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