1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2012-2018, 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 mei_hw_config(dev); 194 195 dev_dbg(dev->dev, "reset in start the mei device.\n"); 196 197 dev->reset_count = 0; 198 do { 199 mei_set_devstate(dev, MEI_DEV_INITIALIZING); 200 ret = mei_reset(dev); 201 202 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 203 dev_err(dev->dev, "reset failed ret = %d", ret); 204 goto err; 205 } 206 } while (ret); 207 208 if (mei_hbm_start_wait(dev)) { 209 dev_err(dev->dev, "HBM haven't started"); 210 goto err; 211 } 212 213 if (!mei_host_is_ready(dev)) { 214 dev_err(dev->dev, "host is not ready.\n"); 215 goto err; 216 } 217 218 if (!mei_hw_is_ready(dev)) { 219 dev_err(dev->dev, "ME is not ready.\n"); 220 goto err; 221 } 222 223 if (!mei_hbm_version_is_supported(dev)) { 224 dev_dbg(dev->dev, "MEI start failed.\n"); 225 goto err; 226 } 227 228 dev_dbg(dev->dev, "link layer has been established.\n"); 229 230 mutex_unlock(&dev->device_lock); 231 return 0; 232 err: 233 dev_err(dev->dev, "link layer initialization failed.\n"); 234 mei_set_devstate(dev, MEI_DEV_DISABLED); 235 mutex_unlock(&dev->device_lock); 236 return -ENODEV; 237 } 238 EXPORT_SYMBOL_GPL(mei_start); 239 240 /** 241 * mei_restart - restart device after suspend 242 * 243 * @dev: the device structure 244 * 245 * Return: 0 on success or -ENODEV if the restart hasn't succeeded 246 */ 247 int mei_restart(struct mei_device *dev) 248 { 249 int err; 250 251 mutex_lock(&dev->device_lock); 252 253 mei_set_devstate(dev, MEI_DEV_POWER_UP); 254 dev->reset_count = 0; 255 256 err = mei_reset(dev); 257 258 mutex_unlock(&dev->device_lock); 259 260 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) { 261 dev_err(dev->dev, "device disabled = %d\n", err); 262 return -ENODEV; 263 } 264 265 /* try to start again */ 266 if (err) 267 schedule_work(&dev->reset_work); 268 269 270 return 0; 271 } 272 EXPORT_SYMBOL_GPL(mei_restart); 273 274 static void mei_reset_work(struct work_struct *work) 275 { 276 struct mei_device *dev = 277 container_of(work, struct mei_device, reset_work); 278 int ret; 279 280 mei_clear_interrupts(dev); 281 mei_synchronize_irq(dev); 282 283 mutex_lock(&dev->device_lock); 284 285 ret = mei_reset(dev); 286 287 mutex_unlock(&dev->device_lock); 288 289 if (dev->dev_state == MEI_DEV_DISABLED) { 290 dev_err(dev->dev, "device disabled = %d\n", ret); 291 return; 292 } 293 294 /* retry reset in case of failure */ 295 if (ret) 296 schedule_work(&dev->reset_work); 297 } 298 299 void mei_stop(struct mei_device *dev) 300 { 301 dev_dbg(dev->dev, "stopping the device.\n"); 302 303 mutex_lock(&dev->device_lock); 304 mei_set_devstate(dev, MEI_DEV_POWER_DOWN); 305 mutex_unlock(&dev->device_lock); 306 mei_cl_bus_remove_devices(dev); 307 308 mei_cancel_work(dev); 309 310 mei_clear_interrupts(dev); 311 mei_synchronize_irq(dev); 312 313 mutex_lock(&dev->device_lock); 314 315 mei_reset(dev); 316 /* move device to disabled state unconditionally */ 317 mei_set_devstate(dev, MEI_DEV_DISABLED); 318 319 mutex_unlock(&dev->device_lock); 320 } 321 EXPORT_SYMBOL_GPL(mei_stop); 322 323 /** 324 * mei_write_is_idle - check if the write queues are idle 325 * 326 * @dev: the device structure 327 * 328 * Return: true of there is no pending write 329 */ 330 bool mei_write_is_idle(struct mei_device *dev) 331 { 332 bool idle = (dev->dev_state == MEI_DEV_ENABLED && 333 list_empty(&dev->ctrl_wr_list) && 334 list_empty(&dev->write_list) && 335 list_empty(&dev->write_waiting_list)); 336 337 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n", 338 idle, 339 mei_dev_state_str(dev->dev_state), 340 list_empty(&dev->ctrl_wr_list), 341 list_empty(&dev->write_list), 342 list_empty(&dev->write_waiting_list)); 343 344 return idle; 345 } 346 EXPORT_SYMBOL_GPL(mei_write_is_idle); 347 348 /** 349 * mei_device_init -- initialize mei_device structure 350 * 351 * @dev: the mei device 352 * @device: the device structure 353 * @hw_ops: hw operations 354 */ 355 void mei_device_init(struct mei_device *dev, 356 struct device *device, 357 const struct mei_hw_ops *hw_ops) 358 { 359 /* setup our list array */ 360 INIT_LIST_HEAD(&dev->file_list); 361 INIT_LIST_HEAD(&dev->device_list); 362 INIT_LIST_HEAD(&dev->me_clients); 363 mutex_init(&dev->device_lock); 364 init_rwsem(&dev->me_clients_rwsem); 365 mutex_init(&dev->cl_bus_lock); 366 init_waitqueue_head(&dev->wait_hw_ready); 367 init_waitqueue_head(&dev->wait_pg); 368 init_waitqueue_head(&dev->wait_hbm_start); 369 dev->dev_state = MEI_DEV_INITIALIZING; 370 dev->reset_count = 0; 371 372 INIT_LIST_HEAD(&dev->write_list); 373 INIT_LIST_HEAD(&dev->write_waiting_list); 374 INIT_LIST_HEAD(&dev->ctrl_wr_list); 375 INIT_LIST_HEAD(&dev->ctrl_rd_list); 376 dev->tx_queue_limit = MEI_TX_QUEUE_LIMIT_DEFAULT; 377 378 INIT_DELAYED_WORK(&dev->timer_work, mei_timer); 379 INIT_WORK(&dev->reset_work, mei_reset_work); 380 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work); 381 382 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX); 383 dev->open_handle_count = 0; 384 385 /* 386 * Reserving the first client ID 387 * 0: Reserved for MEI Bus Message communications 388 */ 389 bitmap_set(dev->host_clients_map, 0, 1); 390 391 dev->pg_event = MEI_PG_EVENT_IDLE; 392 dev->ops = hw_ops; 393 dev->dev = device; 394 } 395 EXPORT_SYMBOL_GPL(mei_device_init); 396 397