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_dev: ec->ec_dev, msg: &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_dev: ec->ec_dev, |
98 | msg: 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(lock: &debug_info->log_mutex); |
118 | |
119 | resched: |
120 | schedule_delayed_work(dwork: &debug_info->log_poll_work, |
121 | delay: 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, filp: 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(lock: &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(to: buf, from: cb->buf + cb->tail, n: 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(lock: &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(filp: file, wait_address: &cros_ec_debugfs_log_wq, p: 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(lock: &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(buf: p, size: sizeof(read_buf) + read_buf - p, |
240 | fmt: "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(to: user_buf, count, ppos, |
246 | from: read_buf, available: 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: &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: &msg.cmd); |
287 | if (ret < 0) |
288 | return ret; |
289 | |
290 | ret = scnprintf(buf: read_buf, size: sizeof(read_buf), fmt: "%u\n" , |
291 | resp->time_since_ec_boot_ms); |
292 | |
293 | return simple_read_from_buffer(to: user_buf, count, ppos, from: read_buf, available: 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(size: 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_dev: ec->ec_dev, msg) >= 0 && |
341 | response->version_mask & EC_VER_MASK(1); |
342 | |
343 | kfree(objp: 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(dev: 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(dev: ec->dev, |
369 | size: 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(name: "console_log" , S_IFREG | 0444, parent: debug_info->dir, |
386 | data: debug_info, fops: &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(dwork: &debug_info->log_poll_work, delay: 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(dwork: &debug_info->log_poll_work); |
399 | mutex_destroy(lock: &debug_info->log_mutex); |
400 | } |
401 | } |
402 | |
403 | /* |
404 | * Returns the size of the panicinfo data fetched from the EC |
405 | */ |
406 | static int cros_ec_get_panicinfo(struct cros_ec_device *ec_dev, uint8_t *data, |
407 | int data_size) |
408 | { |
409 | int ret; |
410 | struct cros_ec_command *msg; |
411 | |
412 | if (!data || data_size <= 0 || data_size > ec_dev->max_response) |
413 | return -EINVAL; |
414 | |
415 | msg = kzalloc(size: sizeof(*msg) + data_size, GFP_KERNEL); |
416 | if (!msg) |
417 | return -ENOMEM; |
418 | |
419 | msg->command = EC_CMD_GET_PANIC_INFO; |
420 | msg->insize = data_size; |
421 | |
422 | ret = cros_ec_cmd_xfer_status(ec_dev, msg); |
423 | if (ret < 0) |
424 | goto free; |
425 | |
426 | memcpy(data, msg->data, data_size); |
427 | |
428 | free: |
429 | kfree(objp: msg); |
430 | return ret; |
431 | } |
432 | |
433 | static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info) |
434 | { |
435 | struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; |
436 | int ret; |
437 | void *data; |
438 | |
439 | data = devm_kzalloc(dev: debug_info->ec->dev, size: ec_dev->max_response, |
440 | GFP_KERNEL); |
441 | if (!data) |
442 | return -ENOMEM; |
443 | |
444 | ret = cros_ec_get_panicinfo(ec_dev, data, data_size: ec_dev->max_response); |
445 | if (ret < 0) { |
446 | ret = 0; |
447 | goto free; |
448 | } |
449 | |
450 | /* No panic data */ |
451 | if (ret == 0) |
452 | goto free; |
453 | |
454 | debug_info->panicinfo_blob.data = data; |
455 | debug_info->panicinfo_blob.size = ret; |
456 | |
457 | debugfs_create_blob(name: "panicinfo" , S_IFREG | 0444, parent: debug_info->dir, |
458 | blob: &debug_info->panicinfo_blob); |
459 | |
460 | return 0; |
461 | |
462 | free: |
463 | devm_kfree(dev: debug_info->ec->dev, p: data); |
464 | return ret; |
465 | } |
466 | |
467 | static int cros_ec_debugfs_panic_event(struct notifier_block *nb, |
468 | unsigned long queued_during_suspend, void *_notify) |
469 | { |
470 | struct cros_ec_debugfs *debug_info = |
471 | container_of(nb, struct cros_ec_debugfs, notifier_panic); |
472 | |
473 | if (debug_info->log_buffer.buf) { |
474 | /* Force log poll work to run immediately */ |
475 | mod_delayed_work(wq: debug_info->log_poll_work.wq, dwork: &debug_info->log_poll_work, delay: 0); |
476 | /* Block until log poll work finishes */ |
477 | flush_delayed_work(dwork: &debug_info->log_poll_work); |
478 | } |
479 | |
480 | return NOTIFY_DONE; |
481 | } |
482 | |
483 | static int cros_ec_debugfs_probe(struct platform_device *pd) |
484 | { |
485 | struct cros_ec_dev *ec = dev_get_drvdata(dev: pd->dev.parent); |
486 | struct cros_ec_platform *ec_platform = dev_get_platdata(dev: ec->dev); |
487 | const char *name = ec_platform->ec_name; |
488 | struct cros_ec_debugfs *debug_info; |
489 | int ret; |
490 | |
491 | debug_info = devm_kzalloc(dev: ec->dev, size: sizeof(*debug_info), GFP_KERNEL); |
492 | if (!debug_info) |
493 | return -ENOMEM; |
494 | |
495 | debug_info->ec = ec; |
496 | debug_info->dir = debugfs_create_dir(name, NULL); |
497 | |
498 | ret = cros_ec_create_panicinfo(debug_info); |
499 | if (ret) |
500 | goto remove_debugfs; |
501 | |
502 | ret = cros_ec_create_console_log(debug_info); |
503 | if (ret) |
504 | goto remove_debugfs; |
505 | |
506 | debugfs_create_file(name: "pdinfo" , mode: 0444, parent: debug_info->dir, data: debug_info, |
507 | fops: &cros_ec_pdinfo_fops); |
508 | |
509 | if (cros_ec_uptime_is_supported(ec_dev: ec->ec_dev)) |
510 | debugfs_create_file(name: "uptime" , mode: 0444, parent: debug_info->dir, data: debug_info, |
511 | fops: &cros_ec_uptime_fops); |
512 | |
513 | debugfs_create_x32(name: "last_resume_result" , mode: 0444, parent: debug_info->dir, |
514 | value: &ec->ec_dev->last_resume_result); |
515 | |
516 | debugfs_create_u16(name: "suspend_timeout_ms" , mode: 0664, parent: debug_info->dir, |
517 | value: &ec->ec_dev->suspend_timeout_ms); |
518 | |
519 | debug_info->notifier_panic.notifier_call = cros_ec_debugfs_panic_event; |
520 | ret = blocking_notifier_chain_register(nh: &ec->ec_dev->panic_notifier, |
521 | nb: &debug_info->notifier_panic); |
522 | if (ret) |
523 | goto remove_debugfs; |
524 | |
525 | ec->debug_info = debug_info; |
526 | |
527 | dev_set_drvdata(dev: &pd->dev, data: ec); |
528 | |
529 | return 0; |
530 | |
531 | remove_debugfs: |
532 | debugfs_remove_recursive(dentry: debug_info->dir); |
533 | return ret; |
534 | } |
535 | |
536 | static void cros_ec_debugfs_remove(struct platform_device *pd) |
537 | { |
538 | struct cros_ec_dev *ec = dev_get_drvdata(dev: pd->dev.parent); |
539 | |
540 | debugfs_remove_recursive(dentry: ec->debug_info->dir); |
541 | cros_ec_cleanup_console_log(debug_info: ec->debug_info); |
542 | } |
543 | |
544 | static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev) |
545 | { |
546 | struct cros_ec_dev *ec = dev_get_drvdata(dev); |
547 | |
548 | if (ec->debug_info->log_buffer.buf) |
549 | cancel_delayed_work_sync(dwork: &ec->debug_info->log_poll_work); |
550 | |
551 | return 0; |
552 | } |
553 | |
554 | static int __maybe_unused cros_ec_debugfs_resume(struct device *dev) |
555 | { |
556 | struct cros_ec_dev *ec = dev_get_drvdata(dev); |
557 | |
558 | if (ec->debug_info->log_buffer.buf) |
559 | schedule_delayed_work(dwork: &ec->debug_info->log_poll_work, delay: 0); |
560 | |
561 | return 0; |
562 | } |
563 | |
564 | static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops, |
565 | cros_ec_debugfs_suspend, cros_ec_debugfs_resume); |
566 | |
567 | static struct platform_driver cros_ec_debugfs_driver = { |
568 | .driver = { |
569 | .name = DRV_NAME, |
570 | .pm = &cros_ec_debugfs_pm_ops, |
571 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
572 | }, |
573 | .probe = cros_ec_debugfs_probe, |
574 | .remove_new = cros_ec_debugfs_remove, |
575 | }; |
576 | |
577 | module_platform_driver(cros_ec_debugfs_driver); |
578 | |
579 | MODULE_LICENSE("GPL" ); |
580 | MODULE_DESCRIPTION("Debug logs for ChromeOS EC" ); |
581 | MODULE_ALIAS("platform:" DRV_NAME); |
582 | |