1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2014-2019 Intel Corporation
4  */
5 
6 #include <linux/debugfs.h>
7 #include <linux/string_helpers.h>
8 
9 #include "gt/intel_gt.h"
10 #include "i915_drv.h"
11 #include "i915_irq.h"
12 #include "i915_memcpy.h"
13 #include "intel_guc_capture.h"
14 #include "intel_guc_log.h"
15 
16 static void guc_log_copy_debuglogs_for_relay(struct intel_guc_log *log);
17 
18 /**
19  * DOC: GuC firmware log
20  *
21  * Firmware log is enabled by setting i915.guc_log_level to the positive level.
22  * Log data is printed out via reading debugfs i915_guc_log_dump. Reading from
23  * i915_guc_load_status will print out firmware loading status and scratch
24  * registers value.
25  */
26 
27 static int guc_action_flush_log_complete(struct intel_guc *guc)
28 {
29 	u32 action[] = {
30 		INTEL_GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE,
31 		GUC_DEBUG_LOG_BUFFER
32 	};
33 
34 	return intel_guc_send_nb(guc, action, ARRAY_SIZE(action), 0);
35 }
36 
37 static int guc_action_flush_log(struct intel_guc *guc)
38 {
39 	u32 action[] = {
40 		INTEL_GUC_ACTION_FORCE_LOG_BUFFER_FLUSH,
41 		0
42 	};
43 
44 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
45 }
46 
47 static int guc_action_control_log(struct intel_guc *guc, bool enable,
48 				  bool default_logging, u32 verbosity)
49 {
50 	u32 action[] = {
51 		INTEL_GUC_ACTION_UK_LOG_ENABLE_LOGGING,
52 		(enable ? GUC_LOG_CONTROL_LOGGING_ENABLED : 0) |
53 		(verbosity << GUC_LOG_CONTROL_VERBOSITY_SHIFT) |
54 		(default_logging ? GUC_LOG_CONTROL_DEFAULT_LOGGING : 0)
55 	};
56 
57 	GEM_BUG_ON(verbosity > GUC_LOG_VERBOSITY_MAX);
58 
59 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
60 }
61 
62 /*
63  * Sub buffer switch callback. Called whenever relay has to switch to a new
64  * sub buffer, relay stays on the same sub buffer if 0 is returned.
65  */
66 static int subbuf_start_callback(struct rchan_buf *buf,
67 				 void *subbuf,
68 				 void *prev_subbuf,
69 				 size_t prev_padding)
70 {
71 	/*
72 	 * Use no-overwrite mode by default, where relay will stop accepting
73 	 * new data if there are no empty sub buffers left.
74 	 * There is no strict synchronization enforced by relay between Consumer
75 	 * and Producer. In overwrite mode, there is a possibility of getting
76 	 * inconsistent/garbled data, the producer could be writing on to the
77 	 * same sub buffer from which Consumer is reading. This can't be avoided
78 	 * unless Consumer is fast enough and can always run in tandem with
79 	 * Producer.
80 	 */
81 	if (relay_buf_full(buf))
82 		return 0;
83 
84 	return 1;
85 }
86 
87 /*
88  * file_create() callback. Creates relay file in debugfs.
89  */
90 static struct dentry *create_buf_file_callback(const char *filename,
91 					       struct dentry *parent,
92 					       umode_t mode,
93 					       struct rchan_buf *buf,
94 					       int *is_global)
95 {
96 	struct dentry *buf_file;
97 
98 	/*
99 	 * This to enable the use of a single buffer for the relay channel and
100 	 * correspondingly have a single file exposed to User, through which
101 	 * it can collect the logs in order without any post-processing.
102 	 * Need to set 'is_global' even if parent is NULL for early logging.
103 	 */
104 	*is_global = 1;
105 
106 	if (!parent)
107 		return NULL;
108 
109 	buf_file = debugfs_create_file(filename, mode,
110 				       parent, buf, &relay_file_operations);
111 	if (IS_ERR(buf_file))
112 		return NULL;
113 
114 	return buf_file;
115 }
116 
117 /*
118  * file_remove() default callback. Removes relay file in debugfs.
119  */
120 static int remove_buf_file_callback(struct dentry *dentry)
121 {
122 	debugfs_remove(dentry);
123 	return 0;
124 }
125 
126 /* relay channel callbacks */
127 static const struct rchan_callbacks relay_callbacks = {
128 	.subbuf_start = subbuf_start_callback,
129 	.create_buf_file = create_buf_file_callback,
130 	.remove_buf_file = remove_buf_file_callback,
131 };
132 
133 static void guc_move_to_next_buf(struct intel_guc_log *log)
134 {
135 	/*
136 	 * Make sure the updates made in the sub buffer are visible when
137 	 * Consumer sees the following update to offset inside the sub buffer.
138 	 */
139 	smp_wmb();
140 
141 	/* All data has been written, so now move the offset of sub buffer. */
142 	relay_reserve(log->relay.channel, log->vma->obj->base.size - CAPTURE_BUFFER_SIZE);
143 
144 	/* Switch to the next sub buffer */
145 	relay_flush(log->relay.channel);
146 }
147 
148 static void *guc_get_write_buffer(struct intel_guc_log *log)
149 {
150 	/*
151 	 * Just get the base address of a new sub buffer and copy data into it
152 	 * ourselves. NULL will be returned in no-overwrite mode, if all sub
153 	 * buffers are full. Could have used the relay_write() to indirectly
154 	 * copy the data, but that would have been bit convoluted, as we need to
155 	 * write to only certain locations inside a sub buffer which cannot be
156 	 * done without using relay_reserve() along with relay_write(). So its
157 	 * better to use relay_reserve() alone.
158 	 */
159 	return relay_reserve(log->relay.channel, 0);
160 }
161 
162 bool intel_guc_check_log_buf_overflow(struct intel_guc_log *log,
163 				      enum guc_log_buffer_type type,
164 				      unsigned int full_cnt)
165 {
166 	unsigned int prev_full_cnt = log->stats[type].sampled_overflow;
167 	bool overflow = false;
168 
169 	if (full_cnt != prev_full_cnt) {
170 		overflow = true;
171 
172 		log->stats[type].overflow = full_cnt;
173 		log->stats[type].sampled_overflow += full_cnt - prev_full_cnt;
174 
175 		if (full_cnt < prev_full_cnt) {
176 			/* buffer_full_cnt is a 4 bit counter */
177 			log->stats[type].sampled_overflow += 16;
178 		}
179 
180 		dev_notice_ratelimited(guc_to_gt(log_to_guc(log))->i915->drm.dev,
181 				       "GuC log buffer overflow\n");
182 	}
183 
184 	return overflow;
185 }
186 
187 unsigned int intel_guc_get_log_buffer_size(enum guc_log_buffer_type type)
188 {
189 	switch (type) {
190 	case GUC_DEBUG_LOG_BUFFER:
191 		return DEBUG_BUFFER_SIZE;
192 	case GUC_CRASH_DUMP_LOG_BUFFER:
193 		return CRASH_BUFFER_SIZE;
194 	case GUC_CAPTURE_LOG_BUFFER:
195 		return CAPTURE_BUFFER_SIZE;
196 	default:
197 		MISSING_CASE(type);
198 	}
199 
200 	return 0;
201 }
202 
203 size_t intel_guc_get_log_buffer_offset(enum guc_log_buffer_type type)
204 {
205 	enum guc_log_buffer_type i;
206 	size_t offset = PAGE_SIZE;/* for the log_buffer_states */
207 
208 	for (i = GUC_DEBUG_LOG_BUFFER; i < GUC_MAX_LOG_BUFFER; ++i) {
209 		if (i == type)
210 			break;
211 		offset += intel_guc_get_log_buffer_size(i);
212 	}
213 
214 	return offset;
215 }
216 
217 static void _guc_log_copy_debuglogs_for_relay(struct intel_guc_log *log)
218 {
219 	unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt;
220 	struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state;
221 	struct guc_log_buffer_state log_buf_state_local;
222 	enum guc_log_buffer_type type;
223 	void *src_data, *dst_data;
224 	bool new_overflow;
225 
226 	mutex_lock(&log->relay.lock);
227 
228 	if (WARN_ON(!intel_guc_log_relay_created(log)))
229 		goto out_unlock;
230 
231 	/* Get the pointer to shared GuC log buffer */
232 	src_data = log->buf_addr;
233 	log_buf_state = src_data;
234 
235 	/* Get the pointer to local buffer to store the logs */
236 	log_buf_snapshot_state = dst_data = guc_get_write_buffer(log);
237 
238 	if (unlikely(!log_buf_snapshot_state)) {
239 		/*
240 		 * Used rate limited to avoid deluge of messages, logs might be
241 		 * getting consumed by User at a slow rate.
242 		 */
243 		DRM_ERROR_RATELIMITED("no sub-buffer to copy general logs\n");
244 		log->relay.full_count++;
245 
246 		goto out_unlock;
247 	}
248 
249 	/* Actual logs are present from the 2nd page */
250 	src_data += PAGE_SIZE;
251 	dst_data += PAGE_SIZE;
252 
253 	/* For relay logging, we exclude error state capture */
254 	for (type = GUC_DEBUG_LOG_BUFFER; type <= GUC_CRASH_DUMP_LOG_BUFFER; type++) {
255 		/*
256 		 * Make a copy of the state structure, inside GuC log buffer
257 		 * (which is uncached mapped), on the stack to avoid reading
258 		 * from it multiple times.
259 		 */
260 		memcpy(&log_buf_state_local, log_buf_state,
261 		       sizeof(struct guc_log_buffer_state));
262 		buffer_size = intel_guc_get_log_buffer_size(type);
263 		read_offset = log_buf_state_local.read_ptr;
264 		write_offset = log_buf_state_local.sampled_write_ptr;
265 		full_cnt = log_buf_state_local.buffer_full_cnt;
266 
267 		/* Bookkeeping stuff */
268 		log->stats[type].flush += log_buf_state_local.flush_to_file;
269 		new_overflow = intel_guc_check_log_buf_overflow(log, type, full_cnt);
270 
271 		/* Update the state of shared log buffer */
272 		log_buf_state->read_ptr = write_offset;
273 		log_buf_state->flush_to_file = 0;
274 		log_buf_state++;
275 
276 		/* First copy the state structure in snapshot buffer */
277 		memcpy(log_buf_snapshot_state, &log_buf_state_local,
278 		       sizeof(struct guc_log_buffer_state));
279 
280 		/*
281 		 * The write pointer could have been updated by GuC firmware,
282 		 * after sending the flush interrupt to Host, for consistency
283 		 * set write pointer value to same value of sampled_write_ptr
284 		 * in the snapshot buffer.
285 		 */
286 		log_buf_snapshot_state->write_ptr = write_offset;
287 		log_buf_snapshot_state++;
288 
289 		/* Now copy the actual logs. */
290 		if (unlikely(new_overflow)) {
291 			/* copy the whole buffer in case of overflow */
292 			read_offset = 0;
293 			write_offset = buffer_size;
294 		} else if (unlikely((read_offset > buffer_size) ||
295 				    (write_offset > buffer_size))) {
296 			DRM_ERROR("invalid log buffer state\n");
297 			/* copy whole buffer as offsets are unreliable */
298 			read_offset = 0;
299 			write_offset = buffer_size;
300 		}
301 
302 		/* Just copy the newly written data */
303 		if (read_offset > write_offset) {
304 			i915_memcpy_from_wc(dst_data, src_data, write_offset);
305 			bytes_to_copy = buffer_size - read_offset;
306 		} else {
307 			bytes_to_copy = write_offset - read_offset;
308 		}
309 		i915_memcpy_from_wc(dst_data + read_offset,
310 				    src_data + read_offset, bytes_to_copy);
311 
312 		src_data += buffer_size;
313 		dst_data += buffer_size;
314 	}
315 
316 	guc_move_to_next_buf(log);
317 
318 out_unlock:
319 	mutex_unlock(&log->relay.lock);
320 }
321 
322 static void copy_debug_logs_work(struct work_struct *work)
323 {
324 	struct intel_guc_log *log =
325 		container_of(work, struct intel_guc_log, relay.flush_work);
326 
327 	guc_log_copy_debuglogs_for_relay(log);
328 }
329 
330 static int guc_log_relay_map(struct intel_guc_log *log)
331 {
332 	lockdep_assert_held(&log->relay.lock);
333 
334 	if (!log->vma || !log->buf_addr)
335 		return -ENODEV;
336 
337 	/*
338 	 * WC vmalloc mapping of log buffer pages was done at
339 	 * GuC Log Init time, but lets keep a ref for book-keeping
340 	 */
341 	i915_gem_object_get(log->vma->obj);
342 	log->relay.buf_in_use = true;
343 
344 	return 0;
345 }
346 
347 static void guc_log_relay_unmap(struct intel_guc_log *log)
348 {
349 	lockdep_assert_held(&log->relay.lock);
350 
351 	i915_gem_object_put(log->vma->obj);
352 	log->relay.buf_in_use = false;
353 }
354 
355 void intel_guc_log_init_early(struct intel_guc_log *log)
356 {
357 	mutex_init(&log->relay.lock);
358 	INIT_WORK(&log->relay.flush_work, copy_debug_logs_work);
359 	log->relay.started = false;
360 }
361 
362 static int guc_log_relay_create(struct intel_guc_log *log)
363 {
364 	struct intel_guc *guc = log_to_guc(log);
365 	struct drm_i915_private *dev_priv = guc_to_gt(guc)->i915;
366 	struct rchan *guc_log_relay_chan;
367 	size_t n_subbufs, subbuf_size;
368 	int ret;
369 
370 	lockdep_assert_held(&log->relay.lock);
371 	GEM_BUG_ON(!log->vma);
372 
373 	 /*
374 	  * Keep the size of sub buffers same as shared log buffer
375 	  * but GuC log-events excludes the error-state-capture logs
376 	  */
377 	subbuf_size = log->vma->size - CAPTURE_BUFFER_SIZE;
378 
379 	/*
380 	 * Store up to 8 snapshots, which is large enough to buffer sufficient
381 	 * boot time logs and provides enough leeway to User, in terms of
382 	 * latency, for consuming the logs from relay. Also doesn't take
383 	 * up too much memory.
384 	 */
385 	n_subbufs = 8;
386 
387 	guc_log_relay_chan = relay_open("guc_log",
388 					dev_priv->drm.primary->debugfs_root,
389 					subbuf_size, n_subbufs,
390 					&relay_callbacks, dev_priv);
391 	if (!guc_log_relay_chan) {
392 		DRM_ERROR("Couldn't create relay chan for GuC logging\n");
393 
394 		ret = -ENOMEM;
395 		return ret;
396 	}
397 
398 	GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
399 	log->relay.channel = guc_log_relay_chan;
400 
401 	return 0;
402 }
403 
404 static void guc_log_relay_destroy(struct intel_guc_log *log)
405 {
406 	lockdep_assert_held(&log->relay.lock);
407 
408 	relay_close(log->relay.channel);
409 	log->relay.channel = NULL;
410 }
411 
412 static void guc_log_copy_debuglogs_for_relay(struct intel_guc_log *log)
413 {
414 	struct intel_guc *guc = log_to_guc(log);
415 	struct drm_i915_private *dev_priv = guc_to_gt(guc)->i915;
416 	intel_wakeref_t wakeref;
417 
418 	_guc_log_copy_debuglogs_for_relay(log);
419 
420 	/*
421 	 * Generally device is expected to be active only at this
422 	 * time, so get/put should be really quick.
423 	 */
424 	with_intel_runtime_pm(&dev_priv->runtime_pm, wakeref)
425 		guc_action_flush_log_complete(guc);
426 }
427 
428 static u32 __get_default_log_level(struct intel_guc_log *log)
429 {
430 	struct intel_guc *guc = log_to_guc(log);
431 	struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
432 
433 	/* A negative value means "use platform/config default" */
434 	if (i915->params.guc_log_level < 0) {
435 		return (IS_ENABLED(CONFIG_DRM_I915_DEBUG) ||
436 			IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) ?
437 			GUC_LOG_LEVEL_MAX : GUC_LOG_LEVEL_NON_VERBOSE;
438 	}
439 
440 	if (i915->params.guc_log_level > GUC_LOG_LEVEL_MAX) {
441 		DRM_WARN("Incompatible option detected: %s=%d, %s!\n",
442 			 "guc_log_level", i915->params.guc_log_level,
443 			 "verbosity too high");
444 		return (IS_ENABLED(CONFIG_DRM_I915_DEBUG) ||
445 			IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) ?
446 			GUC_LOG_LEVEL_MAX : GUC_LOG_LEVEL_DISABLED;
447 	}
448 
449 	GEM_BUG_ON(i915->params.guc_log_level < GUC_LOG_LEVEL_DISABLED);
450 	GEM_BUG_ON(i915->params.guc_log_level > GUC_LOG_LEVEL_MAX);
451 	return i915->params.guc_log_level;
452 }
453 
454 int intel_guc_log_create(struct intel_guc_log *log)
455 {
456 	struct intel_guc *guc = log_to_guc(log);
457 	struct i915_vma *vma;
458 	void *vaddr;
459 	u32 guc_log_size;
460 	int ret;
461 
462 	GEM_BUG_ON(log->vma);
463 
464 	/*
465 	 *  GuC Log buffer Layout
466 	 * (this ordering must follow "enum guc_log_buffer_type" definition)
467 	 *
468 	 *  +===============================+ 00B
469 	 *  |      Debug state header       |
470 	 *  +-------------------------------+ 32B
471 	 *  |    Crash dump state header    |
472 	 *  +-------------------------------+ 64B
473 	 *  |     Capture state header      |
474 	 *  +-------------------------------+ 96B
475 	 *  |                               |
476 	 *  +===============================+ PAGE_SIZE (4KB)
477 	 *  |          Debug logs           |
478 	 *  +===============================+ + DEBUG_SIZE
479 	 *  |        Crash Dump logs        |
480 	 *  +===============================+ + CRASH_SIZE
481 	 *  |         Capture logs          |
482 	 *  +===============================+ + CAPTURE_SIZE
483 	 */
484 	if (intel_guc_capture_output_min_size_est(guc) > CAPTURE_BUFFER_SIZE)
485 		DRM_WARN("GuC log buffer for state_capture maybe too small. %d < %d\n",
486 			 CAPTURE_BUFFER_SIZE, intel_guc_capture_output_min_size_est(guc));
487 
488 	guc_log_size = PAGE_SIZE + CRASH_BUFFER_SIZE + DEBUG_BUFFER_SIZE +
489 		       CAPTURE_BUFFER_SIZE;
490 
491 	vma = intel_guc_allocate_vma(guc, guc_log_size);
492 	if (IS_ERR(vma)) {
493 		ret = PTR_ERR(vma);
494 		goto err;
495 	}
496 
497 	log->vma = vma;
498 	/*
499 	 * Create a WC (Uncached for read) vmalloc mapping up front immediate access to
500 	 * data from memory during  critical events such as error capture
501 	 */
502 	vaddr = i915_gem_object_pin_map_unlocked(log->vma->obj, I915_MAP_WC);
503 	if (IS_ERR(vaddr)) {
504 		ret = PTR_ERR(vaddr);
505 		i915_vma_unpin_and_release(&log->vma, 0);
506 		goto err;
507 	}
508 	log->buf_addr = vaddr;
509 
510 	log->level = __get_default_log_level(log);
511 	DRM_DEBUG_DRIVER("guc_log_level=%d (%s, verbose:%s, verbosity:%d)\n",
512 			 log->level, str_enabled_disabled(log->level),
513 			 str_yes_no(GUC_LOG_LEVEL_IS_VERBOSE(log->level)),
514 			 GUC_LOG_LEVEL_TO_VERBOSITY(log->level));
515 
516 	return 0;
517 
518 err:
519 	DRM_ERROR("Failed to allocate or map GuC log buffer. %d\n", ret);
520 	return ret;
521 }
522 
523 void intel_guc_log_destroy(struct intel_guc_log *log)
524 {
525 	log->buf_addr = NULL;
526 	i915_vma_unpin_and_release(&log->vma, I915_VMA_RELEASE_MAP);
527 }
528 
529 int intel_guc_log_set_level(struct intel_guc_log *log, u32 level)
530 {
531 	struct intel_guc *guc = log_to_guc(log);
532 	struct drm_i915_private *dev_priv = guc_to_gt(guc)->i915;
533 	intel_wakeref_t wakeref;
534 	int ret = 0;
535 
536 	BUILD_BUG_ON(GUC_LOG_VERBOSITY_MIN != 0);
537 	GEM_BUG_ON(!log->vma);
538 
539 	/*
540 	 * GuC is recognizing log levels starting from 0 to max, we're using 0
541 	 * as indication that logging should be disabled.
542 	 */
543 	if (level < GUC_LOG_LEVEL_DISABLED || level > GUC_LOG_LEVEL_MAX)
544 		return -EINVAL;
545 
546 	mutex_lock(&dev_priv->drm.struct_mutex);
547 
548 	if (log->level == level)
549 		goto out_unlock;
550 
551 	with_intel_runtime_pm(&dev_priv->runtime_pm, wakeref)
552 		ret = guc_action_control_log(guc,
553 					     GUC_LOG_LEVEL_IS_VERBOSE(level),
554 					     GUC_LOG_LEVEL_IS_ENABLED(level),
555 					     GUC_LOG_LEVEL_TO_VERBOSITY(level));
556 	if (ret) {
557 		DRM_DEBUG_DRIVER("guc_log_control action failed %d\n", ret);
558 		goto out_unlock;
559 	}
560 
561 	log->level = level;
562 
563 out_unlock:
564 	mutex_unlock(&dev_priv->drm.struct_mutex);
565 
566 	return ret;
567 }
568 
569 bool intel_guc_log_relay_created(const struct intel_guc_log *log)
570 {
571 	return log->buf_addr;
572 }
573 
574 int intel_guc_log_relay_open(struct intel_guc_log *log)
575 {
576 	int ret;
577 
578 	if (!log->vma)
579 		return -ENODEV;
580 
581 	mutex_lock(&log->relay.lock);
582 
583 	if (intel_guc_log_relay_created(log)) {
584 		ret = -EEXIST;
585 		goto out_unlock;
586 	}
587 
588 	/*
589 	 * We require SSE 4.1 for fast reads from the GuC log buffer and
590 	 * it should be present on the chipsets supporting GuC based
591 	 * submissions.
592 	 */
593 	if (!i915_has_memcpy_from_wc()) {
594 		ret = -ENXIO;
595 		goto out_unlock;
596 	}
597 
598 	ret = guc_log_relay_create(log);
599 	if (ret)
600 		goto out_unlock;
601 
602 	ret = guc_log_relay_map(log);
603 	if (ret)
604 		goto out_relay;
605 
606 	mutex_unlock(&log->relay.lock);
607 
608 	return 0;
609 
610 out_relay:
611 	guc_log_relay_destroy(log);
612 out_unlock:
613 	mutex_unlock(&log->relay.lock);
614 
615 	return ret;
616 }
617 
618 int intel_guc_log_relay_start(struct intel_guc_log *log)
619 {
620 	if (log->relay.started)
621 		return -EEXIST;
622 
623 	/*
624 	 * When GuC is logging without us relaying to userspace, we're ignoring
625 	 * the flush notification. This means that we need to unconditionally
626 	 * flush on relay enabling, since GuC only notifies us once.
627 	 */
628 	queue_work(system_highpri_wq, &log->relay.flush_work);
629 
630 	log->relay.started = true;
631 
632 	return 0;
633 }
634 
635 void intel_guc_log_relay_flush(struct intel_guc_log *log)
636 {
637 	struct intel_guc *guc = log_to_guc(log);
638 	intel_wakeref_t wakeref;
639 
640 	if (!log->relay.started)
641 		return;
642 
643 	/*
644 	 * Before initiating the forceful flush, wait for any pending/ongoing
645 	 * flush to complete otherwise forceful flush may not actually happen.
646 	 */
647 	flush_work(&log->relay.flush_work);
648 
649 	with_intel_runtime_pm(guc_to_gt(guc)->uncore->rpm, wakeref)
650 		guc_action_flush_log(guc);
651 
652 	/* GuC would have updated log buffer by now, so copy it */
653 	guc_log_copy_debuglogs_for_relay(log);
654 }
655 
656 /*
657  * Stops the relay log. Called from intel_guc_log_relay_close(), so no
658  * possibility of race with start/flush since relay_write cannot race
659  * relay_close.
660  */
661 static void guc_log_relay_stop(struct intel_guc_log *log)
662 {
663 	struct intel_guc *guc = log_to_guc(log);
664 	struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
665 
666 	if (!log->relay.started)
667 		return;
668 
669 	intel_synchronize_irq(i915);
670 
671 	flush_work(&log->relay.flush_work);
672 
673 	log->relay.started = false;
674 }
675 
676 void intel_guc_log_relay_close(struct intel_guc_log *log)
677 {
678 	guc_log_relay_stop(log);
679 
680 	mutex_lock(&log->relay.lock);
681 	GEM_BUG_ON(!intel_guc_log_relay_created(log));
682 	guc_log_relay_unmap(log);
683 	guc_log_relay_destroy(log);
684 	mutex_unlock(&log->relay.lock);
685 }
686 
687 void intel_guc_log_handle_flush_event(struct intel_guc_log *log)
688 {
689 	if (log->relay.started)
690 		queue_work(system_highpri_wq, &log->relay.flush_work);
691 }
692 
693 static const char *
694 stringify_guc_log_type(enum guc_log_buffer_type type)
695 {
696 	switch (type) {
697 	case GUC_DEBUG_LOG_BUFFER:
698 		return "DEBUG";
699 	case GUC_CRASH_DUMP_LOG_BUFFER:
700 		return "CRASH";
701 	case GUC_CAPTURE_LOG_BUFFER:
702 		return "CAPTURE";
703 	default:
704 		MISSING_CASE(type);
705 	}
706 
707 	return "";
708 }
709 
710 /**
711  * intel_guc_log_info - dump information about GuC log relay
712  * @log: the GuC log
713  * @p: the &drm_printer
714  *
715  * Pretty printer for GuC log info
716  */
717 void intel_guc_log_info(struct intel_guc_log *log, struct drm_printer *p)
718 {
719 	enum guc_log_buffer_type type;
720 
721 	if (!intel_guc_log_relay_created(log)) {
722 		drm_puts(p, "GuC log relay not created\n");
723 		return;
724 	}
725 
726 	drm_puts(p, "GuC logging stats:\n");
727 
728 	drm_printf(p, "\tRelay full count: %u\n", log->relay.full_count);
729 
730 	for (type = GUC_DEBUG_LOG_BUFFER; type < GUC_MAX_LOG_BUFFER; type++) {
731 		drm_printf(p, "\t%s:\tflush count %10u, overflow count %10u\n",
732 			   stringify_guc_log_type(type),
733 			   log->stats[type].flush,
734 			   log->stats[type].sampled_overflow);
735 	}
736 }
737 
738 /**
739  * intel_guc_log_dump - dump the contents of the GuC log
740  * @log: the GuC log
741  * @p: the &drm_printer
742  * @dump_load_err: dump the log saved on GuC load error
743  *
744  * Pretty printer for the GuC log
745  */
746 int intel_guc_log_dump(struct intel_guc_log *log, struct drm_printer *p,
747 		       bool dump_load_err)
748 {
749 	struct intel_guc *guc = log_to_guc(log);
750 	struct intel_uc *uc = container_of(guc, struct intel_uc, guc);
751 	struct drm_i915_gem_object *obj = NULL;
752 	u32 *map;
753 	int i = 0;
754 
755 	if (!intel_guc_is_supported(guc))
756 		return -ENODEV;
757 
758 	if (dump_load_err)
759 		obj = uc->load_err_log;
760 	else if (guc->log.vma)
761 		obj = guc->log.vma->obj;
762 
763 	if (!obj)
764 		return 0;
765 
766 	map = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WC);
767 	if (IS_ERR(map)) {
768 		DRM_DEBUG("Failed to pin object\n");
769 		drm_puts(p, "(log data unaccessible)\n");
770 		return PTR_ERR(map);
771 	}
772 
773 	for (i = 0; i < obj->base.size / sizeof(u32); i += 4)
774 		drm_printf(p, "0x%08x 0x%08x 0x%08x 0x%08x\n",
775 			   *(map + i), *(map + i + 1),
776 			   *(map + i + 2), *(map + i + 3));
777 
778 	drm_puts(p, "\n");
779 
780 	i915_gem_object_unpin_map(obj);
781 
782 	return 0;
783 }
784