1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2012-2019, 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 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr)); 146 147 if (ret) { 148 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret); 149 return ret; 150 } 151 152 if (state == MEI_DEV_POWER_DOWN) { 153 dev_dbg(dev->dev, "powering down: end of reset\n"); 154 mei_set_devstate(dev, MEI_DEV_DISABLED); 155 return 0; 156 } 157 158 ret = mei_hw_start(dev); 159 if (ret) { 160 dev_err(dev->dev, "hw_start failed ret = %d\n", ret); 161 return ret; 162 } 163 164 if (dev->dev_state != MEI_DEV_RESETTING) { 165 dev_dbg(dev->dev, "wrong state = %d on link start\n", dev->dev_state); 166 return 0; 167 } 168 169 dev_dbg(dev->dev, "link is established start sending messages.\n"); 170 171 mei_set_devstate(dev, MEI_DEV_INIT_CLIENTS); 172 ret = mei_hbm_start_req(dev); 173 if (ret) { 174 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret); 175 mei_set_devstate(dev, MEI_DEV_RESETTING); 176 return ret; 177 } 178 179 return 0; 180 } 181 EXPORT_SYMBOL_GPL(mei_reset); 182 183 /** 184 * mei_start - initializes host and fw to start work. 185 * 186 * @dev: the device structure 187 * 188 * Return: 0 on success, <0 on failure. 189 */ 190 int mei_start(struct mei_device *dev) 191 { 192 int ret; 193 194 mutex_lock(&dev->device_lock); 195 196 /* acknowledge interrupt and stop interrupts */ 197 mei_clear_interrupts(dev); 198 199 ret = mei_hw_config(dev); 200 if (ret) 201 goto err; 202 203 dev_dbg(dev->dev, "reset in start the mei device.\n"); 204 205 dev->reset_count = 0; 206 do { 207 mei_set_devstate(dev, MEI_DEV_INITIALIZING); 208 ret = mei_reset(dev); 209 210 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 211 dev_err(dev->dev, "reset failed ret = %d", ret); 212 goto err; 213 } 214 } while (ret); 215 216 if (mei_hbm_start_wait(dev)) { 217 dev_err(dev->dev, "HBM haven't started"); 218 goto err; 219 } 220 221 if (!mei_host_is_ready(dev)) { 222 dev_err(dev->dev, "host is not ready.\n"); 223 goto err; 224 } 225 226 if (!mei_hw_is_ready(dev)) { 227 dev_err(dev->dev, "ME is not ready.\n"); 228 goto err; 229 } 230 231 if (!mei_hbm_version_is_supported(dev)) { 232 dev_dbg(dev->dev, "MEI start failed.\n"); 233 goto err; 234 } 235 236 dev_dbg(dev->dev, "link layer has been established.\n"); 237 238 mutex_unlock(&dev->device_lock); 239 return 0; 240 err: 241 dev_err(dev->dev, "link layer initialization failed.\n"); 242 mei_set_devstate(dev, MEI_DEV_DISABLED); 243 mutex_unlock(&dev->device_lock); 244 return -ENODEV; 245 } 246 EXPORT_SYMBOL_GPL(mei_start); 247 248 /** 249 * mei_restart - restart device after suspend 250 * 251 * @dev: the device structure 252 * 253 * Return: 0 on success or -ENODEV if the restart hasn't succeeded 254 */ 255 int mei_restart(struct mei_device *dev) 256 { 257 int err; 258 259 mutex_lock(&dev->device_lock); 260 261 mei_set_devstate(dev, MEI_DEV_POWER_UP); 262 dev->reset_count = 0; 263 264 err = mei_reset(dev); 265 266 mutex_unlock(&dev->device_lock); 267 268 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 269 dev_err(dev->dev, "device disabled = %d\n", err); 270 return -ENODEV; 271 } 272 273 /* try to start again */ 274 if (err) 275 schedule_work(&dev->reset_work); 276 277 278 return 0; 279 } 280 EXPORT_SYMBOL_GPL(mei_restart); 281 282 static void mei_reset_work(struct work_struct *work) 283 { 284 struct mei_device *dev = 285 container_of(work, struct mei_device, reset_work); 286 int ret; 287 288 mei_clear_interrupts(dev); 289 mei_synchronize_irq(dev); 290 291 mutex_lock(&dev->device_lock); 292 293 ret = mei_reset(dev); 294 295 mutex_unlock(&dev->device_lock); 296 297 if (dev->dev_state == MEI_DEV_DISABLED) { 298 dev_err(dev->dev, "device disabled = %d\n", ret); 299 return; 300 } 301 302 /* retry reset in case of failure */ 303 if (ret) 304 schedule_work(&dev->reset_work); 305 } 306 307 void mei_stop(struct mei_device *dev) 308 { 309 dev_dbg(dev->dev, "stopping the device.\n"); 310 311 mutex_lock(&dev->device_lock); 312 mei_set_devstate(dev, MEI_DEV_POWERING_DOWN); 313 mutex_unlock(&dev->device_lock); 314 mei_cl_bus_remove_devices(dev); 315 mutex_lock(&dev->device_lock); 316 mei_set_devstate(dev, MEI_DEV_POWER_DOWN); 317 mutex_unlock(&dev->device_lock); 318 319 mei_cancel_work(dev); 320 321 mei_clear_interrupts(dev); 322 mei_synchronize_irq(dev); 323 324 mutex_lock(&dev->device_lock); 325 326 mei_reset(dev); 327 /* move device to disabled state unconditionally */ 328 mei_set_devstate(dev, MEI_DEV_DISABLED); 329 330 mutex_unlock(&dev->device_lock); 331 } 332 EXPORT_SYMBOL_GPL(mei_stop); 333 334 /** 335 * mei_write_is_idle - check if the write queues are idle 336 * 337 * @dev: the device structure 338 * 339 * Return: true of there is no pending write 340 */ 341 bool mei_write_is_idle(struct mei_device *dev) 342 { 343 bool idle = (dev->dev_state == MEI_DEV_ENABLED && 344 list_empty(&dev->ctrl_wr_list) && 345 list_empty(&dev->write_list) && 346 list_empty(&dev->write_waiting_list)); 347 348 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n", 349 idle, 350 mei_dev_state_str(dev->dev_state), 351 list_empty(&dev->ctrl_wr_list), 352 list_empty(&dev->write_list), 353 list_empty(&dev->write_waiting_list)); 354 355 return idle; 356 } 357 EXPORT_SYMBOL_GPL(mei_write_is_idle); 358 359 /** 360 * mei_device_init -- initialize mei_device structure 361 * 362 * @dev: the mei device 363 * @device: the device structure 364 * @hw_ops: hw operations 365 */ 366 void mei_device_init(struct mei_device *dev, 367 struct device *device, 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 /* 397 * Reserving the first client ID 398 * 0: Reserved for MEI Bus Message communications 399 */ 400 bitmap_set(dev->host_clients_map, 0, 1); 401 402 dev->pg_event = MEI_PG_EVENT_IDLE; 403 dev->ops = hw_ops; 404 dev->dev = device; 405 } 406 EXPORT_SYMBOL_GPL(mei_device_init); 407 408