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 <linux/io-64-nonatomic-hi-lo.h>
  41 #include "../include/mc.h"
  42
  43 #include "dpmcp.h"
  44
  45 /**
  46  * Timeout in milliseconds to wait for the completion of an MC command
  47  */
  48 #define MC_CMD_COMPLETION_TIMEOUT_MS    500
  49
  50 /*
  51  * usleep_range() min and max values used to throttle down polling
  52  * iterations while waiting for MC command completion
  53  */
  54 #define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
  55 #define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
  56
  57 static enum mc_cmd_status mc_cmd_hdr_read_status(struct mc_command *cmd)
  58 {
  59         struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
  60
  61         return (enum mc_cmd_status)hdr->status;
  62 }
  63
  64 static u16 mc_cmd_hdr_read_cmdid(struct mc_command *cmd)
  65 {
  66         struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
  67         u16 cmd_id = le16_to_cpu(hdr->cmd_id);
  68
  69         return cmd_id;
  70 }
  71
  72 static int mc_status_to_error(enum mc_cmd_status status)
  73 {
  74         static const int mc_status_to_error_map[] = {
  75                 [MC_CMD_STATUS_OK] = 0,
  76                 [MC_CMD_STATUS_AUTH_ERR] = -EACCES,
  77                 [MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
  78                 [MC_CMD_STATUS_DMA_ERR] = -EIO,
  79                 [MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
  80                 [MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
  81                 [MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
  82                 [MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
  83                 [MC_CMD_STATUS_BUSY] = -EBUSY,
  84                 [MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
  85                 [MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
  86         };
  87
  88         if (WARN_ON((u32)status >= ARRAY_SIZE(mc_status_to_error_map)))
  89                 return -EINVAL;
  90
  91         return mc_status_to_error_map[status];
  92 }
  93
  94 static const char *mc_status_to_string(enum mc_cmd_status status)
  95 {
  96         static const char *const status_strings[] = {
  97                 [MC_CMD_STATUS_OK] = "Command completed successfully",
  98                 [MC_CMD_STATUS_READY] = "Command ready to be processed",
  99                 [MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
 100                 [MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
 101                 [MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
 102                 [MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
 103                 [MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
 104                 [MC_CMD_STATUS_NO_RESOURCE] = "No resources",
 105                 [MC_CMD_STATUS_NO_MEMORY] = "No memory available",
 106                 [MC_CMD_STATUS_BUSY] = "Device is busy",
 107                 [MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
 108                 [MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
 109         };
 110
 111         if ((unsigned int)status >= ARRAY_SIZE(status_strings))
 112                 return "Unknown MC error";
 113
 114         return status_strings[status];
 115 }
 116
 117 /**
 118  * mc_write_command - writes a command to a Management Complex (MC) portal
 119  *
 120  * @portal: pointer to an MC portal
 121  * @cmd: pointer to a filled command
 122  */
 123 static inline void mc_write_command(struct mc_command __iomem *portal,
 124                                     struct mc_command *cmd)
 125 {
 126         int i;
 127
 128         /* copy command parameters into the portal */
 129         for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
 130                 /*
 131                  * Data is already in the expected LE byte-order. Do an
 132                  * extra LE -> CPU conversion so that the CPU -> LE done in
 133                  * the device io write api puts it back in the right order.
 134                  */
 135                 writeq_relaxed(le64_to_cpu(cmd->params[i]), &portal->params[i]);
 136
 137         /* submit the command by writing the header */
 138         writeq(le64_to_cpu(cmd->header), &portal->header);
 139 }
 140
 141 /**
 142  * mc_read_response - reads the response for the last MC command from a
 143  * Management Complex (MC) portal
 144  *
 145  * @portal: pointer to an MC portal
 146  * @resp: pointer to command response buffer
 147  *
 148  * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
 149  */
 150 static inline enum mc_cmd_status mc_read_response(struct mc_command __iomem *
 151                                                   portal,
 152                                                   struct mc_command *resp)
 153 {
 154         int i;
 155         enum mc_cmd_status status;
 156
 157         /* Copy command response header from MC portal: */
 158         resp->header = cpu_to_le64(readq_relaxed(&portal->header));
 159         status = mc_cmd_hdr_read_status(resp);
 160         if (status != MC_CMD_STATUS_OK)
 161                 return status;
 162
 163         /* Copy command response data from MC portal: */
 164         for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
 165                 /*
 166                  * Data is expected to be in LE byte-order. Do an
 167                  * extra CPU -> LE to revert the LE -> CPU done in
 168                  * the device io read api.
 169                  */
 170                 resp->params[i] =
 171                         cpu_to_le64(readq_relaxed(&portal->params[i]));
 172
 173         return status;
 174 }
 175
 176 /**
 177  * Waits for the completion of an MC command doing preemptible polling.
 178  * uslepp_range() is called between polling iterations.
 179  *
 180  * @mc_io: MC I/O object to be used
 181  * @cmd: command buffer to receive MC response
 182  * @mc_status: MC command completion status
 183  */
 184 static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
 185                                        struct mc_command *cmd,
 186                                        enum mc_cmd_status *mc_status)
 187 {
 188         enum mc_cmd_status status;
 189         unsigned long jiffies_until_timeout =
 190                 jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);
 191
 192         /*
 193          * Wait for response from the MC hardware:
 194          */
 195         for (;;) {
 196                 status = mc_read_response(mc_io->portal_virt_addr, cmd);
 197                 if (status != MC_CMD_STATUS_READY)
 198                         break;
 199
 200                 /*
 201                  * TODO: When MC command completion interrupts are supported
 202                  * call wait function here instead of usleep_range()
 203                  */
 204                 usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
 205                              MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 206
 207                 if (time_after_eq(jiffies, jiffies_until_timeout)) {
 208                         dev_dbg(mc_io->dev,
 209                                 "MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
 210                                  &mc_io->portal_phys_addr,
 211                                  (unsigned int)mc_cmd_hdr_read_token(cmd),
 212                                  (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
 213
 214                         return -ETIMEDOUT;
 215                 }
 216         }
 217
 218         *mc_status = status;
 219         return 0;
 220 }
 221
 222 /**
 223  * Waits for the completion of an MC command doing atomic polling.
 224  * udelay() is called between polling iterations.
 225  *
 226  * @mc_io: MC I/O object to be used
 227  * @cmd: command buffer to receive MC response
 228  * @mc_status: MC command completion status
 229  */
 230 static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
 231                                   struct mc_command *cmd,
 232                                   enum mc_cmd_status *mc_status)
 233 {
 234         enum mc_cmd_status status;
 235         unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
 236
 237         BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
 238                      MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);
 239
 240         for (;;) {
 241                 status = mc_read_response(mc_io->portal_virt_addr, cmd);
 242                 if (status != MC_CMD_STATUS_READY)
 243                         break;
 244
 245                 udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 246                 timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
 247                 if (timeout_usecs == 0) {
 248                         dev_dbg(mc_io->dev,
 249                                 "MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
 250                                  &mc_io->portal_phys_addr,
 251                                  (unsigned int)mc_cmd_hdr_read_token(cmd),
 252                                  (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
 253
 254                         return -ETIMEDOUT;
 255                 }
 256         }
 257
 258         *mc_status = status;
 259         return 0;
 260 }
 261
 262 /**
 263  * Sends a command to the MC device using the given MC I/O object
 264  *
 265  * @mc_io: MC I/O object to be used
 266  * @cmd: command to be sent
 267  *
 268  * Returns '0' on Success; Error code otherwise.
 269  */
 270 int mc_send_command(struct fsl_mc_io *mc_io, struct mc_command *cmd)
 271 {
 272         int error;
 273         enum mc_cmd_status status;
 274         unsigned long irq_flags = 0;
 275
 276         if (WARN_ON(in_irq() &&
 277                     !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)))
 278                 return -EINVAL;
 279
 280         if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
 281                 spin_lock_irqsave(&mc_io->spinlock, irq_flags);
 282         else
 283                 mutex_lock(&mc_io->mutex);
 284
 285         /*
 286          * Send command to the MC hardware:
 287          */
 288         mc_write_command(mc_io->portal_virt_addr, cmd);
 289
 290         /*
 291          * Wait for response from the MC hardware:
 292          */
 293         if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
 294                 error = mc_polling_wait_preemptible(mc_io, cmd, &status);
 295         else
 296                 error = mc_polling_wait_atomic(mc_io, cmd, &status);
 297
 298         if (error < 0)
 299                 goto common_exit;
 300
 301         if (status != MC_CMD_STATUS_OK) {
 302                 dev_dbg(mc_io->dev,
 303                         "MC command failed: portal: %pa, dprc handle: %#x, command: %#x, status: %s (%#x)\n",
 304                          &mc_io->portal_phys_addr,
 305                          (unsigned int)mc_cmd_hdr_read_token(cmd),
 306                          (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
 307                          mc_status_to_string(status),
 308                          (unsigned int)status);
 309
 310                 error = mc_status_to_error(status);
 311                 goto common_exit;
 312         }
 313
 314         error = 0;
 315 common_exit:
 316         if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
 317                 spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
 318         else
 319                 mutex_unlock(&mc_io->mutex);
 320
 321         return error;
 322 }
 323 EXPORT_SYMBOL(mc_send_command);