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/mod_devicetable.h> 11 #include <linux/module.h> 12 #include <linux/mutex.h> 13 #include <linux/platform_data/cros_ec_commands.h> 14 #include <linux/platform_data/cros_ec_proto.h> 15 #include <linux/platform_device.h> 16 #include <linux/poll.h> 17 #include <linux/sched.h> 18 #include <linux/slab.h> 19 #include <linux/wait.h> 20 21 #define DRV_NAME "cros-ec-debugfs" 22 23 #define LOG_SHIFT 14 24 #define LOG_SIZE (1 << LOG_SHIFT) 25 #define LOG_POLL_SEC 10 26 27 #define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1)) 28 29 /* waitqueue for log readers */ 30 static DECLARE_WAIT_QUEUE_HEAD(cros_ec_debugfs_log_wq); 31 32 /** 33 * struct cros_ec_debugfs - EC debugging information. 34 * 35 * @ec: EC device this debugfs information belongs to 36 * @dir: dentry for debugfs files 37 * @log_buffer: circular buffer for console log information 38 * @read_msg: preallocated EC command and buffer to read console log 39 * @log_mutex: mutex to protect circular buffer 40 * @log_poll_work: recurring task to poll EC for new console log data 41 * @panicinfo_blob: panicinfo debugfs blob 42 * @notifier_panic: notifier_block to let kernel to flush buffered log 43 * when EC panic 44 */ 45 struct cros_ec_debugfs { 46 struct cros_ec_dev *ec; 47 struct dentry *dir; 48 /* EC log */ 49 struct circ_buf log_buffer; 50 struct cros_ec_command *read_msg; 51 struct mutex log_mutex; 52 struct delayed_work log_poll_work; 53 /* EC panicinfo */ 54 struct debugfs_blob_wrapper panicinfo_blob; 55 struct notifier_block notifier_panic; 56 }; 57 58 /* 59 * We need to make sure that the EC log buffer on the UART is large enough, 60 * so that it is unlikely enough to overlow within LOG_POLL_SEC. 61 */ 62 static void cros_ec_console_log_work(struct work_struct *__work) 63 { 64 struct cros_ec_debugfs *debug_info = 65 container_of(to_delayed_work(__work), 66 struct cros_ec_debugfs, 67 log_poll_work); 68 struct cros_ec_dev *ec = debug_info->ec; 69 struct circ_buf *cb = &debug_info->log_buffer; 70 struct cros_ec_command snapshot_msg = { 71 .command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset, 72 }; 73 74 struct ec_params_console_read_v1 *read_params = 75 (struct ec_params_console_read_v1 *)debug_info->read_msg->data; 76 uint8_t *ec_buffer = (uint8_t *)debug_info->read_msg->data; 77 int idx; 78 int buf_space; 79 int ret; 80 81 ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg); 82 if (ret < 0) 83 goto resched; 84 85 /* Loop until we have read everything, or there's an error. */ 86 mutex_lock(&debug_info->log_mutex); 87 buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE); 88 89 while (1) { 90 if (!buf_space) { 91 dev_info_once(ec->dev, 92 "Some logs may have been dropped...\n"); 93 break; 94 } 95 96 memset(read_params, '\0', sizeof(*read_params)); 97 read_params->subcmd = CONSOLE_READ_RECENT; 98 ret = cros_ec_cmd_xfer_status(ec->ec_dev, 99 debug_info->read_msg); 100 if (ret < 0) 101 break; 102 103 /* If the buffer is empty, we're done here. */ 104 if (ret == 0 || ec_buffer[0] == '\0') 105 break; 106 107 idx = 0; 108 while (idx < ret && ec_buffer[idx] != '\0' && buf_space > 0) { 109 cb->buf[cb->head] = ec_buffer[idx]; 110 cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1); 111 idx++; 112 buf_space--; 113 } 114 115 wake_up(&cros_ec_debugfs_log_wq); 116 } 117 118 mutex_unlock(&debug_info->log_mutex); 119 120 resched: 121 schedule_delayed_work(&debug_info->log_poll_work, 122 msecs_to_jiffies(LOG_POLL_SEC * 1000)); 123 } 124 125 static int cros_ec_console_log_open(struct inode *inode, struct file *file) 126 { 127 file->private_data = inode->i_private; 128 129 return stream_open(inode, file); 130 } 131 132 static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf, 133 size_t count, loff_t *ppos) 134 { 135 struct cros_ec_debugfs *debug_info = file->private_data; 136 struct circ_buf *cb = &debug_info->log_buffer; 137 ssize_t ret; 138 139 mutex_lock(&debug_info->log_mutex); 140 141 while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) { 142 if (file->f_flags & O_NONBLOCK) { 143 ret = -EAGAIN; 144 goto error; 145 } 146 147 mutex_unlock(&debug_info->log_mutex); 148 149 ret = wait_event_interruptible(cros_ec_debugfs_log_wq, 150 CIRC_CNT(cb->head, cb->tail, LOG_SIZE)); 151 if (ret < 0) 152 return ret; 153 154 mutex_lock(&debug_info->log_mutex); 155 } 156 157 /* Only copy until the end of the circular buffer, and let userspace 158 * retry to get the rest of the data. 159 */ 160 ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE), 161 count); 162 163 if (copy_to_user(buf, cb->buf + cb->tail, ret)) { 164 ret = -EFAULT; 165 goto error; 166 } 167 168 cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret); 169 170 error: 171 mutex_unlock(&debug_info->log_mutex); 172 return ret; 173 } 174 175 static __poll_t cros_ec_console_log_poll(struct file *file, 176 poll_table *wait) 177 { 178 struct cros_ec_debugfs *debug_info = file->private_data; 179 __poll_t mask = 0; 180 181 poll_wait(file, &cros_ec_debugfs_log_wq, wait); 182 183 mutex_lock(&debug_info->log_mutex); 184 if (CIRC_CNT(debug_info->log_buffer.head, 185 debug_info->log_buffer.tail, 186 LOG_SIZE)) 187 mask |= EPOLLIN | EPOLLRDNORM; 188 mutex_unlock(&debug_info->log_mutex); 189 190 return mask; 191 } 192 193 static int cros_ec_console_log_release(struct inode *inode, struct file *file) 194 { 195 return 0; 196 } 197 198 static ssize_t cros_ec_pdinfo_read(struct file *file, 199 char __user *user_buf, 200 size_t count, 201 loff_t *ppos) 202 { 203 char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf; 204 struct cros_ec_debugfs *debug_info = file->private_data; 205 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 206 struct { 207 struct cros_ec_command msg; 208 union { 209 struct ec_response_usb_pd_control_v1 resp; 210 struct ec_params_usb_pd_control params; 211 }; 212 } __packed ec_buf; 213 struct cros_ec_command *msg; 214 struct ec_response_usb_pd_control_v1 *resp; 215 struct ec_params_usb_pd_control *params; 216 int i; 217 218 msg = &ec_buf.msg; 219 params = (struct ec_params_usb_pd_control *)msg->data; 220 resp = (struct ec_response_usb_pd_control_v1 *)msg->data; 221 222 msg->command = EC_CMD_USB_PD_CONTROL; 223 msg->version = 1; 224 msg->insize = sizeof(*resp); 225 msg->outsize = sizeof(*params); 226 227 /* 228 * Read status from all PD ports until failure, typically caused 229 * by attempting to read status on a port that doesn't exist. 230 */ 231 for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) { 232 params->port = i; 233 params->role = 0; 234 params->mux = 0; 235 params->swap = 0; 236 237 if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0) 238 break; 239 240 p += scnprintf(p, sizeof(read_buf) + read_buf - p, 241 "p%d: %s en:%.2x role:%.2x pol:%.2x\n", i, 242 resp->state, resp->enabled, resp->role, 243 resp->polarity); 244 } 245 246 return simple_read_from_buffer(user_buf, count, ppos, 247 read_buf, p - read_buf); 248 } 249 250 static bool cros_ec_uptime_is_supported(struct cros_ec_device *ec_dev) 251 { 252 struct { 253 struct cros_ec_command cmd; 254 struct ec_response_uptime_info resp; 255 } __packed msg = {}; 256 int ret; 257 258 msg.cmd.command = EC_CMD_GET_UPTIME_INFO; 259 msg.cmd.insize = sizeof(msg.resp); 260 261 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); 262 if (ret == -EPROTO && msg.cmd.result == EC_RES_INVALID_COMMAND) 263 return false; 264 265 /* Other errors maybe a transient error, do not rule about support. */ 266 return true; 267 } 268 269 static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf, 270 size_t count, loff_t *ppos) 271 { 272 struct cros_ec_debugfs *debug_info = file->private_data; 273 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 274 struct { 275 struct cros_ec_command cmd; 276 struct ec_response_uptime_info resp; 277 } __packed msg = {}; 278 struct ec_response_uptime_info *resp; 279 char read_buf[32]; 280 int ret; 281 282 resp = (struct ec_response_uptime_info *)&msg.resp; 283 284 msg.cmd.command = EC_CMD_GET_UPTIME_INFO; 285 msg.cmd.insize = sizeof(*resp); 286 287 ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); 288 if (ret < 0) 289 return ret; 290 291 ret = scnprintf(read_buf, sizeof(read_buf), "%u\n", 292 resp->time_since_ec_boot_ms); 293 294 return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret); 295 } 296 297 static const struct file_operations cros_ec_console_log_fops = { 298 .owner = THIS_MODULE, 299 .open = cros_ec_console_log_open, 300 .read = cros_ec_console_log_read, 301 .llseek = no_llseek, 302 .poll = cros_ec_console_log_poll, 303 .release = cros_ec_console_log_release, 304 }; 305 306 static const struct file_operations cros_ec_pdinfo_fops = { 307 .owner = THIS_MODULE, 308 .open = simple_open, 309 .read = cros_ec_pdinfo_read, 310 .llseek = default_llseek, 311 }; 312 313 static const struct file_operations cros_ec_uptime_fops = { 314 .owner = THIS_MODULE, 315 .open = simple_open, 316 .read = cros_ec_uptime_read, 317 .llseek = default_llseek, 318 }; 319 320 static int ec_read_version_supported(struct cros_ec_dev *ec) 321 { 322 struct ec_params_get_cmd_versions_v1 *params; 323 struct ec_response_get_cmd_versions *response; 324 int ret; 325 326 struct cros_ec_command *msg; 327 328 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)), 329 GFP_KERNEL); 330 if (!msg) 331 return 0; 332 333 msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset; 334 msg->outsize = sizeof(*params); 335 msg->insize = sizeof(*response); 336 337 params = (struct ec_params_get_cmd_versions_v1 *)msg->data; 338 params->cmd = EC_CMD_CONSOLE_READ; 339 response = (struct ec_response_get_cmd_versions *)msg->data; 340 341 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 && 342 response->version_mask & EC_VER_MASK(1); 343 344 kfree(msg); 345 346 return ret; 347 } 348 349 static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info) 350 { 351 struct cros_ec_dev *ec = debug_info->ec; 352 char *buf; 353 int read_params_size; 354 int read_response_size; 355 356 /* 357 * If the console log feature is not supported return silently and 358 * don't create the console_log entry. 359 */ 360 if (!ec_read_version_supported(ec)) 361 return 0; 362 363 buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL); 364 if (!buf) 365 return -ENOMEM; 366 367 read_params_size = sizeof(struct ec_params_console_read_v1); 368 read_response_size = ec->ec_dev->max_response; 369 debug_info->read_msg = devm_kzalloc(ec->dev, 370 sizeof(*debug_info->read_msg) + 371 max(read_params_size, read_response_size), GFP_KERNEL); 372 if (!debug_info->read_msg) 373 return -ENOMEM; 374 375 debug_info->read_msg->version = 1; 376 debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset; 377 debug_info->read_msg->outsize = read_params_size; 378 debug_info->read_msg->insize = read_response_size; 379 380 debug_info->log_buffer.buf = buf; 381 debug_info->log_buffer.head = 0; 382 debug_info->log_buffer.tail = 0; 383 384 mutex_init(&debug_info->log_mutex); 385 386 debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir, 387 debug_info, &cros_ec_console_log_fops); 388 389 INIT_DELAYED_WORK(&debug_info->log_poll_work, 390 cros_ec_console_log_work); 391 schedule_delayed_work(&debug_info->log_poll_work, 0); 392 393 return 0; 394 } 395 396 static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info) 397 { 398 if (debug_info->log_buffer.buf) { 399 cancel_delayed_work_sync(&debug_info->log_poll_work); 400 mutex_destroy(&debug_info->log_mutex); 401 } 402 } 403 404 /* 405 * Returns the size of the panicinfo data fetched from the EC 406 */ 407 static int cros_ec_get_panicinfo(struct cros_ec_device *ec_dev, uint8_t *data, 408 int data_size) 409 { 410 int ret; 411 struct cros_ec_command *msg; 412 413 if (!data || data_size <= 0 || data_size > ec_dev->max_response) 414 return -EINVAL; 415 416 msg = kzalloc(sizeof(*msg) + data_size, GFP_KERNEL); 417 if (!msg) 418 return -ENOMEM; 419 420 msg->command = EC_CMD_GET_PANIC_INFO; 421 msg->insize = data_size; 422 423 ret = cros_ec_cmd_xfer_status(ec_dev, msg); 424 if (ret < 0) 425 goto free; 426 427 memcpy(data, msg->data, data_size); 428 429 free: 430 kfree(msg); 431 return ret; 432 } 433 434 static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info) 435 { 436 struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; 437 int ret; 438 void *data; 439 440 data = devm_kzalloc(debug_info->ec->dev, ec_dev->max_response, 441 GFP_KERNEL); 442 if (!data) 443 return -ENOMEM; 444 445 ret = cros_ec_get_panicinfo(ec_dev, data, ec_dev->max_response); 446 if (ret < 0) { 447 ret = 0; 448 goto free; 449 } 450 451 /* No panic data */ 452 if (ret == 0) 453 goto free; 454 455 debug_info->panicinfo_blob.data = data; 456 debug_info->panicinfo_blob.size = ret; 457 458 debugfs_create_blob("panicinfo", 0444, debug_info->dir, 459 &debug_info->panicinfo_blob); 460 461 return 0; 462 463 free: 464 devm_kfree(debug_info->ec->dev, data); 465 return ret; 466 } 467 468 static int cros_ec_debugfs_panic_event(struct notifier_block *nb, 469 unsigned long queued_during_suspend, void *_notify) 470 { 471 struct cros_ec_debugfs *debug_info = 472 container_of(nb, struct cros_ec_debugfs, notifier_panic); 473 474 if (debug_info->log_buffer.buf) { 475 /* Force log poll work to run immediately */ 476 mod_delayed_work(debug_info->log_poll_work.wq, &debug_info->log_poll_work, 0); 477 /* Block until log poll work finishes */ 478 flush_delayed_work(&debug_info->log_poll_work); 479 } 480 481 return NOTIFY_DONE; 482 } 483 484 static int cros_ec_debugfs_probe(struct platform_device *pd) 485 { 486 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); 487 struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev); 488 const char *name = ec_platform->ec_name; 489 struct cros_ec_debugfs *debug_info; 490 int ret; 491 492 debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL); 493 if (!debug_info) 494 return -ENOMEM; 495 496 debug_info->ec = ec; 497 debug_info->dir = debugfs_create_dir(name, NULL); 498 499 ret = cros_ec_create_panicinfo(debug_info); 500 if (ret) 501 goto remove_debugfs; 502 503 ret = cros_ec_create_console_log(debug_info); 504 if (ret) 505 goto remove_debugfs; 506 507 debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info, 508 &cros_ec_pdinfo_fops); 509 510 if (cros_ec_uptime_is_supported(ec->ec_dev)) 511 debugfs_create_file("uptime", 0444, debug_info->dir, debug_info, 512 &cros_ec_uptime_fops); 513 514 debugfs_create_x32("last_resume_result", 0444, debug_info->dir, 515 &ec->ec_dev->last_resume_result); 516 517 debugfs_create_u16("suspend_timeout_ms", 0664, debug_info->dir, 518 &ec->ec_dev->suspend_timeout_ms); 519 520 debug_info->notifier_panic.notifier_call = cros_ec_debugfs_panic_event; 521 ret = blocking_notifier_chain_register(&ec->ec_dev->panic_notifier, 522 &debug_info->notifier_panic); 523 if (ret) 524 goto remove_debugfs; 525 526 ec->debug_info = debug_info; 527 528 dev_set_drvdata(&pd->dev, ec); 529 530 return 0; 531 532 remove_debugfs: 533 debugfs_remove_recursive(debug_info->dir); 534 return ret; 535 } 536 537 static void cros_ec_debugfs_remove(struct platform_device *pd) 538 { 539 struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent); 540 541 debugfs_remove_recursive(ec->debug_info->dir); 542 cros_ec_cleanup_console_log(ec->debug_info); 543 } 544 545 static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev) 546 { 547 struct cros_ec_dev *ec = dev_get_drvdata(dev); 548 549 if (ec->debug_info->log_buffer.buf) 550 cancel_delayed_work_sync(&ec->debug_info->log_poll_work); 551 552 return 0; 553 } 554 555 static int __maybe_unused cros_ec_debugfs_resume(struct device *dev) 556 { 557 struct cros_ec_dev *ec = dev_get_drvdata(dev); 558 559 if (ec->debug_info->log_buffer.buf) 560 schedule_delayed_work(&ec->debug_info->log_poll_work, 0); 561 562 return 0; 563 } 564 565 static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops, 566 cros_ec_debugfs_suspend, cros_ec_debugfs_resume); 567 568 static const struct platform_device_id cros_ec_debugfs_id[] = { 569 { DRV_NAME, 0 }, 570 {} 571 }; 572 MODULE_DEVICE_TABLE(platform, cros_ec_debugfs_id); 573 574 static struct platform_driver cros_ec_debugfs_driver = { 575 .driver = { 576 .name = DRV_NAME, 577 .pm = &cros_ec_debugfs_pm_ops, 578 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 579 }, 580 .probe = cros_ec_debugfs_probe, 581 .remove_new = cros_ec_debugfs_remove, 582 .id_table = cros_ec_debugfs_id, 583 }; 584 585 module_platform_driver(cros_ec_debugfs_driver); 586 587 MODULE_LICENSE("GPL"); 588 MODULE_DESCRIPTION("Debug logs for ChromeOS EC"); 589