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 /* we're already in reset, cancel the init timer 126 * if the reset was called due the hbm protocol error 127 * we need to call it before hw start 128 * so the hbm watchdog won't kick in 129 */ 130 mei_hbm_idle(dev); 131 132 /* enter reset flow */ 133 interrupts_enabled = state != MEI_DEV_POWER_DOWN; 134 dev->dev_state = MEI_DEV_RESETTING; 135 136 dev->reset_count++; 137 if (dev->reset_count > MEI_MAX_CONSEC_RESET) { 138 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n"); 139 dev->dev_state = MEI_DEV_DISABLED; 140 return -ENODEV; 141 } 142 143 ret = mei_hw_reset(dev, interrupts_enabled); 144 /* fall through and remove the sw state even if hw reset has failed */ 145 146 /* no need to clean up software state in case of power up */ 147 if (state != MEI_DEV_INITIALIZING && 148 state != MEI_DEV_POWER_UP) { 149 150 /* remove all waiting requests */ 151 mei_cl_all_disconnect(dev); 152 153 /* remove entry if already in list */ 154 dev_dbg(dev->dev, "remove iamthif from the file list.\n"); 155 mei_cl_unlink(&dev->iamthif_cl); 156 mei_amthif_reset_params(dev); 157 } 158 159 mei_hbm_reset(dev); 160 161 dev->rd_msg_hdr = 0; 162 163 if (ret) { 164 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret); 165 return ret; 166 } 167 168 if (state == MEI_DEV_POWER_DOWN) { 169 dev_dbg(dev->dev, "powering down: end of reset\n"); 170 dev->dev_state = MEI_DEV_DISABLED; 171 return 0; 172 } 173 174 ret = mei_hw_start(dev); 175 if (ret) { 176 dev_err(dev->dev, "hw_start failed ret = %d\n", ret); 177 return ret; 178 } 179 180 dev_dbg(dev->dev, "link is established start sending messages.\n"); 181 182 dev->dev_state = 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 dev->dev_state = 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 mei_hw_config(dev); 211 212 dev_dbg(dev->dev, "reset in start the mei device.\n"); 213 214 dev->reset_count = 0; 215 do { 216 dev->dev_state = MEI_DEV_INITIALIZING; 217 ret = mei_reset(dev); 218 219 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 220 dev_err(dev->dev, "reset failed ret = %d", ret); 221 goto err; 222 } 223 } while (ret); 224 225 /* we cannot start the device w/o hbm start message completed */ 226 if (dev->dev_state == MEI_DEV_DISABLED) { 227 dev_err(dev->dev, "reset failed"); 228 goto err; 229 } 230 231 if (mei_hbm_start_wait(dev)) { 232 dev_err(dev->dev, "HBM haven't started"); 233 goto err; 234 } 235 236 if (!mei_host_is_ready(dev)) { 237 dev_err(dev->dev, "host is not ready.\n"); 238 goto err; 239 } 240 241 if (!mei_hw_is_ready(dev)) { 242 dev_err(dev->dev, "ME is not ready.\n"); 243 goto err; 244 } 245 246 if (!mei_hbm_version_is_supported(dev)) { 247 dev_dbg(dev->dev, "MEI start failed.\n"); 248 goto err; 249 } 250 251 dev_dbg(dev->dev, "link layer has been established.\n"); 252 253 mutex_unlock(&dev->device_lock); 254 return 0; 255 err: 256 dev_err(dev->dev, "link layer initialization failed.\n"); 257 dev->dev_state = MEI_DEV_DISABLED; 258 mutex_unlock(&dev->device_lock); 259 return -ENODEV; 260 } 261 EXPORT_SYMBOL_GPL(mei_start); 262 263 /** 264 * mei_restart - restart device after suspend 265 * 266 * @dev: the device structure 267 * 268 * Return: 0 on success or -ENODEV if the restart hasn't succeeded 269 */ 270 int mei_restart(struct mei_device *dev) 271 { 272 int err; 273 274 mutex_lock(&dev->device_lock); 275 276 mei_clear_interrupts(dev); 277 278 dev->dev_state = MEI_DEV_POWER_UP; 279 dev->reset_count = 0; 280 281 err = mei_reset(dev); 282 283 mutex_unlock(&dev->device_lock); 284 285 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 286 dev_err(dev->dev, "device disabled = %d\n", err); 287 return -ENODEV; 288 } 289 290 /* try to start again */ 291 if (err) 292 schedule_work(&dev->reset_work); 293 294 295 return 0; 296 } 297 EXPORT_SYMBOL_GPL(mei_restart); 298 299 static void mei_reset_work(struct work_struct *work) 300 { 301 struct mei_device *dev = 302 container_of(work, struct mei_device, reset_work); 303 int ret; 304 305 mutex_lock(&dev->device_lock); 306 307 ret = mei_reset(dev); 308 309 mutex_unlock(&dev->device_lock); 310 311 if (dev->dev_state == MEI_DEV_DISABLED) { 312 dev_err(dev->dev, "device disabled = %d\n", ret); 313 return; 314 } 315 316 /* retry reset in case of failure */ 317 if (ret) 318 schedule_work(&dev->reset_work); 319 } 320 321 void mei_stop(struct mei_device *dev) 322 { 323 dev_dbg(dev->dev, "stopping the device.\n"); 324 325 mei_cl_bus_remove_devices(dev); 326 327 mei_cancel_work(dev); 328 329 mutex_lock(&dev->device_lock); 330 331 dev->dev_state = MEI_DEV_POWER_DOWN; 332 mei_reset(dev); 333 /* move device to disabled state unconditionally */ 334 dev->dev_state = MEI_DEV_DISABLED; 335 336 mutex_unlock(&dev->device_lock); 337 } 338 EXPORT_SYMBOL_GPL(mei_stop); 339 340 /** 341 * mei_write_is_idle - check if the write queues are idle 342 * 343 * @dev: the device structure 344 * 345 * Return: true of there is no pending write 346 */ 347 bool mei_write_is_idle(struct mei_device *dev) 348 { 349 bool idle = (dev->dev_state == MEI_DEV_ENABLED && 350 list_empty(&dev->ctrl_wr_list.list) && 351 list_empty(&dev->write_list.list) && 352 list_empty(&dev->write_waiting_list.list)); 353 354 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n", 355 idle, 356 mei_dev_state_str(dev->dev_state), 357 list_empty(&dev->ctrl_wr_list.list), 358 list_empty(&dev->write_list.list), 359 list_empty(&dev->write_waiting_list.list)); 360 361 return idle; 362 } 363 EXPORT_SYMBOL_GPL(mei_write_is_idle); 364 365 /** 366 * mei_device_init -- initialize mei_device structure 367 * 368 * @dev: the mei device 369 * @device: the device structure 370 * @hw_ops: hw operations 371 */ 372 void mei_device_init(struct mei_device *dev, 373 struct device *device, 374 const struct mei_hw_ops *hw_ops) 375 { 376 /* setup our list array */ 377 INIT_LIST_HEAD(&dev->file_list); 378 INIT_LIST_HEAD(&dev->device_list); 379 INIT_LIST_HEAD(&dev->me_clients); 380 mutex_init(&dev->device_lock); 381 init_rwsem(&dev->me_clients_rwsem); 382 mutex_init(&dev->cl_bus_lock); 383 init_waitqueue_head(&dev->wait_hw_ready); 384 init_waitqueue_head(&dev->wait_pg); 385 init_waitqueue_head(&dev->wait_hbm_start); 386 dev->dev_state = MEI_DEV_INITIALIZING; 387 dev->reset_count = 0; 388 389 mei_io_list_init(&dev->write_list); 390 mei_io_list_init(&dev->write_waiting_list); 391 mei_io_list_init(&dev->ctrl_wr_list); 392 mei_io_list_init(&dev->ctrl_rd_list); 393 394 INIT_DELAYED_WORK(&dev->timer_work, mei_timer); 395 INIT_WORK(&dev->reset_work, mei_reset_work); 396 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work); 397 398 INIT_LIST_HEAD(&dev->iamthif_cl.link); 399 mei_io_list_init(&dev->amthif_cmd_list); 400 401 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX); 402 dev->open_handle_count = 0; 403 404 /* 405 * Reserving the first client ID 406 * 0: Reserved for MEI Bus Message communications 407 */ 408 bitmap_set(dev->host_clients_map, 0, 1); 409 410 dev->pg_event = MEI_PG_EVENT_IDLE; 411 dev->ops = hw_ops; 412 dev->dev = device; 413 } 414 EXPORT_SYMBOL_GPL(mei_device_init); 415 416