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