizeof(serial[0]));
     ata_id_c_string(new_id, serial[1], ATA_ID_SERNO, sizeof(serial[1]));
 
     if (strcmp(model[0], model[1])) {
         ata_dev_info(dev, "model number mismatch '%s' != '%s'\n",
                  model[0], model[1]);
         return 0;
     }
 
     if (strcmp(serial[0], serial[1])) {
         ata_dev_info(dev, "serial number mismatch '%s' != '%s'\n",
                  serial[0], serial[1]);
         return 0;
     }
 
     return 1;
 }
 
 /**
  *  ata_dev_reread_id - Re-read IDENTIFY data
  *  @dev: target ATA device
  *  @readid_flags: read ID flags
  *
  *  Re-read IDENTIFY page and make sure @dev is still attached to
  *  the port.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  *
  *  RETURNS:
  *  0 on success, negative errno otherwise
  */
 int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
 {
     unsigned int class = dev->class;
     u16 *id = (void *)dev->link->ap->sector_buf;
     int rc;
 
     /* read ID data */
     rc = ata_dev_read_id(dev, &class, readid_flags, id);
     if (rc)
         return rc;
 
     /* is the device still there? */
     if (!ata_dev_same_device(dev, class, id))
         return -ENODEV;
 
     memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
     return 0;
 }
 
 /**
  *  ata_dev_revalidate - Revalidate ATA device
  *  @dev: device to revalidate
  *  @new_class: new class code
  *  @readid_flags: read ID flags
  *
  *  Re-read IDENTIFY page, make sure @dev is still attached to the
  *  port and reconfigure it according to the new IDENTIFY page.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  *
  *  RETURNS:
  *  0 on success, negative errno otherwise
  */
 int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
                unsigned int readid_flags)
 {
     u64 n_sectors = dev->n_sectors;
     u64 n_native_sectors = dev->n_native_sectors;
     int rc;
 
     if (!ata_dev_enabled(dev))
         return -ENODEV;
 
     /* fail early if !ATA && !ATAPI to avoid issuing [P]IDENTIFY to PMP */
     if (ata_class_enabled(new_class) &&
         new_class != ATA_DEV_ATA &&
         new_class != ATA_DEV_ATAPI &&
         new_class != ATA_DEV_ZAC &&
         new_class != ATA_DEV_SEMB) {
         ata_dev_info(dev, "class mismatch %u != %u\n",
                  dev->class, new_class);
         rc = -ENODEV;
         goto fail;
     }
 
     /* re-read ID */
     rc = ata_dev_reread_id(dev, readid_flags);
     if (rc)
         goto fail;
 
     /* configure device according to the new ID */
     rc = ata_dev_configure(dev);
     if (rc)
         goto fail;
 
     /* verify n_sectors hasn't changed */
     if (dev->class != ATA_DEV_ATA || !n_sectors ||
         dev->n_sectors == n_sectors)
         return 0;
 
     /* n_sectors has changed */
     ata_dev_warn(dev, "n_sectors mismatch %llu != %llu\n",
              (unsigned long long)n_sectors,
              (unsigned long long)dev->n_sectors);
 
     /*
      * Something could have caused HPA to be unlocked
      * involuntarily.  If n_native_sectors hasn't changed and the
      * new size matches it, keep the device.
      */
     if (dev->n_native_sectors == n_native_sectors &&
         dev->n_sectors > n_sectors && dev->n_sectors == n_native_sectors) {
         ata_dev_warn(dev,
                  "new n_sectors matches native, probably "
                  "late HPA unlock, n_sectors updated\n");
         /* use the larger n_sectors */
         return 0;
     }
 
     /*
      * Some BIOSes boot w/o HPA but resume w/ HPA locked.  Try
      * unlocking HPA in those cases.
      *
      * https://bugzilla.kernel.org/show_bug.cgi?id=15396
      */
     if (dev->n_native_sectors == n_native_sectors &&
         dev->n_sectors < n_sectors && n_sectors == n_native_sectors &&
         !(dev->horkage & ATA_HORKAGE_BROKEN_HPA)) {
         ata_dev_warn(dev,
                  "old n_sectors matches native, probably "
                  "late HPA lock, will try to unlock HPA\n");
         /* try unlocking HPA */
         dev->flags |= ATA_DFLAG_UNLOCK_HPA;
         rc = -EIO;
     } else
         rc = -ENODEV;
 
     /* restore original n_[native_]sectors and fail */
     dev->n_native_sectors = n_native_sectors;
     dev->n_sectors = n_sectors;
  fail:
     ata_dev_err(dev, "revalidation failed (errno=%d)\n", rc);
     return rc;
 }
 
 struct ata_blacklist_entry {
     const char *model_num;
     const char *model_rev;
     unsigned long horkage;
 };
 
 static const struct ata_blacklist_entry ata_device_blacklist [] = {
     /* Devices with DMA related problems under Linux */
     { "WDC AC11000H",   NULL,       ATA_HORKAGE_NODMA },
     { "WDC AC22100H",   NULL,       ATA_HORKAGE_NODMA },
     { "WDC AC32500H",   NULL,       ATA_HORKAGE_NODMA },
     { "WDC AC33100H",   NULL,       ATA_HORKAGE_NODMA },
     { "WDC AC31600H",   NULL,       ATA_HORKAGE_NODMA },
     { "WDC AC32100H",   "24.09P07", ATA_HORKAGE_NODMA },
     { "WDC AC23200L",   "21.10N21", ATA_HORKAGE_NODMA },
     { "Compaq CRD-8241B",   NULL,       ATA_HORKAGE_NODMA },
     { "CRD-8400B",      NULL,       ATA_HORKAGE_NODMA },
     { "CRD-848[02]B",   NULL,       ATA_HORKAGE_NODMA },
     { "CRD-84",     NULL,       ATA_HORKAGE_NODMA },
     { "SanDisk SDP3B",  NULL,       ATA_HORKAGE_NODMA },
     { "SanDisk SDP3B-64",   NULL,       ATA_HORKAGE_NODMA },
     { "SANYO CD-ROM CRD",   NULL,       ATA_HORKAGE_NODMA },
     { "HITACHI CDR-8",  NULL,       ATA_HORKAGE_NODMA },
     { "HITACHI CDR-8[34]35",NULL,       ATA_HORKAGE_NODMA },
     { "Toshiba CD-ROM XM-6202B", NULL,  ATA_HORKAGE_NODMA },
     { "TOSHIBA CD-ROM XM-1702BC", NULL, ATA_HORKAGE_NODMA },
     { "CD-532E-A",      NULL,       ATA_HORKAGE_NODMA },
     { "E-IDE CD-ROM CR-840",NULL,       ATA_HORKAGE_NODMA },
     { "CD-ROM Drive/F5A",   NULL,       ATA_HORKAGE_NODMA },
     { "WPI CDD-820",    NULL,       ATA_HORKAGE_NODMA },
     { "SAMSUNG CD-ROM SC-148C", NULL,   ATA_HORKAGE_NODMA },
     { "SAMSUNG CD-ROM SC",  NULL,       ATA_HORKAGE_NODMA },
     { "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
     { "_NEC DV5800A",   NULL,       ATA_HORKAGE_NODMA },
     { "SAMSUNG CD-ROM SN-124", "N001",  ATA_HORKAGE_NODMA },
     { "Seagate STT20000A", NULL,        ATA_HORKAGE_NODMA },
     { " 2GB ATA Flash Disk", "ADMA428M",    ATA_HORKAGE_NODMA },
     { "VRFDFC22048UCHC-TE*", NULL,      ATA_HORKAGE_NODMA },
     /* Odd clown on sil3726/4726 PMPs */
     { "Config  Disk",   NULL,       ATA_HORKAGE_DISABLE },
     /* Similar story with ASMedia 1092 */
     { "ASMT109x- Config",   NULL,       ATA_HORKAGE_DISABLE },
 
     /* Weird ATAPI devices */
     { "TORiSAN DVD-ROM DRD-N216", NULL, ATA_HORKAGE_MAX_SEC_128 },
     { "QUANTUM DAT    DAT72-000", NULL, ATA_HORKAGE_ATAPI_MOD16_DMA },
     { "Slimtype DVD A  DS8A8SH", NULL,  ATA_HORKAGE_MAX_SEC_LBA48 },
     { "Slimtype DVD A  DS8A9SH", NULL,  ATA_HORKAGE_MAX_SEC_LBA48 },
 
     /*
      * Causes silent data corruption with higher max sects.
      * http://lkml.kernel.org/g/x49wpy40ysk.fsf@segfault.boston.devel.redhat.com
      */
     { "ST380013AS",     "3.20",     ATA_HORKAGE_MAX_SEC_1024 },
 
     /*
      * These devices time out with higher max sects.
      * https://bugzilla.kernel.org/show_bug.cgi?id=121671
      */
     { "LITEON CX1-JB*-HP",  NULL,       ATA_HORKAGE_MAX_SEC_1024 },
     { "LITEON EP1-*",   NULL,       ATA_HORKAGE_MAX_SEC_1024 },
 
     /* Devices we expect to fail diagnostics */
 
     /* Devices where NCQ should be avoided */
     /* NCQ is slow */
     { "WDC WD740ADFD-00",   NULL,       ATA_HORKAGE_NONCQ },
     { "WDC WD740ADFD-00NLR1", NULL,     ATA_HORKAGE_NONCQ },
     /* http://thread.gmane.org/gmane.linux.ide/14907 */
     { "FUJITSU MHT2060BH",  NULL,       ATA_HORKAGE_NONCQ },
     /* NCQ is broken */
     { "Maxtor *",       "BANC*",    ATA_HORKAGE_NONCQ },
     { "Maxtor 7V300F0", "VA111630", ATA_HORKAGE_NONCQ },
     { "ST380817AS",     "3.42",     ATA_HORKAGE_NONCQ },
     { "ST3160023AS",    "3.42",     ATA_HORKAGE_NONCQ },
     { "OCZ CORE_SSD",   "02.10104", ATA_HORKAGE_NONCQ },
 
     /* Seagate NCQ + FLUSH CACHE firmware bug */
     { "ST31500341AS",   "SD1[5-9]", ATA_HORKAGE_NONCQ |
                         ATA_HORKAGE_FIRMWARE_WARN },
 
     { "ST31000333AS",   "SD1[5-9]", ATA_HORKAGE_NONCQ |
                         ATA_HORKAGE_FIRMWARE_WARN },
 
     { "ST3640[36]23AS", "SD1[5-9]", ATA_HORKAGE_NONCQ |
                         ATA_HORKAGE_FIRMWARE_WARN },
 
     { "ST3320[68]13AS", "SD1[5-9]", ATA_HORKAGE_NONCQ |
                         ATA_HORKAGE_FIRMWARE_WARN },
 
     /* drives which fail FPDMA_AA activation (some may freeze afterwards)
        the ST disks also have LPM issues */
     { "ST1000LM024 HN-M101MBB", NULL,   ATA_HORKAGE_BROKEN_FPDMA_AA |
                         ATA_HORKAGE_NOLPM },
     { "VB0250EAVER",    "HPG7",     ATA_HORKAGE_BROKEN_FPDMA_AA },
 
     /* Blacklist entries taken from Silicon Image 3124/3132
        Windows driver .inf file - also several Linux problem reports */
     { "HTS541060G9SA00",    "MB3OC60D",     ATA_HORKAGE_NONCQ },
     { "HTS541080G9SA00",    "MB4OC60D",     ATA_HORKAGE_NONCQ },
     { "HTS541010G9SA00",    "MBZOC60D",     ATA_HORKAGE_NONCQ },
 
     /* https://bugzilla.kernel.org/show_bug.cgi?id=15573 */
     { "C300-CTFDDAC128MAG", "0001",     ATA_HORKAGE_NONCQ },
 
     /* Sandisk SD7/8/9s lock up hard on large trims */
     { "SanDisk SD[789]*",   NULL,       ATA_HORKAGE_MAX_TRIM_128M },
 
     /* devices which puke on READ_NATIVE_MAX */
     { "HDS724040KLSA80",    "KFAOA20N", ATA_HORKAGE_BROKEN_HPA },
     { "WDC WD3200JD-00KLB0", "WD-WCAMR1130137", ATA_HORKAGE_BROKEN_HPA },
     { "WDC WD2500JD-00HBB0", "WD-WMAL71490727", ATA_HORKAGE_BROKEN_HPA },
     { "MAXTOR 6L080L4", "A93.0500", ATA_HORKAGE_BROKEN_HPA },
 
     /* this one allows HPA unlocking but fails IOs on the area */
     { "OCZ-VERTEX",         "1.30", ATA_HORKAGE_BROKEN_HPA },
 
     /* Devices which report 1 sector over size HPA */
     { "ST340823A",      NULL,       ATA_HORKAGE_HPA_SIZE },
     { "ST320413A",      NULL,       ATA_HORKAGE_HPA_SIZE },
     { "ST310211A",      NULL,       ATA_HORKAGE_HPA_SIZE },
 
     /* Devices which get the IVB wrong */
     { "QUANTUM FIREBALLlct10 05", "A03.0900", ATA_HORKAGE_IVB },
     /* Maybe we should just blacklist TSSTcorp... */
     { "TSSTcorp CDDVDW SH-S202[HJN]", "SB0[01]",  ATA_HORKAGE_IVB },
 
     /* Devices that do not need bridging limits applied */
     { "MTRON MSP-SATA*",        NULL,   ATA_HORKAGE_BRIDGE_OK },
     { "BUFFALO HD-QSU2/R5",     NULL,   ATA_HORKAGE_BRIDGE_OK },
 
     /* Devices which aren't very happy with higher link speeds */
     { "WD My Book",         NULL,   ATA_HORKAGE_1_5_GBPS },
     { "Seagate FreeAgent GoFlex",   NULL,   ATA_HORKAGE_1_5_GBPS },
 
     /*
      * Devices which choke on SETXFER.  Applies only if both the
      * device and controller are SATA.
      */
     { "PIONEER DVD-RW  DVRTD08",    NULL,   ATA_HORKAGE_NOSETXFER },
     { "PIONEER DVD-RW  DVRTD08A",   NULL,   ATA_HORKAGE_NOSETXFER },
     { "PIONEER DVD-RW  DVR-215",    NULL,   ATA_HORKAGE_NOSETXFER },
     { "PIONEER DVD-RW  DVR-212D",   NULL,   ATA_HORKAGE_NOSETXFER },
     { "PIONEER DVD-RW  DVR-216D",   NULL,   ATA_HORKAGE_NOSETXFER },
 
     /* These specific Pioneer models have LPM issues */
     { "PIONEER BD-RW   BDR-207M",   NULL,   ATA_HORKAGE_NOLPM },
     { "PIONEER BD-RW   BDR-205",    NULL,   ATA_HORKAGE_NOLPM },
 
     /* Crucial BX100 SSD 500GB has broken LPM support */
     { "CT500BX100SSD1",     NULL,   ATA_HORKAGE_NOLPM },
 
     /* 512GB MX100 with MU01 firmware has both queued TRIM and LPM issues */
     { "Crucial_CT512MX100*",    "MU01", ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM |
                         ATA_HORKAGE_NOLPM },
     /* 512GB MX100 with newer firmware has only LPM issues */
     { "Crucial_CT512MX100*",    NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM |
                         ATA_HORKAGE_NOLPM },
 
     /* 480GB+ M500 SSDs have both queued TRIM and LPM issues */
     { "Crucial_CT480M500*",     NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM |
                         ATA_HORKAGE_NOLPM },
     { "Crucial_CT960M500*",     NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM |
                         ATA_HORKAGE_NOLPM },
 
     /* These specific Samsung models/firmware-revs do not handle LPM well */
     { "SAMSUNG MZMPC128HBFU-000MV", "CXM14M1Q", ATA_HORKAGE_NOLPM },
     { "SAMSUNG SSD PM830 mSATA *",  "CXM13D1Q", ATA_HORKAGE_NOLPM },
     { "SAMSUNG MZ7TD256HAFV-000L9", NULL,       ATA_HORKAGE_NOLPM },
     { "SAMSUNG MZ7TE512HMHP-000L1", "EXT06L0Q", ATA_HORKAGE_NOLPM },
 
     /* devices that don't properly handle queued TRIM commands */
     { "Micron_M500IT_*",        "MU01", ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Micron_M500_*",      NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Crucial_CT*M500*",       NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Micron_M5[15]0_*",       "MU01", ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Crucial_CT*M550*",       "MU01", ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Crucial_CT*MX100*",      "MU01", ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Samsung SSD 840 EVO*",   NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_NO_DMA_LOG |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Samsung SSD 840*",       NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Samsung SSD 850*",       NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Samsung SSD 860*",       NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM |
                         ATA_HORKAGE_NO_NCQ_ON_ATI },
     { "Samsung SSD 870*",       NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM |
                         ATA_HORKAGE_NO_NCQ_ON_ATI },
     { "FCCT*M500*",         NULL,   ATA_HORKAGE_NO_NCQ_TRIM |
                         ATA_HORKAGE_ZERO_AFTER_TRIM },
 
     /* devices that don't properly handle TRIM commands */
     { "SuperSSpeed S238*",      NULL,   ATA_HORKAGE_NOTRIM },
     { "M88V29*",            NULL,   ATA_HORKAGE_NOTRIM },
 
     /*
      * As defined, the DRAT (Deterministic Read After Trim) and RZAT
      * (Return Zero After Trim) flags in the ATA Command Set are
      * unreliable in the sense that they only define what happens if
      * the device successfully executed the DSM TRIM command. TRIM
      * is only advisory, however, and the device is free to silently
      * ignore all or parts of the request.
      *
      * Whitelist drives that are known to reliably return zeroes
      * after TRIM.
      */
 
     /*
      * The intel 510 drive has buggy DRAT/RZAT. Explicitly exclude
      * that model before whitelisting all other intel SSDs.
      */
     { "INTEL*SSDSC2MH*",        NULL,   0 },
 
     { "Micron*",            NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Crucial*",           NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "INTEL*SSD*",         NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "SSD*INTEL*",         NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "Samsung*SSD*",       NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "SAMSUNG*SSD*",       NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "SAMSUNG*MZ7KM*",     NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM },
     { "ST[1248][0248]0[FH]*",   NULL,   ATA_HORKAGE_ZERO_AFTER_TRIM },
 
     /*
      * Some WD SATA-I drives spin up and down erratically when the link
      * is put into the slumber mode.  We don't have full list of the
      * affected devices.  Disable LPM if the device matches one of the
      * known prefixes and is SATA-1.  As a side effect LPM partial is
      * lost too.
      *
      * https://bugzilla.kernel.org/show_bug.cgi?id=57211
      */
     { "WDC WD800JD-*",      NULL,   ATA_HORKAGE_WD_BROKEN_LPM },
     { "WDC WD1200JD-*",     NULL,   ATA_HORKAGE_WD_BROKEN_LPM },
     { "WDC WD1600JD-*",     NULL,   ATA_HORKAGE_WD_BROKEN_LPM },
     { "WDC WD2000JD-*",     NULL,   ATA_HORKAGE_WD_BROKEN_LPM },
     { "WDC WD2500JD-*",     NULL,   ATA_HORKAGE_WD_BROKEN_LPM },
     { "WDC WD3000JD-*",     NULL,   ATA_HORKAGE_WD_BROKEN_LPM },
     { "WDC WD3200JD-*",     NULL,   ATA_HORKAGE_WD_BROKEN_LPM },
 
     /*
      * This sata dom device goes on a walkabout when the ATA_LOG_DIRECTORY
      * log page is accessed. Ensure we never ask for this log page with
      * these devices.
      */
     { "SATADOM-ML 3ME",     NULL,   ATA_HORKAGE_NO_LOG_DIR },
 
     /* End Marker */
     { }
 };
 
 static unsigned long ata_dev_blacklisted(const struct ata_device *dev)
 {
     unsigned char model_num[ATA_ID_PROD_LEN + 1];
     unsigned char model_rev[ATA_ID_FW_REV_LEN + 1];
     const struct ata_blacklist_entry *ad = ata_device_blacklist;
 
     ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
     ata_id_c_string(dev->id, model_rev, ATA_ID_FW_REV, sizeof(model_rev));
 
     while (ad->model_num) {
         if (glob_match(ad->model_num, model_num)) {
             if (ad->model_rev == NULL)
                 return ad->horkage;
             if (glob_match(ad->model_rev, model_rev))
                 return ad->horkage;
         }
         ad++;
     }
     return 0;
 }
 
 static int ata_dma_blacklisted(const struct ata_device *dev)
 {
     /* We don't support polling DMA.
      * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
      * if the LLDD handles only interrupts in the HSM_ST_LAST state.
      */
     if ((dev->link->ap->flags & ATA_FLAG_PIO_POLLING) &&
         (dev->flags & ATA_DFLAG_CDB_INTR))
         return 1;
     return (dev->horkage & ATA_HORKAGE_NODMA) ? 1 : 0;
 }
 
 /**
  *  ata_is_40wire       -   check drive side detection
  *  @dev: device
  *
  *  Perform drive side detection decoding, allowing for device vendors
  *  who can't follow the documentation.
  */
 
 static int ata_is_40wire(struct ata_device *dev)
 {
     if (dev->horkage & ATA_HORKAGE_IVB)
         return ata_drive_40wire_relaxed(dev->id);
     return ata_drive_40wire(dev->id);
 }
 
 /**
  *  cable_is_40wire     -   40/80/SATA decider
  *  @ap: port to consider
  *
  *  This function encapsulates the policy for speed management
  *  in one place. At the moment we don't cache the result but
  *  there is a good case for setting ap->cbl to the result when
  *  we are called with unknown cables (and figuring out if it
  *  impacts hotplug at all).
  *
  *  Return 1 if the cable appears to be 40 wire.
  */
 
 static int cable_is_40wire(struct ata_port *ap)
 {
     struct ata_link *link;
     struct ata_device *dev;
 
     /* If the controller thinks we are 40 wire, we are. */
     if (ap->cbl == ATA_CBL_PATA40)
         return 1;
 
     /* If the controller thinks we are 80 wire, we are. */
     if (ap->cbl == ATA_CBL_PATA80 || ap->cbl == ATA_CBL_SATA)
         return 0;
 
     /* If the system is known to be 40 wire short cable (eg
      * laptop), then we allow 80 wire modes even if the drive
      * isn't sure.
      */
     if (ap->cbl == ATA_CBL_PATA40_SHORT)
         return 0;
 
     /* If the controller doesn't know, we scan.
      *
      * Note: We look for all 40 wire detects at this point.  Any
      *       80 wire detect is taken to be 80 wire cable because
      * - in many setups only the one drive (slave if present) will
      *   give a valid detect
      * - if you have a non detect capable drive you don't want it
      *   to colour the choice
      */
     ata_for_each_link(link, ap, EDGE) {
         ata_for_each_dev(dev, link, ENABLED) {
             if (!ata_is_40wire(dev))
                 return 0;
         }
     }
     return 1;
 }
 
 /**
  *  ata_dev_xfermask - Compute supported xfermask of the given device
  *  @dev: Device to compute xfermask for
  *
  *  Compute supported xfermask of @dev and store it in
  *  dev->*_mask.  This function is responsible for applying all
  *  known limits including host controller limits, device
  *  blacklist, etc...
  *
  *  LOCKING:
  *  None.
  */
 static void ata_dev_xfermask(struct ata_device *dev)
 {
     struct ata_link *link = dev->link;
     struct ata_port *ap = link->ap;
     struct ata_host *host = ap->host;
     unsigned int xfer_mask;
 
     /* controller modes available */
     xfer_mask = ata_pack_xfermask(ap->pio_mask,
                       ap->mwdma_mask, ap->udma_mask);
 
     /* drive modes available */
     xfer_mask &= ata_pack_xfermask(dev->pio_mask,
                        dev->mwdma_mask, dev->udma_mask);
     xfer_mask &= ata_id_xfermask(dev->id);
 
     /*
      *  CFA Advanced TrueIDE timings are not allowed on a shared
      *  cable
      */
     if (ata_dev_pair(dev)) {
         /* No PIO5 or PIO6 */
         xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
         /* No MWDMA3 or MWDMA 4 */
         xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
     }
 
     if (ata_dma_blacklisted(dev)) {
         xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
         ata_dev_warn(dev,
                  "device is on DMA blacklist, disabling DMA\n");
     }
 
     if ((host->flags & ATA_HOST_SIMPLEX) &&
         host->simplex_claimed && host->simplex_claimed != ap) {
         xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
         ata_dev_warn(dev,
                  "simplex DMA is claimed by other device, disabling DMA\n");
     }
 
     if (ap->flags & ATA_FLAG_NO_IORDY)
         xfer_mask &= ata_pio_mask_no_iordy(dev);
 
     if (ap->ops->mode_filter)
         xfer_mask = ap->ops->mode_filter(dev, xfer_mask);
 
     /* Apply cable rule here.  Don't apply it early because when
      * we handle hot plug the cable type can itself change.
      * Check this last so that we know if the transfer rate was
      * solely limited by the cable.
      * Unknown or 80 wire cables reported host side are checked
      * drive side as well. Cases where we know a 40wire cable
      * is used safely for 80 are not checked here.
      */
     if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
         /* UDMA/44 or higher would be available */
         if (cable_is_40wire(ap)) {
             ata_dev_warn(dev,
                      "limited to UDMA/33 due to 40-wire cable\n");
             xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
         }
 
     ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
                 &dev->mwdma_mask, &dev->udma_mask);
 }
 
 /**
  *  ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
  *  @dev: Device to which command will be sent
  *
  *  Issue SET FEATURES - XFER MODE command to device @dev
  *  on port @ap.
  *
  *  LOCKING:
  *  PCI/etc. bus probe sem.
  *
  *  RETURNS:
  *  0 on success, AC_ERR_* mask otherwise.
  */
 
 static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
 {
     struct ata_taskfile tf;
     unsigned int err_mask;
 
     /* set up set-features taskfile */
     ata_dev_dbg(dev, "set features - xfer mode\n");
 
     /* Some controllers and ATAPI devices show flaky interrupt
      * behavior after setting xfer mode.  Use polling instead.
      */
     ata_tf_init(dev, &tf);
     tf.command = ATA_CMD_SET_FEATURES;
     tf.feature = SETFEATURES_XFER;
     tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_POLLING;
     tf.protocol = ATA_PROT_NODATA;
     /* If we are using IORDY we must send the mode setting command */
     if (ata_pio_need_iordy(dev))
         tf.nsect = dev->xfer_mode;
     /* If the device has IORDY and the controller does not - turn it off */
     else if (ata_id_has_iordy(dev->id))
         tf.nsect = 0x01;
     else /* In the ancient relic department - skip all of this */
         return 0;
 
     /* On some disks, this command causes spin-up, so we need longer timeout */
     err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 15000);
 
     return err_mask;
 }
 
 /**
  *  ata_dev_set_feature - Issue SET FEATURES - SATA FEATURES
  *  @dev: Device to which command will be sent
  *  @enable: Whether to enable or disable the feature
  *  @feature: The sector count represents the feature to set
  *
  *  Issue SET FEATURES - SATA FEATURES command to device @dev
  *  on port @ap with sector count
  *
  *  LOCKING:
  *  PCI/etc. bus probe sem.
  *
  *  RETURNS:
  *  0 on success, AC_ERR_* mask otherwise.
  */
 unsigned int ata_dev_set_feature(struct ata_device *dev, u8 enable, u8 feature)
 {
     struct ata_taskfile tf;
     unsigned int err_mask;
     unsigned int timeout = 0;
 
     /* set up set-features taskfile */
     ata_dev_dbg(dev, "set features - SATA features\n");
 
     ata_tf_init(dev, &tf);
     tf.command = ATA_CMD_SET_FEATURES;
     tf.feature = enable;
     tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
     tf.protocol = ATA_PROT_NODATA;
     tf.nsect = feature;
 
     if (enable == SETFEATURES_SPINUP)
         timeout = ata_probe_timeout ?
               ata_probe_timeout * 1000 : SETFEATURES_SPINUP_TIMEOUT;
     err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, timeout);
 
     return err_mask;
 }
 EXPORT_SYMBOL_GPL(ata_dev_set_feature);
 
 /**
  *  ata_dev_init_params - Issue INIT DEV PARAMS command
  *  @dev: Device to which command will be sent
  *  @heads: Number of heads (taskfile parameter)
  *  @sectors: Number of sectors (taskfile parameter)
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  *
  *  RETURNS:
  *  0 on success, AC_ERR_* mask otherwise.
  */
 static unsigned int ata_dev_init_params(struct ata_device *dev,
                     u16 heads, u16 sectors)
 {
     struct ata_taskfile tf;
     unsigned int err_mask;
 
     /* Number of sectors per track 1-255. Number of heads 1-16 */
     if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
         return AC_ERR_INVALID;
 
     /* set up init dev params taskfile */
     ata_dev_dbg(dev, "init dev params \n");
 
     ata_tf_init(dev, &tf);
     tf.command = ATA_CMD_INIT_DEV_PARAMS;
     tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
     tf.protocol = ATA_PROT_NODATA;
     tf.nsect = sectors;
     tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */
 
     err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
     /* A clean abort indicates an original or just out of spec drive
        and we should continue as we issue the setup based on the
        drive reported working geometry */
     if (err_mask == AC_ERR_DEV && (tf.error & ATA_ABORTED))
         err_mask = 0;
 
     return err_mask;
 }
 
 /**
  *  atapi_check_dma - Check whether ATAPI DMA can be supported
  *  @qc: Metadata associated with taskfile to check
  *
  *  Allow low-level driver to filter ATA PACKET commands, returning
  *  a status indicating whether or not it is OK to use DMA for the
  *  supplied PACKET command.
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  *
  *  RETURNS: 0 when ATAPI DMA can be used
  *               nonzero otherwise
  */
 int atapi_check_dma(struct ata_queued_cmd *qc)
 {
     struct ata_port *ap = qc->ap;
 
     /* Don't allow DMA if it isn't multiple of 16 bytes.  Quite a
      * few ATAPI devices choke on such DMA requests.
      */
     if (!(qc->dev->horkage & ATA_HORKAGE_ATAPI_MOD16_DMA) &&
         unlikely(qc->nbytes & 15))
         return 1;
 
     if (ap->ops->check_atapi_dma)
         return ap->ops->check_atapi_dma(qc);
 
     return 0;
 }
 
 /**
  *  ata_std_qc_defer - Check whether a qc needs to be deferred
  *  @qc: ATA command in question
  *
  *  Non-NCQ commands cannot run with any other command, NCQ or
  *  not.  As upper layer only knows the queue depth, we are
  *  responsible for maintaining exclusion.  This function checks
  *  whether a new command @qc can be issued.
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  *
  *  RETURNS:
  *  ATA_DEFER_* if deferring is needed, 0 otherwise.
  */
 int ata_std_qc_defer(struct ata_queued_cmd *qc)
 {
     struct ata_link *link = qc->dev->link;
 
     if (ata_is_ncq(qc->tf.protocol)) {
         if (!ata_tag_valid(link->active_tag))
             return 0;
     } else {
         if (!ata_tag_valid(link->active_tag) && !link->sactive)
             return 0;
     }
 
     return ATA_DEFER_LINK;
 }
 EXPORT_SYMBOL_GPL(ata_std_qc_defer);
 
 enum ata_completion_errors ata_noop_qc_prep(struct ata_queued_cmd *qc)
 {
     return AC_ERR_OK;
 }
 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
 
 /**
  *  ata_sg_init - Associate command with scatter-gather table.
  *  @qc: Command to be associated
  *  @sg: Scatter-gather table.
  *  @n_elem: Number of elements in s/g table.
  *
  *  Initialize the data-related elements of queued_cmd @qc
  *  to point to a scatter-gather table @sg, containing @n_elem
  *  elements.
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  */
 void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
          unsigned int n_elem)
 {
     qc->sg = sg;
     qc->n_elem = n_elem;
     qc->cursg = qc->sg;
 }
 
 #ifdef CONFIG_HAS_DMA
 
 /**
  *  ata_sg_clean - Unmap DMA memory associated with command
  *  @qc: Command containing DMA memory to be released
  *
  *  Unmap all mapped DMA memory associated with this command.
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  */
 static void ata_sg_clean(struct ata_queued_cmd *qc)
 {
     struct ata_port *ap = qc->ap;
     struct scatterlist *sg = qc->sg;
     int dir = qc->dma_dir;
 
     WARN_ON_ONCE(sg == NULL);
 
     if (qc->n_elem)
         dma_unmap_sg(ap->dev, sg, qc->orig_n_elem, dir);
 
     qc->flags &= ~ATA_QCFLAG_DMAMAP;
     qc->sg = NULL;
 }
 
 /**
  *  ata_sg_setup - DMA-map the scatter-gather table associated with a command.
  *  @qc: Command with scatter-gather table to be mapped.
  *
  *  DMA-map the scatter-gather table associated with queued_cmd @qc.
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  *
  *  RETURNS:
  *  Zero on success, negative on error.
  *
  */
 static int ata_sg_setup(struct ata_queued_cmd *qc)
 {
     struct ata_port *ap = qc->ap;
     unsigned int n_elem;
 
     n_elem = dma_map_sg(ap->dev, qc->sg, qc->n_elem, qc->dma_dir);
     if (n_elem < 1)
         return -1;
 
     qc->orig_n_elem = qc->n_elem;
     qc->n_elem = n_elem;
     qc->flags |= ATA_QCFLAG_DMAMAP;
 
     return 0;
 }
 
 #else /* !CONFIG_HAS_DMA */
 
 static inline void ata_sg_clean(struct ata_queued_cmd *qc) {}
 static inline int ata_sg_setup(struct ata_queued_cmd *qc) { return -1; }
 
 #endif /* !CONFIG_HAS_DMA */
 
 /**
  *  swap_buf_le16 - swap halves of 16-bit words in place
  *  @buf:  Buffer to swap
  *  @buf_words:  Number of 16-bit words in buffer.
  *
  *  Swap halves of 16-bit words if needed to convert from
  *  little-endian byte order to native cpu byte order, or
  *  vice-versa.
  *
  *  LOCKING:
  *  Inherited from caller.
  */
 void swap_buf_le16(u16 *buf, unsigned int buf_words)
 {
 #ifdef __BIG_ENDIAN
     unsigned int i;
 
     for (i = 0; i < buf_words; i++)
         buf[i] = le16_to_cpu(buf[i]);
 #endif /* __BIG_ENDIAN */
 }
 
 /**
  *  ata_qc_free - free unused ata_queued_cmd
  *  @qc: Command to complete
  *
  *  Designed to free unused ata_queued_cmd object
  *  in case something prevents using it.
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  */
 void ata_qc_free(struct ata_queued_cmd *qc)
 {
     qc->flags = 0;
     if (ata_tag_valid(qc->tag))
         qc->tag = ATA_TAG_POISON;
 }
 
 void __ata_qc_complete(struct ata_queued_cmd *qc)
 {
     struct ata_port *ap;
     struct ata_link *link;
 
     WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
     WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_ACTIVE));
     ap = qc->ap;
     link = qc->dev->link;
 
     if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
         ata_sg_clean(qc);
 
     /* command should be marked inactive atomically with qc completion */
     if (ata_is_ncq(qc->tf.protocol)) {
         link->sactive &= ~(1 << qc->hw_tag);
         if (!link->sactive)
             ap->nr_active_links--;
     } else {
         link->active_tag = ATA_TAG_POISON;
         ap->nr_active_links--;
     }
 
     /* clear exclusive status */
     if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
              ap->excl_link == link))
         ap->excl_link = NULL;
 
     /* atapi: mark qc as inactive to prevent the interrupt handler
      * from completing the command twice later, before the error handler
      * is called. (when rc != 0 and atapi request sense is needed)
      */
     qc->flags &= ~ATA_QCFLAG_ACTIVE;
     ap->qc_active &= ~(1ULL << qc->tag);
 
     /* call completion callback */
     qc->complete_fn(qc);
 }
 
 static void fill_result_tf(struct ata_queued_cmd *qc)
 {
     struct ata_port *ap = qc->ap;
 
     qc->result_tf.flags = qc->tf.flags;
     ap->ops->qc_fill_rtf(qc);
 }
 
 static void ata_verify_xfer(struct ata_queued_cmd *qc)
 {
     struct ata_device *dev = qc->dev;
 
     if (!ata_is_data(qc->tf.protocol))
         return;
 
     if ((dev->mwdma_mask || dev->udma_mask) && ata_is_pio(qc->tf.protocol))
         return;
 
     dev->flags &= ~ATA_DFLAG_DUBIOUS_XFER;
 }
 
 /**
  *  ata_qc_complete - Complete an active ATA command
  *  @qc: Command to complete
  *
  *  Indicate to the mid and upper layers that an ATA command has
  *  completed, with either an ok or not-ok status.
  *
  *  Refrain from calling this function multiple times when
  *  successfully completing multiple NCQ commands.
  *  ata_qc_complete_multiple() should be used instead, which will
  *  properly update IRQ expect state.
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  */
 void ata_qc_complete(struct ata_queued_cmd *qc)
 {
     struct ata_port *ap = qc->ap;
 
     /* Trigger the LED (if available) */
     ledtrig_disk_activity(!!(qc->tf.flags & ATA_TFLAG_WRITE));
 
     /* XXX: New EH and old EH use different mechanisms to
      * synchronize EH with regular execution path.
      *
      * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
      * Normal execution path is responsible for not accessing a
      * failed qc.  libata core enforces the rule by returning NULL
      * from ata_qc_from_tag() for failed qcs.
      *
      * Old EH depends on ata_qc_complete() nullifying completion
      * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
      * not synchronize with interrupt handler.  Only PIO task is
      * taken care of.
      */
     if (ap->ops->error_handler) {
         struct ata_device *dev = qc->dev;
         struct ata_eh_info *ehi = &dev->link->eh_info;
 
         if (unlikely(qc->err_mask))
             qc->flags |= ATA_QCFLAG_FAILED;
 
         /*
          * Finish internal commands without any further processing
          * and always with the result TF filled.
          */
         if (unlikely(ata_tag_internal(qc->tag))) {
             fill_result_tf(qc);
             trace_ata_qc_complete_internal(qc);
             __ata_qc_complete(qc);
             return;
         }
 
         /*
          * Non-internal qc has failed.  Fill the result TF and
          * summon EH.
          */
         if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
             fill_result_tf(qc);
             trace_ata_qc_complete_failed(qc);
             ata_qc_schedule_eh(qc);
             return;
         }
 
         WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN);
 
         /* read result TF if requested */
         if (qc->flags & ATA_QCFLAG_RESULT_TF)
             fill_result_tf(qc);
 
         trace_ata_qc_complete_done(qc);
         /* Some commands need post-processing after successful
          * completion.
          */
         switch (qc->tf.command) {
         case ATA_CMD_SET_FEATURES:
             if (qc->tf.feature != SETFEATURES_WC_ON &&
                 qc->tf.feature != SETFEATURES_WC_OFF &&
                 qc->tf.feature != SETFEATURES_RA_ON &&
                 qc->tf.feature != SETFEATURES_RA_OFF)
                 break;
             fallthrough;
         case ATA_CMD_INIT_DEV_PARAMS: /* CHS translation changed */
         case ATA_CMD_SET_MULTI: /* multi_count changed */
             /* revalidate device */
             ehi->dev_action[dev->devno] |= ATA_EH_REVALIDATE;
             ata_port_schedule_eh(ap);
             break;
 
         case ATA_CMD_SLEEP:
             dev->flags |= ATA_DFLAG_SLEEPING;
             break;
         }
 
         if (unlikely(dev->flags & ATA_DFLAG_DUBIOUS_XFER))
             ata_verify_xfer(qc);
 
         __ata_qc_complete(qc);
     } else {
         if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
             return;
 
         /* read result TF if failed or requested */
         if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
             fill_result_tf(qc);
 
         __ata_qc_complete(qc);
     }
 }
 EXPORT_SYMBOL_GPL(ata_qc_complete);
 
 /**
  *  ata_qc_get_active - get bitmask of active qcs
  *  @ap: port in question
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  *
  *  RETURNS:
  *  Bitmask of active qcs
  */
 u64 ata_qc_get_active(struct ata_port *ap)
 {
     u64 qc_active = ap->qc_active;
 
     /* ATA_TAG_INTERNAL is sent to hw as tag 0 */
     if (qc_active & (1ULL << ATA_TAG_INTERNAL)) {
         qc_active |= (1 << 0);
         qc_active &= ~(1ULL << ATA_TAG_INTERNAL);
     }
 
     return qc_active;
 }
 EXPORT_SYMBOL_GPL(ata_qc_get_active);
 
 /**
  *  ata_qc_issue - issue taskfile to device
  *  @qc: command to issue to device
  *
  *  Prepare an ATA command to submission to device.
  *  This includes mapping the data into a DMA-able
  *  area, filling in the S/G table, and finally
  *  writing the taskfile to hardware, starting the command.
  *
  *  LOCKING:
  *  spin_lock_irqsave(host lock)
  */
 void ata_qc_issue(struct ata_queued_cmd *qc)
 {
     struct ata_port *ap = qc->ap;
     struct ata_link *link = qc->dev->link;
     u8 prot = qc->tf.protocol;
 
     /* Make sure only one non-NCQ command is outstanding.  The
      * check is skipped for old EH because it reuses active qc to
      * request ATAPI sense.
      */
     WARN_ON_ONCE(ap->ops->error_handler && ata_tag_valid(link->active_tag));
 
     if (ata_is_ncq(prot)) {
         WARN_ON_ONCE(link->sactive & (1 << qc->hw_tag));
 
         if (!link->sactive)
             ap->nr_active_links++;
         link->sactive |= 1 << qc->hw_tag;
     } else {
         WARN_ON_ONCE(link->sactive);
 
         ap->nr_active_links++;
         link->active_tag = qc->tag;
     }
 
     qc->flags |= ATA_QCFLAG_ACTIVE;
     ap->qc_active |= 1ULL << qc->tag;
 
     /*
      * We guarantee to LLDs that they will have at least one
      * non-zero sg if the command is a data command.
      */
     if (ata_is_data(prot) && (!qc->sg || !qc->n_elem || !qc->nbytes))
         goto sys_err;
 
     if (ata_is_dma(prot) || (ata_is_pio(prot) &&
                  (ap->flags & ATA_FLAG_PIO_DMA)))
         if (ata_sg_setup(qc))
             goto sys_err;
 
     /* if device is sleeping, schedule reset and abort the link */
     if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) {
         link->eh_info.action |= ATA_EH_RESET;
         ata_ehi_push_desc(&link->eh_info, "waking up from sleep");
         ata_link_abort(link);
         return;
     }
 
     trace_ata_qc_prep(qc);
     qc->err_mask |= ap->ops->qc_prep(qc);
     if (unlikely(qc->err_mask))
         goto err;
     trace_ata_qc_issue(qc);
     qc->err_mask |= ap->ops->qc_issue(qc);
     if (unlikely(qc->err_mask))
         goto err;
     return;
 
 sys_err:
     qc->err_mask |= AC_ERR_SYSTEM;
 err:
     ata_qc_complete(qc);
 }
 
 /**
  *  ata_phys_link_online - test whether the given link is online
  *  @link: ATA link to test
  *
  *  Test whether @link is online.  Note that this function returns
  *  0 if online status of @link cannot be obtained, so
  *  ata_link_online(link) != !ata_link_offline(link).
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  True if the port online status is available and online.
  */
 bool ata_phys_link_online(struct ata_link *link)
 {
     u32 sstatus;
 
     if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
         ata_sstatus_online(sstatus))
         return true;
     return false;
 }
 
 /**
  *  ata_phys_link_offline - test whether the given link is offline
  *  @link: ATA link to test
  *
  *  Test whether @link is offline.  Note that this function
  *  returns 0 if offline status of @link cannot be obtained, so
  *  ata_link_online(link) != !ata_link_offline(link).
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  True if the port offline status is available and offline.
  */
 bool ata_phys_link_offline(struct ata_link *link)
 {
     u32 sstatus;
 
     if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
         !ata_sstatus_online(sstatus))
         return true;
     return false;
 }
 
 /**
  *  ata_link_online - test whether the given link is online
  *  @link: ATA link to test
  *
  *  Test whether @link is online.  This is identical to
  *  ata_phys_link_online() when there's no slave link.  When
  *  there's a slave link, this function should only be called on
  *  the master link and will return true if any of M/S links is
  *  online.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  True if the port online status is available and online.
  */
 bool ata_link_online(struct ata_link *link)
 {
     struct ata_link *slave = link->ap->slave_link;
 
     WARN_ON(link == slave); /* shouldn't be called on slave link */
 
     return ata_phys_link_online(link) ||
         (slave && ata_phys_link_online(slave));
 }
 EXPORT_SYMBOL_GPL(ata_link_online);
 
 /**
  *  ata_link_offline - test whether the given link is offline
  *  @link: ATA link to test
  *
  *  Test whether @link is offline.  This is identical to
  *  ata_phys_link_offline() when there's no slave link.  When
  *  there's a slave link, this function should only be called on
  *  the master link and will return true if both M/S links are
  *  offline.
  *
  *  LOCKING:
  *  None.
  *
  *  RETURNS:
  *  True if the port offline status is available and offline.
  */
 bool ata_link_offline(struct ata_link *link)
 {
     struct ata_link *slave = link->ap->slave_link;
 
     WARN_ON(link == slave); /* shouldn't be called on slave link */
 
     return ata_phys_link_offline(link) &&
         (!slave || ata_phys_link_offline(slave));
 }
 EXPORT_SYMBOL_GPL(ata_link_offline);
 
 #ifdef CONFIG_PM
 static void ata_port_request_pm(struct ata_port *ap, pm_message_t mesg,
                 unsigned int action, unsigned int ehi_flags,
                 bool async)
 {
     struct ata_link *link;
     unsigned long flags;
 
     /* Previous resume operation might still be in
      * progress.  Wait for PM_PENDING to clear.
      */
     if (ap->pflags & ATA_PFLAG_PM_PENDING) {
         ata_port_wait_eh(ap);
         WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
     }
 
     /* request PM ops to EH */
     spin_lock_irqsave(ap->lock, flags);
 
     ap->pm_mesg = mesg;
     ap->pflags |= ATA_PFLAG_PM_PENDING;
     ata_for_each_link(link, ap, HOST_FIRST) {
         link->eh_info.action |= action;
         link->eh_info.flags |= ehi_flags;
     }
 
     ata_port_schedule_eh(ap);
 
     spin_unlock_irqrestore(ap->lock, flags);
 
     if (!async) {
         ata_port_wait_eh(ap);
         WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
     }
 }
 
 /*
  * On some hardware, device fails to respond after spun down for suspend.  As
  * the device won't be used before being resumed, we don't need to touch the
  * device.  Ask EH to skip the usual stuff and proceed directly to suspend.
  *
  * http://thread.gmane.org/gmane.linux.ide/46764
  */
 static const unsigned int ata_port_suspend_ehi = ATA_EHI_QUIET
                          | ATA_EHI_NO_AUTOPSY
                          | ATA_EHI_NO_RECOVERY;
 
 static void ata_port_suspend(struct ata_port *ap, pm_message_t mesg)
 {
     ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, false);
 }
 
 static void ata_port_suspend_async(struct ata_port *ap, pm_message_t mesg)
 {
     ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, true);
 }
 
 static int ata_port_pm_suspend(struct device *dev)
 {
     struct ata_port *ap = to_ata_port(dev);
 
     if (pm_runtime_suspended(dev))
         return 0;
 
     ata_port_suspend(ap, PMSG_SUSPEND);
     return 0;
 }
 
 static int ata_port_pm_freeze(struct device *dev)
 {
     struct ata_port *ap = to_ata_port(dev);
 
     if (pm_runtime_suspended(dev))
         return 0;
 
     ata_port_suspend(ap, PMSG_FREEZE);
     return 0;
 }
 
 static int ata_port_pm_poweroff(struct device *dev)
 {
     ata_port_suspend(to_ata_port(dev), PMSG_HIBERNATE);
     return 0;
 }
 
 static const unsigned int ata_port_resume_ehi = ATA_EHI_NO_AUTOPSY
                         | ATA_EHI_QUIET;
 
 static void ata_port_resume(struct ata_port *ap, pm_message_t mesg)
 {
     ata_port_request_pm(ap, mesg, ATA_EH_RESET, ata_port_resume_ehi, false);
 }
 
 static void ata_port_resume_async(struct ata_port *ap, pm_message_t mesg)
 {
     ata_port_request_pm(ap, mesg, ATA_EH_RESET, ata_port_resume_ehi, true);
 }
 
 static int ata_port_pm_resume(struct device *dev)
 {
     ata_port_resume_async(to_ata_port(dev), PMSG_RESUME);
     pm_runtime_disable(dev);
     pm_runtime_set_active(dev);
     pm_runtime_enable(dev);
     return 0;
 }
 
 /*
  * For ODDs, the upper layer will poll for media change every few seconds,
  * which will make it enter and leave suspend state every few seconds. And
  * as each suspend will cause a hard/soft reset, the gain of runtime suspend
  * is very little and the ODD may malfunction after constantly being reset.
  * So the idle callback here will not proceed to suspend if a non-ZPODD capable
  * ODD is attached to the port.
  */
 static int ata_port_runtime_idle(struct device *dev)
 {
     struct ata_port *ap = to_ata_port(dev);
     struct ata_link *link;
     struct ata_device *adev;
 
     ata_for_each_link(link, ap, HOST_FIRST) {
         ata_for_each_dev(adev, link, ENABLED)
             if (adev->class == ATA_DEV_ATAPI &&
                 !zpodd_dev_enabled(adev))
                 return -EBUSY;
     }
 
     return 0;
 }
 
 static int ata_port_runtime_suspend(struct device *dev)
 {
     ata_port_suspend(to_ata_port(dev), PMSG_AUTO_SUSPEND);
     return 0;
 }
 
 static int ata_port_runtime_resume(struct device *dev)
 {
     ata_port_resume(to_ata_port(dev), PMSG_AUTO_RESUME);
     return 0;
 }
 
 static const struct dev_pm_ops ata_port_pm_ops = {
     .suspend = ata_port_pm_suspend,
     .resume = ata_port_pm_resume,
     .freeze = ata_port_pm_freeze,
     .thaw = ata_port_pm_resume,
     .poweroff = ata_port_pm_poweroff,
     .restore = ata_port_pm_resume,
 
     .runtime_suspend = ata_port_runtime_suspend,
     .runtime_resume = ata_port_runtime_resume,
     .runtime_idle = ata_port_runtime_idle,
 };
 
 /* sas ports don't participate in pm runtime management of ata_ports,
  * and need to resume ata devices at the domain level, not the per-port
  * level. sas suspend/resume is async to allow parallel port recovery
  * since sas has multiple ata_port instances per Scsi_Host.
  */
 void ata_sas_port_suspend(struct ata_port *ap)
 {
     ata_port_suspend_async(ap, PMSG_SUSPEND);
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_suspend);
 
 void ata_sas_port_resume(struct ata_port *ap)
 {
     ata_port_resume_async(ap, PMSG_RESUME);
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_resume);
 
 /**
  *  ata_host_suspend - suspend host
  *  @host: host to suspend
  *  @mesg: PM message
  *
  *  Suspend @host.  Actual operation is performed by port suspend.
  */
 void ata_host_suspend(struct ata_host *host, pm_message_t mesg)
 {
     host->dev->power.power_state = mesg;
 }
 EXPORT_SYMBOL_GPL(ata_host_suspend);
 
 /**
  *  ata_host_resume - resume host
  *  @host: host to resume
  *
  *  Resume @host.  Actual operation is performed by port resume.
  */
 void ata_host_resume(struct ata_host *host)
 {
     host->dev->power.power_state = PMSG_ON;
 }
 EXPORT_SYMBOL_GPL(ata_host_resume);
 #endif
 
 const struct device_type ata_port_type = {
     .name = "ata_port",
 #ifdef CONFIG_PM
     .pm = &ata_port_pm_ops,
 #endif
 };
 
 /**
  *  ata_dev_init - Initialize an ata_device structure
  *  @dev: Device structure to initialize
  *
  *  Initialize @dev in preparation for probing.
  *
  *  LOCKING:
  *  Inherited from caller.
  */
 void ata_dev_init(struct ata_device *dev)
 {
     struct ata_link *link = ata_dev_phys_link(dev);
     struct ata_port *ap = link->ap;
     unsigned long flags;
 
     /* SATA spd limit is bound to the attached device, reset together */
     link->sata_spd_limit = link->hw_sata_spd_limit;
     link->sata_spd = 0;
 
     /* High bits of dev->flags are used to record warm plug
      * requests which occur asynchronously.  Synchronize using
      * host lock.
      */
     spin_lock_irqsave(ap->lock, flags);
     dev->flags &= ~ATA_DFLAG_INIT_MASK;
     dev->horkage = 0;
     spin_unlock_irqrestore(ap->lock, flags);
 
     memset((void *)dev + ATA_DEVICE_CLEAR_BEGIN, 0,
            ATA_DEVICE_CLEAR_END - ATA_DEVICE_CLEAR_BEGIN);
     dev->pio_mask = UINT_MAX;
     dev->mwdma_mask = UINT_MAX;
     dev->udma_mask = UINT_MAX;
 }
 
 /**
  *  ata_link_init - Initialize an ata_link structure
  *  @ap: ATA port link is attached to
  *  @link: Link structure to initialize
  *  @pmp: Port multiplier port number
  *
  *  Initialize @link.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  */
 void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
 {
     int i;
 
     /* clear everything except for devices */
     memset((void *)link + ATA_LINK_CLEAR_BEGIN, 0,
            ATA_LINK_CLEAR_END - ATA_LINK_CLEAR_BEGIN);
 
     link->ap = ap;
     link->pmp = pmp;
     link->active_tag = ATA_TAG_POISON;
     link->hw_sata_spd_limit = UINT_MAX;
 
     /* can't use iterator, ap isn't initialized yet */
     for (i = 0; i < ATA_MAX_DEVICES; i++) {
         struct ata_device *dev = &link->device[i];
 
         dev->link = link;
         dev->devno = dev - link->device;
 #ifdef CONFIG_ATA_ACPI
         dev->gtf_filter = ata_acpi_gtf_filter;
 #endif
         ata_dev_init(dev);
     }
 }
 
 /**
  *  sata_link_init_spd - Initialize link->sata_spd_limit
  *  @link: Link to configure sata_spd_limit for
  *
  *  Initialize ``link->[hw_]sata_spd_limit`` to the currently
  *  configured value.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep).
  *
  *  RETURNS:
  *  0 on success, -errno on failure.
  */
 int sata_link_init_spd(struct ata_link *link)
 {
     u8 spd;
     int rc;
 
     rc = sata_scr_read(link, SCR_CONTROL, &link->saved_scontrol);
     if (rc)
         return rc;
 
     spd = (link->saved_scontrol >> 4) & 0xf;
     if (spd)
         link->hw_sata_spd_limit &= (1 << spd) - 1;
 
     ata_force_link_limits(link);
 
     link->sata_spd_limit = link->hw_sata_spd_limit;
 
     return 0;
 }
 
 /**
  *  ata_port_alloc - allocate and initialize basic ATA port resources
  *  @host: ATA host this allocated port belongs to
  *
  *  Allocate and initialize basic ATA port resources.
  *
  *  RETURNS:
  *  Allocate ATA port on success, NULL on failure.
  *
  *  LOCKING:
  *  Inherited from calling layer (may sleep).
  */
 struct ata_port *ata_port_alloc(struct ata_host *host)
 {
     struct ata_port *ap;
 
     ap = kzalloc(sizeof(*ap), GFP_KERNEL);
     if (!ap)
         return NULL;
 
     ap->pflags |= ATA_PFLAG_INITIALIZING | ATA_PFLAG_FROZEN;
     ap->lock = &host->lock;
     ap->print_id = -1;
     ap->local_port_no = -1;
     ap->host = host;
     ap->dev = host->dev;
 
     mutex_init(&ap->scsi_scan_mutex);
     INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
     INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
     INIT_LIST_HEAD(&ap->eh_done_q);
     init_waitqueue_head(&ap->eh_wait_q);
     init_completion(&ap->park_req_pending);
     timer_setup(&ap->fastdrain_timer, ata_eh_fastdrain_timerfn,
             TIMER_DEFERRABLE);
 
     ap->cbl = ATA_CBL_NONE;
 
     ata_link_init(ap, &ap->link, 0);
 
 #ifdef ATA_IRQ_TRAP
     ap->stats.unhandled_irq = 1;
     ap->stats.idle_irq = 1;
 #endif
     ata_sff_port_init(ap);
 
     return ap;
 }
 
 static void ata_devres_release(struct device *gendev, void *res)
 {
     struct ata_host *host = dev_get_drvdata(gendev);
     int i;
 
     for (i = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
 
         if (!ap)
             continue;
 
         if (ap->scsi_host)
             scsi_host_put(ap->scsi_host);
 
     }
 
     dev_set_drvdata(gendev, NULL);
     ata_host_put(host);
 }
 
 static void ata_host_release(struct kref *kref)
 {
     struct ata_host *host = container_of(kref, struct ata_host, kref);
     int i;
 
     for (i = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
 
         kfree(ap->pmp_link);
         kfree(ap->slave_link);
         kfree(ap);
         host->ports[i] = NULL;
     }
     kfree(host);
 }
 
 void ata_host_get(struct ata_host *host)
 {
     kref_get(&host->kref);
 }
 
 void ata_host_put(struct ata_host *host)
 {
     kref_put(&host->kref, ata_host_release);
 }
 EXPORT_SYMBOL_GPL(ata_host_put);
 
 /**
  *  ata_host_alloc - allocate and init basic ATA host resources
  *  @dev: generic device this host is associated with
  *  @max_ports: maximum number of ATA ports associated with this host
  *
  *  Allocate and initialize basic ATA host resources.  LLD calls
  *  this function to allocate a host, initializes it fully and
  *  attaches it using ata_host_register().
  *
  *  @max_ports ports are allocated and host->n_ports is
  *  initialized to @max_ports.  The caller is allowed to decrease
  *  host->n_ports before calling ata_host_register().  The unused
  *  ports will be automatically freed on registration.
  *
  *  RETURNS:
  *  Allocate ATA host on success, NULL on failure.
  *
  *  LOCKING:
  *  Inherited from calling layer (may sleep).
  */
 struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
 {
     struct ata_host *host;
     size_t sz;
     int i;
     void *dr;
 
     /* alloc a container for our list of ATA ports (buses) */
     sz = sizeof(struct ata_host) + (max_ports + 1) * sizeof(void *);
     host = kzalloc(sz, GFP_KERNEL);
     if (!host)
         return NULL;
 
     if (!devres_open_group(dev, NULL, GFP_KERNEL))
         goto err_free;
 
     dr = devres_alloc(ata_devres_release, 0, GFP_KERNEL);
     if (!dr)
         goto err_out;
 
     devres_add(dev, dr);
     dev_set_drvdata(dev, host);
 
     spin_lock_init(&host->lock);
     mutex_init(&host->eh_mutex);
     host->dev = dev;
     host->n_ports = max_ports;
     kref_init(&host->kref);
 
     /* allocate ports bound to this host */
     for (i = 0; i < max_ports; i++) {
         struct ata_port *ap;
 
         ap = ata_port_alloc(host);
         if (!ap)
             goto err_out;
 
         ap->port_no = i;
         host->ports[i] = ap;
     }
 
     devres_remove_group(dev, NULL);
     return host;
 
  err_out:
     devres_release_group(dev, NULL);
  err_free:
     kfree(host);
     return NULL;
 }
 EXPORT_SYMBOL_GPL(ata_host_alloc);
 
 /**
  *  ata_host_alloc_pinfo - alloc host and init with port_info array
  *  @dev: generic device this host is associated with
  *  @ppi: array of ATA port_info to initialize host with
  *  @n_ports: number of ATA ports attached to this host
  *
  *  Allocate ATA host and initialize with info from @ppi.  If NULL
  *  terminated, @ppi may contain fewer entries than @n_ports.  The
  *  last entry will be used for the remaining ports.
  *
  *  RETURNS:
  *  Allocate ATA host on success, NULL on failure.
  *
  *  LOCKING:
  *  Inherited from calling layer (may sleep).
  */
 struct ata_host *ata_host_alloc_pinfo(struct device *dev,
                       const struct ata_port_info * const * ppi,
                       int n_ports)
 {
     const struct ata_port_info *pi = &ata_dummy_port_info;
     struct ata_host *host;
     int i, j;
 
     host = ata_host_alloc(dev, n_ports);
     if (!host)
         return NULL;
 
     for (i = 0, j = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
 
         if (ppi[j])
             pi = ppi[j++];
 
         ap->pio_mask = pi->pio_mask;
         ap->mwdma_mask = pi->mwdma_mask;
         ap->udma_mask = pi->udma_mask;
         ap->flags |= pi->flags;
         ap->link.flags |= pi->link_flags;
         ap->ops = pi->port_ops;
 
         if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
             host->ops = pi->port_ops;
     }
 
     return host;
 }
 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
 
 static void ata_host_stop(struct device *gendev, void *res)
 {
     struct ata_host *host = dev_get_drvdata(gendev);
     int i;
 
     WARN_ON(!(host->flags & ATA_HOST_STARTED));
 
     for (i = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
 
         if (ap->ops->port_stop)
             ap->ops->port_stop(ap);
     }
 
     if (host->ops->host_stop)
         host->ops->host_stop(host);
 }
 
 /**
  *  ata_finalize_port_ops - finalize ata_port_operations
  *  @ops: ata_port_operations to finalize
  *
  *  An ata_port_operations can inherit from another ops and that
  *  ops can again inherit from another.  This can go on as many
  *  times as necessary as long as there is no loop in the
  *  inheritance chain.
  *
  *  Ops tables are finalized when the host is started.  NULL or
  *  unspecified entries are inherited from the closet ancestor
  *  which has the method and the entry is populated with it.
  *  After finalization, the ops table directly points to all the
  *  methods and ->inherits is no longer necessary and cleared.
  *
  *  Using ATA_OP_NULL, inheriting ops can force a method to NULL.
  *
  *  LOCKING:
  *  None.
  */
 static void ata_finalize_port_ops(struct ata_port_operations *ops)
 {
     static DEFINE_SPINLOCK(lock);
     const struct ata_port_operations *cur;
     void **begin = (void **)ops;
     void **end = (void **)&ops->inherits;
     void **pp;
 
     if (!ops || !ops->inherits)
         return;
 
     spin_lock(&lock);
 
     for (cur = ops->inherits; cur; cur = cur->inherits) {
         void **inherit = (void **)cur;
 
         for (pp = begin; pp < end; pp++, inherit++)
             if (!*pp)
                 *pp = *inherit;
     }
 
     for (pp = begin; pp < end; pp++)
         if (IS_ERR(*pp))
             *pp = NULL;
 
     ops->inherits = NULL;
 
     spin_unlock(&lock);
 }
 
 /**
  *  ata_host_start - start and freeze ports of an ATA host
  *  @host: ATA host to start ports for
  *
  *  Start and then freeze ports of @host.  Started status is
  *  recorded in host->flags, so this function can be called
  *  multiple times.  Ports are guaranteed to get started only
  *  once.  If host->ops is not initialized yet, it is set to the
  *  first non-dummy port ops.
  *
  *  LOCKING:
  *  Inherited from calling layer (may sleep).
  *
  *  RETURNS:
  *  0 if all ports are started successfully, -errno otherwise.
  */
 int ata_host_start(struct ata_host *host)
 {
     int have_stop = 0;
     void *start_dr = NULL;
     int i, rc;
 
     if (host->flags & ATA_HOST_STARTED)
         return 0;
 
     ata_finalize_port_ops(host->ops);
 
     for (i = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
 
         ata_finalize_port_ops(ap->ops);
 
         if (!host->ops && !ata_port_is_dummy(ap))
             host->ops = ap->ops;
 
         if (ap->ops->port_stop)
             have_stop = 1;
     }
 
     if (host->ops && host->ops->host_stop)
         have_stop = 1;
 
     if (have_stop) {
         start_dr = devres_alloc(ata_host_stop, 0, GFP_KERNEL);
         if (!start_dr)
             return -ENOMEM;
     }
 
     for (i = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
 
         if (ap->ops->port_start) {
             rc = ap->ops->port_start(ap);
             if (rc) {
                 if (rc != -ENODEV)
                     dev_err(host->dev,
                         "failed to start port %d (errno=%d)\n",
                         i, rc);
                 goto err_out;
             }
         }
         ata_eh_freeze_port(ap);
     }
 
     if (start_dr)
         devres_add(host->dev, start_dr);
     host->flags |= ATA_HOST_STARTED;
     return 0;
 
  err_out:
     while (--i >= 0) {
         struct ata_port *ap = host->ports[i];
 
         if (ap->ops->port_stop)
             ap->ops->port_stop(ap);
     }
     devres_free(start_dr);
     return rc;
 }
 EXPORT_SYMBOL_GPL(ata_host_start);
 
 /**
  *  ata_host_init - Initialize a host struct for sas (ipr, libsas)
  *  @host:  host to initialize
  *  @dev:   device host is attached to
  *  @ops:   port_ops
  *
  */
 void ata_host_init(struct ata_host *host, struct device *dev,
            struct ata_port_operations *ops)
 {
     spin_lock_init(&host->lock);
     mutex_init(&host->eh_mutex);
     host->n_tags = ATA_MAX_QUEUE;
     host->dev = dev;
     host->ops = ops;
     kref_init(&host->kref);
 }
 EXPORT_SYMBOL_GPL(ata_host_init);
 
 void __ata_port_probe(struct ata_port *ap)
 {
     struct ata_eh_info *ehi = &ap->link.eh_info;
     unsigned long flags;
 
     /* kick EH for boot probing */
     spin_lock_irqsave(ap->lock, flags);
 
     ehi->probe_mask |= ATA_ALL_DEVICES;
     ehi->action |= ATA_EH_RESET;
     ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
 
     ap->pflags &= ~ATA_PFLAG_INITIALIZING;
     ap->pflags |= ATA_PFLAG_LOADING;
     ata_port_schedule_eh(ap);
 
     spin_unlock_irqrestore(ap->lock, flags);
 }
 
 int ata_port_probe(struct ata_port *ap)
 {
     int rc = 0;
 
     if (ap->ops->error_handler) {
         __ata_port_probe(ap);
         ata_port_wait_eh(ap);
     } else {
         rc = ata_bus_probe(ap);
     }
     return rc;
 }
 
 
 static void async_port_probe(void *data, async_cookie_t cookie)
 {
     struct ata_port *ap = data;
 
     /*
      * If we're not allowed to scan this host in parallel,
      * we need to wait until all previous scans have completed
      * before going further.
      * Jeff Garzik says this is only within a controller, so we
      * don't need to wait for port 0, only for later ports.
      */
     if (!(ap->host->flags & ATA_HOST_PARALLEL_SCAN) && ap->port_no != 0)
         async_synchronize_cookie(cookie);
 
     (void)ata_port_probe(ap);
 
     /* in order to keep device order, we need to synchronize at this point */
     async_synchronize_cookie(cookie);
 
     ata_scsi_scan_host(ap, 1);
 }
 
 /**
  *  ata_host_register - register initialized ATA host
  *  @host: ATA host to register
  *  @sht: template for SCSI host
  *
  *  Register initialized ATA host.  @host is allocated using
  *  ata_host_alloc() and fully initialized by LLD.  This function
  *  starts ports, registers @host with ATA and SCSI layers and
  *  probe registered devices.
  *
  *  LOCKING:
  *  Inherited from calling layer (may sleep).
  *
  *  RETURNS:
  *  0 on success, -errno otherwise.
  */
 int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
 {
     int i, rc;
 
     host->n_tags = clamp(sht->can_queue, 1, ATA_MAX_QUEUE);
 
     /* host must have been started */
     if (!(host->flags & ATA_HOST_STARTED)) {
         dev_err(host->dev, "BUG: trying to register unstarted host\n");
         WARN_ON(1);
         return -EINVAL;
     }
 
     /* Blow away unused ports.  This happens when LLD can't
      * determine the exact number of ports to allocate at
      * allocation time.
      */
     for (i = host->n_ports; host->ports[i]; i++)
         kfree(host->ports[i]);
 
     /* give ports names and add SCSI hosts */
     for (i = 0; i < host->n_ports; i++) {
         host->ports[i]->print_id = atomic_inc_return(&ata_print_id);
         host->ports[i]->local_port_no = i + 1;
     }
 
     /* Create associated sysfs transport objects  */
     for (i = 0; i < host->n_ports; i++) {
         rc = ata_tport_add(host->dev,host->ports[i]);
         if (rc) {
             goto err_tadd;
         }
     }
 
     rc = ata_scsi_add_hosts(host, sht);
     if (rc)
         goto err_tadd;
 
     /* set cable, sata_spd_limit and report */
     for (i = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
         unsigned int xfer_mask;
 
         /* set SATA cable type if still unset */
         if (ap->cbl == ATA_CBL_NONE && (ap->flags & ATA_FLAG_SATA))
             ap->cbl = ATA_CBL_SATA;
 
         /* init sata_spd_limit to the current value */
         sata_link_init_spd(&ap->link);
         if (ap->slave_link)
             sata_link_init_spd(ap->slave_link);
 
         /* print per-port info to dmesg */
         xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
                           ap->udma_mask);
 
         if (!ata_port_is_dummy(ap)) {
             ata_port_info(ap, "%cATA max %s %s\n",
                       (ap->flags & ATA_FLAG_SATA) ? 'S' : 'P',
                       ata_mode_string(xfer_mask),
                       ap->link.eh_info.desc);
             ata_ehi_clear_desc(&ap->link.eh_info);
         } else
             ata_port_info(ap, "DUMMY\n");
     }
 
     /* perform each probe asynchronously */
     for (i = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
         ap->cookie = async_schedule(async_port_probe, ap);
     }
 
     return 0;
 
  err_tadd:
     while (--i >= 0) {
         ata_tport_delete(host->ports[i]);
     }
     return rc;
 
 }
 EXPORT_SYMBOL_GPL(ata_host_register);
 
 /**
  *  ata_host_activate - start host, request IRQ and register it
  *  @host: target ATA host
  *  @irq: IRQ to request
  *  @irq_handler: irq_handler used when requesting IRQ
  *  @irq_flags: irq_flags used when requesting IRQ
  *  @sht: scsi_host_template to use when registering the host
  *
  *  After allocating an ATA host and initializing it, most libata
  *  LLDs perform three steps to activate the host - start host,
  *  request IRQ and register it.  This helper takes necessary
  *  arguments and performs the three steps in one go.
  *
  *  An invalid IRQ skips the IRQ registration and expects the host to
  *  have set polling mode on the port. In this case, @irq_handler
  *  should be NULL.
  *
  *  LOCKING:
  *  Inherited from calling layer (may sleep).
  *
  *  RETURNS:
  *  0 on success, -errno otherwise.
  */
 int ata_host_activate(struct ata_host *host, int irq,
               irq_handler_t irq_handler, unsigned long irq_flags,
               struct scsi_host_template *sht)
 {
     int i, rc;
     char *irq_desc;
 
     rc = ata_host_start(host);
     if (rc)
         return rc;
 
     /* Special case for polling mode */
     if (!irq) {
         WARN_ON(irq_handler);
         return ata_host_register(host, sht);
     }
 
     irq_desc = devm_kasprintf(host->dev, GFP_KERNEL, "%s[%s]",
                   dev_driver_string(host->dev),
                   dev_name(host->dev));
     if (!irq_desc)
         return -ENOMEM;
 
     rc = devm_request_irq(host->dev, irq, irq_handler, irq_flags,
                   irq_desc, host);
     if (rc)
         return rc;
 
     for (i = 0; i < host->n_ports; i++)
         ata_port_desc(host->ports[i], "irq %d", irq);
 
     rc = ata_host_register(host, sht);
     /* if failed, just free the IRQ and leave ports alone */
     if (rc)
         devm_free_irq(host->dev, irq, host);
 
     return rc;
 }
 EXPORT_SYMBOL_GPL(ata_host_activate);
 
 /**
  *  ata_port_detach - Detach ATA port in preparation of device removal
  *  @ap: ATA port to be detached
  *
  *  Detach all ATA devices and the associated SCSI devices of @ap;
  *  then, remove the associated SCSI host.  @ap is guaranteed to
  *  be quiescent on return from this function.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep).
  */
 static void ata_port_detach(struct ata_port *ap)
 {
     unsigned long flags;
     struct ata_link *link;
     struct ata_device *dev;
 
     if (!ap->ops->error_handler)
         goto skip_eh;
 
     /* tell EH we're leaving & flush EH */
     spin_lock_irqsave(ap->lock, flags);
     ap->pflags |= ATA_PFLAG_UNLOADING;
     ata_port_schedule_eh(ap);
     spin_unlock_irqrestore(ap->lock, flags);
 
     /* wait till EH commits suicide */
     ata_port_wait_eh(ap);
 
     /* it better be dead now */
     WARN_ON(!(ap->pflags & ATA_PFLAG_UNLOADED));
 
     cancel_delayed_work_sync(&ap->hotplug_task);
 
  skip_eh:
     /* clean up zpodd on port removal */
     ata_for_each_link(link, ap, HOST_FIRST) {
         ata_for_each_dev(dev, link, ALL) {
             if (zpodd_dev_enabled(dev))
                 zpodd_exit(dev);
         }
     }
     if (ap->pmp_link) {
         int i;
         for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
             ata_tlink_delete(&ap->pmp_link[i]);
     }
     /* remove the associated SCSI host */
     scsi_remove_host(ap->scsi_host);
     ata_tport_delete(ap);
 }
 
 /**
  *  ata_host_detach - Detach all ports of an ATA host
  *  @host: Host to detach
  *
  *  Detach all ports of @host.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep).
  */
 void ata_host_detach(struct ata_host *host)
 {
     int i;
 
     for (i = 0; i < host->n_ports; i++) {
         /* Ensure ata_port probe has completed */
         async_synchronize_cookie(host->ports[i]->cookie + 1);
         ata_port_detach(host->ports[i]);
     }
 
     /* the host is dead now, dissociate ACPI */
     ata_acpi_dissociate(host);
 }
 EXPORT_SYMBOL_GPL(ata_host_detach);
 
 #ifdef CONFIG_PCI
 
 /**
  *  ata_pci_remove_one - PCI layer callback for device removal
  *  @pdev: PCI device that was removed
  *
  *  PCI layer indicates to libata via this hook that hot-unplug or
  *  module unload event has occurred.  Detach all ports.  Resource
  *  release is handled via devres.
  *
  *  LOCKING:
  *  Inherited from PCI layer (may sleep).
  */
 void ata_pci_remove_one(struct pci_dev *pdev)
 {
     struct ata_host *host = pci_get_drvdata(pdev);
 
     ata_host_detach(host);
 }
 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
 
 void ata_pci_shutdown_one(struct pci_dev *pdev)
 {
     struct ata_host *host = pci_get_drvdata(pdev);
     int i;
 
     for (i = 0; i < host->n_ports; i++) {
         struct ata_port *ap = host->ports[i];
 
         ap->pflags |= ATA_PFLAG_FROZEN;
 
         /* Disable port interrupts */
         if (ap->ops->freeze)
             ap->ops->freeze(ap);
 
         /* Stop the port DMA engines */
         if (ap->ops->port_stop)
             ap->ops->port_stop(ap);
     }
 }
 EXPORT_SYMBOL_GPL(ata_pci_shutdown_one);
 
 /* move to PCI subsystem */
 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
 {
     unsigned long tmp = 0;
 
     switch (bits->width) {
     case 1: {
         u8 tmp8 = 0;
         pci_read_config_byte(pdev, bits->reg, &tmp8);
         tmp = tmp8;
         break;
     }
     case 2: {
         u16 tmp16 = 0;
         pci_read_config_word(pdev, bits->reg, &tmp16);
         tmp = tmp16;
         break;
     }
     case 4: {
         u32 tmp32 = 0;
         pci_read_config_dword(pdev, bits->reg, &tmp32);
         tmp = tmp32;
         break;
     }
 
     default:
         return -EINVAL;
     }
 
     tmp &= bits->mask;
 
     return (tmp == bits->val) ? 1 : 0;
 }
 EXPORT_SYMBOL_GPL(pci_test_config_bits);
 
 #ifdef CONFIG_PM
 void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
 {
     pci_save_state(pdev);
     pci_disable_device(pdev);
 
     if (mesg.event & PM_EVENT_SLEEP)
         pci_set_power_state(pdev, PCI_D3hot);
 }
 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
 
 int ata_pci_device_do_resume(struct pci_dev *pdev)
 {
     int rc;
 
     pci_set_power_state(pdev, PCI_D0);
     pci_restore_state(pdev);
 
     rc = pcim_enable_device(pdev);
     if (rc) {
         dev_err(&pdev->dev,
             "failed to enable device after resume (%d)\n", rc);
         return rc;
     }
 
     pci_set_master(pdev);
     return 0;
 }
 EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
 
 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
 {
     struct ata_host *host = pci_get_drvdata(pdev);
 
     ata_host_suspend(host, mesg);
 
     ata_pci_device_do_suspend(pdev, mesg);
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
 
 int ata_pci_device_resume(struct pci_dev *pdev)
 {
     struct ata_host *host = pci_get_drvdata(pdev);
     int rc;
 
     rc = ata_pci_device_do_resume(pdev);
     if (rc == 0)
         ata_host_resume(host);
     return rc;
 }
 EXPORT_SYMBOL_GPL(ata_pci_device_resume);
 #endif /* CONFIG_PM */
 #endif /* CONFIG_PCI */
 
 /**
  *  ata_platform_remove_one - Platform layer callback for device removal
  *  @pdev: Platform device that was removed
  *
  *  Platform layer indicates to libata via this hook that hot-unplug or
  *  module unload event has occurred.  Detach all ports.  Resource
  *  release is handled via devres.
  *
  *  LOCKING:
  *  Inherited from platform layer (may sleep).
  */
 int ata_platform_remove_one(struct platform_device *pdev)
 {
     struct ata_host *host = platform_get_drvdata(pdev);
 
     ata_host_detach(host);
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(ata_platform_remove_one);
 
 #ifdef CONFIG_ATA_FORCE
 
 #define force_cbl(name, flag)               \
     { #name,    .cbl        = (flag) }
 
 #define force_spd_limit(spd, val)           \
     { #spd, .spd_limit      = (val) }
 
 #define force_xfer(mode, shift)             \
     { #mode,    .xfer_mask  = (1UL << (shift)) }
 
 #define force_lflag_on(name, flags)         \
     { #name,    .lflags_on  = (flags) }
 
 #define force_lflag_onoff(name, flags)          \
     { "no" #name,   .lflags_on  = (flags) },    \
     { #name,    .lflags_off = (flags) }
 
 #define force_horkage_on(name, flag)            \
     { #name,    .horkage_on = (flag) }
 
 #define force_horkage_onoff(name, flag)         \
     { "no" #name,   .horkage_on = (flag) }, \
     { #name,    .horkage_off    = (flag) }
 
 static const struct ata_force_param force_tbl[] __initconst = {
     force_cbl(40c,          ATA_CBL_PATA40),
     force_cbl(80c,          ATA_CBL_PATA80),
     force_cbl(short40c,     ATA_CBL_PATA40_SHORT),
     force_cbl(unk,          ATA_CBL_PATA_UNK),
     force_cbl(ign,          ATA_CBL_PATA_IGN),
     force_cbl(sata,         ATA_CBL_SATA),
 
     force_spd_limit(1.5Gbps,    1),
     force_spd_limit(3.0Gbps,    2),
 
     force_xfer(pio0,        ATA_SHIFT_PIO + 0),
     force_xfer(pio1,        ATA_SHIFT_PIO + 1),
     force_xfer(pio2,        ATA_SHIFT_PIO + 2),
     force_xfer(pio3,        ATA_SHIFT_PIO + 3),
     force_xfer(pio4,        ATA_SHIFT_PIO + 4),
     force_xfer(pio5,        ATA_SHIFT_PIO + 5),
     force_xfer(pio6,        ATA_SHIFT_PIO + 6),
     force_xfer(mwdma0,      ATA_SHIFT_MWDMA + 0),
     force_xfer(mwdma1,      ATA_SHIFT_MWDMA + 1),
     force_xfer(mwdma2,      ATA_SHIFT_MWDMA + 2),
     force_xfer(mwdma3,      ATA_SHIFT_MWDMA + 3),
     force_xfer(mwdma4,      ATA_SHIFT_MWDMA + 4),
     force_xfer(udma0,       ATA_SHIFT_UDMA + 0),
     force_xfer(udma16,      ATA_SHIFT_UDMA + 0),
     force_xfer(udma/16,     ATA_SHIFT_UDMA + 0),
     force_xfer(udma1,       ATA_SHIFT_UDMA + 1),
     force_xfer(udma25,      ATA_SHIFT_UDMA + 1),
     force_xfer(udma/25,     ATA_SHIFT_UDMA + 1),
     force_xfer(udma2,       ATA_SHIFT_UDMA + 2),
     force_xfer(udma33,      ATA_SHIFT_UDMA + 2),
     force_xfer(udma/33,     ATA_SHIFT_UDMA + 2),
     force_xfer(udma3,       ATA_SHIFT_UDMA + 3),
     force_xfer(udma44,      ATA_SHIFT_UDMA + 3),
     force_xfer(udma/44,     ATA_SHIFT_UDMA + 3),
     force_xfer(udma4,       ATA_SHIFT_UDMA + 4),
     force_xfer(udma66,      ATA_SHIFT_UDMA + 4),
     force_xfer(udma/66,     ATA_SHIFT_UDMA + 4),
     force_xfer(udma5,       ATA_SHIFT_UDMA + 5),
     force_xfer(udma100,     ATA_SHIFT_UDMA + 5),
     force_xfer(udma/100,        ATA_SHIFT_UDMA + 5),
     force_xfer(udma6,       ATA_SHIFT_UDMA + 6),
     force_xfer(udma133,     ATA_SHIFT_UDMA + 6),
     force_xfer(udma/133,        ATA_SHIFT_UDMA + 6),
     force_xfer(udma7,       ATA_SHIFT_UDMA + 7),
 
     force_lflag_on(nohrst,      ATA_LFLAG_NO_HRST),
     force_lflag_on(nosrst,      ATA_LFLAG_NO_SRST),
     force_lflag_on(norst,       ATA_LFLAG_NO_HRST | ATA_LFLAG_NO_SRST),
     force_lflag_on(rstonce,     ATA_LFLAG_RST_ONCE),
     force_lflag_onoff(dbdelay,  ATA_LFLAG_NO_DEBOUNCE_DELAY),
 
     force_horkage_onoff(ncq,    ATA_HORKAGE_NONCQ),
     force_horkage_onoff(ncqtrim,    ATA_HORKAGE_NO_NCQ_TRIM),
     force_horkage_onoff(ncqati, ATA_HORKAGE_NO_NCQ_ON_ATI),
 
     force_horkage_onoff(trim,   ATA_HORKAGE_NOTRIM),
     force_horkage_on(trim_zero, ATA_HORKAGE_ZERO_AFTER_TRIM),
     force_horkage_on(max_trim_128m, ATA_HORKAGE_MAX_TRIM_128M),
 
     force_horkage_onoff(dma,    ATA_HORKAGE_NODMA),
     force_horkage_on(atapi_dmadir,  ATA_HORKAGE_ATAPI_DMADIR),
     force_horkage_on(atapi_mod16_dma, ATA_HORKAGE_ATAPI_MOD16_DMA),
 
     force_horkage_onoff(dmalog, ATA_HORKAGE_NO_DMA_LOG),
     force_horkage_onoff(iddevlog,   ATA_HORKAGE_NO_ID_DEV_LOG),
     force_horkage_onoff(logdir, ATA_HORKAGE_NO_LOG_DIR),
 
     force_horkage_on(max_sec_128,   ATA_HORKAGE_MAX_SEC_128),
     force_horkage_on(max_sec_1024,  ATA_HORKAGE_MAX_SEC_1024),
     force_horkage_on(max_sec_lba48, ATA_HORKAGE_MAX_SEC_LBA48),
 
     force_horkage_onoff(lpm,    ATA_HORKAGE_NOLPM),
     force_horkage_onoff(setxfer,    ATA_HORKAGE_NOSETXFER),
     force_horkage_on(dump_id,   ATA_HORKAGE_DUMP_ID),
 
     force_horkage_on(disable,   ATA_HORKAGE_DISABLE),
 };
 
 static int __init ata_parse_force_one(char **cur,
                       struct ata_force_ent *force_ent,
                       const char **reason)
 {
     char *start = *cur, *p = *cur;
     char *id, *val, *endp;
     const struct ata_force_param *match_fp = NULL;
     int nr_matches = 0, i;
 
     /* find where this param ends and update *cur */
     while (*p != '\0' && *p != ',')
         p++;
 
     if (*p == '\0')
         *cur = p;
     else
         *cur = p + 1;
 
     *p = '\0';
 
     /* parse */
     p = strchr(start, ':');
     if (!p) {
         val = strstrip(start);
         goto parse_val;
     }
     *p = '\0';
 
     id = strstrip(start);
     val = strstrip(p + 1);
 
     /* parse id */
     p = strchr(id, '.');
     if (p) {
         *p++ = '\0';
         force_ent->device = simple_strtoul(p, &endp, 10);
         if (p == endp || *endp != '\0') {
             *reason = "invalid device";
             return -EINVAL;
         }
     }
 
     force_ent->port = simple_strtoul(id, &endp, 10);
     if (id == endp || *endp != '\0') {
         *reason = "invalid port/link";
         return -EINVAL;
     }
 
  parse_val:
     /* parse val, allow shortcuts so that both 1.5 and 1.5Gbps work */
     for (i = 0; i < ARRAY_SIZE(force_tbl); i++) {
         const struct ata_force_param *fp = &force_tbl[i];
 
         if (strncasecmp(val, fp->name, strlen(val)))
             continue;
 
         nr_matches++;
         match_fp = fp;
 
         if (strcasecmp(val, fp->name) == 0) {
             nr_matches = 1;
             break;
         }
     }
 
     if (!nr_matches) {
         *reason = "unknown value";
         return -EINVAL;
     }
     if (nr_matches > 1) {
         *reason = "ambiguous value";
         return -EINVAL;
     }
 
     force_ent->param = *match_fp;
 
     return 0;
 }
 
 static void __init ata_parse_force_param(void)
 {
     int idx = 0, size = 1;
     int last_port = -1, last_device = -1;
     char *p, *cur, *next;
 
     /* Calculate maximum number of params and allocate ata_force_tbl */
     for (p = ata_force_param_buf; *p; p++)
         if (*p == ',')
             size++;
 
     ata_force_tbl = kcalloc(size, sizeof(ata_force_tbl[0]), GFP_KERNEL);
     if (!ata_force_tbl) {
         printk(KERN_WARNING "ata: failed to extend force table, "
                "libata.force ignored\n");
         return;
     }
 
     /* parse and populate the table */
     for (cur = ata_force_param_buf; *cur != '\0'; cur = next) {
         const char *reason = "";
         struct ata_force_ent te = { .port = -1, .device = -1 };
 
         next = cur;
         if (ata_parse_force_one(&next, &te, &reason)) {
             printk(KERN_WARNING "ata: failed to parse force "
                    "parameter \"%s\" (%s)\n",
                    cur, reason);
             continue;
         }
 
         if (te.port == -1) {
             te.port = last_port;
             te.device = last_device;
         }
 
         ata_force_tbl[idx++] = te;
 
         last_port = te.port;
         last_device = te.device;
     }
 
     ata_force_tbl_size = idx;
 }
 
 static void ata_free_force_param(void)
 {
     kfree(ata_force_tbl);
 }
 #else
 static inline void ata_parse_force_param(void) { }
 static inline void ata_free_force_param(void) { }
 #endif
 
 static int __init ata_init(void)
 {
     int rc;
 
     ata_parse_force_param();
 
     rc = ata_sff_init();
     if (rc) {
         ata_free_force_param();
         return rc;
     }
 
     libata_transport_init();
     ata_scsi_transport_template = ata_attach_transport();
     if (!ata_scsi_transport_template) {
         ata_sff_exit();
         rc = -ENOMEM;
         goto err_out;
     }
 
     printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
     return 0;
 
 err_out:
     return rc;
 }
 
 static void __exit ata_exit(void)
 {
     ata_release_transport(ata_scsi_transport_template);
     libata_transport_exit();
     ata_sff_exit();
     ata_free_force_param();
 }
 
 subsys_initcall(ata_init);
 module_exit(ata_exit);
 
 static DEFINE_RATELIMIT_STATE(ratelimit, HZ / 5, 1);
 
 int ata_ratelimit(void)
 {
     return __ratelimit(&ratelimit);
 }
 EXPORT_SYMBOL_GPL(ata_ratelimit);
 
 /**
  *  ata_msleep - ATA EH owner aware msleep
  *  @ap: ATA port to attribute the sleep to
  *  @msecs: duration to sleep in milliseconds
  *
  *  Sleeps @msecs.  If the current task is owner of @ap's EH, the
  *  ownership is released before going to sleep and reacquired
  *  after the sleep is complete.  IOW, other ports sharing the
  *  @ap->host will be allowed to own the EH while this task is
  *  sleeping.
  *
  *  LOCKING:
  *  Might sleep.
  */
 void ata_msleep(struct ata_port *ap, unsigned int msecs)
 {
     bool owns_eh = ap && ap->host->eh_owner == current;
 
     if (owns_eh)
         ata_eh_release(ap);
 
     if (msecs < 20) {
         unsigned long usecs = msecs * USEC_PER_MSEC;
         usleep_range(usecs, usecs + 50);
     } else {
         msleep(msecs);
     }
 
     if (owns_eh)
         ata_eh_acquire(ap);
 }
 EXPORT_SYMBOL_GPL(ata_msleep);
 
 /**
  *  ata_wait_register - wait until register value changes
  *  @ap: ATA port to wait register for, can be NULL
  *  @reg: IO-mapped register
  *  @mask: Mask to apply to read register value
  *  @val: Wait condition
  *  @interval: polling interval in milliseconds
  *  @timeout: timeout in milliseconds
  *
  *  Waiting for some bits of register to change is a common
  *  operation for ATA controllers.  This function reads 32bit LE
  *  IO-mapped register @reg and tests for the following condition.
  *
  *  (*@reg & mask) != val
  *
  *  If the condition is met, it returns; otherwise, the process is
  *  repeated after @interval_msec until timeout.
  *
  *  LOCKING:
  *  Kernel thread context (may sleep)
  *
  *  RETURNS:
  *  The final register value.
  */
 u32 ata_wait_register(struct ata_port *ap, void __iomem *reg, u32 mask, u32 val,
               unsigned long interval, unsigned long timeout)
 {
     unsigned long deadline;
     u32 tmp;
 
     tmp = ioread32(reg);
 
     /* Calculate timeout _after_ the first read to make sure
      * preceding writes reach the controller before starting to
      * eat away the timeout.
      */
     deadline = ata_deadline(jiffies, timeout);
 
     while ((tmp & mask) == val && time_before(jiffies, deadline)) {
         ata_msleep(ap, interval);
         tmp = ioread32(reg);
     }
 
     return tmp;
 }
 EXPORT_SYMBOL_GPL(ata_wait_register);
 
 /*
  * Dummy port_ops
  */
 static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
 {
     return AC_ERR_SYSTEM;
 }
 
 static void ata_dummy_error_handler(struct ata_port *ap)
 {
     /* truly dummy */
 }
 
 struct ata_port_operations ata_dummy_port_ops = {
     .qc_prep        = ata_noop_qc_prep,
     .qc_issue       = ata_dummy_qc_issue,
     .error_handler      = ata_dummy_error_handler,
     .sched_eh       = ata_std_sched_eh,
     .end_eh         = ata_std_end_eh,
 };
 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
 
 const struct ata_port_info ata_dummy_port_info = {
     .port_ops       = &ata_dummy_port_ops,
 };
 EXPORT_SYMBOL_GPL(ata_dummy_port_info);
 
 void ata_print_version(const struct device *dev, const char *version)
 {
     dev_printk(KERN_DEBUG, dev, "version %s\n", version);
 }
 EXPORT_SYMBOL(ata_print_version);
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(ata_tf_load);
 EXPORT_TRACEPOINT_SYMBOL_GPL(ata_exec_command);
 EXPORT_TRACEPOINT_SYMBOL_GPL(ata_bmdma_setup);
 EXPORT_TRACEPOINT_SYMBOL_GPL(ata_bmdma_start);
 EXPORT_TRACEPOINT_SYMBOL_GPL(ata_bmdma_status);