bus/fsl-mc/mc-sys.c

0001 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
0002 /*
0003  * Copyright 2013-2016 Freescale Semiconductor Inc.
0004  *
0005  * I/O services to send MC commands to the MC hardware
0006  *
0007  */
0008
0009 #include <linux/delay.h>
0010 #include <linux/slab.h>
0011 #include <linux/ioport.h>
0012 #include <linux/device.h>
0013 #include <linux/io.h>
0014 #include <linux/io-64-nonatomic-hi-lo.h>
0015 #include <linux/fsl/mc.h>
0016
0017 #include "fsl-mc-private.h"
0018
0019 /*
0020  * Timeout in milliseconds to wait for the completion of an MC command
0021  */
0022 #define MC_CMD_COMPLETION_TIMEOUT_MS    500
0023
0024 /*
0025  * usleep_range() min and max values used to throttle down polling
0026  * iterations while waiting for MC command completion
0027  */
0028 #define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
0029 #define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
0030
0031 static enum mc_cmd_status mc_cmd_hdr_read_status(struct fsl_mc_command *cmd)
0032 {
0033     struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
0034
0035     return (enum mc_cmd_status)hdr->status;
0036 }
0037
0038 u16 mc_cmd_hdr_read_cmdid(struct fsl_mc_command *cmd)
0039 {
0040     struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
0041     u16 cmd_id = le16_to_cpu(hdr->cmd_id);
0042
0043     return cmd_id;
0044 }
0045
0046 static int mc_status_to_error(enum mc_cmd_status status)
0047 {
0048     static const int mc_status_to_error_map[] = {
0049         [MC_CMD_STATUS_OK] = 0,
0050         [MC_CMD_STATUS_AUTH_ERR] = -EACCES,
0051         [MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
0052         [MC_CMD_STATUS_DMA_ERR] = -EIO,
0053         [MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
0054         [MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
0055         [MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
0056         [MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
0057         [MC_CMD_STATUS_BUSY] = -EBUSY,
0058         [MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
0059         [MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
0060     };
0061
0062     if ((u32)status >= ARRAY_SIZE(mc_status_to_error_map))
0063         return -EINVAL;
0064
0065     return mc_status_to_error_map[status];
0066 }
0067
0068 static const char *mc_status_to_string(enum mc_cmd_status status)
0069 {
0070     static const char *const status_strings[] = {
0071         [MC_CMD_STATUS_OK] = "Command completed successfully",
0072         [MC_CMD_STATUS_READY] = "Command ready to be processed",
0073         [MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
0074         [MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
0075         [MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
0076         [MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
0077         [MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
0078         [MC_CMD_STATUS_NO_RESOURCE] = "No resources",
0079         [MC_CMD_STATUS_NO_MEMORY] = "No memory available",
0080         [MC_CMD_STATUS_BUSY] = "Device is busy",
0081         [MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
0082         [MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
0083     };
0084
0085     if ((unsigned int)status >= ARRAY_SIZE(status_strings))
0086         return "Unknown MC error";
0087
0088     return status_strings[status];
0089 }
0090
0091 /**
0092  * mc_write_command - writes a command to a Management Complex (MC) portal
0093  *
0094  * @portal: pointer to an MC portal
0095  * @cmd: pointer to a filled command
0096  */
0097 static inline void mc_write_command(struct fsl_mc_command __iomem *portal,
0098                     struct fsl_mc_command *cmd)
0099 {
0100     int i;
0101
0102     /* copy command parameters into the portal */
0103     for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
0104         /*
0105          * Data is already in the expected LE byte-order. Do an
0106          * extra LE -> CPU conversion so that the CPU -> LE done in
0107          * the device io write api puts it back in the right order.
0108          */
0109         writeq_relaxed(le64_to_cpu(cmd->params[i]), &portal->params[i]);
0110
0111     /* submit the command by writing the header */
0112     writeq(le64_to_cpu(cmd->header), &portal->header);
0113 }
0114
0115 /**
0116  * mc_read_response - reads the response for the last MC command from a
0117  * Management Complex (MC) portal
0118  *
0119  * @portal: pointer to an MC portal
0120  * @resp: pointer to command response buffer
0121  *
0122  * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
0123  */
0124 static inline enum mc_cmd_status mc_read_response(struct fsl_mc_command __iomem
0125                           *portal,
0126                           struct fsl_mc_command *resp)
0127 {
0128     int i;
0129     enum mc_cmd_status status;
0130
0131     /* Copy command response header from MC portal: */
0132     resp->header = cpu_to_le64(readq_relaxed(&portal->header));
0133     status = mc_cmd_hdr_read_status(resp);
0134     if (status != MC_CMD_STATUS_OK)
0135         return status;
0136
0137     /* Copy command response data from MC portal: */
0138     for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
0139         /*
0140          * Data is expected to be in LE byte-order. Do an
0141          * extra CPU -> LE to revert the LE -> CPU done in
0142          * the device io read api.
0143          */
0144         resp->params[i] =
0145             cpu_to_le64(readq_relaxed(&portal->params[i]));
0146
0147     return status;
0148 }
0149
0150 /**
0151  * mc_polling_wait_preemptible() - Waits for the completion of an MC
0152  *                                 command doing preemptible polling.
0153  *                                 uslepp_range() is called between
0154  *                                 polling iterations.
0155  * @mc_io: MC I/O object to be used
0156  * @cmd: command buffer to receive MC response
0157  * @mc_status: MC command completion status
0158  */
0159 static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
0160                        struct fsl_mc_command *cmd,
0161                        enum mc_cmd_status *mc_status)
0162 {
0163     enum mc_cmd_status status;
0164     unsigned long jiffies_until_timeout =
0165         jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);
0166
0167     /*
0168      * Wait for response from the MC hardware:
0169      */
0170     for (;;) {
0171         status = mc_read_response(mc_io->portal_virt_addr, cmd);
0172         if (status != MC_CMD_STATUS_READY)
0173             break;
0174
0175         /*
0176          * TODO: When MC command completion interrupts are supported
0177          * call wait function here instead of usleep_range()
0178          */
0179         usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
0180                  MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
0181
0182         if (time_after_eq(jiffies, jiffies_until_timeout)) {
0183             dev_dbg(mc_io->dev,
0184                 "MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
0185                  &mc_io->portal_phys_addr,
0186                  (unsigned int)mc_cmd_hdr_read_token(cmd),
0187                  (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
0188
0189             return -ETIMEDOUT;
0190         }
0191     }
0192
0193     *mc_status = status;
0194     return 0;
0195 }
0196
0197 /**
0198  * mc_polling_wait_atomic() - Waits for the completion of an MC command
0199  *                            doing atomic polling. udelay() is called
0200  *                            between polling iterations.
0201  * @mc_io: MC I/O object to be used
0202  * @cmd: command buffer to receive MC response
0203  * @mc_status: MC command completion status
0204  */
0205 static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
0206                   struct fsl_mc_command *cmd,
0207                   enum mc_cmd_status *mc_status)
0208 {
0209     enum mc_cmd_status status;
0210     unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
0211
0212     BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
0213              MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);
0214
0215     for (;;) {
0216         status = mc_read_response(mc_io->portal_virt_addr, cmd);
0217         if (status != MC_CMD_STATUS_READY)
0218             break;
0219
0220         udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
0221         timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
0222         if (timeout_usecs == 0) {
0223             dev_dbg(mc_io->dev,
0224                 "MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
0225                  &mc_io->portal_phys_addr,
0226                  (unsigned int)mc_cmd_hdr_read_token(cmd),
0227                  (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
0228
0229             return -ETIMEDOUT;
0230         }
0231     }
0232
0233     *mc_status = status;
0234     return 0;
0235 }
0236
0237 /**
0238  * mc_send_command() - Sends a command to the MC device using the given
0239  *                     MC I/O object
0240  * @mc_io: MC I/O object to be used
0241  * @cmd: command to be sent
0242  *
0243  * Returns '0' on Success; Error code otherwise.
0244  */
0245 int mc_send_command(struct fsl_mc_io *mc_io, struct fsl_mc_command *cmd)
0246 {
0247     int error;
0248     enum mc_cmd_status status;
0249     unsigned long irq_flags = 0;
0250
0251     if (in_irq() && !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
0252         return -EINVAL;
0253
0254     if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
0255         raw_spin_lock_irqsave(&mc_io->spinlock, irq_flags);
0256     else
0257         mutex_lock(&mc_io->mutex);
0258
0259     /*
0260      * Send command to the MC hardware:
0261      */
0262     mc_write_command(mc_io->portal_virt_addr, cmd);
0263
0264     /*
0265      * Wait for response from the MC hardware:
0266      */
0267     if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
0268         error = mc_polling_wait_preemptible(mc_io, cmd, &status);
0269     else
0270         error = mc_polling_wait_atomic(mc_io, cmd, &status);
0271
0272     if (error < 0)
0273         goto common_exit;
0274
0275     if (status != MC_CMD_STATUS_OK) {
0276         dev_dbg(mc_io->dev,
0277             "MC command failed: portal: %pa, dprc handle: %#x, command: %#x, status: %s (%#x)\n",
0278              &mc_io->portal_phys_addr,
0279              (unsigned int)mc_cmd_hdr_read_token(cmd),
0280              (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
0281              mc_status_to_string(status),
0282              (unsigned int)status);
0283
0284         error = mc_status_to_error(status);
0285         goto common_exit;
0286     }
0287
0288     error = 0;
0289 common_exit:
0290     if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
0291         raw_spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
0292     else
0293         mutex_unlock(&mc_io->mutex);
0294
0295     return error;
0296 }
0297 EXPORT_SYMBOL_GPL(mc_send_command);