OSCL-LXR linux-6.0.1/​drivers/​s390/​cio/​cmf.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Linux on zSeries Channel Measurement Facility support
  *
  * Copyright IBM Corp. 2000, 2006
  *
  * Authors: Arnd Bergmann <arndb@de.ibm.com>
  *      Cornelia Huck <cornelia.huck@de.ibm.com>
  *
  * original idea from Natarajan Krishnaswami <nkrishna@us.ibm.com>
  */
 
 #define KMSG_COMPONENT "cio"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/memblock.h>
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/export.h>
 #include <linux/moduleparam.h>
 #include <linux/slab.h>
 #include <linux/timex.h>    /* get_tod_clock() */
 
 #include <asm/ccwdev.h>
 #include <asm/cio.h>
 #include <asm/cmb.h>
 #include <asm/div64.h>
 
 #include "cio.h"
 #include "css.h"
 #include "device.h"
 #include "ioasm.h"
 #include "chsc.h"
 
 /*
  * parameter to enable cmf during boot, possible uses are:
  *  "s390cmf" -- enable cmf and allocate 2 MB of ram so measuring can be
  *               used on any subchannel
  *  "s390cmf=<num>" -- enable cmf and allocate enough memory to measure
  *                     <num> subchannel, where <num> is an integer
  *                     between 1 and 65535, default is 1024
  */
 #define ARGSTRING "s390cmf"
 
 /* indices for READCMB */
 enum cmb_index {
     avg_utilization = -1,
  /* basic and exended format: */
     cmb_ssch_rsch_count = 0,
     cmb_sample_count,
     cmb_device_connect_time,
     cmb_function_pending_time,
     cmb_device_disconnect_time,
     cmb_control_unit_queuing_time,
     cmb_device_active_only_time,
  /* extended format only: */
     cmb_device_busy_time,
     cmb_initial_command_response_time,
 };
 
 /**
  * enum cmb_format - types of supported measurement block formats
  *
  * @CMF_BASIC:      traditional channel measurement blocks supported
  *          by all machines that we run on
  * @CMF_EXTENDED:   improved format that was introduced with the z990
  *          machine
  * @CMF_AUTODETECT: default: use extended format when running on a machine
  *          supporting extended format, otherwise fall back to
  *          basic format
  */
 enum cmb_format {
     CMF_BASIC,
     CMF_EXTENDED,
     CMF_AUTODETECT = -1,
 };
 
 /*
  * format - actual format for all measurement blocks
  *
  * The format module parameter can be set to a value of 0 (zero)
  * or 1, indicating basic or extended format as described for
  * enum cmb_format.
  */
 static int format = CMF_AUTODETECT;
 module_param(format, bint, 0444);
 
 /**
  * struct cmb_operations - functions to use depending on cmb_format
  *
  * Most of these functions operate on a struct ccw_device. There is only
  * one instance of struct cmb_operations because the format of the measurement
  * data is guaranteed to be the same for every ccw_device.
  *
  * @alloc:  allocate memory for a channel measurement block,
  *      either with the help of a special pool or with kmalloc
  * @free:   free memory allocated with @alloc
  * @set:    enable or disable measurement
  * @read:   read a measurement entry at an index
  * @readall:    read a measurement block in a common format
  * @reset:  clear the data in the associated measurement block and
  *      reset its time stamp
  */
 struct cmb_operations {
     int  (*alloc)  (struct ccw_device *);
     void (*free)   (struct ccw_device *);
     int  (*set)    (struct ccw_device *, u32);
     u64  (*read)   (struct ccw_device *, int);
     int  (*readall)(struct ccw_device *, struct cmbdata *);
     void (*reset)  (struct ccw_device *);
 /* private: */
     struct attribute_group *attr_group;
 };
 static struct cmb_operations *cmbops;
 
 struct cmb_data {
     void *hw_block;   /* Pointer to block updated by hardware */
     void *last_block; /* Last changed block copied from hardware block */
     int size;     /* Size of hw_block and last_block */
     unsigned long long last_update;  /* when last_block was updated */
 };
 
 /*
  * Our user interface is designed in terms of nanoseconds,
  * while the hardware measures total times in its own
  * unit.
  */
 static inline u64 time_to_nsec(u32 value)
 {
     return ((u64)value) * 128000ull;
 }
 
 /*
  * Users are usually interested in average times,
  * not accumulated time.
  * This also helps us with atomicity problems
  * when reading sinlge values.
  */
 static inline u64 time_to_avg_nsec(u32 value, u32 count)
 {
     u64 ret;
 
     /* no samples yet, avoid division by 0 */
     if (count == 0)
         return 0;
 
     /* value comes in units of 128 µsec */
     ret = time_to_nsec(value);
     do_div(ret, count);
 
     return ret;
 }
 
 #define CMF_OFF 0
 #define CMF_ON  2
 
 /*
  * Activate or deactivate the channel monitor. When area is NULL,
  * the monitor is deactivated. The channel monitor needs to
  * be active in order to measure subchannels, which also need
  * to be enabled.
  */
 static inline void cmf_activate(void *area, unsigned int onoff)
 {
     /* activate channel measurement */
     asm volatile(
         "   lgr 1,%[r1]\n"
         "   lgr 2,%[mbo]\n"
         "   schm\n"
         :
         : [r1] "d" ((unsigned long)onoff), [mbo] "d" (area)
         : "1", "2");
 }
 
 static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
              unsigned long address)
 {
     struct subchannel *sch = to_subchannel(cdev->dev.parent);
     int ret;
 
     sch->config.mme = mme;
     sch->config.mbfc = mbfc;
     /* address can be either a block address or a block index */
     if (mbfc)
         sch->config.mba = address;
     else
         sch->config.mbi = address;
 
     ret = cio_commit_config(sch);
     if (!mme && ret == -ENODEV) {
         /*
          * The task was to disable measurement block updates but
          * the subchannel is already gone. Report success.
          */
         ret = 0;
     }
     return ret;
 }
 
 struct set_schib_struct {
     u32 mme;
     int mbfc;
     unsigned long address;
     wait_queue_head_t wait;
     int ret;
 };
 
 #define CMF_PENDING 1
 #define SET_SCHIB_TIMEOUT (10 * HZ)
 
 static int set_schib_wait(struct ccw_device *cdev, u32 mme,
               int mbfc, unsigned long address)
 {
     struct set_schib_struct set_data;
     int ret = -ENODEV;
 
     spin_lock_irq(cdev->ccwlock);
     if (!cdev->private->cmb)
         goto out;
 
     ret = set_schib(cdev, mme, mbfc, address);
     if (ret != -EBUSY)
         goto out;
 
     /* if the device is not online, don't even try again */
     if (cdev->private->state != DEV_STATE_ONLINE)
         goto out;
 
     init_waitqueue_head(&set_data.wait);
     set_data.mme = mme;
     set_data.mbfc = mbfc;
     set_data.address = address;
     set_data.ret = CMF_PENDING;
 
     cdev->private->state = DEV_STATE_CMFCHANGE;
     cdev->private->cmb_wait = &set_data;
     spin_unlock_irq(cdev->ccwlock);
 
     ret = wait_event_interruptible_timeout(set_data.wait,
                            set_data.ret != CMF_PENDING,
                            SET_SCHIB_TIMEOUT);
     spin_lock_irq(cdev->ccwlock);
     if (ret <= 0) {
         if (set_data.ret == CMF_PENDING) {
             set_data.ret = (ret == 0) ? -ETIME : ret;
             if (cdev->private->state == DEV_STATE_CMFCHANGE)
                 cdev->private->state = DEV_STATE_ONLINE;
         }
     }
     cdev->private->cmb_wait = NULL;
     ret = set_data.ret;
 out:
     spin_unlock_irq(cdev->ccwlock);
     return ret;
 }
 
 void retry_set_schib(struct ccw_device *cdev)
 {
     struct set_schib_struct *set_data = cdev->private->cmb_wait;
 
     if (!set_data)
         return;
 
     set_data->ret = set_schib(cdev, set_data->mme, set_data->mbfc,
                   set_data->address);
     wake_up(&set_data->wait);
 }
 
 static int cmf_copy_block(struct ccw_device *cdev)
 {
     struct subchannel *sch = to_subchannel(cdev->dev.parent);
     struct cmb_data *cmb_data;
     void *hw_block;
 
     if (cio_update_schib(sch))
         return -ENODEV;
 
     if (scsw_fctl(&sch->schib.scsw) & SCSW_FCTL_START_FUNC) {
         /* Don't copy if a start function is in progress. */
         if ((!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_SUSPENDED)) &&
             (scsw_actl(&sch->schib.scsw) &
              (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)) &&
             (!(scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_SEC_STATUS)))
             return -EBUSY;
     }
     cmb_data = cdev->private->cmb;
     hw_block = cmb_data->hw_block;
     memcpy(cmb_data->last_block, hw_block, cmb_data->size);
     cmb_data->last_update = get_tod_clock();
     return 0;
 }
 
 struct copy_block_struct {
     wait_queue_head_t wait;
     int ret;
 };
 
 static int cmf_cmb_copy_wait(struct ccw_device *cdev)
 {
     struct copy_block_struct copy_block;
     int ret = -ENODEV;
 
     spin_lock_irq(cdev->ccwlock);
     if (!cdev->private->cmb)
         goto out;
 
     ret = cmf_copy_block(cdev);
     if (ret != -EBUSY)
         goto out;
 
     if (cdev->private->state != DEV_STATE_ONLINE)
         goto out;
 
     init_waitqueue_head(&copy_block.wait);
     copy_block.ret = CMF_PENDING;
 
     cdev->private->state = DEV_STATE_CMFUPDATE;
     cdev->private->cmb_wait = &copy_block;
     spin_unlock_irq(cdev->ccwlock);
 
     ret = wait_event_interruptible(copy_block.wait,
                        copy_block.ret != CMF_PENDING);
     spin_lock_irq(cdev->ccwlock);
     if (ret) {
         if (copy_block.ret == CMF_PENDING) {
             copy_block.ret = -ERESTARTSYS;
             if (cdev->private->state == DEV_STATE_CMFUPDATE)
                 cdev->private->state = DEV_STATE_ONLINE;
         }
     }
     cdev->private->cmb_wait = NULL;
     ret = copy_block.ret;
 out:
     spin_unlock_irq(cdev->ccwlock);
     return ret;
 }
 
 void cmf_retry_copy_block(struct ccw_device *cdev)
 {
     struct copy_block_struct *copy_block = cdev->private->cmb_wait;
 
     if (!copy_block)
         return;
 
     copy_block->ret = cmf_copy_block(cdev);
     wake_up(&copy_block->wait);
 }
 
 static void cmf_generic_reset(struct ccw_device *cdev)
 {
     struct cmb_data *cmb_data;
 
     spin_lock_irq(cdev->ccwlock);
     cmb_data = cdev->private->cmb;
     if (cmb_data) {
         memset(cmb_data->last_block, 0, cmb_data->size);
         /*
          * Need to reset hw block as well to make the hardware start
          * from 0 again.
          */
         memset(cmb_data->hw_block, 0, cmb_data->size);
         cmb_data->last_update = 0;
     }
     cdev->private->cmb_start_time = get_tod_clock();
     spin_unlock_irq(cdev->ccwlock);
 }
 
 /**
  * struct cmb_area - container for global cmb data
  *
  * @mem:    pointer to CMBs (only in basic measurement mode)
  * @list:   contains a linked list of all subchannels
  * @num_channels: number of channels to be measured
  * @lock:   protect concurrent access to @mem and @list
  */
 struct cmb_area {
     struct cmb *mem;
     struct list_head list;
     int num_channels;
     spinlock_t lock;
 };
 
 static struct cmb_area cmb_area = {
     .lock = __SPIN_LOCK_UNLOCKED(cmb_area.lock),
     .list = LIST_HEAD_INIT(cmb_area.list),
     .num_channels  = 1024,
 };
 
 /* ****** old style CMB handling ********/
 
 /*
  * Basic channel measurement blocks are allocated in one contiguous
  * block of memory, which can not be moved as long as any channel
  * is active. Therefore, a maximum number of subchannels needs to
  * be defined somewhere. This is a module parameter, defaulting to
  * a reasonable value of 1024, or 32 kb of memory.
  * Current kernels don't allow kmalloc with more than 128kb, so the
  * maximum is 4096.
  */
 
 module_param_named(maxchannels, cmb_area.num_channels, uint, 0444);
 
 /**
  * struct cmb - basic channel measurement block
  * @ssch_rsch_count: number of ssch and rsch
  * @sample_count: number of samples
  * @device_connect_time: time of device connect
  * @function_pending_time: time of function pending
  * @device_disconnect_time: time of device disconnect
  * @control_unit_queuing_time: time of control unit queuing
  * @device_active_only_time: time of device active only
  * @reserved: unused in basic measurement mode
  *
  * The measurement block as used by the hardware. The fields are described
  * further in z/Architecture Principles of Operation, chapter 17.
  *
  * The cmb area made up from these blocks must be a contiguous array and may
  * not be reallocated or freed.
  * Only one cmb area can be present in the system.
  */
 struct cmb {
     u16 ssch_rsch_count;
     u16 sample_count;
     u32 device_connect_time;
     u32 function_pending_time;
     u32 device_disconnect_time;
     u32 control_unit_queuing_time;
     u32 device_active_only_time;
     u32 reserved[2];
 };
 
 /*
  * Insert a single device into the cmb_area list.
  * Called with cmb_area.lock held from alloc_cmb.
  */
 static int alloc_cmb_single(struct ccw_device *cdev,
                 struct cmb_data *cmb_data)
 {
     struct cmb *cmb;
     struct ccw_device_private *node;
     int ret;
 
     spin_lock_irq(cdev->ccwlock);
     if (!list_empty(&cdev->private->cmb_list)) {
         ret = -EBUSY;
         goto out;
     }
 
     /*
      * Find first unused cmb in cmb_area.mem.
      * This is a little tricky: cmb_area.list
      * remains sorted by ->cmb->hw_data pointers.
      */
     cmb = cmb_area.mem;
     list_for_each_entry(node, &cmb_area.list, cmb_list) {
         struct cmb_data *data;
         data = node->cmb;
         if ((struct cmb*)data->hw_block > cmb)
             break;
         cmb++;
     }
     if (cmb - cmb_area.mem >= cmb_area.num_channels) {
         ret = -ENOMEM;
         goto out;
     }
 
     /* insert new cmb */
     list_add_tail(&cdev->private->cmb_list, &node->cmb_list);
     cmb_data->hw_block = cmb;
     cdev->private->cmb = cmb_data;
     ret = 0;
 out:
     spin_unlock_irq(cdev->ccwlock);
     return ret;
 }
 
 static int alloc_cmb(struct ccw_device *cdev)
 {
     int ret;
     struct cmb *mem;
     ssize_t size;
     struct cmb_data *cmb_data;
 
     /* Allocate private cmb_data. */
     cmb_data = kzalloc(sizeof(struct cmb_data), GFP_KERNEL);
     if (!cmb_data)
         return -ENOMEM;
 
     cmb_data->last_block = kzalloc(sizeof(struct cmb), GFP_KERNEL);
     if (!cmb_data->last_block) {
         kfree(cmb_data);
         return -ENOMEM;
     }
     cmb_data->size = sizeof(struct cmb);
     spin_lock(&cmb_area.lock);
 
     if (!cmb_area.mem) {
         /* there is no user yet, so we need a new area */
         size = sizeof(struct cmb) * cmb_area.num_channels;
         WARN_ON(!list_empty(&cmb_area.list));
 
         spin_unlock(&cmb_area.lock);
         mem = (void*)__get_free_pages(GFP_KERNEL | GFP_DMA,
                  get_order(size));
         spin_lock(&cmb_area.lock);
 
         if (cmb_area.mem) {
             /* ok, another thread was faster */
             free_pages((unsigned long)mem, get_order(size));
         } else if (!mem) {
             /* no luck */
             ret = -ENOMEM;
             goto out;
         } else {
             /* everything ok */
             memset(mem, 0, size);
             cmb_area.mem = mem;
             cmf_activate(cmb_area.mem, CMF_ON);
         }
     }
 
     /* do the actual allocation */
     ret = alloc_cmb_single(cdev, cmb_data);
 out:
     spin_unlock(&cmb_area.lock);
     if (ret) {
         kfree(cmb_data->last_block);
         kfree(cmb_data);
     }
     return ret;
 }
 
 static void free_cmb(struct ccw_device *cdev)
 {
     struct ccw_device_private *priv;
     struct cmb_data *cmb_data;
 
     spin_lock(&cmb_area.lock);
     spin_lock_irq(cdev->ccwlock);
 
     priv = cdev->private;
     cmb_data = priv->cmb;
     priv->cmb = NULL;
     if (cmb_data)
         kfree(cmb_data->last_block);
     kfree(cmb_data);
     list_del_init(&priv->cmb_list);
 
     if (list_empty(&cmb_area.list)) {
         ssize_t size;
         size = sizeof(struct cmb) * cmb_area.num_channels;
         cmf_activate(NULL, CMF_OFF);
         free_pages((unsigned long)cmb_area.mem, get_order(size));
         cmb_area.mem = NULL;
     }
     spin_unlock_irq(cdev->ccwlock);
     spin_unlock(&cmb_area.lock);
 }
 
 static int set_cmb(struct ccw_device *cdev, u32 mme)
 {
     u16 offset;
     struct cmb_data *cmb_data;
     unsigned long flags;
 
     spin_lock_irqsave(cdev->ccwlock, flags);
     if (!cdev->private->cmb) {
         spin_unlock_irqrestore(cdev->ccwlock, flags);
         return -EINVAL;
     }
     cmb_data = cdev->private->cmb;
     offset = mme ? (struct cmb *)cmb_data->hw_block - cmb_area.mem : 0;
     spin_unlock_irqrestore(cdev->ccwlock, flags);
 
     return set_schib_wait(cdev, mme, 0, offset);
 }
 
 /* calculate utilization in 0.1 percent units */
 static u64 __cmb_utilization(u64 device_connect_time, u64 function_pending_time,
                  u64 device_disconnect_time, u64 start_time)
 {
     u64 utilization, elapsed_time;
 
     utilization = time_to_nsec(device_connect_time +
                    function_pending_time +
                    device_disconnect_time);
 
     elapsed_time = get_tod_clock() - start_time;
     elapsed_time = tod_to_ns(elapsed_time);
     elapsed_time /= 1000;
 
     return elapsed_time ? (utilization / elapsed_time) : 0;
 }
 
 static u64 read_cmb(struct ccw_device *cdev, int index)
 {
     struct cmb_data *cmb_data;
     unsigned long flags;
     struct cmb *cmb;
     u64 ret = 0;
     u32 val;
 
     spin_lock_irqsave(cdev->ccwlock, flags);
     cmb_data = cdev->private->cmb;
     if (!cmb_data)
         goto out;
 
     cmb = cmb_data->hw_block;
     switch (index) {
     case avg_utilization:
         ret = __cmb_utilization(cmb->device_connect_time,
                     cmb->function_pending_time,
                     cmb->device_disconnect_time,
                     cdev->private->cmb_start_time);
         goto out;
     case cmb_ssch_rsch_count:
         ret = cmb->ssch_rsch_count;
         goto out;
     case cmb_sample_count:
         ret = cmb->sample_count;
         goto out;
     case cmb_device_connect_time:
         val = cmb->device_connect_time;
         break;
     case cmb_function_pending_time:
         val = cmb->function_pending_time;
         break;
     case cmb_device_disconnect_time:
         val = cmb->device_disconnect_time;
         break;
     case cmb_control_unit_queuing_time:
         val = cmb->control_unit_queuing_time;
         break;
     case cmb_device_active_only_time:
         val = cmb->device_active_only_time;
         break;
     default:
         goto out;
     }
     ret = time_to_avg_nsec(val, cmb->sample_count);
 out:
     spin_unlock_irqrestore(cdev->ccwlock, flags);
     return ret;
 }
 
 static int readall_cmb(struct ccw_device *cdev, struct cmbdata *data)
 {
     struct cmb *cmb;
     struct cmb_data *cmb_data;
     u64 time;
     unsigned long flags;
     int ret;
 
     ret = cmf_cmb_copy_wait(cdev);
     if (ret < 0)
         return ret;
     spin_lock_irqsave(cdev->ccwlock, flags);
     cmb_data = cdev->private->cmb;
     if (!cmb_data) {
         ret = -ENODEV;
         goto out;
     }
     if (cmb_data->last_update == 0) {
         ret = -EAGAIN;
         goto out;
     }
     cmb = cmb_data->last_block;
     time = cmb_data->last_update - cdev->private->cmb_start_time;
 
     memset(data, 0, sizeof(struct cmbdata));
 
     /* we only know values before device_busy_time */
     data->size = offsetof(struct cmbdata, device_busy_time);
 
     data->elapsed_time = tod_to_ns(time);
 
     /* copy data to new structure */
     data->ssch_rsch_count = cmb->ssch_rsch_count;
     data->sample_count = cmb->sample_count;
 
     /* time fields are converted to nanoseconds while copying */
     data->device_connect_time = time_to_nsec(cmb->device_connect_time);
     data->function_pending_time = time_to_nsec(cmb->function_pending_time);
     data->device_disconnect_time =
         time_to_nsec(cmb->device_disconnect_time);
     data->control_unit_queuing_time
         = time_to_nsec(cmb->control_unit_queuing_time);
     data->device_active_only_time
         = time_to_nsec(cmb->device_active_only_time);
     ret = 0;
 out:
     spin_unlock_irqrestore(cdev->ccwlock, flags);
     return ret;
 }
 
 static void reset_cmb(struct ccw_device *cdev)
 {
     cmf_generic_reset(cdev);
 }
 
 static int cmf_enabled(struct ccw_device *cdev)
 {
     int enabled;
 
     spin_lock_irq(cdev->ccwlock);
     enabled = !!cdev->private->cmb;
     spin_unlock_irq(cdev->ccwlock);
 
     return enabled;
 }
 
 static struct attribute_group cmf_attr_group;
 
 static struct cmb_operations cmbops_basic = {
     .alloc  = alloc_cmb,
     .free   = free_cmb,
     .set    = set_cmb,
     .read   = read_cmb,
     .readall    = readall_cmb,
     .reset      = reset_cmb,
     .attr_group = &cmf_attr_group,
 };
 
 /* ******** extended cmb handling ********/
 
 /**
  * struct cmbe - extended channel measurement block
  * @ssch_rsch_count: number of ssch and rsch
  * @sample_count: number of samples
  * @device_connect_time: time of device connect
  * @function_pending_time: time of function pending
  * @device_disconnect_time: time of device disconnect
  * @control_unit_queuing_time: time of control unit queuing
  * @device_active_only_time: time of device active only
  * @device_busy_time: time of device busy
  * @initial_command_response_time: initial command response time
  * @reserved: unused
  *
  * The measurement block as used by the hardware. May be in any 64 bit physical
  * location.
  * The fields are described further in z/Architecture Principles of Operation,
  * third edition, chapter 17.
  */
 struct cmbe {
     u32 ssch_rsch_count;
     u32 sample_count;
     u32 device_connect_time;
     u32 function_pending_time;
     u32 device_disconnect_time;
     u32 control_unit_queuing_time;
     u32 device_active_only_time;
     u32 device_busy_time;
     u32 initial_command_response_time;
     u32 reserved[7];
 } __packed __aligned(64);
 
 static struct kmem_cache *cmbe_cache;
 
 static int alloc_cmbe(struct ccw_device *cdev)
 {
     struct cmb_data *cmb_data;
     struct cmbe *cmbe;
     int ret = -ENOMEM;
 
     cmbe = kmem_cache_zalloc(cmbe_cache, GFP_KERNEL);
     if (!cmbe)
         return ret;
 
     cmb_data = kzalloc(sizeof(*cmb_data), GFP_KERNEL);
     if (!cmb_data)
         goto out_free;
 
     cmb_data->last_block = kzalloc(sizeof(struct cmbe), GFP_KERNEL);
     if (!cmb_data->last_block)
         goto out_free;
 
     cmb_data->size = sizeof(*cmbe);
     cmb_data->hw_block = cmbe;
 
     spin_lock(&cmb_area.lock);
     spin_lock_irq(cdev->ccwlock);
     if (cdev->private->cmb)
         goto out_unlock;
 
     cdev->private->cmb = cmb_data;
 
     /* activate global measurement if this is the first channel */
     if (list_empty(&cmb_area.list))
         cmf_activate(NULL, CMF_ON);
     list_add_tail(&cdev->private->cmb_list, &cmb_area.list);
 
     spin_unlock_irq(cdev->ccwlock);
     spin_unlock(&cmb_area.lock);
     return 0;
 
 out_unlock:
     spin_unlock_irq(cdev->ccwlock);
     spin_unlock(&cmb_area.lock);
     ret = -EBUSY;
 out_free:
     if (cmb_data)
         kfree(cmb_data->last_block);
     kfree(cmb_data);
     kmem_cache_free(cmbe_cache, cmbe);
 
     return ret;
 }
 
 static void free_cmbe(struct ccw_device *cdev)
 {
     struct cmb_data *cmb_data;
 
     spin_lock(&cmb_area.lock);
     spin_lock_irq(cdev->ccwlock);
     cmb_data = cdev->private->cmb;
     cdev->private->cmb = NULL;
     if (cmb_data) {
         kfree(cmb_data->last_block);
         kmem_cache_free(cmbe_cache, cmb_data->hw_block);
     }
     kfree(cmb_data);
 
     /* deactivate global measurement if this is the last channel */
     list_del_init(&cdev->private->cmb_list);
     if (list_empty(&cmb_area.list))
         cmf_activate(NULL, CMF_OFF);
     spin_unlock_irq(cdev->ccwlock);
     spin_unlock(&cmb_area.lock);
 }
 
 static int set_cmbe(struct ccw_device *cdev, u32 mme)
 {
     unsigned long mba;
     struct cmb_data *cmb_data;
     unsigned long flags;
 
     spin_lock_irqsave(cdev->ccwlock, flags);
     if (!cdev->private->cmb) {
         spin_unlock_irqrestore(cdev->ccwlock, flags);
         return -EINVAL;
     }
     cmb_data = cdev->private->cmb;
     mba = mme ? (unsigned long) cmb_data->hw_block : 0;
     spin_unlock_irqrestore(cdev->ccwlock, flags);
 
     return set_schib_wait(cdev, mme, 1, mba);
 }
 
 static u64 read_cmbe(struct ccw_device *cdev, int index)
 {
     struct cmb_data *cmb_data;
     unsigned long flags;
     struct cmbe *cmb;
     u64 ret = 0;
     u32 val;
 
     spin_lock_irqsave(cdev->ccwlock, flags);
     cmb_data = cdev->private->cmb;
     if (!cmb_data)
         goto out;
 
     cmb = cmb_data->hw_block;
     switch (index) {
     case avg_utilization:
         ret = __cmb_utilization(cmb->device_connect_time,
                     cmb->function_pending_time,
                     cmb->device_disconnect_time,
                     cdev->private->cmb_start_time);
         goto out;
     case cmb_ssch_rsch_count:
         ret = cmb->ssch_rsch_count;
         goto out;
     case cmb_sample_count:
         ret = cmb->sample_count;
         goto out;
     case cmb_device_connect_time:
         val = cmb->device_connect_time;
         break;
     case cmb_function_pending_time:
         val = cmb->function_pending_time;
         break;
     case cmb_device_disconnect_time:
         val = cmb->device_disconnect_time;
         break;
     case cmb_control_unit_queuing_time:
         val = cmb->control_unit_queuing_time;
         break;
     case cmb_device_active_only_time:
         val = cmb->device_active_only_time;
         break;
     case cmb_device_busy_time:
         val = cmb->device_busy_time;
         break;
     case cmb_initial_command_response_time:
         val = cmb->initial_command_response_time;
         break;
     default:
         goto out;
     }
     ret = time_to_avg_nsec(val, cmb->sample_count);
 out:
     spin_unlock_irqrestore(cdev->ccwlock, flags);
     return ret;
 }
 
 static int readall_cmbe(struct ccw_device *cdev, struct cmbdata *data)
 {
     struct cmbe *cmb;
     struct cmb_data *cmb_data;
     u64 time;
     unsigned long flags;
     int ret;
 
     ret = cmf_cmb_copy_wait(cdev);
     if (ret < 0)
         return ret;
     spin_lock_irqsave(cdev->ccwlock, flags);
     cmb_data = cdev->private->cmb;
     if (!cmb_data) {
         ret = -ENODEV;
         goto out;
     }
     if (cmb_data->last_update == 0) {
         ret = -EAGAIN;
         goto out;
     }
     time = cmb_data->last_update - cdev->private->cmb_start_time;
 
     memset (data, 0, sizeof(struct cmbdata));
 
     /* we only know values before device_busy_time */
     data->size = offsetof(struct cmbdata, device_busy_time);
 
     data->elapsed_time = tod_to_ns(time);
 
     cmb = cmb_data->last_block;
     /* copy data to new structure */
     data->ssch_rsch_count = cmb->ssch_rsch_count;
     data->sample_count = cmb->sample_count;
 
     /* time fields are converted to nanoseconds while copying */
     data->device_connect_time = time_to_nsec(cmb->device_connect_time);
     data->function_pending_time = time_to_nsec(cmb->function_pending_time);
     data->device_disconnect_time =
         time_to_nsec(cmb->device_disconnect_time);
     data->control_unit_queuing_time
         = time_to_nsec(cmb->control_unit_queuing_time);
     data->device_active_only_time
         = time_to_nsec(cmb->device_active_only_time);
     data->device_busy_time = time_to_nsec(cmb->device_busy_time);
     data->initial_command_response_time
         = time_to_nsec(cmb->initial_command_response_time);
 
     ret = 0;
 out:
     spin_unlock_irqrestore(cdev->ccwlock, flags);
     return ret;
 }
 
 static void reset_cmbe(struct ccw_device *cdev)
 {
     cmf_generic_reset(cdev);
 }
 
 static struct attribute_group cmf_attr_group_ext;
 
 static struct cmb_operations cmbops_extended = {
     .alloc      = alloc_cmbe,
     .free       = free_cmbe,
     .set        = set_cmbe,
     .read       = read_cmbe,
     .readall    = readall_cmbe,
     .reset      = reset_cmbe,
     .attr_group = &cmf_attr_group_ext,
 };
 
 static ssize_t cmb_show_attr(struct device *dev, char *buf, enum cmb_index idx)
 {
     return sprintf(buf, "%lld\n",
         (unsigned long long) cmf_read(to_ccwdev(dev), idx));
 }
 
 static ssize_t cmb_show_avg_sample_interval(struct device *dev,
                         struct device_attribute *attr,
                         char *buf)
 {
     struct ccw_device *cdev = to_ccwdev(dev);
     unsigned long count;
     long interval;
 
     count = cmf_read(cdev, cmb_sample_count);
     spin_lock_irq(cdev->ccwlock);
     if (count) {
         interval = get_tod_clock() - cdev->private->cmb_start_time;
         interval = tod_to_ns(interval);
         interval /= count;
     } else
         interval = -1;
     spin_unlock_irq(cdev->ccwlock);
     return sprintf(buf, "%ld\n", interval);
 }
 
 static ssize_t cmb_show_avg_utilization(struct device *dev,
                     struct device_attribute *attr,
                     char *buf)
 {
     unsigned long u = cmf_read(to_ccwdev(dev), avg_utilization);
 
     return sprintf(buf, "%02lu.%01lu%%\n", u / 10, u % 10);
 }
 
 #define cmf_attr(name) \
 static ssize_t show_##name(struct device *dev, \
                struct device_attribute *attr, char *buf)    \
 { return cmb_show_attr((dev), buf, cmb_##name); } \
 static DEVICE_ATTR(name, 0444, show_##name, NULL);
 
 #define cmf_attr_avg(name) \
 static ssize_t show_avg_##name(struct device *dev, \
                    struct device_attribute *attr, char *buf) \
 { return cmb_show_attr((dev), buf, cmb_##name); } \
 static DEVICE_ATTR(avg_##name, 0444, show_avg_##name, NULL);
 
 cmf_attr(ssch_rsch_count);
 cmf_attr(sample_count);
 cmf_attr_avg(device_connect_time);
 cmf_attr_avg(function_pending_time);
 cmf_attr_avg(device_disconnect_time);
 cmf_attr_avg(control_unit_queuing_time);
 cmf_attr_avg(device_active_only_time);
 cmf_attr_avg(device_busy_time);
 cmf_attr_avg(initial_command_response_time);
 
 static DEVICE_ATTR(avg_sample_interval, 0444, cmb_show_avg_sample_interval,
            NULL);
 static DEVICE_ATTR(avg_utilization, 0444, cmb_show_avg_utilization, NULL);
 
 static struct attribute *cmf_attributes[] = {
     &dev_attr_avg_sample_interval.attr,
     &dev_attr_avg_utilization.attr,
     &dev_attr_ssch_rsch_count.attr,
     &dev_attr_sample_count.attr,
     &dev_attr_avg_device_connect_time.attr,
     &dev_attr_avg_function_pending_time.attr,
     &dev_attr_avg_device_disconnect_time.attr,
     &dev_attr_avg_control_unit_queuing_time.attr,
     &dev_attr_avg_device_active_only_time.attr,
     NULL,
 };
 
 static struct attribute_group cmf_attr_group = {
     .name  = "cmf",
     .attrs = cmf_attributes,
 };
 
 static struct attribute *cmf_attributes_ext[] = {
     &dev_attr_avg_sample_interval.attr,
     &dev_attr_avg_utilization.attr,
     &dev_attr_ssch_rsch_count.attr,
     &dev_attr_sample_count.attr,
     &dev_attr_avg_device_connect_time.attr,
     &dev_attr_avg_function_pending_time.attr,
     &dev_attr_avg_device_disconnect_time.attr,
     &dev_attr_avg_control_unit_queuing_time.attr,
     &dev_attr_avg_device_active_only_time.attr,
     &dev_attr_avg_device_busy_time.attr,
     &dev_attr_avg_initial_command_response_time.attr,
     NULL,
 };
 
 static struct attribute_group cmf_attr_group_ext = {
     .name  = "cmf",
     .attrs = cmf_attributes_ext,
 };
 
 static ssize_t cmb_enable_show(struct device *dev,
                    struct device_attribute *attr,
                    char *buf)
 {
     struct ccw_device *cdev = to_ccwdev(dev);
 
     return sprintf(buf, "%d\n", cmf_enabled(cdev));
 }
 
 static ssize_t cmb_enable_store(struct device *dev,
                 struct device_attribute *attr, const char *buf,
                 size_t c)
 {
     struct ccw_device *cdev = to_ccwdev(dev);
     unsigned long val;
     int ret;
 
     ret = kstrtoul(buf, 16, &val);
     if (ret)
         return ret;
 
     switch (val) {
     case 0:
         ret = disable_cmf(cdev);
         break;
     case 1:
         ret = enable_cmf(cdev);
         break;
     default:
         ret = -EINVAL;
     }
 
     return ret ? ret : c;
 }
 DEVICE_ATTR_RW(cmb_enable);
 
 /**
  * enable_cmf() - switch on the channel measurement for a specific device
  *  @cdev:  The ccw device to be enabled
  *
  *  Enable channel measurements for @cdev. If this is called on a device
  *  for which channel measurement is already enabled a reset of the
  *  measurement data is triggered.
  *  Returns: %0 for success or a negative error value.
  *  Context:
  *    non-atomic
  */
 int enable_cmf(struct ccw_device *cdev)
 {
     int ret = 0;
 
     device_lock(&cdev->dev);
     if (cmf_enabled(cdev)) {
         cmbops->reset(cdev);
         goto out_unlock;
     }
     get_device(&cdev->dev);
     ret = cmbops->alloc(cdev);
     if (ret)
         goto out;
     cmbops->reset(cdev);
     ret = sysfs_create_group(&cdev->dev.kobj, cmbops->attr_group);
     if (ret) {
         cmbops->free(cdev);
         goto out;
     }
     ret = cmbops->set(cdev, 2);
     if (ret) {
         sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group);
         cmbops->free(cdev);
     }
 out:
     if (ret)
         put_device(&cdev->dev);
 out_unlock:
     device_unlock(&cdev->dev);
     return ret;
 }
 
 /**
  * __disable_cmf() - switch off the channel measurement for a specific device
  *  @cdev:  The ccw device to be disabled
  *
  *  Returns: %0 for success or a negative error value.
  *
  *  Context:
  *    non-atomic, device_lock() held.
  */
 int __disable_cmf(struct ccw_device *cdev)
 {
     int ret;
 
     ret = cmbops->set(cdev, 0);
     if (ret)
         return ret;
 
     sysfs_remove_group(&cdev->dev.kobj, cmbops->attr_group);
     cmbops->free(cdev);
     put_device(&cdev->dev);
 
     return ret;
 }
 
 /**
  * disable_cmf() - switch off the channel measurement for a specific device
  *  @cdev:  The ccw device to be disabled
  *
  *  Returns: %0 for success or a negative error value.
  *
  *  Context:
  *    non-atomic
  */
 int disable_cmf(struct ccw_device *cdev)
 {
     int ret;
 
     device_lock(&cdev->dev);
     ret = __disable_cmf(cdev);
     device_unlock(&cdev->dev);
 
     return ret;
 }
 
 /**
  * cmf_read() - read one value from the current channel measurement block
  * @cdev:   the channel to be read
  * @index:  the index of the value to be read
  *
  * Returns: The value read or %0 if the value cannot be read.
  *
  *  Context:
  *    any
  */
 u64 cmf_read(struct ccw_device *cdev, int index)
 {
     return cmbops->read(cdev, index);
 }
 
 /**
  * cmf_readall() - read the current channel measurement block
  * @cdev:   the channel to be read
  * @data:   a pointer to a data block that will be filled
  *
  * Returns: %0 on success, a negative error value otherwise.
  *
  *  Context:
  *    any
  */
 int cmf_readall(struct ccw_device *cdev, struct cmbdata *data)
 {
     return cmbops->readall(cdev, data);
 }
 
 /* Reenable cmf when a disconnected device becomes available again. */
 int cmf_reenable(struct ccw_device *cdev)
 {
     cmbops->reset(cdev);
     return cmbops->set(cdev, 2);
 }
 
 /**
  * cmf_reactivate() - reactivate measurement block updates
  *
  * Use this during resume from hibernate.
  */
 void cmf_reactivate(void)
 {
     spin_lock(&cmb_area.lock);
     if (!list_empty(&cmb_area.list))
         cmf_activate(cmb_area.mem, CMF_ON);
     spin_unlock(&cmb_area.lock);
 }
 
 static int __init init_cmbe(void)
 {
     cmbe_cache = kmem_cache_create("cmbe_cache", sizeof(struct cmbe),
                        __alignof__(struct cmbe), 0, NULL);
 
     return cmbe_cache ? 0 : -ENOMEM;
 }
 
 static int __init init_cmf(void)
 {
     char *format_string;
     char *detect_string;
     int ret;
 
     /*
      * If the user did not give a parameter, see if we are running on a
      * machine supporting extended measurement blocks, otherwise fall back
      * to basic mode.
      */
     if (format == CMF_AUTODETECT) {
         if (!css_general_characteristics.ext_mb) {
             format = CMF_BASIC;
         } else {
             format = CMF_EXTENDED;
         }
         detect_string = "autodetected";
     } else {
         detect_string = "parameter";
     }
 
     switch (format) {
     case CMF_BASIC:
         format_string = "basic";
         cmbops = &cmbops_basic;
         break;
     case CMF_EXTENDED:
         format_string = "extended";
         cmbops = &cmbops_extended;
 
         ret = init_cmbe();
         if (ret)
             return ret;
         break;
     default:
         return -EINVAL;
     }
     pr_info("Channel measurement facility initialized using format "
         "%s (mode %s)\n", format_string, detect_string);
     return 0;
 }
 device_initcall(init_cmf);
 
 EXPORT_SYMBOL_GPL(enable_cmf);
 EXPORT_SYMBOL_GPL(disable_cmf);
 EXPORT_SYMBOL_GPL(cmf_read);
 EXPORT_SYMBOL_GPL(cmf_readall);

This page was automatically generated by the 2.1.0 LXR engine. The LXR team