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