1 // SPDX-License-Identifier: GPL-2.0+ 2 // Debug logs for the ChromeOS EC 3 // 4 // Copyright (C) 2015 Google, Inc. 5 6 #include <linux/circ_buf.h> 7 #include <linux/debugfs.h> 8 #include <linux/delay.h> 9 #include <linux/fs.h> 10 #include <linux/module.h> 11 #include <linux/mutex.h> 12 #include <linux/platform_data/cros_ec_commands.h> 13 #include <linux/platform_data/cros_ec_proto.h> 14 #include <linux/platform_device.h> 15 #include <linux/poll.h> 16 #include <linux/sched.h> 17 #include <linux/slab.h> 18 #include <linux/wait.h> 19 20 #define DRV_NAME "cros-ec-debugfs" 21 22 #define LOG_SHIFT 14 23 #define LOG_SIZE (1 << LOG_SHIFT) 24 #define LOG_POLL_SEC 10 25 26 #define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1)) 27 28 static unsigned int log_poll_period_ms = LOG_POLL_SEC * MSEC_PER_SEC; 29 module_param(log_poll_period_ms, uint, 0644); 30 MODULE_PARM_DESC(log_poll_period_ms, "EC log polling period(ms)"); 31 32 /* waitqueue for log readers */ 33 static DECLARE_WAIT_QUEUE_HEAD(cros_ec_debugfs_log_wq); 34 35 /** 36 * struct cros_ec_debugfs - EC debugging information. 37 * 38 * @ec: EC device this debugfs information belongs to 39 * @dir: dentry for debugfs files 40 * @log_buffer: circular buffer for console log information 41 * @read_msg: preallocated EC command and buffer to read console log 42 * @log_mutex: mutex to protect circular buffer 43 * @log_poll_work: recurring task to poll EC for new console log data 44 * @panicinfo_blob: panicinfo debugfs blob 45 * @notifier_panic: notifier_block to let kernel to flush buffered log 46 * when EC panic 47 */ 48 struct cros_ec_debugfs { 49 struct cros_ec_dev *ec; 50 struct dentry *dir; 51 /* EC log */ 52 struct circ_buf log_buffer; 53 struct cros_ec_command *read_msg; 54 struct mutex log_mutex; 55 struct delayed_work log_poll_work; 56 /* EC panicinfo */ 57 struct debugfs_blob_wrapper panicinfo_blob; 58 struct notifier_block notifier_panic; 59 }; 60 61 /* 62 * We need to make sure that the EC log buffer on the UART is large enough, 63 * so that it is unlikely enough to overlow within log_poll_period_ms. 64 */ 65 static void cros_ec_console_log_work(struct work_struct *__work) 66 { 67 struct cros_ec_debugfs *debug_info = 68 container_of(to_delayed_work(__work), 69 struct cros_ec_debugfs, 70 log_poll_work); 71 struct cros_ec_dev *ec = debug_info->ec; 72 struct circ_buf *cb = &debug_info->log_buffer; 73 struct cros_ec_command snapshot_msg = { 74 .command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset, 75 }; 76 77 struct ec_params_console_read_v1 *read_params = 78 (struct ec_params_console_read_v1 *)debug_info->read_msg->data; 79 uint8_t *ec_buffer = (uint8_t *)debug_info->read_msg->data; 80 int idx; 81 int buf_space; 82 int ret; 83 84 ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg); 85 if (ret < 0) 86 goto resched; 87 88 /* Loop until we have read everything, or there's an error. */ 89 mutex_lock(&debug_info->log_mutex); 90 buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE); 91 92 while (1) { 93 if (!buf_space) { 94 dev_info_once(ec->dev, 95 "Some logs may have been dropped...\n"); 96 break; 97 } 98 99 memset(read_params, '\0', sizeof(*read_params)); 100 read_params->subcmd = CONSOLE_READ_RECENT; 101 ret = cros_ec_cmd_xfer_status(ec->ec_dev, 102 debug_info->read_msg); 103 if (ret < 0) 104 break; 105 106 /* If the buffer is empty, we're done here. */ 107 if (ret == 0 || ec_buffer[0] == '\0') 108 break; 109 110 idx = 0; 111 while (idx < ret && ec_buffer[idx] != '\0' && buf_space > 0) { 112 cb->buf[cb->head] = ec_buffer[idx]; 113 cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1); 114 idx++; 115 buf_space--; 116 } 117 118 wake_up(&cros_ec_debugfs_log_wq); 119 } 120 121 mutex_unlock(&debug_info->log_mutex); 122 123 resched: 124 schedule_delayed_work(&debug_info->log_poll_work, 125 msecs_to_jiffies(log_poll_period_ms)); 126 } 127 128 static int cros_ec_console_log_open(struct inode *inode, struct file *file) 129 { 130 file->private_data = inode->i_private; 131 132 return stream_open(inode, file); 133 } 134 135 static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf, 136 size_t count, loff_t *ppos) 137 { 138 struct cros_ec_debugfs *debug_info = file->private_data; 139 struct circ_buf *cb = &debug_info->log_buffer; 140 ssize_t ret; 141 142 mutex_lock(&debug_info->log_mutex); 143 144 while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) { 145 if (file->f_flags & O_NONBLOCK) { 146 ret = -EAGAIN; 147 goto error; 148 } 149 150 mutex_unlock(&debug_info->log_mutex); 151 152 ret = wait_event_interruptible(cros_ec_debugfs_log_wq, 153 CIRC_CNT(cb->head, cb->tail, LOG_SIZE)); 154 if (ret < 0) 155 return ret; 156 157 mutex_lock(&debug_info->log_mutex); 158 } 159 160 /* Only copy until the end of the circular buffer, and let userspace 161 * retry to get the rest of the data. 162 */ 163 ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE), 164 count); 165 166 if (copy_to_user(buf, cb->buf + cb->tail, ret)) { 167 ret = -EFAULT; 168 goto error; 169 } 170 171 cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret); 172 173 error: 174 mutex_unlock(&debug_info->log_mutex); 175 return ret; 176 } 177 178 static __poll_t cros_ec_console_log_poll(struct file *file, 179 poll_table *wait) 180 { 181 struct cros_ec_debugfs *debug_info = file->private_data; 182 __poll_t mask = 0; 183 184 poll_wait(file, &cros_ec_debugfs_log_wq, wait); 185 186 mutex_lock(&debug_info->log_mutex); 187 if (CIRC_CNT(debug_info->log_buffer.head, 188 debug_info->log_buffer.tail, 189 LOG_SIZE)) 190 mask |= EPOLLIN | EPOLLRDNORM; 191 mutex_unlock(&debug_info->log_mutex); 192 193 return mask; 194 } 195 196 static int cros_ec_console_log_release(struct inode *inode, struct file *file) 197 { 198 return 0; 199 } 200 201 static ssize_t cros_ec_pdinfo_read(struct file *file, 202 char __user *user_buf, 203 size_t count, 204 loff_t *ppos) 205 { 206 char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf; 207 struct cros_ec_debugfs *debug_info = file->private_data; 208 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 209 DEFINE_RAW_FLEX(struct cros_ec_command, msg, data, 210 MAX(sizeof(struct ec_response_usb_pd_control_v1), 211 sizeof(struct ec_params_usb_pd_control))); 212 struct ec_response_usb_pd_control_v1 *resp = 213 (struct ec_response_usb_pd_control_v1 *)msg->data; 214 struct ec_params_usb_pd_control *params = 215 (struct ec_params_usb_pd_control *)msg->data; 216 int i; 217 218 msg->command = EC_CMD_USB_PD_CONTROL; 219 msg->version = 1; 220 msg->insize = sizeof(*resp); 221 msg->outsize = sizeof(*params); 222 223 /* 224 * Read status from all PD ports until failure, typically caused 225 * by attempting to read status on a port that doesn't exist. 226 */ 227 for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) { 228 params->port = i; 229 params->role = 0; 230 params->mux = 0; 231 params->swap = 0; 232 233 if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0) 234 break; 235 236 p += scnprintf(p, sizeof(read_buf) + read_buf - p, 237 "p%d: %s en:%.2x role:%.2x pol:%.2x\n", i, 238 resp->state, resp->enabled, resp->role, 239 resp->polarity); 240 } 241 242 return simple_read_from_buffer(user_buf, count, ppos, 243 read_buf, p - read_buf); 244 } 245 246 static bool cros_ec_uptime_is_supported(struct cros_ec_device *ec_dev) 247 { 248 DEFINE_RAW_FLEX(struct cros_ec_command, msg, data, 249 sizeof(struct ec_response_uptime_info)); 250 int ret; 251 252 msg->command = EC_CMD_GET_UPTIME_INFO; 253 msg->insize = sizeof(struct ec_response_uptime_info); 254 255 ret = cros_ec_cmd_xfer_status(ec_dev, msg); 256 if (ret == -EPROTO && msg->result == EC_RES_INVALID_COMMAND) 257 return false; 258 259 /* Other errors maybe a transient error, do not rule about support. */ 260 return true; 261 } 262 263 static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf, 264 size_t count, loff_t *ppos) 265 { 266 struct cros_ec_debugfs *debug_info = file->private_data; 267 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 268 DEFINE_RAW_FLEX(struct cros_ec_command, msg, data, 269 sizeof(struct ec_response_uptime_info)); 270 struct ec_response_uptime_info *resp = 271 (struct ec_response_uptime_info *)msg->data; 272 char read_buf[32]; 273 int ret; 274 275 msg->command = EC_CMD_GET_UPTIME_INFO; 276 msg->insize = sizeof(*resp); 277 278 ret = cros_ec_cmd_xfer_status(ec_dev, msg); 279 if (ret < 0) 280 return ret; 281 282 ret = scnprintf(read_buf, sizeof(read_buf), "%u\n", 283 resp->time_since_ec_boot_ms); 284 285 return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret); 286 } 287 288 static const struct file_operations cros_ec_console_log_fops = { 289 .owner = THIS_MODULE, 290 .open = cros_ec_console_log_open, 291 .read = cros_ec_console_log_read, 292 .poll = cros_ec_console_log_poll, 293 .release = cros_ec_console_log_release, 294 }; 295 296 static const struct file_operations cros_ec_pdinfo_fops = { 297 .owner = THIS_MODULE, 298 .open = simple_open, 299 .read = cros_ec_pdinfo_read, 300 .llseek = default_llseek, 301 }; 302 303 static const struct file_operations cros_ec_uptime_fops = { 304 .owner = THIS_MODULE, 305 .open = simple_open, 306 .read = cros_ec_uptime_read, 307 .llseek = default_llseek, 308 }; 309 310 static int ec_read_version_supported(struct cros_ec_dev *ec) 311 { 312 struct ec_params_get_cmd_versions_v1 *params; 313 struct ec_response_get_cmd_versions *response; 314 int ret; 315 316 struct cros_ec_command *msg; 317 318 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), 319 GFP_KERNEL); 320 if (!msg) 321 return 0; 322 323 msg->version = 1; 324 msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset; 325 msg->outsize = sizeof(*params); 326 msg->insize = sizeof(*response); 327 328 params = (struct ec_params_get_cmd_versions_v1 *)msg->data; 329 params->cmd = EC_CMD_CONSOLE_READ; 330 response = (struct ec_response_get_cmd_versions *)msg->data; 331 332 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 && 333 response->version_mask & EC_VER_MASK(1); 334 335 kfree(msg); 336 337 return ret; 338 } 339 340 static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info) 341 { 342 struct cros_ec_dev *ec = debug_info->ec; 343 char *buf; 344 int read_params_size; 345 int read_response_size; 346 347 /* 348 * If the console log feature is not supported return silently and 349 * don't create the console_log entry. 350 */ 351 if (!ec_read_version_supported(ec)) 352 return 0; 353 354 buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL); 355 if (!buf) 356 return -ENOMEM; 357 358 read_params_size = sizeof(struct ec_params_console_read_v1); 359 read_response_size = ec->ec_dev->max_response; 360 debug_info->read_msg = devm_kzalloc(ec->dev, 361 sizeof(*debug_info->read_msg) + 362 max(read_params_size, read_response_size), GFP_KERNEL); 363 if (!debug_info->read_msg) 364 return -ENOMEM; 365 366 debug_info->read_msg->version = 1; 367 debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset; 368 debug_info->read_msg->outsize = read_params_size; 369 debug_info->read_msg->insize = read_response_size; 370 371 debug_info->log_buffer.buf = buf; 372 debug_info->log_buffer.head = 0; 373 debug_info->log_buffer.tail = 0; 374 375 mutex_init(&debug_info->log_mutex); 376 377 debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir, 378 debug_info, &cros_ec_console_log_fops); 379 380 INIT_DELAYED_WORK(&debug_info->log_poll_work, 381 cros_ec_console_log_work); 382 schedule_delayed_work(&debug_info->log_poll_work, 0); 383 384 return 0; 385 } 386 387 static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info) 388 { 389 if (debug_info->log_buffer.buf) { 390 cancel_delayed_work_sync(&debug_info->log_poll_work); 391 mutex_destroy(&debug_info->log_mutex); 392 } 393 } 394 395 /* 396 * Returns the size of the panicinfo data fetched from the EC 397 */ 398 static int cros_ec_get_panicinfo(struct cros_ec_device *ec_dev, uint8_t *data, 399 int data_size) 400 { 401 int ret; 402 struct cros_ec_command *msg; 403 404 if (!data || data_size <= 0 || data_size > ec_dev->max_response) 405 return -EINVAL; 406 407 msg = kzalloc(sizeof(*msg) + data_size, GFP_KERNEL); 408 if (!msg) 409 return -ENOMEM; 410 411 msg->command = EC_CMD_GET_PANIC_INFO; 412 msg->insize = data_size; 413 414 ret = cros_ec_cmd_xfer_status(ec_dev, msg); 415 if (ret < 0) 416 goto free; 417 418 memcpy(data, msg->data, data_size); 419 420 free: 421 kfree(msg); 422 return ret; 423 } 424 425 static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info) 426 { 427 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 428 int ret; 429 void *data; 430 431 data = devm_kzalloc(debug_info->ec->dev, ec_dev->max_response, 432 GFP_KERNEL); 433 if (!data) 434 return -ENOMEM; 435 436 ret = cros_ec_get_panicinfo(ec_dev, data, ec_dev->max_response); 437 if (ret < 0) { 438 ret = 0; 439 goto free; 440 } 441 442 /* No panic data */ 443 if (ret == 0) 444 goto free; 445 446 debug_info->panicinfo_blob.data = data; 447 debug_info->panicinfo_blob.size = ret; 448 449 debugfs_create_blob("panicinfo", 0444, debug_info->dir, 450 &debug_info->panicinfo_blob); 451 452 return 0; 453 454 free: 455 devm_kfree(debug_info->ec->dev, data); 456 return ret; 457 } 458 459 static int cros_ec_debugfs_panic_event(struct notifier_block *nb, 460 unsigned long queued_during_suspend, void *_notify) 461 { 462 struct cros_ec_debugfs *debug_info = 463 container_of(nb, struct cros_ec_debugfs, notifier_panic); 464 465 if (debug_info->log_buffer.buf) { 466 /* Force log poll work to run immediately */ 467 mod_delayed_work(debug_info->log_poll_work.wq, &debug_info->log_poll_work, 0); 468 /* Block until log poll work finishes */ 469 flush_delayed_work(&debug_info->log_poll_work); 470 } 471 472 return NOTIFY_DONE; 473 } 474 475 static int cros_ec_debugfs_probe(struct platform_device *pd) 476 { 477 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); 478 struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev); 479 const char *name = ec_platform->ec_name; 480 struct cros_ec_debugfs *debug_info; 481 int ret; 482 483 debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL); 484 if (!debug_info) 485 return -ENOMEM; 486 487 debug_info->ec = ec; 488 debug_info->dir = debugfs_create_dir(name, NULL); 489 490 ret = cros_ec_create_panicinfo(debug_info); 491 if (ret) 492 goto remove_debugfs; 493 494 ret = cros_ec_create_console_log(debug_info); 495 if (ret) 496 goto remove_debugfs; 497 498 debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info, 499 &cros_ec_pdinfo_fops); 500 501 if (cros_ec_uptime_is_supported(ec->ec_dev)) 502 debugfs_create_file("uptime", 0444, debug_info->dir, debug_info, 503 &cros_ec_uptime_fops); 504 505 debugfs_create_x32("last_resume_result", 0444, debug_info->dir, 506 &ec->ec_dev->last_resume_result); 507 508 debugfs_create_u16("suspend_timeout_ms", 0664, debug_info->dir, 509 &ec->ec_dev->suspend_timeout_ms); 510 511 debug_info->notifier_panic.notifier_call = cros_ec_debugfs_panic_event; 512 ret = blocking_notifier_chain_register(&ec->ec_dev->panic_notifier, 513 &debug_info->notifier_panic); 514 if (ret) 515 goto remove_debugfs; 516 517 ec->debug_info = debug_info; 518 519 dev_set_drvdata(&pd->dev, ec); 520 521 return 0; 522 523 remove_debugfs: 524 debugfs_remove_recursive(debug_info->dir); 525 return ret; 526 } 527 528 static void cros_ec_debugfs_remove(struct platform_device *pd) 529 { 530 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); 531 532 debugfs_remove_recursive(ec->debug_info->dir); 533 cros_ec_cleanup_console_log(ec->debug_info); 534 } 535 536 static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev) 537 { 538 struct cros_ec_dev *ec = dev_get_drvdata(dev); 539 540 if (ec->debug_info->log_buffer.buf) 541 cancel_delayed_work_sync(&ec->debug_info->log_poll_work); 542 543 return 0; 544 } 545 546 static int __maybe_unused cros_ec_debugfs_resume(struct device *dev) 547 { 548 struct cros_ec_dev *ec = dev_get_drvdata(dev); 549 550 if (ec->debug_info->log_buffer.buf) 551 schedule_delayed_work(&ec->debug_info->log_poll_work, 0); 552 553 return 0; 554 } 555 556 static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops, 557 cros_ec_debugfs_suspend, cros_ec_debugfs_resume); 558 559 static const struct platform_device_id cros_ec_debugfs_id[] = { 560 { DRV_NAME, 0 }, 561 {} 562 }; 563 MODULE_DEVICE_TABLE(platform, cros_ec_debugfs_id); 564 565 static struct platform_driver cros_ec_debugfs_driver = { 566 .driver = { 567 .name = DRV_NAME, 568 .pm = &cros_ec_debugfs_pm_ops, 569 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 570 }, 571 .probe = cros_ec_debugfs_probe, 572 .remove = cros_ec_debugfs_remove, 573 .id_table = cros_ec_debugfs_id, 574 }; 575 576 module_platform_driver(cros_ec_debugfs_driver); 577 578 MODULE_LICENSE("GPL"); 579 MODULE_DESCRIPTION("Debug logs for ChromeOS EC"); 580