LXR linux/drivers/bus/fsl-mc/mc-sys.c

   1// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
   2/*
   3 * Copyright 2013-2016 Freescale Semiconductor Inc.
   4 *
   5 * I/O services to send MC commands to the MC hardware
   6 *
   7 */
   8
   9#include <linux/delay.h>
  10#include <linux/slab.h>
  11#include <linux/ioport.h>
  12#include <linux/device.h>
  13#include <linux/io.h>
  14#include <linux/io-64-nonatomic-hi-lo.h>
  15#include <linux/fsl/mc.h>
  16
  17#include "fsl-mc-private.h"
  18
  19/*
  20 * Timeout in milliseconds to wait for the completion of an MC command
  21 */
  22#define MC_CMD_COMPLETION_TIMEOUT_MS    500
  23
  24/*
  25 * usleep_range() min and max values used to throttle down polling
  26 * iterations while waiting for MC command completion
  27 */
  28#define MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS    10
  29#define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
  30
  31static enum mc_cmd_status mc_cmd_hdr_read_status(struct fsl_mc_command *cmd)
  32{
  33        struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
  34
  35        return (enum mc_cmd_status)hdr->status;
  36}
  37
  38u16 mc_cmd_hdr_read_cmdid(struct fsl_mc_command *cmd)
  39{
  40        struct mc_cmd_header *hdr = (struct mc_cmd_header *)&cmd->header;
  41        u16 cmd_id = le16_to_cpu(hdr->cmd_id);
  42
  43        return cmd_id;
  44}
  45
  46static int mc_status_to_error(enum mc_cmd_status status)
  47{
  48        static const int mc_status_to_error_map[] = {
  49                [MC_CMD_STATUS_OK] = 0,
  50                [MC_CMD_STATUS_AUTH_ERR] = -EACCES,
  51                [MC_CMD_STATUS_NO_PRIVILEGE] = -EPERM,
  52                [MC_CMD_STATUS_DMA_ERR] = -EIO,
  53                [MC_CMD_STATUS_CONFIG_ERR] = -ENXIO,
  54                [MC_CMD_STATUS_TIMEOUT] = -ETIMEDOUT,
  55                [MC_CMD_STATUS_NO_RESOURCE] = -ENAVAIL,
  56                [MC_CMD_STATUS_NO_MEMORY] = -ENOMEM,
  57                [MC_CMD_STATUS_BUSY] = -EBUSY,
  58                [MC_CMD_STATUS_UNSUPPORTED_OP] = -ENOTSUPP,
  59                [MC_CMD_STATUS_INVALID_STATE] = -ENODEV,
  60        };
  61
  62        if ((u32)status >= ARRAY_SIZE(mc_status_to_error_map))
  63                return -EINVAL;
  64
  65        return mc_status_to_error_map[status];
  66}
  67
  68static const char *mc_status_to_string(enum mc_cmd_status status)
  69{
  70        static const char *const status_strings[] = {
  71                [MC_CMD_STATUS_OK] = "Command completed successfully",
  72                [MC_CMD_STATUS_READY] = "Command ready to be processed",
  73                [MC_CMD_STATUS_AUTH_ERR] = "Authentication error",
  74                [MC_CMD_STATUS_NO_PRIVILEGE] = "No privilege",
  75                [MC_CMD_STATUS_DMA_ERR] = "DMA or I/O error",
  76                [MC_CMD_STATUS_CONFIG_ERR] = "Configuration error",
  77                [MC_CMD_STATUS_TIMEOUT] = "Operation timed out",
  78                [MC_CMD_STATUS_NO_RESOURCE] = "No resources",
  79                [MC_CMD_STATUS_NO_MEMORY] = "No memory available",
  80                [MC_CMD_STATUS_BUSY] = "Device is busy",
  81                [MC_CMD_STATUS_UNSUPPORTED_OP] = "Unsupported operation",
  82                [MC_CMD_STATUS_INVALID_STATE] = "Invalid state"
  83        };
  84
  85        if ((unsigned int)status >= ARRAY_SIZE(status_strings))
  86                return "Unknown MC error";
  87
  88        return status_strings[status];
  89}
  90
  91/**
  92 * mc_write_command - writes a command to a Management Complex (MC) portal
  93 *
  94 * @portal: pointer to an MC portal
  95 * @cmd: pointer to a filled command
  96 */
  97static inline void mc_write_command(struct fsl_mc_command __iomem *portal,
  98                                    struct fsl_mc_command *cmd)
  99{
 100        int i;
 101
 102        /* copy command parameters into the portal */
 103        for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
 104                /*
 105                 * Data is already in the expected LE byte-order. Do an
 106                 * extra LE -> CPU conversion so that the CPU -> LE done in
 107                 * the device io write api puts it back in the right order.
 108                 */
 109                writeq_relaxed(le64_to_cpu(cmd->params[i]), &portal->params[i]);
 110
 111        /* submit the command by writing the header */
 112        writeq(le64_to_cpu(cmd->header), &portal->header);
 113}
 114
 115/**
 116 * mc_read_response - reads the response for the last MC command from a
 117 * Management Complex (MC) portal
 118 *
 119 * @portal: pointer to an MC portal
 120 * @resp: pointer to command response buffer
 121 *
 122 * Returns MC_CMD_STATUS_OK on Success; Error code otherwise.
 123 */
 124static inline enum mc_cmd_status mc_read_response(struct fsl_mc_command __iomem
 125                                                  *portal,
 126                                                  struct fsl_mc_command *resp)
 127{
 128        int i;
 129        enum mc_cmd_status status;
 130
 131        /* Copy command response header from MC portal: */
 132        resp->header = cpu_to_le64(readq_relaxed(&portal->header));
 133        status = mc_cmd_hdr_read_status(resp);
 134        if (status != MC_CMD_STATUS_OK)
 135                return status;
 136
 137        /* Copy command response data from MC portal: */
 138        for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)
 139                /*
 140                 * Data is expected to be in LE byte-order. Do an
 141                 * extra CPU -> LE to revert the LE -> CPU done in
 142                 * the device io read api.
 143                 */
 144                resp->params[i] =
 145                        cpu_to_le64(readq_relaxed(&portal->params[i]));
 146
 147        return status;
 148}
 149
 150/**
 151 * mc_polling_wait_preemptible() - Waits for the completion of an MC
 152 *                                 command doing preemptible polling.
 153 *                                 uslepp_range() is called between
 154 *                                 polling iterations.
 155 * @mc_io: MC I/O object to be used
 156 * @cmd: command buffer to receive MC response
 157 * @mc_status: MC command completion status
 158 */
 159static int mc_polling_wait_preemptible(struct fsl_mc_io *mc_io,
 160                                       struct fsl_mc_command *cmd,
 161                                       enum mc_cmd_status *mc_status)
 162{
 163        enum mc_cmd_status status;
 164        unsigned long jiffies_until_timeout =
 165                jiffies + msecs_to_jiffies(MC_CMD_COMPLETION_TIMEOUT_MS);
 166
 167        /*
 168         * Wait for response from the MC hardware:
 169         */
 170        for (;;) {
 171                status = mc_read_response(mc_io->portal_virt_addr, cmd);
 172                if (status != MC_CMD_STATUS_READY)
 173                        break;
 174
 175                /*
 176                 * TODO: When MC command completion interrupts are supported
 177                 * call wait function here instead of usleep_range()
 178                 */
 179                usleep_range(MC_CMD_COMPLETION_POLLING_MIN_SLEEP_USECS,
 180                             MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 181
 182                if (time_after_eq(jiffies, jiffies_until_timeout)) {
 183                        dev_dbg(mc_io->dev,
 184                                "MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
 185                                 &mc_io->portal_phys_addr,
 186                                 (unsigned int)mc_cmd_hdr_read_token(cmd),
 187                                 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
 188
 189                        return -ETIMEDOUT;
 190                }
 191        }
 192
 193        *mc_status = status;
 194        return 0;
 195}
 196
 197/**
 198 * mc_polling_wait_atomic() - Waits for the completion of an MC command
 199 *                            doing atomic polling. udelay() is called
 200 *                            between polling iterations.
 201 * @mc_io: MC I/O object to be used
 202 * @cmd: command buffer to receive MC response
 203 * @mc_status: MC command completion status
 204 */
 205static int mc_polling_wait_atomic(struct fsl_mc_io *mc_io,
 206                                  struct fsl_mc_command *cmd,
 207                                  enum mc_cmd_status *mc_status)
 208{
 209        enum mc_cmd_status status;
 210        unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
 211
 212        BUILD_BUG_ON((MC_CMD_COMPLETION_TIMEOUT_MS * 1000) %
 213                     MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS != 0);
 214
 215        for (;;) {
 216                status = mc_read_response(mc_io->portal_virt_addr, cmd);
 217                if (status != MC_CMD_STATUS_READY)
 218                        break;
 219
 220                udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 221                timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
 222                if (timeout_usecs == 0) {
 223                        dev_dbg(mc_io->dev,
 224                                "MC command timed out (portal: %pa, dprc handle: %#x, command: %#x)\n",
 225                                 &mc_io->portal_phys_addr,
 226                                 (unsigned int)mc_cmd_hdr_read_token(cmd),
 227                                 (unsigned int)mc_cmd_hdr_read_cmdid(cmd));
 228
 229                        return -ETIMEDOUT;
 230                }
 231        }
 232
 233        *mc_status = status;
 234        return 0;
 235}
 236
 237/**
 238 * mc_send_command() - Sends a command to the MC device using the given
 239 *                     MC I/O object
 240 * @mc_io: MC I/O object to be used
 241 * @cmd: command to be sent
 242 *
 243 * Returns '0' on Success; Error code otherwise.
 244 */
 245int mc_send_command(struct fsl_mc_io *mc_io, struct fsl_mc_command *cmd)
 246{
 247        int error;
 248        enum mc_cmd_status status;
 249        unsigned long irq_flags = 0;
 250
 251        if (in_irq() && !(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
 252                return -EINVAL;
 253
 254        if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
 255                raw_spin_lock_irqsave(&mc_io->spinlock, irq_flags);
 256        else
 257                mutex_lock(&mc_io->mutex);
 258
 259        /*
 260         * Send command to the MC hardware:
 261         */
 262        mc_write_command(mc_io->portal_virt_addr, cmd);
 263
 264        /*
 265         * Wait for response from the MC hardware:
 266         */
 267        if (!(mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL))
 268                error = mc_polling_wait_preemptible(mc_io, cmd, &status);
 269        else
 270                error = mc_polling_wait_atomic(mc_io, cmd, &status);
 271
 272        if (error < 0)
 273                goto common_exit;
 274
 275        if (status != MC_CMD_STATUS_OK) {
 276                dev_dbg(mc_io->dev,
 277                        "MC command failed: portal: %pa, dprc handle: %#x, command: %#x, status: %s (%#x)\n",
 278                         &mc_io->portal_phys_addr,
 279                         (unsigned int)mc_cmd_hdr_read_token(cmd),
 280                         (unsigned int)mc_cmd_hdr_read_cmdid(cmd),
 281                         mc_status_to_string(status),
 282                         (unsigned int)status);
 283
 284                error = mc_status_to_error(status);
 285                goto common_exit;
 286        }
 287
 288        error = 0;
 289common_exit:
 290        if (mc_io->flags & FSL_MC_IO_ATOMIC_CONTEXT_PORTAL)
 291                raw_spin_unlock_irqrestore(&mc_io->spinlock, irq_flags);
 292        else
 293                mutex_unlock(&mc_io->mutex);
 294
 295        return error;
 296}
 297EXPORT_SYMBOL_GPL(mc_send_command);
 298