1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright © 2023 Intel Corporation
4 */
5
6 #include "xe_devcoredump.h"
7 #include "xe_devcoredump_types.h"
8
9 #include <linux/ascii85.h>
10 #include <linux/devcoredump.h>
11 #include <generated/utsrelease.h>
12
13 #include <drm/drm_managed.h>
14
15 #include "xe_device.h"
16 #include "xe_exec_queue.h"
17 #include "xe_force_wake.h"
18 #include "xe_gt.h"
19 #include "xe_gt_printk.h"
20 #include "xe_guc_capture.h"
21 #include "xe_guc_ct.h"
22 #include "xe_guc_log.h"
23 #include "xe_guc_submit.h"
24 #include "xe_hw_engine.h"
25 #include "xe_module.h"
26 #include "xe_pm.h"
27 #include "xe_sched_job.h"
28 #include "xe_vm.h"
29
30 /**
31 * DOC: Xe device coredump
32 *
33 * Xe uses dev_coredump infrastructure for exposing the crash errors in a
34 * standardized way. Once a crash occurs, devcoredump exposes a temporary
35 * node under ``/sys/class/devcoredump/devcd<m>/``. The same node is also
36 * accessible in ``/sys/class/drm/card<n>/device/devcoredump/``. The
37 * ``failing_device`` symlink points to the device that crashed and created the
38 * coredump.
39 *
40 * The following characteristics are observed by xe when creating a device
41 * coredump:
42 *
43 * **Snapshot at hang**:
44 * The 'data' file contains a snapshot of the HW and driver states at the time
45 * the hang happened. Due to the driver recovering from resets/crashes, it may
46 * not correspond to the state of the system when the file is read by
47 * userspace.
48 *
49 * **Coredump release**:
50 * After a coredump is generated, it stays in kernel memory until released by
51 * userspace by writing anything to it, or after an internal timer expires. The
52 * exact timeout may vary and should not be relied upon. Example to release
53 * a coredump:
54 *
55 * .. code-block:: shell
56 *
57 * $ > /sys/class/drm/card0/device/devcoredump/data
58 *
59 * **First failure only**:
60 * In general, the first hang is the most critical one since the following
61 * hangs can be a consequence of the initial hang. For this reason a snapshot
62 * is taken only for the first failure. Until the devcoredump is released by
63 * userspace or kernel, all subsequent hangs do not override the snapshot nor
64 * create new ones. Devcoredump has a delayed work queue that will eventually
65 * delete the file node and free all the dump information.
66 */
67
68 #ifdef CONFIG_DEV_COREDUMP
69
70 /* 1 hour timeout */
71 #define XE_COREDUMP_TIMEOUT_JIFFIES (60 * 60 * HZ)
72
coredump_to_xe(const struct xe_devcoredump * coredump)73 static struct xe_device *coredump_to_xe(const struct xe_devcoredump *coredump)
74 {
75 return container_of(coredump, struct xe_device, devcoredump);
76 }
77
exec_queue_to_guc(struct xe_exec_queue * q)78 static struct xe_guc *exec_queue_to_guc(struct xe_exec_queue *q)
79 {
80 return &q->gt->uc.guc;
81 }
82
__xe_devcoredump_read(char * buffer,size_t count,struct xe_devcoredump * coredump)83 static ssize_t __xe_devcoredump_read(char *buffer, size_t count,
84 struct xe_devcoredump *coredump)
85 {
86 struct xe_device *xe;
87 struct xe_devcoredump_snapshot *ss;
88 struct drm_printer p;
89 struct drm_print_iterator iter;
90 struct timespec64 ts;
91 int i;
92
93 xe = coredump_to_xe(coredump);
94 ss = &coredump->snapshot;
95
96 iter.data = buffer;
97 iter.start = 0;
98 iter.remain = count;
99
100 p = drm_coredump_printer(&iter);
101
102 drm_puts(&p, "**** Xe Device Coredump ****\n");
103 drm_printf(&p, "Reason: %s\n", ss->reason);
104 drm_puts(&p, "kernel: " UTS_RELEASE "\n");
105 drm_puts(&p, "module: " KBUILD_MODNAME "\n");
106
107 ts = ktime_to_timespec64(ss->snapshot_time);
108 drm_printf(&p, "Snapshot time: %lld.%09ld\n", ts.tv_sec, ts.tv_nsec);
109 ts = ktime_to_timespec64(ss->boot_time);
110 drm_printf(&p, "Uptime: %lld.%09ld\n", ts.tv_sec, ts.tv_nsec);
111 drm_printf(&p, "Process: %s [%d]\n", ss->process_name, ss->pid);
112 xe_device_snapshot_print(xe, &p);
113
114 drm_printf(&p, "\n**** GT #%d ****\n", ss->gt->info.id);
115 drm_printf(&p, "\tTile: %d\n", ss->gt->tile->id);
116
117 drm_puts(&p, "\n**** GuC Log ****\n");
118 xe_guc_log_snapshot_print(ss->guc.log, &p);
119 drm_puts(&p, "\n**** GuC CT ****\n");
120 xe_guc_ct_snapshot_print(ss->guc.ct, &p);
121
122 drm_puts(&p, "\n**** Contexts ****\n");
123 xe_guc_exec_queue_snapshot_print(ss->ge, &p);
124
125 drm_puts(&p, "\n**** Job ****\n");
126 xe_sched_job_snapshot_print(ss->job, &p);
127
128 drm_puts(&p, "\n**** HW Engines ****\n");
129 for (i = 0; i < XE_NUM_HW_ENGINES; i++)
130 if (ss->hwe[i])
131 xe_engine_snapshot_print(ss->hwe[i], &p);
132
133 drm_puts(&p, "\n**** VM state ****\n");
134 xe_vm_snapshot_print(ss->vm, &p);
135
136 return count - iter.remain;
137 }
138
xe_devcoredump_snapshot_free(struct xe_devcoredump_snapshot * ss)139 static void xe_devcoredump_snapshot_free(struct xe_devcoredump_snapshot *ss)
140 {
141 int i;
142
143 kfree(ss->reason);
144 ss->reason = NULL;
145
146 xe_guc_log_snapshot_free(ss->guc.log);
147 ss->guc.log = NULL;
148
149 xe_guc_ct_snapshot_free(ss->guc.ct);
150 ss->guc.ct = NULL;
151
152 xe_guc_capture_put_matched_nodes(&ss->gt->uc.guc);
153 ss->matched_node = NULL;
154
155 xe_guc_exec_queue_snapshot_free(ss->ge);
156 ss->ge = NULL;
157
158 xe_sched_job_snapshot_free(ss->job);
159 ss->job = NULL;
160
161 for (i = 0; i < XE_NUM_HW_ENGINES; i++)
162 if (ss->hwe[i]) {
163 xe_hw_engine_snapshot_free(ss->hwe[i]);
164 ss->hwe[i] = NULL;
165 }
166
167 xe_vm_snapshot_free(ss->vm);
168 ss->vm = NULL;
169 }
170
xe_devcoredump_read(char * buffer,loff_t offset,size_t count,void * data,size_t datalen)171 static ssize_t xe_devcoredump_read(char *buffer, loff_t offset,
172 size_t count, void *data, size_t datalen)
173 {
174 struct xe_devcoredump *coredump = data;
175 struct xe_devcoredump_snapshot *ss;
176 ssize_t byte_copied;
177
178 if (!coredump)
179 return -ENODEV;
180
181 ss = &coredump->snapshot;
182
183 /* Ensure delayed work is captured before continuing */
184 flush_work(&ss->work);
185
186 mutex_lock(&coredump->lock);
187
188 if (!ss->read.buffer) {
189 mutex_unlock(&coredump->lock);
190 return -ENODEV;
191 }
192
193 if (offset >= ss->read.size) {
194 mutex_unlock(&coredump->lock);
195 return 0;
196 }
197
198 byte_copied = count < ss->read.size - offset ? count :
199 ss->read.size - offset;
200 memcpy(buffer, ss->read.buffer + offset, byte_copied);
201
202 mutex_unlock(&coredump->lock);
203
204 return byte_copied;
205 }
206
xe_devcoredump_free(void * data)207 static void xe_devcoredump_free(void *data)
208 {
209 struct xe_devcoredump *coredump = data;
210
211 /* Our device is gone. Nothing to do... */
212 if (!data || !coredump_to_xe(coredump))
213 return;
214
215 cancel_work_sync(&coredump->snapshot.work);
216
217 mutex_lock(&coredump->lock);
218
219 xe_devcoredump_snapshot_free(&coredump->snapshot);
220 kvfree(coredump->snapshot.read.buffer);
221
222 /* To prevent stale data on next snapshot, clear everything */
223 memset(&coredump->snapshot, 0, sizeof(coredump->snapshot));
224 coredump->captured = false;
225 drm_info(&coredump_to_xe(coredump)->drm,
226 "Xe device coredump has been deleted.\n");
227
228 mutex_unlock(&coredump->lock);
229 }
230
xe_devcoredump_deferred_snap_work(struct work_struct * work)231 static void xe_devcoredump_deferred_snap_work(struct work_struct *work)
232 {
233 struct xe_devcoredump_snapshot *ss = container_of(work, typeof(*ss), work);
234 struct xe_devcoredump *coredump = container_of(ss, typeof(*coredump), snapshot);
235 struct xe_device *xe = coredump_to_xe(coredump);
236 unsigned int fw_ref;
237
238 /*
239 * NB: Despite passing a GFP_ flags parameter here, more allocations are done
240 * internally using GFP_KERNEL expliictly. Hence this call must be in the worker
241 * thread and not in the initial capture call.
242 */
243 dev_coredumpm_timeout(gt_to_xe(ss->gt)->drm.dev, THIS_MODULE, coredump, 0, GFP_KERNEL,
244 xe_devcoredump_read, xe_devcoredump_free,
245 XE_COREDUMP_TIMEOUT_JIFFIES);
246
247 xe_pm_runtime_get(xe);
248
249 /* keep going if fw fails as we still want to save the memory and SW data */
250 fw_ref = xe_force_wake_get(gt_to_fw(ss->gt), XE_FORCEWAKE_ALL);
251 if (!xe_force_wake_ref_has_domain(fw_ref, XE_FORCEWAKE_ALL))
252 xe_gt_info(ss->gt, "failed to get forcewake for coredump capture\n");
253 xe_vm_snapshot_capture_delayed(ss->vm);
254 xe_guc_exec_queue_snapshot_capture_delayed(ss->ge);
255 xe_force_wake_put(gt_to_fw(ss->gt), fw_ref);
256
257 xe_pm_runtime_put(xe);
258
259 /* Calculate devcoredump size */
260 ss->read.size = __xe_devcoredump_read(NULL, INT_MAX, coredump);
261
262 ss->read.buffer = kvmalloc(ss->read.size, GFP_USER);
263 if (!ss->read.buffer)
264 return;
265
266 __xe_devcoredump_read(ss->read.buffer, ss->read.size, coredump);
267 xe_devcoredump_snapshot_free(ss);
268 }
269
devcoredump_snapshot(struct xe_devcoredump * coredump,struct xe_exec_queue * q,struct xe_sched_job * job)270 static void devcoredump_snapshot(struct xe_devcoredump *coredump,
271 struct xe_exec_queue *q,
272 struct xe_sched_job *job)
273 {
274 struct xe_devcoredump_snapshot *ss = &coredump->snapshot;
275 struct xe_guc *guc = exec_queue_to_guc(q);
276 u32 adj_logical_mask = q->logical_mask;
277 u32 width_mask = (0x1 << q->width) - 1;
278 const char *process_name = "no process";
279
280 unsigned int fw_ref;
281 bool cookie;
282 int i;
283
284 ss->snapshot_time = ktime_get_real();
285 ss->boot_time = ktime_get_boottime();
286
287 if (q->vm && q->vm->xef) {
288 process_name = q->vm->xef->process_name;
289 ss->pid = q->vm->xef->pid;
290 }
291
292 strscpy(ss->process_name, process_name);
293
294 ss->gt = q->gt;
295 INIT_WORK(&ss->work, xe_devcoredump_deferred_snap_work);
296
297 cookie = dma_fence_begin_signalling();
298 for (i = 0; q->width > 1 && i < XE_HW_ENGINE_MAX_INSTANCE;) {
299 if (adj_logical_mask & BIT(i)) {
300 adj_logical_mask |= width_mask << i;
301 i += q->width;
302 } else {
303 ++i;
304 }
305 }
306
307 /* keep going if fw fails as we still want to save the memory and SW data */
308 fw_ref = xe_force_wake_get(gt_to_fw(q->gt), XE_FORCEWAKE_ALL);
309
310 ss->guc.log = xe_guc_log_snapshot_capture(&guc->log, true);
311 ss->guc.ct = xe_guc_ct_snapshot_capture(&guc->ct);
312 ss->ge = xe_guc_exec_queue_snapshot_capture(q);
313 if (job)
314 ss->job = xe_sched_job_snapshot_capture(job);
315 ss->vm = xe_vm_snapshot_capture(q->vm);
316
317 xe_engine_snapshot_capture_for_queue(q);
318
319 queue_work(system_unbound_wq, &ss->work);
320
321 xe_force_wake_put(gt_to_fw(q->gt), fw_ref);
322 dma_fence_end_signalling(cookie);
323 }
324
325 /**
326 * xe_devcoredump - Take the required snapshots and initialize coredump device.
327 * @q: The faulty xe_exec_queue, where the issue was detected.
328 * @job: The faulty xe_sched_job, where the issue was detected.
329 * @fmt: Printf format + args to describe the reason for the core dump
330 *
331 * This function should be called at the crash time within the serialized
332 * gt_reset. It is skipped if we still have the core dump device available
333 * with the information of the 'first' snapshot.
334 */
335 __printf(3, 4)
xe_devcoredump(struct xe_exec_queue * q,struct xe_sched_job * job,const char * fmt,...)336 void xe_devcoredump(struct xe_exec_queue *q, struct xe_sched_job *job, const char *fmt, ...)
337 {
338 struct xe_device *xe = gt_to_xe(q->gt);
339 struct xe_devcoredump *coredump = &xe->devcoredump;
340 va_list varg;
341
342 mutex_lock(&coredump->lock);
343
344 if (coredump->captured) {
345 drm_dbg(&xe->drm, "Multiple hangs are occurring, but only the first snapshot was taken\n");
346 mutex_unlock(&coredump->lock);
347 return;
348 }
349
350 coredump->captured = true;
351
352 va_start(varg, fmt);
353 coredump->snapshot.reason = kvasprintf(GFP_ATOMIC, fmt, varg);
354 va_end(varg);
355
356 devcoredump_snapshot(coredump, q, job);
357
358 drm_info(&xe->drm, "Xe device coredump has been created\n");
359 drm_info(&xe->drm, "Check your /sys/class/drm/card%d/device/devcoredump/data\n",
360 xe->drm.primary->index);
361
362 mutex_unlock(&coredump->lock);
363 }
364
xe_driver_devcoredump_fini(void * arg)365 static void xe_driver_devcoredump_fini(void *arg)
366 {
367 struct drm_device *drm = arg;
368
369 dev_coredump_put(drm->dev);
370 }
371
xe_devcoredump_init(struct xe_device * xe)372 int xe_devcoredump_init(struct xe_device *xe)
373 {
374 int err;
375
376 err = drmm_mutex_init(&xe->drm, &xe->devcoredump.lock);
377 if (err)
378 return err;
379
380 if (IS_ENABLED(CONFIG_LOCKDEP)) {
381 fs_reclaim_acquire(GFP_KERNEL);
382 might_lock(&xe->devcoredump.lock);
383 fs_reclaim_release(GFP_KERNEL);
384 }
385
386 return devm_add_action_or_reset(xe->drm.dev, xe_driver_devcoredump_fini, &xe->drm);
387 }
388
389 #endif
390
391 /**
392 * xe_print_blob_ascii85 - print a BLOB to some useful location in ASCII85
393 *
394 * The output is split into multiple calls to drm_puts() because some print
395 * targets, e.g. dmesg, cannot handle arbitrarily long lines. These targets may
396 * add newlines, as is the case with dmesg: each drm_puts() call creates a
397 * separate line.
398 *
399 * There is also a scheduler yield call to prevent the 'task has been stuck for
400 * 120s' kernel hang check feature from firing when printing to a slow target
401 * such as dmesg over a serial port.
402 *
403 * @p: the printer object to output to
404 * @prefix: optional prefix to add to output string
405 * @suffix: optional suffix to add at the end. 0 disables it and is
406 * not added to the output, which is useful when using multiple calls
407 * to dump data to @p
408 * @blob: the Binary Large OBject to dump out
409 * @offset: offset in bytes to skip from the front of the BLOB, must be a multiple of sizeof(u32)
410 * @size: the size in bytes of the BLOB, must be a multiple of sizeof(u32)
411 */
xe_print_blob_ascii85(struct drm_printer * p,const char * prefix,char suffix,const void * blob,size_t offset,size_t size)412 void xe_print_blob_ascii85(struct drm_printer *p, const char *prefix, char suffix,
413 const void *blob, size_t offset, size_t size)
414 {
415 const u32 *blob32 = (const u32 *)blob;
416 char buff[ASCII85_BUFSZ], *line_buff;
417 size_t line_pos = 0;
418
419 #define DMESG_MAX_LINE_LEN 800
420 /* Always leave space for the suffix char and the \0 */
421 #define MIN_SPACE (ASCII85_BUFSZ + 2) /* 85 + "<suffix>\0" */
422
423 if (size & 3)
424 drm_printf(p, "Size not word aligned: %zu", size);
425 if (offset & 3)
426 drm_printf(p, "Offset not word aligned: %zu", size);
427
428 line_buff = kzalloc(DMESG_MAX_LINE_LEN, GFP_KERNEL);
429 if (IS_ERR_OR_NULL(line_buff)) {
430 drm_printf(p, "Failed to allocate line buffer: %pe", line_buff);
431 return;
432 }
433
434 blob32 += offset / sizeof(*blob32);
435 size /= sizeof(*blob32);
436
437 if (prefix) {
438 strscpy(line_buff, prefix, DMESG_MAX_LINE_LEN - MIN_SPACE - 2);
439 line_pos = strlen(line_buff);
440
441 line_buff[line_pos++] = ':';
442 line_buff[line_pos++] = ' ';
443 }
444
445 while (size--) {
446 u32 val = *(blob32++);
447
448 strscpy(line_buff + line_pos, ascii85_encode(val, buff),
449 DMESG_MAX_LINE_LEN - line_pos);
450 line_pos += strlen(line_buff + line_pos);
451
452 if ((line_pos + MIN_SPACE) >= DMESG_MAX_LINE_LEN) {
453 line_buff[line_pos++] = 0;
454
455 drm_puts(p, line_buff);
456
457 line_pos = 0;
458
459 /* Prevent 'stuck thread' time out errors */
460 cond_resched();
461 }
462 }
463
464 if (suffix)
465 line_buff[line_pos++] = suffix;
466
467 if (line_pos) {
468 line_buff[line_pos++] = 0;
469 drm_puts(p, line_buff);
470 }
471
472 kfree(line_buff);
473
474 #undef MIN_SPACE
475 #undef DMESG_MAX_LINE_LEN
476 }
477