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 18 const 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 36 const 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 */ 57 ssize_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 } 76 EXPORT_SYMBOL_GPL(mei_fw_status2str); 77 78 /** 79 * mei_cancel_work - Cancel mei background jobs 80 * 81 * @dev: the device structure 82 */ 83 void 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 } 90 EXPORT_SYMBOL_GPL(mei_cancel_work); 91 92 /** 93 * mei_reset - resets host and fw. 94 * 95 * @dev: the device structure 96 * 97 * Return: 0 on success or < 0 if the reset hasn't succeeded 98 */ 99 int mei_reset(struct mei_device *dev) 100 { 101 enum mei_dev_state state = dev->dev_state; 102 bool interrupts_enabled; 103 int ret; 104 105 if (state != MEI_DEV_INITIALIZING && 106 state != MEI_DEV_DISABLED && 107 state != MEI_DEV_POWER_DOWN && 108 state != MEI_DEV_POWER_UP) { 109 char fw_sts_str[MEI_FW_STATUS_STR_SZ]; 110 111 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ); 112 if (kind_is_gsc(dev) || kind_is_gscfi(dev)) { 113 dev_dbg(&dev->dev, "unexpected reset: dev_state = %s fw status = %s\n", 114 mei_dev_state_str(state), fw_sts_str); 115 } else { 116 dev_warn(&dev->dev, "unexpected reset: dev_state = %s fw status = %s\n", 117 mei_dev_state_str(state), fw_sts_str); 118 } 119 } 120 121 mei_clear_interrupts(dev); 122 123 /* we're already in reset, cancel the init timer 124 * if the reset was called due the hbm protocol error 125 * we need to call it before hw start 126 * so the hbm watchdog won't kick in 127 */ 128 mei_hbm_idle(dev); 129 130 /* enter reset flow */ 131 interrupts_enabled = state != MEI_DEV_POWER_DOWN; 132 mei_set_devstate(dev, MEI_DEV_RESETTING); 133 134 dev->reset_count++; 135 if (dev->reset_count > MEI_MAX_CONSEC_RESET) { 136 dev_err(&dev->dev, "reset: reached maximal consecutive resets: disabling the device\n"); 137 mei_set_devstate(dev, MEI_DEV_DISABLED); 138 return -ENODEV; 139 } 140 141 ret = mei_hw_reset(dev, interrupts_enabled); 142 /* fall through and remove the sw state even if hw reset has failed */ 143 144 /* no need to clean up software state in case of power up */ 145 if (state != MEI_DEV_INITIALIZING && state != MEI_DEV_POWER_UP) 146 mei_cl_all_disconnect(dev); 147 148 mei_hbm_reset(dev); 149 150 /* clean stale FW version */ 151 dev->fw_ver_received = 0; 152 153 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr)); 154 155 if (ret) { 156 dev_err(&dev->dev, "hw_reset failed ret = %d\n", ret); 157 return ret; 158 } 159 160 if (state == MEI_DEV_POWER_DOWN) { 161 dev_dbg(&dev->dev, "powering down: end of reset\n"); 162 mei_set_devstate(dev, MEI_DEV_DISABLED); 163 return 0; 164 } 165 166 ret = mei_hw_start(dev); 167 if (ret) { 168 char fw_sts_str[MEI_FW_STATUS_STR_SZ]; 169 170 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ); 171 dev_err(&dev->dev, "hw_start failed ret = %d fw status = %s\n", ret, fw_sts_str); 172 return ret; 173 } 174 175 if (dev->dev_state != MEI_DEV_RESETTING) { 176 dev_dbg(&dev->dev, "wrong state = %d on link start\n", dev->dev_state); 177 return 0; 178 } 179 180 dev_dbg(&dev->dev, "link is established start sending messages.\n"); 181 182 mei_set_devstate(dev, MEI_DEV_INIT_CLIENTS); 183 ret = mei_hbm_start_req(dev); 184 if (ret) { 185 dev_err(&dev->dev, "hbm_start failed ret = %d\n", ret); 186 mei_set_devstate(dev, MEI_DEV_RESETTING); 187 return ret; 188 } 189 190 return 0; 191 } 192 EXPORT_SYMBOL_GPL(mei_reset); 193 194 /** 195 * mei_start - initializes host and fw to start work. 196 * 197 * @dev: the device structure 198 * 199 * Return: 0 on success, <0 on failure. 200 */ 201 int mei_start(struct mei_device *dev) 202 { 203 int ret; 204 205 mutex_lock(&dev->device_lock); 206 207 /* acknowledge interrupt and stop interrupts */ 208 mei_clear_interrupts(dev); 209 210 ret = mei_hw_config(dev); 211 if (ret) 212 goto err; 213 214 dev_dbg(&dev->dev, "reset in start the mei device.\n"); 215 216 dev->reset_count = 0; 217 do { 218 mei_set_devstate(dev, MEI_DEV_INITIALIZING); 219 ret = mei_reset(dev); 220 221 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 222 dev_err(&dev->dev, "reset failed ret = %d", ret); 223 goto err; 224 } 225 } while (ret); 226 227 if (mei_hbm_start_wait(dev)) { 228 dev_err(&dev->dev, "HBM haven't started"); 229 goto err; 230 } 231 232 if (!mei_hbm_version_is_supported(dev)) { 233 dev_dbg(&dev->dev, "MEI start failed.\n"); 234 goto err; 235 } 236 237 dev_dbg(&dev->dev, "link layer has been established.\n"); 238 239 mutex_unlock(&dev->device_lock); 240 return 0; 241 err: 242 dev_err(&dev->dev, "link layer initialization failed.\n"); 243 mei_set_devstate(dev, MEI_DEV_DISABLED); 244 mutex_unlock(&dev->device_lock); 245 return -ENODEV; 246 } 247 EXPORT_SYMBOL_GPL(mei_start); 248 249 /** 250 * mei_restart - restart device after suspend 251 * 252 * @dev: the device structure 253 * 254 * Return: 0 on success or -ENODEV if the restart hasn't succeeded 255 */ 256 int mei_restart(struct mei_device *dev) 257 { 258 int err; 259 260 mutex_lock(&dev->device_lock); 261 262 mei_set_devstate(dev, MEI_DEV_POWER_UP); 263 dev->reset_count = 0; 264 265 err = mei_reset(dev); 266 267 mutex_unlock(&dev->device_lock); 268 269 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 270 dev_err(&dev->dev, "device disabled = %d\n", err); 271 return -ENODEV; 272 } 273 274 /* try to start again */ 275 if (err) 276 schedule_work(&dev->reset_work); 277 278 279 return 0; 280 } 281 EXPORT_SYMBOL_GPL(mei_restart); 282 283 static void mei_reset_work(struct work_struct *work) 284 { 285 struct mei_device *dev = 286 container_of(work, struct mei_device, reset_work); 287 int ret; 288 289 mei_clear_interrupts(dev); 290 mei_synchronize_irq(dev); 291 292 mutex_lock(&dev->device_lock); 293 294 ret = mei_reset(dev); 295 296 mutex_unlock(&dev->device_lock); 297 298 if (dev->dev_state == MEI_DEV_DISABLED) { 299 dev_err(&dev->dev, "device disabled = %d\n", ret); 300 return; 301 } 302 303 /* retry reset in case of failure */ 304 if (ret) 305 schedule_work(&dev->reset_work); 306 } 307 308 void mei_stop(struct mei_device *dev) 309 { 310 dev_dbg(&dev->dev, "stopping the device.\n"); 311 312 mutex_lock(&dev->device_lock); 313 mei_set_devstate(dev, MEI_DEV_POWERING_DOWN); 314 mutex_unlock(&dev->device_lock); 315 mei_cl_bus_remove_devices(dev); 316 mutex_lock(&dev->device_lock); 317 mei_set_devstate(dev, MEI_DEV_POWER_DOWN); 318 mutex_unlock(&dev->device_lock); 319 320 mei_cancel_work(dev); 321 322 mei_clear_interrupts(dev); 323 mei_synchronize_irq(dev); 324 /* to catch HW-initiated reset */ 325 mei_cancel_work(dev); 326 327 mutex_lock(&dev->device_lock); 328 329 mei_reset(dev); 330 /* move device to disabled state unconditionally */ 331 mei_set_devstate(dev, MEI_DEV_DISABLED); 332 333 mutex_unlock(&dev->device_lock); 334 } 335 EXPORT_SYMBOL_GPL(mei_stop); 336 337 /** 338 * mei_write_is_idle - check if the write queues are idle 339 * 340 * @dev: the device structure 341 * 342 * Return: true of there is no pending write 343 */ 344 bool mei_write_is_idle(struct mei_device *dev) 345 { 346 bool idle = (dev->dev_state == MEI_DEV_ENABLED && 347 list_empty(&dev->ctrl_wr_list) && 348 list_empty(&dev->write_list) && 349 list_empty(&dev->write_waiting_list)); 350 351 dev_dbg(&dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n", 352 idle, 353 mei_dev_state_str(dev->dev_state), 354 list_empty(&dev->ctrl_wr_list), 355 list_empty(&dev->write_list), 356 list_empty(&dev->write_waiting_list)); 357 358 return idle; 359 } 360 EXPORT_SYMBOL_GPL(mei_write_is_idle); 361 362 /** 363 * mei_device_init - initialize mei_device structure 364 * 365 * @dev: the mei device 366 * @parent: the parent device 367 * @slow_fw: configure longer timeouts as FW is slow 368 * @hw_ops: hw operations 369 */ 370 void mei_device_init(struct mei_device *dev, 371 struct device *parent, 372 bool slow_fw, 373 const struct mei_hw_ops *hw_ops) 374 { 375 /* setup our list array */ 376 INIT_LIST_HEAD(&dev->file_list); 377 INIT_LIST_HEAD(&dev->device_list); 378 INIT_LIST_HEAD(&dev->me_clients); 379 mutex_init(&dev->device_lock); 380 init_rwsem(&dev->me_clients_rwsem); 381 mutex_init(&dev->cl_bus_lock); 382 init_waitqueue_head(&dev->wait_hw_ready); 383 init_waitqueue_head(&dev->wait_pg); 384 init_waitqueue_head(&dev->wait_hbm_start); 385 dev->dev_state = MEI_DEV_UNINITIALIZED; 386 init_waitqueue_head(&dev->wait_dev_state); 387 dev->reset_count = 0; 388 389 INIT_LIST_HEAD(&dev->write_list); 390 INIT_LIST_HEAD(&dev->write_waiting_list); 391 INIT_LIST_HEAD(&dev->ctrl_wr_list); 392 INIT_LIST_HEAD(&dev->ctrl_rd_list); 393 dev->tx_queue_limit = MEI_TX_QUEUE_LIMIT_DEFAULT; 394 395 INIT_DELAYED_WORK(&dev->timer_work, mei_timer); 396 INIT_WORK(&dev->reset_work, mei_reset_work); 397 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work); 398 399 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX); 400 dev->open_handle_count = 0; 401 402 dev->pxp_mode = MEI_DEV_PXP_DEFAULT; 403 dev->gsc_reset_to_pxp = MEI_DEV_RESET_TO_PXP_DEFAULT; 404 405 /* 406 * Reserving the first client ID 407 * 0: Reserved for MEI Bus Message communications 408 */ 409 bitmap_set(dev->host_clients_map, 0, 1); 410 411 dev->pg_event = MEI_PG_EVENT_IDLE; 412 dev->ops = hw_ops; 413 dev->parent = parent; 414 415 dev->timeouts.hw_ready = mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT); 416 dev->timeouts.connect = MEI_CONNECT_TIMEOUT; 417 dev->timeouts.client_init = MEI_CLIENTS_INIT_TIMEOUT; 418 dev->timeouts.pgi = mei_secs_to_jiffies(MEI_PGI_TIMEOUT); 419 dev->timeouts.d0i3 = mei_secs_to_jiffies(MEI_D0I3_TIMEOUT); 420 if (slow_fw) { 421 dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT_SLOW); 422 dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT_SLOW); 423 dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT_SLOW); 424 } else { 425 dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT); 426 dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT); 427 dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT); 428 } 429 dev->timeouts.link_reset_wait = msecs_to_jiffies(MEI_LINK_RESET_WAIT_TIMEOUT_MSEC); 430 } 431 EXPORT_SYMBOL_GPL(mei_device_init); 432