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 && state != MEI_DEV_POWER_UP) 150 mei_cl_all_disconnect(dev); 151 152 mei_hbm_reset(dev); 153 154 dev->rd_msg_hdr = 0; 155 156 if (ret) { 157 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret); 158 return ret; 159 } 160 161 if (state == MEI_DEV_POWER_DOWN) { 162 dev_dbg(dev->dev, "powering down: end of reset\n"); 163 dev->dev_state = MEI_DEV_DISABLED; 164 return 0; 165 } 166 167 ret = mei_hw_start(dev); 168 if (ret) { 169 dev_err(dev->dev, "hw_start failed ret = %d\n", ret); 170 return ret; 171 } 172 173 dev_dbg(dev->dev, "link is established start sending messages.\n"); 174 175 dev->dev_state = MEI_DEV_INIT_CLIENTS; 176 ret = mei_hbm_start_req(dev); 177 if (ret) { 178 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret); 179 dev->dev_state = MEI_DEV_RESETTING; 180 return ret; 181 } 182 183 return 0; 184 } 185 EXPORT_SYMBOL_GPL(mei_reset); 186 187 /** 188 * mei_start - initializes host and fw to start work. 189 * 190 * @dev: the device structure 191 * 192 * Return: 0 on success, <0 on failure. 193 */ 194 int mei_start(struct mei_device *dev) 195 { 196 int ret; 197 198 mutex_lock(&dev->device_lock); 199 200 /* acknowledge interrupt and stop interrupts */ 201 mei_clear_interrupts(dev); 202 203 mei_hw_config(dev); 204 205 dev_dbg(dev->dev, "reset in start the mei device.\n"); 206 207 dev->reset_count = 0; 208 do { 209 dev->dev_state = MEI_DEV_INITIALIZING; 210 ret = mei_reset(dev); 211 212 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 213 dev_err(dev->dev, "reset failed ret = %d", ret); 214 goto err; 215 } 216 } while (ret); 217 218 if (mei_hbm_start_wait(dev)) { 219 dev_err(dev->dev, "HBM haven't started"); 220 goto err; 221 } 222 223 if (!mei_host_is_ready(dev)) { 224 dev_err(dev->dev, "host is not ready.\n"); 225 goto err; 226 } 227 228 if (!mei_hw_is_ready(dev)) { 229 dev_err(dev->dev, "ME is not ready.\n"); 230 goto err; 231 } 232 233 if (!mei_hbm_version_is_supported(dev)) { 234 dev_dbg(dev->dev, "MEI start failed.\n"); 235 goto err; 236 } 237 238 dev_dbg(dev->dev, "link layer has been established.\n"); 239 240 mutex_unlock(&dev->device_lock); 241 return 0; 242 err: 243 dev_err(dev->dev, "link layer initialization failed.\n"); 244 dev->dev_state = MEI_DEV_DISABLED; 245 mutex_unlock(&dev->device_lock); 246 return -ENODEV; 247 } 248 EXPORT_SYMBOL_GPL(mei_start); 249 250 /** 251 * mei_restart - restart device after suspend 252 * 253 * @dev: the device structure 254 * 255 * Return: 0 on success or -ENODEV if the restart hasn't succeeded 256 */ 257 int mei_restart(struct mei_device *dev) 258 { 259 int err; 260 261 mutex_lock(&dev->device_lock); 262 263 dev->dev_state = MEI_DEV_POWER_UP; 264 dev->reset_count = 0; 265 266 err = mei_reset(dev); 267 268 mutex_unlock(&dev->device_lock); 269 270 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 271 dev_err(dev->dev, "device disabled = %d\n", err); 272 return -ENODEV; 273 } 274 275 /* try to start again */ 276 if (err) 277 schedule_work(&dev->reset_work); 278 279 280 return 0; 281 } 282 EXPORT_SYMBOL_GPL(mei_restart); 283 284 static void mei_reset_work(struct work_struct *work) 285 { 286 struct mei_device *dev = 287 container_of(work, struct mei_device, reset_work); 288 int ret; 289 290 mei_clear_interrupts(dev); 291 mei_synchronize_irq(dev); 292 293 mutex_lock(&dev->device_lock); 294 295 ret = mei_reset(dev); 296 297 mutex_unlock(&dev->device_lock); 298 299 if (dev->dev_state == MEI_DEV_DISABLED) { 300 dev_err(dev->dev, "device disabled = %d\n", ret); 301 return; 302 } 303 304 /* retry reset in case of failure */ 305 if (ret) 306 schedule_work(&dev->reset_work); 307 } 308 309 void mei_stop(struct mei_device *dev) 310 { 311 dev_dbg(dev->dev, "stopping the device.\n"); 312 313 mei_cl_bus_remove_devices(dev); 314 315 mei_cancel_work(dev); 316 317 mei_clear_interrupts(dev); 318 mei_synchronize_irq(dev); 319 320 mutex_lock(&dev->device_lock); 321 322 dev->dev_state = MEI_DEV_POWER_DOWN; 323 mei_reset(dev); 324 /* move device to disabled state unconditionally */ 325 dev->dev_state = MEI_DEV_DISABLED; 326 327 mutex_unlock(&dev->device_lock); 328 } 329 EXPORT_SYMBOL_GPL(mei_stop); 330 331 /** 332 * mei_write_is_idle - check if the write queues are idle 333 * 334 * @dev: the device structure 335 * 336 * Return: true of there is no pending write 337 */ 338 bool mei_write_is_idle(struct mei_device *dev) 339 { 340 bool idle = (dev->dev_state == MEI_DEV_ENABLED && 341 list_empty(&dev->ctrl_wr_list) && 342 list_empty(&dev->write_list) && 343 list_empty(&dev->write_waiting_list)); 344 345 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n", 346 idle, 347 mei_dev_state_str(dev->dev_state), 348 list_empty(&dev->ctrl_wr_list), 349 list_empty(&dev->write_list), 350 list_empty(&dev->write_waiting_list)); 351 352 return idle; 353 } 354 EXPORT_SYMBOL_GPL(mei_write_is_idle); 355 356 /** 357 * mei_device_init -- initialize mei_device structure 358 * 359 * @dev: the mei device 360 * @device: the device structure 361 * @hw_ops: hw operations 362 */ 363 void mei_device_init(struct mei_device *dev, 364 struct device *device, 365 const struct mei_hw_ops *hw_ops) 366 { 367 /* setup our list array */ 368 INIT_LIST_HEAD(&dev->file_list); 369 INIT_LIST_HEAD(&dev->device_list); 370 INIT_LIST_HEAD(&dev->me_clients); 371 mutex_init(&dev->device_lock); 372 init_rwsem(&dev->me_clients_rwsem); 373 mutex_init(&dev->cl_bus_lock); 374 init_waitqueue_head(&dev->wait_hw_ready); 375 init_waitqueue_head(&dev->wait_pg); 376 init_waitqueue_head(&dev->wait_hbm_start); 377 dev->dev_state = MEI_DEV_INITIALIZING; 378 dev->reset_count = 0; 379 380 INIT_LIST_HEAD(&dev->write_list); 381 INIT_LIST_HEAD(&dev->write_waiting_list); 382 INIT_LIST_HEAD(&dev->ctrl_wr_list); 383 INIT_LIST_HEAD(&dev->ctrl_rd_list); 384 385 INIT_DELAYED_WORK(&dev->timer_work, mei_timer); 386 INIT_WORK(&dev->reset_work, mei_reset_work); 387 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work); 388 389 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX); 390 dev->open_handle_count = 0; 391 392 /* 393 * Reserving the first client ID 394 * 0: Reserved for MEI Bus Message communications 395 */ 396 bitmap_set(dev->host_clients_map, 0, 1); 397 398 dev->pg_event = MEI_PG_EVENT_IDLE; 399 dev->ops = hw_ops; 400 dev->dev = device; 401 } 402 EXPORT_SYMBOL_GPL(mei_device_init); 403 404