1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (c) 2012-2022, Intel Corporation. All rights reserved. 4 * Intel Management Engine Interface (Intel MEI) Linux driver 5 */ 6 7#include <linux/export.h> 8#include <linux/sched.h> 9#include <linux/wait.h> 10#include <linux/delay.h> 11 12#include <linux/mei.h> 13 14#include "mei_dev.h" 15#include "hbm.h" 16#include "client.h" 17 18const char *mei_dev_state_str(int state) 19{ 20#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state 21 switch (state) { 22 MEI_DEV_STATE(INITIALIZING); 23 MEI_DEV_STATE(INIT_CLIENTS); 24 MEI_DEV_STATE(ENABLED); 25 MEI_DEV_STATE(RESETTING); 26 MEI_DEV_STATE(DISABLED); 27 MEI_DEV_STATE(POWERING_DOWN); 28 MEI_DEV_STATE(POWER_DOWN); 29 MEI_DEV_STATE(POWER_UP); 30 default: 31 return "unknown"; 32 } 33#undef MEI_DEV_STATE 34} 35 36const char *mei_pg_state_str(enum mei_pg_state state) 37{ 38#define MEI_PG_STATE(state) case MEI_PG_##state: return #state 39 switch (state) { 40 MEI_PG_STATE(OFF); 41 MEI_PG_STATE(ON); 42 default: 43 return "unknown"; 44 } 45#undef MEI_PG_STATE 46} 47 48/** 49 * mei_fw_status2str - convert fw status registers to printable string 50 * 51 * @fw_status: firmware status 52 * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ 53 * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ 54 * 55 * Return: number of bytes written or -EINVAL if buffer is to small 56 */ 57ssize_t mei_fw_status2str(struct mei_fw_status *fw_status, 58 char *buf, size_t len) 59{ 60 ssize_t cnt = 0; 61 int i; 62 63 buf[0] = '\0'; 64 65 if (len < MEI_FW_STATUS_STR_SZ) 66 return -EINVAL; 67 68 for (i = 0; i < fw_status->count; i++) 69 cnt += scnprintf(buf + cnt, len - cnt, "%08X ", 70 fw_status->status[i]); 71 72 /* drop last space */ 73 buf[cnt] = '\0'; 74 return cnt; 75} 76EXPORT_SYMBOL_GPL(mei_fw_status2str); 77 78/** 79 * mei_cancel_work - Cancel mei background jobs 80 * 81 * @dev: the device structure 82 */ 83void mei_cancel_work(struct mei_device *dev) 84{ 85 cancel_work_sync(&dev->reset_work); 86 cancel_work_sync(&dev->bus_rescan_work); 87 88 cancel_delayed_work_sync(&dev->timer_work); 89} 90EXPORT_SYMBOL_GPL(mei_cancel_work); 91 92static void mei_save_fw_status(struct mei_device *dev) 93{ 94 struct mei_fw_status fw_status; 95 int ret; 96 97 ret = mei_fw_status(dev, &fw_status); 98 if (ret) { 99 dev_err(dev->dev, "failed to read firmware status: %d\n", ret); 100 return; 101 } 102 103 dev->saved_dev_state = dev->dev_state; 104 dev->saved_fw_status_flag = true; 105 memcpy(&dev->saved_fw_status, &fw_status, sizeof(fw_status)); 106} 107 108/** 109 * mei_reset - resets host and fw. 110 * 111 * @dev: the device structure 112 * 113 * Return: 0 on success or < 0 if the reset hasn't succeeded 114 */ 115int mei_reset(struct mei_device *dev) 116{ 117 enum mei_dev_state state = dev->dev_state; 118 bool interrupts_enabled; 119 int ret; 120 121 if (state != MEI_DEV_INITIALIZING && 122 state != MEI_DEV_DISABLED && 123 state != MEI_DEV_POWER_DOWN && 124 state != MEI_DEV_POWER_UP) { 125 char fw_sts_str[MEI_FW_STATUS_STR_SZ]; 126 127 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ); 128 if (kind_is_gsc(dev) || kind_is_gscfi(dev)) { 129 dev_dbg(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n", 130 mei_dev_state_str(state), fw_sts_str); 131 mei_save_fw_status(dev); 132 } else { 133 dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n", 134 mei_dev_state_str(state), fw_sts_str); 135 } 136 } 137 138 mei_clear_interrupts(dev); 139 140 /* we're already in reset, cancel the init timer 141 * if the reset was called due the hbm protocol error 142 * we need to call it before hw start 143 * so the hbm watchdog won't kick in 144 */ 145 mei_hbm_idle(dev); 146 147 /* enter reset flow */ 148 interrupts_enabled = state != MEI_DEV_POWER_DOWN; 149 mei_set_devstate(dev, MEI_DEV_RESETTING); 150 151 dev->reset_count++; 152 if (dev->reset_count > MEI_MAX_CONSEC_RESET) { 153 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n"); 154 mei_set_devstate(dev, MEI_DEV_DISABLED); 155 return -ENODEV; 156 } 157 158 ret = mei_hw_reset(dev, interrupts_enabled); 159 /* fall through and remove the sw state even if hw reset has failed */ 160 161 /* no need to clean up software state in case of power up */ 162 if (state != MEI_DEV_INITIALIZING && state != MEI_DEV_POWER_UP) 163 mei_cl_all_disconnect(dev); 164 165 mei_hbm_reset(dev); 166 167 /* clean stale FW version */ 168 dev->fw_ver_received = 0; 169 170 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr)); 171 172 if (ret) { 173 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret); 174 return ret; 175 } 176 177 if (state == MEI_DEV_POWER_DOWN) { 178 dev_dbg(dev->dev, "powering down: end of reset\n"); 179 mei_set_devstate(dev, MEI_DEV_DISABLED); 180 return 0; 181 } 182 183 ret = mei_hw_start(dev); 184 if (ret) { 185 char fw_sts_str[MEI_FW_STATUS_STR_SZ]; 186 187 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ); 188 dev_err(dev->dev, "hw_start failed ret = %d fw status = %s\n", ret, fw_sts_str); 189 return ret; 190 } 191 192 if (dev->dev_state != MEI_DEV_RESETTING) { 193 dev_dbg(dev->dev, "wrong state = %d on link start\n", dev->dev_state); 194 return 0; 195 } 196 197 dev_dbg(dev->dev, "link is established start sending messages.\n"); 198 199 mei_set_devstate(dev, MEI_DEV_INIT_CLIENTS); 200 ret = mei_hbm_start_req(dev); 201 if (ret) { 202 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret); 203 mei_set_devstate(dev, MEI_DEV_RESETTING); 204 return ret; 205 } 206 207 return 0; 208} 209EXPORT_SYMBOL_GPL(mei_reset); 210 211/** 212 * mei_start - initializes host and fw to start work. 213 * 214 * @dev: the device structure 215 * 216 * Return: 0 on success, <0 on failure. 217 */ 218int mei_start(struct mei_device *dev) 219{ 220 int ret; 221 222 mutex_lock(&dev->device_lock); 223 224 /* acknowledge interrupt and stop interrupts */ 225 mei_clear_interrupts(dev); 226 227 ret = mei_hw_config(dev); 228 if (ret) 229 goto err; 230 231 dev_dbg(dev->dev, "reset in start the mei device.\n"); 232 233 dev->reset_count = 0; 234 do { 235 mei_set_devstate(dev, MEI_DEV_INITIALIZING); 236 ret = mei_reset(dev); 237 238 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 239 dev_err(dev->dev, "reset failed ret = %d", ret); 240 goto err; 241 } 242 } while (ret); 243 244 if (mei_hbm_start_wait(dev)) { 245 dev_err(dev->dev, "HBM haven't started"); 246 goto err; 247 } 248 249 if (!mei_hbm_version_is_supported(dev)) { 250 dev_dbg(dev->dev, "MEI start failed.\n"); 251 goto err; 252 } 253 254 dev_dbg(dev->dev, "link layer has been established.\n"); 255 256 mutex_unlock(&dev->device_lock); 257 return 0; 258err: 259 dev_err(dev->dev, "link layer initialization failed.\n"); 260 mei_set_devstate(dev, MEI_DEV_DISABLED); 261 mutex_unlock(&dev->device_lock); 262 return -ENODEV; 263} 264EXPORT_SYMBOL_GPL(mei_start); 265 266/** 267 * mei_restart - restart device after suspend 268 * 269 * @dev: the device structure 270 * 271 * Return: 0 on success or -ENODEV if the restart hasn't succeeded 272 */ 273int mei_restart(struct mei_device *dev) 274{ 275 int err; 276 277 mutex_lock(&dev->device_lock); 278 279 mei_set_devstate(dev, MEI_DEV_POWER_UP); 280 dev->reset_count = 0; 281 282 err = mei_reset(dev); 283 284 mutex_unlock(&dev->device_lock); 285 286 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 287 dev_err(dev->dev, "device disabled = %d\n", err); 288 return -ENODEV; 289 } 290 291 /* try to start again */ 292 if (err) 293 schedule_work(&dev->reset_work); 294 295 296 return 0; 297} 298EXPORT_SYMBOL_GPL(mei_restart); 299 300static void mei_reset_work(struct work_struct *work) 301{ 302 struct mei_device *dev = 303 container_of(work, struct mei_device, reset_work); 304 int ret; 305 306 mei_clear_interrupts(dev); 307 mei_synchronize_irq(dev); 308 309 mutex_lock(&dev->device_lock); 310 311 ret = mei_reset(dev); 312 313 mutex_unlock(&dev->device_lock); 314 315 if (dev->dev_state == MEI_DEV_DISABLED) { 316 dev_err(dev->dev, "device disabled = %d\n", ret); 317 return; 318 } 319 320 /* retry reset in case of failure */ 321 if (ret) 322 schedule_work(&dev->reset_work); 323} 324 325void mei_stop(struct mei_device *dev) 326{ 327 dev_dbg(dev->dev, "stopping the device.\n"); 328 329 mutex_lock(&dev->device_lock); 330 mei_set_devstate(dev, MEI_DEV_POWERING_DOWN); 331 mutex_unlock(&dev->device_lock); 332 mei_cl_bus_remove_devices(dev); 333 mutex_lock(&dev->device_lock); 334 mei_set_devstate(dev, MEI_DEV_POWER_DOWN); 335 mutex_unlock(&dev->device_lock); 336 337 mei_cancel_work(dev); 338 339 mei_clear_interrupts(dev); 340 mei_synchronize_irq(dev); 341 /* to catch HW-initiated reset */ 342 mei_cancel_work(dev); 343 344 mutex_lock(&dev->device_lock); 345 346 mei_reset(dev); 347 /* move device to disabled state unconditionally */ 348 mei_set_devstate(dev, MEI_DEV_DISABLED); 349 350 mutex_unlock(&dev->device_lock); 351} 352EXPORT_SYMBOL_GPL(mei_stop); 353 354/** 355 * mei_write_is_idle - check if the write queues are idle 356 * 357 * @dev: the device structure 358 * 359 * Return: true of there is no pending write 360 */ 361bool mei_write_is_idle(struct mei_device *dev) 362{ 363 bool idle = (dev->dev_state == MEI_DEV_ENABLED && 364 list_empty(&dev->ctrl_wr_list) && 365 list_empty(&dev->write_list) && 366 list_empty(&dev->write_waiting_list)); 367 368 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n", 369 idle, 370 mei_dev_state_str(dev->dev_state), 371 list_empty(&dev->ctrl_wr_list), 372 list_empty(&dev->write_list), 373 list_empty(&dev->write_waiting_list)); 374 375 return idle; 376} 377EXPORT_SYMBOL_GPL(mei_write_is_idle); 378 379/** 380 * mei_device_init - initialize mei_device structure 381 * 382 * @dev: the mei device 383 * @device: the device structure 384 * @slow_fw: configure longer timeouts as FW is slow 385 * @hw_ops: hw operations 386 */ 387void mei_device_init(struct mei_device *dev, 388 struct device *device, 389 bool slow_fw, 390 const struct mei_hw_ops *hw_ops) 391{ 392 /* setup our list array */ 393 INIT_LIST_HEAD(&dev->file_list); 394 INIT_LIST_HEAD(&dev->device_list); 395 INIT_LIST_HEAD(&dev->me_clients); 396 mutex_init(&dev->device_lock); 397 init_rwsem(&dev->me_clients_rwsem); 398 mutex_init(&dev->cl_bus_lock); 399 init_waitqueue_head(&dev->wait_hw_ready); 400 init_waitqueue_head(&dev->wait_pg); 401 init_waitqueue_head(&dev->wait_hbm_start); 402 dev->dev_state = MEI_DEV_INITIALIZING; 403 dev->reset_count = 0; 404 405 INIT_LIST_HEAD(&dev->write_list); 406 INIT_LIST_HEAD(&dev->write_waiting_list); 407 INIT_LIST_HEAD(&dev->ctrl_wr_list); 408 INIT_LIST_HEAD(&dev->ctrl_rd_list); 409 dev->tx_queue_limit = MEI_TX_QUEUE_LIMIT_DEFAULT; 410 411 INIT_DELAYED_WORK(&dev->timer_work, mei_timer); 412 INIT_WORK(&dev->reset_work, mei_reset_work); 413 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work); 414 415 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX); 416 dev->open_handle_count = 0; 417 418 dev->pxp_mode = MEI_DEV_PXP_DEFAULT; 419 dev->gsc_reset_to_pxp = MEI_DEV_RESET_TO_PXP_DEFAULT; 420 421 /* 422 * Reserving the first client ID 423 * 0: Reserved for MEI Bus Message communications 424 */ 425 bitmap_set(dev->host_clients_map, 0, 1); 426 427 dev->pg_event = MEI_PG_EVENT_IDLE; 428 dev->ops = hw_ops; 429 dev->dev = device; 430 431 dev->timeouts.hw_ready = mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT); 432 dev->timeouts.connect = MEI_CONNECT_TIMEOUT; 433 dev->timeouts.client_init = MEI_CLIENTS_INIT_TIMEOUT; 434 dev->timeouts.pgi = mei_secs_to_jiffies(MEI_PGI_TIMEOUT); 435 dev->timeouts.d0i3 = mei_secs_to_jiffies(MEI_D0I3_TIMEOUT); 436 if (slow_fw) { 437 dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT_SLOW); 438 dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT_SLOW); 439 dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT_SLOW); 440 } else { 441 dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT); 442 dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT); 443 dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT); 444 } 445} 446EXPORT_SYMBOL_GPL(mei_device_init); 447 448