| 1 | /* |
| 2 | * |
| 3 | * Intel Management Engine Interface (Intel MEI) Linux driver |
| 4 | * Copyright (c) 2003-2012, Intel Corporation. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms and conditions of the GNU General Public License, |
| 8 | * version 2, as published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope it will be useful, but WITHOUT |
| 11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 13 | * more details. |
| 14 | * |
| 15 | */ |
| 16 | |
| 17 | #include <linux/export.h> |
| 18 | #include <linux/sched.h> |
| 19 | #include <linux/wait.h> |
| 20 | #include <linux/delay.h> |
| 21 | |
| 22 | #include <linux/mei.h> |
| 23 | |
| 24 | #include "mei_dev.h" |
| 25 | #include "hbm.h" |
| 26 | #include "client.h" |
| 27 | |
| 28 | const char *mei_dev_state_str(int state) |
| 29 | { |
| 30 | #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state |
| 31 | switch (state) { |
| 32 | MEI_DEV_STATE(INITIALIZING); |
| 33 | MEI_DEV_STATE(INIT_CLIENTS); |
| 34 | MEI_DEV_STATE(ENABLED); |
| 35 | MEI_DEV_STATE(RESETTING); |
| 36 | MEI_DEV_STATE(DISABLED); |
| 37 | MEI_DEV_STATE(POWER_DOWN); |
| 38 | MEI_DEV_STATE(POWER_UP); |
| 39 | default: |
| 40 | return "unknown"; |
| 41 | } |
| 42 | #undef MEI_DEV_STATE |
| 43 | } |
| 44 | |
| 45 | const char *mei_pg_state_str(enum mei_pg_state state) |
| 46 | { |
| 47 | #define MEI_PG_STATE(state) case MEI_PG_##state: return #state |
| 48 | switch (state) { |
| 49 | MEI_PG_STATE(OFF); |
| 50 | MEI_PG_STATE(ON); |
| 51 | default: |
| 52 | return "unknown"; |
| 53 | } |
| 54 | #undef MEI_PG_STATE |
| 55 | } |
| 56 | |
| 57 | /** |
| 58 | * mei_fw_status2str - convert fw status registers to printable string |
| 59 | * |
| 60 | * @fw_status: firmware status |
| 61 | * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ |
| 62 | * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ |
| 63 | * |
| 64 | * Return: number of bytes written or -EINVAL if buffer is to small |
| 65 | */ |
| 66 | ssize_t mei_fw_status2str(struct mei_fw_status *fw_status, |
| 67 | char *buf, size_t len) |
| 68 | { |
| 69 | ssize_t cnt = 0; |
| 70 | int i; |
| 71 | |
| 72 | buf[0] = '\0'; |
| 73 | |
| 74 | if (len < MEI_FW_STATUS_STR_SZ) |
| 75 | return -EINVAL; |
| 76 | |
| 77 | for (i = 0; i < fw_status->count; i++) |
| 78 | cnt += scnprintf(buf + cnt, len - cnt, "%08X ", |
| 79 | fw_status->status[i]); |
| 80 | |
| 81 | /* drop last space */ |
| 82 | buf[cnt] = '\0'; |
| 83 | return cnt; |
| 84 | } |
| 85 | EXPORT_SYMBOL_GPL(mei_fw_status2str); |
| 86 | |
| 87 | /** |
| 88 | * mei_cancel_work - Cancel mei background jobs |
| 89 | * |
| 90 | * @dev: the device structure |
| 91 | */ |
| 92 | void mei_cancel_work(struct mei_device *dev) |
| 93 | { |
| 94 | cancel_work_sync(&dev->init_work); |
| 95 | cancel_work_sync(&dev->reset_work); |
| 96 | |
| 97 | cancel_delayed_work(&dev->timer_work); |
| 98 | } |
| 99 | EXPORT_SYMBOL_GPL(mei_cancel_work); |
| 100 | |
| 101 | /** |
| 102 | * mei_reset - resets host and fw. |
| 103 | * |
| 104 | * @dev: the device structure |
| 105 | * |
| 106 | * Return: 0 on success or < 0 if the reset hasn't succeeded |
| 107 | */ |
| 108 | int mei_reset(struct mei_device *dev) |
| 109 | { |
| 110 | enum mei_dev_state state = dev->dev_state; |
| 111 | bool interrupts_enabled; |
| 112 | int ret; |
| 113 | |
| 114 | if (state != MEI_DEV_INITIALIZING && |
| 115 | state != MEI_DEV_DISABLED && |
| 116 | state != MEI_DEV_POWER_DOWN && |
| 117 | state != MEI_DEV_POWER_UP) { |
| 118 | char fw_sts_str[MEI_FW_STATUS_STR_SZ]; |
| 119 | |
| 120 | mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ); |
| 121 | dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n", |
| 122 | mei_dev_state_str(state), fw_sts_str); |
| 123 | } |
| 124 | |
| 125 | /* we're already in reset, cancel the init timer |
| 126 | * if the reset was called due the hbm protocol error |
| 127 | * we need to call it before hw start |
| 128 | * so the hbm watchdog won't kick in |
| 129 | */ |
| 130 | mei_hbm_idle(dev); |
| 131 | |
| 132 | /* enter reset flow */ |
| 133 | interrupts_enabled = state != MEI_DEV_POWER_DOWN; |
| 134 | dev->dev_state = MEI_DEV_RESETTING; |
| 135 | |
| 136 | dev->reset_count++; |
| 137 | if (dev->reset_count > MEI_MAX_CONSEC_RESET) { |
| 138 | dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n"); |
| 139 | dev->dev_state = MEI_DEV_DISABLED; |
| 140 | return -ENODEV; |
| 141 | } |
| 142 | |
| 143 | ret = mei_hw_reset(dev, interrupts_enabled); |
| 144 | /* fall through and remove the sw state even if hw reset has failed */ |
| 145 | |
| 146 | /* no need to clean up software state in case of power up */ |
| 147 | if (state != MEI_DEV_INITIALIZING && |
| 148 | state != MEI_DEV_POWER_UP) { |
| 149 | |
| 150 | /* remove all waiting requests */ |
| 151 | mei_cl_all_write_clear(dev); |
| 152 | |
| 153 | mei_cl_all_disconnect(dev); |
| 154 | |
| 155 | /* wake up all readers and writers so they can be interrupted */ |
| 156 | mei_cl_all_wakeup(dev); |
| 157 | |
| 158 | /* remove entry if already in list */ |
| 159 | dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n"); |
| 160 | mei_cl_unlink(&dev->wd_cl); |
| 161 | mei_cl_unlink(&dev->iamthif_cl); |
| 162 | mei_amthif_reset_params(dev); |
| 163 | } |
| 164 | |
| 165 | mei_hbm_reset(dev); |
| 166 | |
| 167 | dev->rd_msg_hdr = 0; |
| 168 | dev->wd_pending = false; |
| 169 | |
| 170 | if (ret) { |
| 171 | dev_err(dev->dev, "hw_reset failed ret = %d\n", ret); |
| 172 | return ret; |
| 173 | } |
| 174 | |
| 175 | if (state == MEI_DEV_POWER_DOWN) { |
| 176 | dev_dbg(dev->dev, "powering down: end of reset\n"); |
| 177 | dev->dev_state = MEI_DEV_DISABLED; |
| 178 | return 0; |
| 179 | } |
| 180 | |
| 181 | ret = mei_hw_start(dev); |
| 182 | if (ret) { |
| 183 | dev_err(dev->dev, "hw_start failed ret = %d\n", ret); |
| 184 | return ret; |
| 185 | } |
| 186 | |
| 187 | dev_dbg(dev->dev, "link is established start sending messages.\n"); |
| 188 | |
| 189 | dev->dev_state = MEI_DEV_INIT_CLIENTS; |
| 190 | ret = mei_hbm_start_req(dev); |
| 191 | if (ret) { |
| 192 | dev_err(dev->dev, "hbm_start failed ret = %d\n", ret); |
| 193 | dev->dev_state = MEI_DEV_RESETTING; |
| 194 | return ret; |
| 195 | } |
| 196 | |
| 197 | return 0; |
| 198 | } |
| 199 | EXPORT_SYMBOL_GPL(mei_reset); |
| 200 | |
| 201 | /** |
| 202 | * mei_start - initializes host and fw to start work. |
| 203 | * |
| 204 | * @dev: the device structure |
| 205 | * |
| 206 | * Return: 0 on success, <0 on failure. |
| 207 | */ |
| 208 | int mei_start(struct mei_device *dev) |
| 209 | { |
| 210 | int ret; |
| 211 | |
| 212 | mutex_lock(&dev->device_lock); |
| 213 | |
| 214 | /* acknowledge interrupt and stop interrupts */ |
| 215 | mei_clear_interrupts(dev); |
| 216 | |
| 217 | mei_hw_config(dev); |
| 218 | |
| 219 | dev_dbg(dev->dev, "reset in start the mei device.\n"); |
| 220 | |
| 221 | dev->reset_count = 0; |
| 222 | do { |
| 223 | dev->dev_state = MEI_DEV_INITIALIZING; |
| 224 | ret = mei_reset(dev); |
| 225 | |
| 226 | if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { |
| 227 | dev_err(dev->dev, "reset failed ret = %d", ret); |
| 228 | goto err; |
| 229 | } |
| 230 | } while (ret); |
| 231 | |
| 232 | /* we cannot start the device w/o hbm start message completed */ |
| 233 | if (dev->dev_state == MEI_DEV_DISABLED) { |
| 234 | dev_err(dev->dev, "reset failed"); |
| 235 | goto err; |
| 236 | } |
| 237 | |
| 238 | if (mei_hbm_start_wait(dev)) { |
| 239 | dev_err(dev->dev, "HBM haven't started"); |
| 240 | goto err; |
| 241 | } |
| 242 | |
| 243 | if (!mei_host_is_ready(dev)) { |
| 244 | dev_err(dev->dev, "host is not ready.\n"); |
| 245 | goto err; |
| 246 | } |
| 247 | |
| 248 | if (!mei_hw_is_ready(dev)) { |
| 249 | dev_err(dev->dev, "ME is not ready.\n"); |
| 250 | goto err; |
| 251 | } |
| 252 | |
| 253 | if (!mei_hbm_version_is_supported(dev)) { |
| 254 | dev_dbg(dev->dev, "MEI start failed.\n"); |
| 255 | goto err; |
| 256 | } |
| 257 | |
| 258 | dev_dbg(dev->dev, "link layer has been established.\n"); |
| 259 | |
| 260 | mutex_unlock(&dev->device_lock); |
| 261 | return 0; |
| 262 | err: |
| 263 | dev_err(dev->dev, "link layer initialization failed.\n"); |
| 264 | dev->dev_state = MEI_DEV_DISABLED; |
| 265 | mutex_unlock(&dev->device_lock); |
| 266 | return -ENODEV; |
| 267 | } |
| 268 | EXPORT_SYMBOL_GPL(mei_start); |
| 269 | |
| 270 | /** |
| 271 | * mei_restart - restart device after suspend |
| 272 | * |
| 273 | * @dev: the device structure |
| 274 | * |
| 275 | * Return: 0 on success or -ENODEV if the restart hasn't succeeded |
| 276 | */ |
| 277 | int mei_restart(struct mei_device *dev) |
| 278 | { |
| 279 | int err; |
| 280 | |
| 281 | mutex_lock(&dev->device_lock); |
| 282 | |
| 283 | mei_clear_interrupts(dev); |
| 284 | |
| 285 | dev->dev_state = MEI_DEV_POWER_UP; |
| 286 | dev->reset_count = 0; |
| 287 | |
| 288 | err = mei_reset(dev); |
| 289 | |
| 290 | mutex_unlock(&dev->device_lock); |
| 291 | |
| 292 | if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { |
| 293 | dev_err(dev->dev, "device disabled = %d\n", err); |
| 294 | return -ENODEV; |
| 295 | } |
| 296 | |
| 297 | /* try to start again */ |
| 298 | if (err) |
| 299 | schedule_work(&dev->reset_work); |
| 300 | |
| 301 | |
| 302 | return 0; |
| 303 | } |
| 304 | EXPORT_SYMBOL_GPL(mei_restart); |
| 305 | |
| 306 | static void mei_reset_work(struct work_struct *work) |
| 307 | { |
| 308 | struct mei_device *dev = |
| 309 | container_of(work, struct mei_device, reset_work); |
| 310 | int ret; |
| 311 | |
| 312 | mutex_lock(&dev->device_lock); |
| 313 | |
| 314 | ret = mei_reset(dev); |
| 315 | |
| 316 | mutex_unlock(&dev->device_lock); |
| 317 | |
| 318 | if (dev->dev_state == MEI_DEV_DISABLED) { |
| 319 | dev_err(dev->dev, "device disabled = %d\n", ret); |
| 320 | return; |
| 321 | } |
| 322 | |
| 323 | /* retry reset in case of failure */ |
| 324 | if (ret) |
| 325 | schedule_work(&dev->reset_work); |
| 326 | } |
| 327 | |
| 328 | void mei_stop(struct mei_device *dev) |
| 329 | { |
| 330 | dev_dbg(dev->dev, "stopping the device.\n"); |
| 331 | |
| 332 | mei_cancel_work(dev); |
| 333 | |
| 334 | mei_nfc_host_exit(dev); |
| 335 | |
| 336 | mei_cl_bus_remove_devices(dev); |
| 337 | |
| 338 | mutex_lock(&dev->device_lock); |
| 339 | |
| 340 | mei_wd_stop(dev); |
| 341 | |
| 342 | dev->dev_state = MEI_DEV_POWER_DOWN; |
| 343 | mei_reset(dev); |
| 344 | /* move device to disabled state unconditionally */ |
| 345 | dev->dev_state = MEI_DEV_DISABLED; |
| 346 | |
| 347 | mutex_unlock(&dev->device_lock); |
| 348 | |
| 349 | mei_watchdog_unregister(dev); |
| 350 | } |
| 351 | EXPORT_SYMBOL_GPL(mei_stop); |
| 352 | |
| 353 | /** |
| 354 | * mei_write_is_idle - check if the write queues are idle |
| 355 | * |
| 356 | * @dev: the device structure |
| 357 | * |
| 358 | * Return: true of there is no pending write |
| 359 | */ |
| 360 | bool mei_write_is_idle(struct mei_device *dev) |
| 361 | { |
| 362 | bool idle = (dev->dev_state == MEI_DEV_ENABLED && |
| 363 | list_empty(&dev->ctrl_wr_list.list) && |
| 364 | list_empty(&dev->write_list.list)); |
| 365 | |
| 366 | dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%d write=%d\n", |
| 367 | idle, |
| 368 | mei_dev_state_str(dev->dev_state), |
| 369 | list_empty(&dev->ctrl_wr_list.list), |
| 370 | list_empty(&dev->write_list.list)); |
| 371 | |
| 372 | return idle; |
| 373 | } |
| 374 | EXPORT_SYMBOL_GPL(mei_write_is_idle); |
| 375 | |
| 376 | /** |
| 377 | * mei_device_init -- initialize mei_device structure |
| 378 | * |
| 379 | * @dev: the mei device |
| 380 | * @device: the device structure |
| 381 | * @hw_ops: hw operations |
| 382 | */ |
| 383 | void mei_device_init(struct mei_device *dev, |
| 384 | struct device *device, |
| 385 | const struct mei_hw_ops *hw_ops) |
| 386 | { |
| 387 | /* setup our list array */ |
| 388 | INIT_LIST_HEAD(&dev->file_list); |
| 389 | INIT_LIST_HEAD(&dev->device_list); |
| 390 | INIT_LIST_HEAD(&dev->me_clients); |
| 391 | mutex_init(&dev->device_lock); |
| 392 | init_waitqueue_head(&dev->wait_hw_ready); |
| 393 | init_waitqueue_head(&dev->wait_pg); |
| 394 | init_waitqueue_head(&dev->wait_hbm_start); |
| 395 | init_waitqueue_head(&dev->wait_stop_wd); |
| 396 | dev->dev_state = MEI_DEV_INITIALIZING; |
| 397 | dev->reset_count = 0; |
| 398 | |
| 399 | mei_io_list_init(&dev->read_list); |
| 400 | mei_io_list_init(&dev->write_list); |
| 401 | mei_io_list_init(&dev->write_waiting_list); |
| 402 | mei_io_list_init(&dev->ctrl_wr_list); |
| 403 | mei_io_list_init(&dev->ctrl_rd_list); |
| 404 | |
| 405 | INIT_DELAYED_WORK(&dev->timer_work, mei_timer); |
| 406 | INIT_WORK(&dev->init_work, mei_host_client_init); |
| 407 | INIT_WORK(&dev->reset_work, mei_reset_work); |
| 408 | |
| 409 | INIT_LIST_HEAD(&dev->wd_cl.link); |
| 410 | INIT_LIST_HEAD(&dev->iamthif_cl.link); |
| 411 | mei_io_list_init(&dev->amthif_cmd_list); |
| 412 | mei_io_list_init(&dev->amthif_rd_complete_list); |
| 413 | |
| 414 | bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX); |
| 415 | dev->open_handle_count = 0; |
| 416 | |
| 417 | /* |
| 418 | * Reserving the first client ID |
| 419 | * 0: Reserved for MEI Bus Message communications |
| 420 | */ |
| 421 | bitmap_set(dev->host_clients_map, 0, 1); |
| 422 | |
| 423 | dev->pg_event = MEI_PG_EVENT_IDLE; |
| 424 | dev->ops = hw_ops; |
| 425 | dev->dev = device; |
| 426 | } |
| 427 | EXPORT_SYMBOL_GPL(mei_device_init); |
| 428 | |