drivers/staging/fsl-mc/bus/mc-sys.c

   1 /*
   2  * Copyright 2013-2016 Freescale Semiconductor Inc.
   3  *
   4  * I/O services to send MC commands to the MC hardware
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *     * Redistributions of source code must retain the above copyright
   9  *       notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above copyright
  11  *       notice, this list of conditions and the following disclaimer in the
  12  *       documentation and/or other materials provided with the distribution.
  13  *     * Neither the name of the above-listed copyright holders nor the
  14  *       names of any contributors may be used to endorse or promote products
  15  *       derived from this software without specific prior written permission.
  16  *
  17  * ALTERNATIVELY, this software may be distributed under the terms of the
  18  * GNU General Public License ("GPL") as published by the Free Software
  19  * Foundation, either version 2 of that License or (at your option) any
  20  * later version.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
  26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <linux/delay.h>
  36 #include <linux/slab.h>
  37 #include <linux/ioport.h>
  38 #include <linux/device.h>
  39 #include <linux/io.h>
  40 #include "../include/mc.h"
  41
  42 #include "dpmcp.h"
  43
  44 /**
  45  * Timeout in milliseconds to wait for the completion of an MC command
  46  */
  47 #define MC_CMD_COMPLETION_TIMEOUT_MS    500
  48
  49 /*
  50  * usleep_range() min and max values used to throttle down polling
  51  * iterations while waiting for MC command completion
  52  */
  53 #define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
  54 #define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
  55
  56 static enum mc_cmd_status mc_cmd_hdr_read_status(struct mc_command *cmd)
  57 {
  58         struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
  59
  60         return (enum mc_cmd_status)hdr->status;
  61 }
  62
  63 static u16 mc_cmd_hdr_read_cmdid(struct mc_command *cmd)
  64 {
  65         struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
  66         u16 cmd_id = le16_to_cpu(hdr->cmd_id);
  67
  68         return cmd_id;
  69 }
  70
  71 static int mc_status_to_error(enum mc_cmd_status status)
  72 {
  73         static const int mc_status_to_error_map[] = {
  74                 [MC_CMD_STATUS_OK] = 0,
  75                 [MC_CMD_STATUS_AUTH_ERR] = -EACCES,
  76                 [MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
  77                 [MC_CMD_STATUS_DMA_ERR] = -EIO,
  78                 [MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
  79                 [MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
  80                 [MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
  81                 [MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
  82                 [MC_CMD_STATUS_BUSY] = -EBUSY,
  83                 [MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
  84                 [MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
  85         };
  86
  87         if (WARN_ON((u32)status >= ARRAY_SIZE(mc_status_to_error_map)))
  88                 return -EINVAL;
  89
  90         return mc_status_to_error_map[status];
  91 }
  92
  93 static const char *mc_status_to_string(enum mc_cmd_status status)
  94 {
  95         static const char *const status_strings[] = {
  96                 [MC_CMD_STATUS_OK] = "Command completed successfully",
  97                 [MC_CMD_STATUS_READY] = "Command ready to be processed",
  98                 [MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
  99                 [MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
 100                 [MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
 101                 [MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
 102                 [MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
 103                 [MC_CMD_STATUS_NO_RESOURCE] = "No resources",
 104                 [MC_CMD_STATUS_NO_MEMORY] = "No memory available",
 105                 [MC_CMD_STATUS_BUSY] = "Device is busy",
 106                 [MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
 107                 [MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
 108         };
 109
 110         if ((unsigned int)status >= ARRAY_SIZE(status_strings))
 111                 return "Unknown MC error";
 112
 113         return status_strings[status];
 114 }
 115
 116 /**
 117  * mc_write_command - writes a command to a Management Complex (MC) portal
 118  *
 119  * @portal: pointer to an MC portal
 120  * @cmd: pointer to a filled command
 121  */
 122 static inline void mc_write_command(struct mc_command __iomem *portal,
 123                                     struct mc_command *cmd)
 124 {
 125         int i;
 126
 127         /* copy command parameters into the portal */
 128         for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
 129                 __raw_writeq(cmd->params[i], &portal->params[i]);
 130         __iowmb();
 131
 132         /* submit the command by writing the header */
 133         __raw_writeq(cmd->header, &portal->header);
 134 }
 135
 136 /**
 137  * mc_read_response - reads the response for the last MC command from a
 138  * Management Complex (MC) portal
 139  *
 140  * @portal: pointer to an MC portal
 141  * @resp: pointer to command response buffer
 142  *
 143  * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
 144  */
 145 static inline enum mc_cmd_status mc_read_response(struct mc_command __iomem *
 146                                                   portal,
 147                                                   struct mc_command *resp)
 148 {
 149         int i;
 150         enum mc_cmd_status status;
 151
 152         /* Copy command response header from MC portal: */
 153         __iormb();
 154         resp->header = __raw_readq(&portal->header);
 155         __iormb();
 156         status = mc_cmd_hdr_read_status(resp);
 157         if (status != MC_CMD_STATUS_OK)
 158                 return status;
 159
 160         /* Copy command response data from MC portal: */
 161         for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
 162                 resp->params[i] = __raw_readq(&portal->params[i]);
 163         __iormb();
 164
 165         return status;
 166 }
 167
 168 /**
 169  * Waits for the completion of an MC command doing preemptible polling.
 170  * uslepp_range() is called between polling iterations.
 171  *
 172  * @mc_io: MC I/O object to be used
 173  * @cmd: command buffer to receive MC response
 174  * @mc_status: MC command completion status
 175  */
 176 static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
 177                                        struct mc_command *cmd,
 178                                        enum mc_cmd_status *mc_status)
 179 {
 180         enum mc_cmd_status status;
 181         unsigned long jiffies_until_timeout =
 182                 jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);
 183
 184         /*
 185          * Wait for response from the MC hardware:
 186          */
 187         for (;;) {
 188                 status = mc_read_response(mc_io->portal_virt_addr, cmd);
 189                 if (status != MC_CMD_STATUS_READY)
 190                         break;
 191
 192                 /*
 193                  * TODO: When MC command completion interrupts are supported
 194                  * call wait function here instead of usleep_range()
 195                  */
 196                 usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
 197                              MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 198
 199                 if (time_after_eq(jiffies, jiffies_until_timeout)) {
 200                         dev_dbg(mc_io->dev,
 201                                 "MC command timed out (portal: %#llx, dprc handle: %#x, command: %#x)\n",
 202                                  mc_io->portal_phys_addr,
 203                                  (unsigned int)mc_cmd_hdr_read_token(cmd),
 204                                  (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
 205
 206                         return -ETIMEDOUT;
 207                 }
 208         }
 209
 210         *mc_status = status;
 211         return 0;
 212 }
 213
 214 /**
 215  * Waits for the completion of an MC command doing atomic polling.
 216  * udelay() is called between polling iterations.
 217  *
 218  * @mc_io: MC I/O object to be used
 219  * @cmd: command buffer to receive MC response
 220  * @mc_status: MC command completion status
 221  */
 222 static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
 223                                   struct mc_command *cmd,
 224                                   enum mc_cmd_status *mc_status)
 225 {
 226         enum mc_cmd_status status;
 227         unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
 228
 229         BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
 230                      MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);
 231
 232         for (;;) {
 233                 status = mc_read_response(mc_io->portal_virt_addr, cmd);
 234                 if (status != MC_CMD_STATUS_READY)
 235                         break;
 236
 237                 udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 238                 timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
 239                 if (timeout_usecs == 0) {
 240                         dev_dbg(mc_io->dev,
 241                                 "MC command timed out (portal: %#llx, dprc handle: %#x, command: %#x)\n",
 242                                  mc_io->portal_phys_addr,
 243                                  (unsigned int)mc_cmd_hdr_read_token(cmd),
 244                                  (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
 245
 246                         return -ETIMEDOUT;
 247                 }
 248         }
 249
 250         *mc_status = status;
 251         return 0;
 252 }
 253
 254 /**
 255  * Sends a command to the MC device using the given MC I/O object
 256  *
 257  * @mc_io: MC I/O object to be used
 258  * @cmd: command to be sent
 259  *
 260  * Returns '0' on Success; Error code otherwise.
 261  */
 262 int mc_send_command(struct fsl_mc_io *mc_io, struct mc_command *cmd)
 263 {
 264         int error;
 265         enum mc_cmd_status status;
 266         unsigned long irq_flags = 0;
 267
 268         if (WARN_ON(in_irq() &&
 269                     !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)))
 270                 return -EINVAL;
 271
 272         if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
 273                 spin_lock_irqsave(&mc_io->spinlock, irq_flags);
 274         else
 275                 mutex_lock(&mc_io->mutex);
 276
 277         /*
 278          * Send command to the MC hardware:
 279          */
 280         mc_write_command(mc_io->portal_virt_addr, cmd);
 281
 282         /*
 283          * Wait for response from the MC hardware:
 284          */
 285         if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
 286                 error = mc_polling_wait_preemptible(mc_io, cmd, &status);
 287         else
 288                 error = mc_polling_wait_atomic(mc_io, cmd, &status);
 289
 290         if (error < 0)
 291                 goto common_exit;
 292
 293         if (status != MC_CMD_STATUS_OK) {
 294                 dev_dbg(mc_io->dev,
 295                         "MC command failed: portal: %#llx, dprc handle: %#x, command: %#x, status: %s (%#x)\n",
 296                          mc_io->portal_phys_addr,
 297                          (unsigned int)mc_cmd_hdr_read_token(cmd),
 298                          (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
 299                          mc_status_to_string(status),
 300                          (unsigned int)status);
 301
 302                 error = mc_status_to_error(status);
 303                 goto common_exit;
 304         }
 305
 306         error = 0;
 307 common_exit:
 308         if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
 309                 spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
 310         else
 311                 mutex_unlock(&mc_io->mutex);
 312
 313         return error;
 314 }
 315 EXPORT_SYMBOL(mc_send_command);