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

   1 /* Copyright 2013-2014 Freescale Semiconductor Inc.
   2  *
   3  * I/O services to send MC commands to the MC hardware
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *     * Redistributions of source code must retain the above copyright
   8  *       notice, this list of conditions and the following disclaimer.
   9  *     * Redistributions in binary form must reproduce the above copyright
  10  *       notice, this list of conditions and the following disclaimer in the
  11  *       documentation and/or other materials provided with the distribution.
  12  *     * Neither the name of the above-listed copyright holders nor the
  13  *       names of any contributors may be used to endorse or promote products
  14  *       derived from this software without specific prior written permission.
  15  *
  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-sys.h"
  41 #include "../include/mc-cmd.h"
  42 #include "../include/mc.h"
  43
  44 #include "dpmcp.h"
  45
  46 /**
  47  * Timeout in milliseconds to wait for the completion of an MC command
  48  */
  49 #define MC_CMD_COMPLETION_TIMEOUT_MS    500
  50
  51 /*
  52  * usleep_range() min and max values used to throttle down polling
  53  * iterations while waiting for MC command completion
  54  */
  55 #define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
  56 #define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
  57
  58 static enum mc_cmd_status mc_cmd_hdr_read_status(struct mc_command *cmd)
  59 {
  60         struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
  61
  62         return (enum mc_cmd_status)hdr->status;
  63 }
  64
  65 static u16 mc_cmd_hdr_read_cmdid(struct mc_command *cmd)
  66 {
  67         struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
  68         u16 cmd_id = le16_to_cpu(hdr->cmd_id);
  69
  70         return (cmd_id & MC_CMD_HDR_CMDID_MASK) >> MC_CMD_HDR_CMDID_SHIFT;
  71 }
  72
  73 static int mc_status_to_error(enum mc_cmd_status status)
  74 {
  75         static const int mc_status_to_error_map[] = {
  76                 [MC_CMD_STATUS_OK] = 0,
  77                 [MC_CMD_STATUS_AUTH_ERR] = -EACCES,
  78                 [MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
  79                 [MC_CMD_STATUS_DMA_ERR] = -EIO,
  80                 [MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
  81                 [MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
  82                 [MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
  83                 [MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
  84                 [MC_CMD_STATUS_BUSY] = -EBUSY,
  85                 [MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
  86                 [MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
  87         };
  88
  89         if (WARN_ON((u32)status >= ARRAY_SIZE(mc_status_to_error_map)))
  90                 return -EINVAL;
  91
  92         return mc_status_to_error_map[status];
  93 }
  94
  95 static const char *mc_status_to_string(enum mc_cmd_status status)
  96 {
  97         static const char *const status_strings[] = {
  98                 [MC_CMD_STATUS_OK] = "Command completed successfully",
  99                 [MC_CMD_STATUS_READY] = "Command ready to be processed",
 100                 [MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
 101                 [MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
 102                 [MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
 103                 [MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
 104                 [MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
 105                 [MC_CMD_STATUS_NO_RESOURCE] = "No resources",
 106                 [MC_CMD_STATUS_NO_MEMORY] = "No memory available",
 107                 [MC_CMD_STATUS_BUSY] = "Device is busy",
 108                 [MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
 109                 [MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
 110         };
 111
 112         if ((unsigned int)status >= ARRAY_SIZE(status_strings))
 113                 return "Unknown MC error";
 114
 115         return status_strings[status];
 116 }
 117
 118 /**
 119  * mc_write_command - writes a command to a Management Complex (MC) portal
 120  *
 121  * @portal: pointer to an MC portal
 122  * @cmd: pointer to a filled command
 123  */
 124 static inline void mc_write_command(struct mc_command __iomem *portal,
 125                                     struct mc_command *cmd)
 126 {
 127         int i;
 128
 129         /* copy command parameters into the portal */
 130         for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
 131                 __raw_writeq(cmd->params[i], &portal->params[i]);
 132         __iowmb();
 133
 134         /* submit the command by writing the header */
 135         __raw_writeq(cmd->header, &portal->header);
 136 }
 137
 138 /**
 139  * mc_read_response - reads the response for the last MC command from a
 140  * Management Complex (MC) portal
 141  *
 142  * @portal: pointer to an MC portal
 143  * @resp: pointer to command response buffer
 144  *
 145  * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
 146  */
 147 static inline enum mc_cmd_status mc_read_response(struct mc_command __iomem *
 148                                                   portal,
 149                                                   struct mc_command *resp)
 150 {
 151         int i;
 152         enum mc_cmd_status status;
 153
 154         /* Copy command response header from MC portal: */
 155         __iormb();
 156         resp->header = __raw_readq(&portal->header);
 157         __iormb();
 158         status = mc_cmd_hdr_read_status(resp);
 159         if (status != MC_CMD_STATUS_OK)
 160                 return status;
 161
 162         /* Copy command response data from MC portal: */
 163         for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
 164                 resp->params[i] = __raw_readq(&portal->params[i]);
 165         __iormb();
 166
 167         return status;
 168 }
 169
 170 /**
 171  * Waits for the completion of an MC command doing preemptible polling.
 172  * uslepp_range() is called between polling iterations.
 173  *
 174  * @mc_io: MC I/O object to be used
 175  * @cmd: command buffer to receive MC response
 176  * @mc_status: MC command completion status
 177  */
 178 static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
 179                                        struct mc_command *cmd,
 180                                        enum mc_cmd_status *mc_status)
 181 {
 182         enum mc_cmd_status status;
 183         unsigned long jiffies_until_timeout =
 184                 jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);
 185
 186         /*
 187          * Wait for response from the MC hardware:
 188          */
 189         for (;;) {
 190                 status = mc_read_response(mc_io->portal_virt_addr, cmd);
 191                 if (status != MC_CMD_STATUS_READY)
 192                         break;
 193
 194                 /*
 195                  * TODO: When MC command completion interrupts are supported
 196                  * call wait function here instead of usleep_range()
 197                  */
 198                 usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
 199                              MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 200
 201                 if (time_after_eq(jiffies, jiffies_until_timeout)) {
 202                         dev_dbg(mc_io->dev,
 203                                 "MC command timed out (portal: %#llx, obj handle: %#x, command: %#x)\n",
 204                                  mc_io->portal_phys_addr,
 205                                  (unsigned int)mc_cmd_hdr_read_token(cmd),
 206                                  (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
 207
 208                         return -ETIMEDOUT;
 209                 }
 210         }
 211
 212         *mc_status = status;
 213         return 0;
 214 }
 215
 216 /**
 217  * Waits for the completion of an MC command doing atomic polling.
 218  * udelay() is called between polling iterations.
 219  *
 220  * @mc_io: MC I/O object to be used
 221  * @cmd: command buffer to receive MC response
 222  * @mc_status: MC command completion status
 223  */
 224 static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
 225                                   struct mc_command *cmd,
 226                                   enum mc_cmd_status *mc_status)
 227 {
 228         enum mc_cmd_status status;
 229         unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
 230
 231         BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
 232                      MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);
 233
 234         for (;;) {
 235                 status = mc_read_response(mc_io->portal_virt_addr, cmd);
 236                 if (status != MC_CMD_STATUS_READY)
 237                         break;
 238
 239                 udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 240                 timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
 241                 if (timeout_usecs == 0) {
 242                         dev_dbg(mc_io->dev,
 243                                 "MC command timed out (portal: %#llx, obj handle: %#x, command: %#x)\n",
 244                                  mc_io->portal_phys_addr,
 245                                  (unsigned int)mc_cmd_hdr_read_token(cmd),
 246                                  (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
 247
 248                         return -ETIMEDOUT;
 249                 }
 250         }
 251
 252         *mc_status = status;
 253         return 0;
 254 }
 255
 256 /**
 257  * Sends a command to the MC device using the given MC I/O object
 258  *
 259  * @mc_io: MC I/O object to be used
 260  * @cmd: command to be sent
 261  *
 262  * Returns '0' on Success; Error code otherwise.
 263  */
 264 int mc_send_command(struct fsl_mc_io *mc_io, struct mc_command *cmd)
 265 {
 266         int error;
 267         enum mc_cmd_status status;
 268         unsigned long irq_flags = 0;
 269
 270         if (WARN_ON(in_irq() &&
 271                     !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)))
 272                 return -EINVAL;
 273
 274         if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
 275                 spin_lock_irqsave(&mc_io->spinlock, irq_flags);
 276         else
 277                 mutex_lock(&mc_io->mutex);
 278
 279         /*
 280          * Send command to the MC hardware:
 281          */
 282         mc_write_command(mc_io->portal_virt_addr, cmd);
 283
 284         /*
 285          * Wait for response from the MC hardware:
 286          */
 287         if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
 288                 error = mc_polling_wait_preemptible(mc_io, cmd, &status);
 289         else
 290                 error = mc_polling_wait_atomic(mc_io, cmd, &status);
 291
 292         if (error < 0)
 293                 goto common_exit;
 294
 295         if (status != MC_CMD_STATUS_OK) {
 296                 dev_dbg(mc_io->dev,
 297                         "MC command failed: portal: %#llx, obj handle: %#x, command: %#x, status: %s (%#x)\n",
 298                          mc_io->portal_phys_addr,
 299                          (unsigned int)mc_cmd_hdr_read_token(cmd),
 300                          (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
 301                          mc_status_to_string(status),
 302                          (unsigned int)status);
 303
 304                 error = mc_status_to_error(status);
 305                 goto common_exit;
 306         }
 307
 308         error = 0;
 309 common_exit:
 310         if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
 311                 spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
 312         else
 313                 mutex_unlock(&mc_io->mutex);
 314
 315         return error;
 316 }
 317 EXPORT_SYMBOL(mc_send_command);