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_cl_bus_remove_devices(dev); 335 336 mutex_lock(&dev->device_lock); 337 338 mei_wd_stop(dev); 339 340 dev->dev_state = MEI_DEV_POWER_DOWN; 341 mei_reset(dev); 342 /* move device to disabled state unconditionally */ 343 dev->dev_state = MEI_DEV_DISABLED; 344 345 mutex_unlock(&dev->device_lock); 346 347 mei_watchdog_unregister(dev); 348 } 349 EXPORT_SYMBOL_GPL(mei_stop); 350 351 /** 352 * mei_write_is_idle - check if the write queues are idle 353 * 354 * @dev: the device structure 355 * 356 * Return: true of there is no pending write 357 */ 358 bool mei_write_is_idle(struct mei_device *dev) 359 { 360 bool idle = (dev->dev_state == MEI_DEV_ENABLED && 361 list_empty(&dev->ctrl_wr_list.list) && 362 list_empty(&dev->write_list.list) && 363 list_empty(&dev->write_waiting_list.list)); 364 365 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n", 366 idle, 367 mei_dev_state_str(dev->dev_state), 368 list_empty(&dev->ctrl_wr_list.list), 369 list_empty(&dev->write_list.list), 370 list_empty(&dev->write_waiting_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_rwsem(&dev->me_clients_rwsem); 393 mutex_init(&dev->cl_bus_lock); 394 init_waitqueue_head(&dev->wait_hw_ready); 395 init_waitqueue_head(&dev->wait_pg); 396 init_waitqueue_head(&dev->wait_hbm_start); 397 init_waitqueue_head(&dev->wait_stop_wd); 398 dev->dev_state = MEI_DEV_INITIALIZING; 399 dev->reset_count = 0; 400 401 mei_io_list_init(&dev->write_list); 402 mei_io_list_init(&dev->write_waiting_list); 403 mei_io_list_init(&dev->ctrl_wr_list); 404 mei_io_list_init(&dev->ctrl_rd_list); 405 406 INIT_DELAYED_WORK(&dev->timer_work, mei_timer); 407 INIT_WORK(&dev->init_work, mei_host_client_init); 408 INIT_WORK(&dev->reset_work, mei_reset_work); 409 410 INIT_LIST_HEAD(&dev->wd_cl.link); 411 INIT_LIST_HEAD(&dev->iamthif_cl.link); 412 mei_io_list_init(&dev->amthif_cmd_list); 413 mei_io_list_init(&dev->amthif_rd_complete_list); 414 415 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX); 416 dev->open_handle_count = 0; 417 418 /* 419 * Reserving the first client ID 420 * 0: Reserved for MEI Bus Message communications 421 */ 422 bitmap_set(dev->host_clients_map, 0, 1); 423 424 dev->pg_event = MEI_PG_EVENT_IDLE; 425 dev->ops = hw_ops; 426 dev->dev = device; 427 } 428 EXPORT_SYMBOL_GPL(mei_device_init); 429 430