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