1 /* 2 * 3 * Intel Management Engine Interface (Intel MEI) Linux driver 4 * Copyright (c) 2003-2012, Intel Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 */ 16 17 #include <linux/export.h> 18 #include <linux/sched.h> 19 #include <linux/wait.h> 20 #include <linux/delay.h> 21 22 #include <linux/mei.h> 23 24 #include "mei_dev.h" 25 #include "hbm.h" 26 #include "client.h" 27 28 const char *mei_dev_state_str(int state) 29 { 30 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state 31 switch (state) { 32 MEI_DEV_STATE(INITIALIZING); 33 MEI_DEV_STATE(INIT_CLIENTS); 34 MEI_DEV_STATE(ENABLED); 35 MEI_DEV_STATE(RESETTING); 36 MEI_DEV_STATE(DISABLED); 37 MEI_DEV_STATE(POWER_DOWN); 38 MEI_DEV_STATE(POWER_UP); 39 default: 40 return "unknown"; 41 } 42 #undef MEI_DEV_STATE 43 } 44 45 const char *mei_pg_state_str(enum mei_pg_state state) 46 { 47 #define MEI_PG_STATE(state) case MEI_PG_##state: return #state 48 switch (state) { 49 MEI_PG_STATE(OFF); 50 MEI_PG_STATE(ON); 51 default: 52 return "unknown"; 53 } 54 #undef MEI_PG_STATE 55 } 56 57 /** 58 * mei_fw_status2str - convert fw status registers to printable string 59 * 60 * @fw_status: firmware status 61 * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ 62 * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ 63 * 64 * Return: number of bytes written or -EINVAL if buffer is to small 65 */ 66 ssize_t mei_fw_status2str(struct mei_fw_status *fw_status, 67 char *buf, size_t len) 68 { 69 ssize_t cnt = 0; 70 int i; 71 72 buf[0] = '\0'; 73 74 if (len < MEI_FW_STATUS_STR_SZ) 75 return -EINVAL; 76 77 for (i = 0; i < fw_status->count; i++) 78 cnt += scnprintf(buf + cnt, len - cnt, "%08X ", 79 fw_status->status[i]); 80 81 /* drop last space */ 82 buf[cnt] = '\0'; 83 return cnt; 84 } 85 EXPORT_SYMBOL_GPL(mei_fw_status2str); 86 87 /** 88 * mei_cancel_work - Cancel mei background jobs 89 * 90 * @dev: the device structure 91 */ 92 void mei_cancel_work(struct mei_device *dev) 93 { 94 cancel_work_sync(&dev->reset_work); 95 cancel_work_sync(&dev->bus_rescan_work); 96 97 cancel_delayed_work_sync(&dev->timer_work); 98 } 99 EXPORT_SYMBOL_GPL(mei_cancel_work); 100 101 /** 102 * mei_reset - resets host and fw. 103 * 104 * @dev: the device structure 105 * 106 * Return: 0 on success or < 0 if the reset hasn't succeeded 107 */ 108 int mei_reset(struct mei_device *dev) 109 { 110 enum mei_dev_state state = dev->dev_state; 111 bool interrupts_enabled; 112 int ret; 113 114 if (state != MEI_DEV_INITIALIZING && 115 state != MEI_DEV_DISABLED && 116 state != MEI_DEV_POWER_DOWN && 117 state != MEI_DEV_POWER_UP) { 118 char fw_sts_str[MEI_FW_STATUS_STR_SZ]; 119 120 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ); 121 dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n", 122 mei_dev_state_str(state), fw_sts_str); 123 } 124 125 mei_clear_interrupts(dev); 126 127 mei_synchronize_irq(dev); 128 129 /* we're already in reset, cancel the init timer 130 * if the reset was called due the hbm protocol error 131 * we need to call it before hw start 132 * so the hbm watchdog won't kick in 133 */ 134 mei_hbm_idle(dev); 135 136 /* enter reset flow */ 137 interrupts_enabled = state != MEI_DEV_POWER_DOWN; 138 dev->dev_state = MEI_DEV_RESETTING; 139 140 dev->reset_count++; 141 if (dev->reset_count > MEI_MAX_CONSEC_RESET) { 142 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n"); 143 dev->dev_state = MEI_DEV_DISABLED; 144 return -ENODEV; 145 } 146 147 ret = mei_hw_reset(dev, interrupts_enabled); 148 /* fall through and remove the sw state even if hw reset has failed */ 149 150 /* no need to clean up software state in case of power up */ 151 if (state != MEI_DEV_INITIALIZING && 152 state != MEI_DEV_POWER_UP) { 153 154 /* remove all waiting requests */ 155 mei_cl_all_disconnect(dev); 156 157 /* remove entry if already in list */ 158 dev_dbg(dev->dev, "remove iamthif from the file list.\n"); 159 mei_cl_unlink(&dev->iamthif_cl); 160 mei_amthif_reset_params(dev); 161 } 162 163 mei_hbm_reset(dev); 164 165 dev->rd_msg_hdr = 0; 166 167 if (ret) { 168 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret); 169 return ret; 170 } 171 172 if (state == MEI_DEV_POWER_DOWN) { 173 dev_dbg(dev->dev, "powering down: end of reset\n"); 174 dev->dev_state = MEI_DEV_DISABLED; 175 return 0; 176 } 177 178 ret = mei_hw_start(dev); 179 if (ret) { 180 dev_err(dev->dev, "hw_start failed ret = %d\n", ret); 181 return ret; 182 } 183 184 dev_dbg(dev->dev, "link is established start sending messages.\n"); 185 186 dev->dev_state = MEI_DEV_INIT_CLIENTS; 187 ret = mei_hbm_start_req(dev); 188 if (ret) { 189 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret); 190 dev->dev_state = MEI_DEV_RESETTING; 191 return ret; 192 } 193 194 return 0; 195 } 196 EXPORT_SYMBOL_GPL(mei_reset); 197 198 /** 199 * mei_start - initializes host and fw to start work. 200 * 201 * @dev: the device structure 202 * 203 * Return: 0 on success, <0 on failure. 204 */ 205 int mei_start(struct mei_device *dev) 206 { 207 int ret; 208 209 mutex_lock(&dev->device_lock); 210 211 /* acknowledge interrupt and stop interrupts */ 212 mei_clear_interrupts(dev); 213 214 mei_hw_config(dev); 215 216 dev_dbg(dev->dev, "reset in start the mei device.\n"); 217 218 dev->reset_count = 0; 219 do { 220 dev->dev_state = MEI_DEV_INITIALIZING; 221 ret = mei_reset(dev); 222 223 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 224 dev_err(dev->dev, "reset failed ret = %d", ret); 225 goto err; 226 } 227 } while (ret); 228 229 /* we cannot start the device w/o hbm start message completed */ 230 if (dev->dev_state == MEI_DEV_DISABLED) { 231 dev_err(dev->dev, "reset failed"); 232 goto err; 233 } 234 235 if (mei_hbm_start_wait(dev)) { 236 dev_err(dev->dev, "HBM haven't started"); 237 goto err; 238 } 239 240 if (!mei_host_is_ready(dev)) { 241 dev_err(dev->dev, "host is not ready.\n"); 242 goto err; 243 } 244 245 if (!mei_hw_is_ready(dev)) { 246 dev_err(dev->dev, "ME is not ready.\n"); 247 goto err; 248 } 249 250 if (!mei_hbm_version_is_supported(dev)) { 251 dev_dbg(dev->dev, "MEI start failed.\n"); 252 goto err; 253 } 254 255 dev_dbg(dev->dev, "link layer has been established.\n"); 256 257 mutex_unlock(&dev->device_lock); 258 return 0; 259 err: 260 dev_err(dev->dev, "link layer initialization failed.\n"); 261 dev->dev_state = MEI_DEV_DISABLED; 262 mutex_unlock(&dev->device_lock); 263 return -ENODEV; 264 } 265 EXPORT_SYMBOL_GPL(mei_start); 266 267 /** 268 * mei_restart - restart device after suspend 269 * 270 * @dev: the device structure 271 * 272 * Return: 0 on success or -ENODEV if the restart hasn't succeeded 273 */ 274 int mei_restart(struct mei_device *dev) 275 { 276 int err; 277 278 mutex_lock(&dev->device_lock); 279 280 dev->dev_state = MEI_DEV_POWER_UP; 281 dev->reset_count = 0; 282 283 err = mei_reset(dev); 284 285 mutex_unlock(&dev->device_lock); 286 287 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 288 dev_err(dev->dev, "device disabled = %d\n", err); 289 return -ENODEV; 290 } 291 292 /* try to start again */ 293 if (err) 294 schedule_work(&dev->reset_work); 295 296 297 return 0; 298 } 299 EXPORT_SYMBOL_GPL(mei_restart); 300 301 static void mei_reset_work(struct work_struct *work) 302 { 303 struct mei_device *dev = 304 container_of(work, struct mei_device, reset_work); 305 int ret; 306 307 mutex_lock(&dev->device_lock); 308 309 ret = mei_reset(dev); 310 311 mutex_unlock(&dev->device_lock); 312 313 if (dev->dev_state == MEI_DEV_DISABLED) { 314 dev_err(dev->dev, "device disabled = %d\n", ret); 315 return; 316 } 317 318 /* retry reset in case of failure */ 319 if (ret) 320 schedule_work(&dev->reset_work); 321 } 322 323 void mei_stop(struct mei_device *dev) 324 { 325 dev_dbg(dev->dev, "stopping the device.\n"); 326 327 mei_cl_bus_remove_devices(dev); 328 329 mei_cancel_work(dev); 330 331 mutex_lock(&dev->device_lock); 332 333 dev->dev_state = MEI_DEV_POWER_DOWN; 334 mei_reset(dev); 335 /* move device to disabled state unconditionally */ 336 dev->dev_state = MEI_DEV_DISABLED; 337 338 mutex_unlock(&dev->device_lock); 339 } 340 EXPORT_SYMBOL_GPL(mei_stop); 341 342 /** 343 * mei_write_is_idle - check if the write queues are idle 344 * 345 * @dev: the device structure 346 * 347 * Return: true of there is no pending write 348 */ 349 bool mei_write_is_idle(struct mei_device *dev) 350 { 351 bool idle = (dev->dev_state == MEI_DEV_ENABLED && 352 list_empty(&dev->ctrl_wr_list) && 353 list_empty(&dev->write_list) && 354 list_empty(&dev->write_waiting_list)); 355 356 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n", 357 idle, 358 mei_dev_state_str(dev->dev_state), 359 list_empty(&dev->ctrl_wr_list), 360 list_empty(&dev->write_list), 361 list_empty(&dev->write_waiting_list)); 362 363 return idle; 364 } 365 EXPORT_SYMBOL_GPL(mei_write_is_idle); 366 367 /** 368 * mei_device_init -- initialize mei_device structure 369 * 370 * @dev: the mei device 371 * @device: the device structure 372 * @hw_ops: hw operations 373 */ 374 void mei_device_init(struct mei_device *dev, 375 struct device *device, 376 const struct mei_hw_ops *hw_ops) 377 { 378 /* setup our list array */ 379 INIT_LIST_HEAD(&dev->file_list); 380 INIT_LIST_HEAD(&dev->device_list); 381 INIT_LIST_HEAD(&dev->me_clients); 382 mutex_init(&dev->device_lock); 383 init_rwsem(&dev->me_clients_rwsem); 384 mutex_init(&dev->cl_bus_lock); 385 init_waitqueue_head(&dev->wait_hw_ready); 386 init_waitqueue_head(&dev->wait_pg); 387 init_waitqueue_head(&dev->wait_hbm_start); 388 dev->dev_state = MEI_DEV_INITIALIZING; 389 dev->reset_count = 0; 390 391 INIT_LIST_HEAD(&dev->write_list); 392 INIT_LIST_HEAD(&dev->write_waiting_list); 393 INIT_LIST_HEAD(&dev->ctrl_wr_list); 394 INIT_LIST_HEAD(&dev->ctrl_rd_list); 395 396 INIT_DELAYED_WORK(&dev->timer_work, mei_timer); 397 INIT_WORK(&dev->reset_work, mei_reset_work); 398 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work); 399 400 INIT_LIST_HEAD(&dev->iamthif_cl.link); 401 INIT_LIST_HEAD(&dev->amthif_cmd_list); 402 403 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX); 404 dev->open_handle_count = 0; 405 406 /* 407 * Reserving the first client ID 408 * 0: Reserved for MEI Bus Message communications 409 */ 410 bitmap_set(dev->host_clients_map, 0, 1); 411 412 dev->pg_event = MEI_PG_EVENT_IDLE; 413 dev->ops = hw_ops; 414 dev->dev = device; 415 } 416 EXPORT_SYMBOL_GPL(mei_device_init); 417 418