1/*
  2 * Copyright © 2014-2017 Intel Corporation
  3 *
  4 * Permission is hereby granted, free of charge, to any person obtaining a
  5 * copy of this software and associated documentation files (the "Software"),
  6 * to deal in the Software without restriction, including without limitation
  7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  8 * and/or sell copies of the Software, and to permit persons to whom the
  9 * Software is furnished to do so, subject to the following conditions:
 10 *
 11 * The above copyright notice and this permission notice (including the next
 12 * paragraph) shall be included in all copies or substantial portions of the
 13 * Software.
 14 *
 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 21 * IN THE SOFTWARE.
 22 *
 23 */
 24
 25#include <linux/debugfs.h>
 26#include <linux/relay.h>
 27
 28#include "intel_guc_log.h"
 29#include "i915_drv.h"
 30
 31static void guc_log_capture_logs(struct intel_guc *guc);
 32
 33/**
 34 * DOC: GuC firmware log
 35 *
 36 * Firmware log is enabled by setting i915.guc_log_level to the positive level.
 37 * Log data is printed out via reading debugfs i915_guc_log_dump. Reading from
 38 * i915_guc_load_status will print out firmware loading status and scratch
 39 * registers value.
 40 */
 41
 42static int guc_log_flush_complete(struct intel_guc *guc)
 43{
 44	u32 action[] = {
 45		INTEL_GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE
 46	};
 47
 48	return intel_guc_send(guc, action, ARRAY_SIZE(action));
 49}
 50
 51static int guc_log_flush(struct intel_guc *guc)
 52{
 53	u32 action[] = {
 54		INTEL_GUC_ACTION_FORCE_LOG_BUFFER_FLUSH,
 55		0
 56	};
 57
 58	return intel_guc_send(guc, action, ARRAY_SIZE(action));
 59}
 60
 61static int guc_log_control(struct intel_guc *guc, bool enable, u32 verbosity)
 62{
 63	union guc_log_control control_val = {
 64		{
 65			.logging_enabled = enable,
 66			.verbosity = verbosity,
 67		},
 68	};
 69	u32 action[] = {
 70		INTEL_GUC_ACTION_UK_LOG_ENABLE_LOGGING,
 71		control_val.value
 72	};
 73
 74	return intel_guc_send(guc, action, ARRAY_SIZE(action));
 75}
 76
 77/*
 78 * Sub buffer switch callback. Called whenever relay has to switch to a new
 79 * sub buffer, relay stays on the same sub buffer if 0 is returned.
 80 */
 81static int subbuf_start_callback(struct rchan_buf *buf,
 82				 void *subbuf,
 83				 void *prev_subbuf,
 84				 size_t prev_padding)
 85{
 86	/*
 87	 * Use no-overwrite mode by default, where relay will stop accepting
 88	 * new data if there are no empty sub buffers left.
 89	 * There is no strict synchronization enforced by relay between Consumer
 90	 * and Producer. In overwrite mode, there is a possibility of getting
 91	 * inconsistent/garbled data, the producer could be writing on to the
 92	 * same sub buffer from which Consumer is reading. This can't be avoided
 93	 * unless Consumer is fast enough and can always run in tandem with
 94	 * Producer.
 95	 */
 96	if (relay_buf_full(buf))
 97		return 0;
 98
 99	return 1;
100}
101
102/*
103 * file_create() callback. Creates relay file in debugfs.
104 */
105static struct dentry *create_buf_file_callback(const char *filename,
106					       struct dentry *parent,
107					       umode_t mode,
108					       struct rchan_buf *buf,
109					       int *is_global)
110{
111	struct dentry *buf_file;
112
113	/*
114	 * This to enable the use of a single buffer for the relay channel and
115	 * correspondingly have a single file exposed to User, through which
116	 * it can collect the logs in order without any post-processing.
117	 * Need to set 'is_global' even if parent is NULL for early logging.
118	 */
119	*is_global = 1;
120
121	if (!parent)
122		return NULL;
123
124	/*
125	 * Not using the channel filename passed as an argument, since for each
126	 * channel relay appends the corresponding CPU number to the filename
127	 * passed in relay_open(). This should be fine as relay just needs a
128	 * dentry of the file associated with the channel buffer and that file's
129	 * name need not be same as the filename passed as an argument.
130	 */
131	buf_file = debugfs_create_file("guc_log", mode,
132				       parent, buf, &relay_file_operations);
133	return buf_file;
134}
135
136/*
137 * file_remove() default callback. Removes relay file in debugfs.
138 */
139static int remove_buf_file_callback(struct dentry *dentry)
140{
141	debugfs_remove(dentry);
142	return 0;
143}
144
145/* relay channel callbacks */
146static struct rchan_callbacks relay_callbacks = {
147	.subbuf_start = subbuf_start_callback,
148	.create_buf_file = create_buf_file_callback,
149	.remove_buf_file = remove_buf_file_callback,
150};
151
152static int guc_log_relay_file_create(struct intel_guc *guc)
153{
154	struct drm_i915_private *dev_priv = guc_to_i915(guc);
155	struct dentry *log_dir;
156	int ret;
157
158	if (!i915_modparams.guc_log_level)
159		return 0;
160
161	mutex_lock(&guc->log.runtime.relay_lock);
162
163	/* For now create the log file in /sys/kernel/debug/dri/0 dir */
164	log_dir = dev_priv->drm.primary->debugfs_root;
165
166	/*
167	 * If /sys/kernel/debug/dri/0 location do not exist, then debugfs is
168	 * not mounted and so can't create the relay file.
169	 * The relay API seems to fit well with debugfs only, for availing relay
170	 * there are 3 requirements which can be met for debugfs file only in a
171	 * straightforward/clean manner :-
172	 * i)   Need the associated dentry pointer of the file, while opening the
173	 *      relay channel.
174	 * ii)  Should be able to use 'relay_file_operations' fops for the file.
175	 * iii) Set the 'i_private' field of file's inode to the pointer of
176	 *	relay channel buffer.
177	 */
178	if (!log_dir) {
179		DRM_ERROR("Debugfs dir not available yet for GuC log file\n");
180		ret = -ENODEV;
181		goto out_unlock;
182	}
183
184	ret = relay_late_setup_files(guc->log.runtime.relay_chan, "guc_log", log_dir);
185	if (ret < 0 && ret != -EEXIST) {
186		DRM_ERROR("Couldn't associate relay chan with file %d\n", ret);
187		goto out_unlock;
188	}
189
190	ret = 0;
191
192out_unlock:
193	mutex_unlock(&guc->log.runtime.relay_lock);
194	return ret;
195}
196
197static bool guc_log_has_relay(struct intel_guc *guc)
198{
199	lockdep_assert_held(&guc->log.runtime.relay_lock);
200
201	return guc->log.runtime.relay_chan != NULL;
202}
203
204static void guc_move_to_next_buf(struct intel_guc *guc)
205{
206	/*
207	 * Make sure the updates made in the sub buffer are visible when
208	 * Consumer sees the following update to offset inside the sub buffer.
209	 */
210	smp_wmb();
211
212	if (!guc_log_has_relay(guc))
213		return;
214
215	/* All data has been written, so now move the offset of sub buffer. */
216	relay_reserve(guc->log.runtime.relay_chan, guc->log.vma->obj->base.size);
217
218	/* Switch to the next sub buffer */
219	relay_flush(guc->log.runtime.relay_chan);
220}
221
222static void *guc_get_write_buffer(struct intel_guc *guc)
223{
224	if (!guc_log_has_relay(guc))
225		return NULL;
226
227	/*
228	 * Just get the base address of a new sub buffer and copy data into it
229	 * ourselves. NULL will be returned in no-overwrite mode, if all sub
230	 * buffers are full. Could have used the relay_write() to indirectly
231	 * copy the data, but that would have been bit convoluted, as we need to
232	 * write to only certain locations inside a sub buffer which cannot be
233	 * done without using relay_reserve() along with relay_write(). So its
234	 * better to use relay_reserve() alone.
235	 */
236	return relay_reserve(guc->log.runtime.relay_chan, 0);
237}
238
239static bool guc_check_log_buf_overflow(struct intel_guc *guc,
240				       enum guc_log_buffer_type type,
241				       unsigned int full_cnt)
242{
243	unsigned int prev_full_cnt = guc->log.prev_overflow_count[type];
244	bool overflow = false;
245
246	if (full_cnt != prev_full_cnt) {
247		overflow = true;
248
249		guc->log.prev_overflow_count[type] = full_cnt;
250		guc->log.total_overflow_count[type] += full_cnt - prev_full_cnt;
251
252		if (full_cnt < prev_full_cnt) {
253			/* buffer_full_cnt is a 4 bit counter */
254			guc->log.total_overflow_count[type] += 16;
255		}
256		DRM_ERROR_RATELIMITED("GuC log buffer overflow\n");
257	}
258
259	return overflow;
260}
261
262static unsigned int guc_get_log_buffer_size(enum guc_log_buffer_type type)
263{
264	switch (type) {
265	case GUC_ISR_LOG_BUFFER:
266		return (GUC_LOG_ISR_PAGES + 1) * PAGE_SIZE;
267	case GUC_DPC_LOG_BUFFER:
268		return (GUC_LOG_DPC_PAGES + 1) * PAGE_SIZE;
269	case GUC_CRASH_DUMP_LOG_BUFFER:
270		return (GUC_LOG_CRASH_PAGES + 1) * PAGE_SIZE;
271	default:
272		MISSING_CASE(type);
273	}
274
275	return 0;
276}
277
278static void guc_read_update_log_buffer(struct intel_guc *guc)
279{
280	unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt;
281	struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state;
282	struct guc_log_buffer_state log_buf_state_local;
283	enum guc_log_buffer_type type;
284	void *src_data, *dst_data;
285	bool new_overflow;
286
287	if (WARN_ON(!guc->log.runtime.buf_addr))
288		return;
289
290	/* Get the pointer to shared GuC log buffer */
291	log_buf_state = src_data = guc->log.runtime.buf_addr;
292
293	mutex_lock(&guc->log.runtime.relay_lock);
294
295	/* Get the pointer to local buffer to store the logs */
296	log_buf_snapshot_state = dst_data = guc_get_write_buffer(guc);
297
298	if (unlikely(!log_buf_snapshot_state)) {
299		/*
300		 * Used rate limited to avoid deluge of messages, logs might be
301		 * getting consumed by User at a slow rate.
302		 */
303		DRM_ERROR_RATELIMITED("no sub-buffer to capture logs\n");
304		guc->log.capture_miss_count++;
305		mutex_unlock(&guc->log.runtime.relay_lock);
306
307		return;
308	}
309
310	/* Actual logs are present from the 2nd page */
311	src_data += PAGE_SIZE;
312	dst_data += PAGE_SIZE;
313
314	for (type = GUC_ISR_LOG_BUFFER; type < GUC_MAX_LOG_BUFFER; type++) {
315		/*
316		 * Make a copy of the state structure, inside GuC log buffer
317		 * (which is uncached mapped), on the stack to avoid reading
318		 * from it multiple times.
319		 */
320		memcpy(&log_buf_state_local, log_buf_state,
321		       sizeof(struct guc_log_buffer_state));
322		buffer_size = guc_get_log_buffer_size(type);
323		read_offset = log_buf_state_local.read_ptr;
324		write_offset = log_buf_state_local.sampled_write_ptr;
325		full_cnt = log_buf_state_local.buffer_full_cnt;
326
327		/* Bookkeeping stuff */
328		guc->log.flush_count[type] += log_buf_state_local.flush_to_file;
329		new_overflow = guc_check_log_buf_overflow(guc, type, full_cnt);
330
331		/* Update the state of shared log buffer */
332		log_buf_state->read_ptr = write_offset;
333		log_buf_state->flush_to_file = 0;
334		log_buf_state++;
335
336		/* First copy the state structure in snapshot buffer */
337		memcpy(log_buf_snapshot_state, &log_buf_state_local,
338		       sizeof(struct guc_log_buffer_state));
339
340		/*
341		 * The write pointer could have been updated by GuC firmware,
342		 * after sending the flush interrupt to Host, for consistency
343		 * set write pointer value to same value of sampled_write_ptr
344		 * in the snapshot buffer.
345		 */
346		log_buf_snapshot_state->write_ptr = write_offset;
347		log_buf_snapshot_state++;
348
349		/* Now copy the actual logs. */
350		if (unlikely(new_overflow)) {
351			/* copy the whole buffer in case of overflow */
352			read_offset = 0;
353			write_offset = buffer_size;
354		} else if (unlikely((read_offset > buffer_size) ||
355				    (write_offset > buffer_size))) {
356			DRM_ERROR("invalid log buffer state\n");
357			/* copy whole buffer as offsets are unreliable */
358			read_offset = 0;
359			write_offset = buffer_size;
360		}
361
362		/* Just copy the newly written data */
363		if (read_offset > write_offset) {
364			i915_memcpy_from_wc(dst_data, src_data, write_offset);
365			bytes_to_copy = buffer_size - read_offset;
366		} else {
367			bytes_to_copy = write_offset - read_offset;
368		}
369		i915_memcpy_from_wc(dst_data + read_offset,
370				    src_data + read_offset, bytes_to_copy);
371
372		src_data += buffer_size;
373		dst_data += buffer_size;
374	}
375
376	guc_move_to_next_buf(guc);
377
378	mutex_unlock(&guc->log.runtime.relay_lock);
379}
380
381static void capture_logs_work(struct work_struct *work)
382{
383	struct intel_guc *guc =
384		container_of(work, struct intel_guc, log.runtime.flush_work);
385
386	guc_log_capture_logs(guc);
387}
388
389static bool guc_log_has_runtime(struct intel_guc *guc)
390{
391	return guc->log.runtime.buf_addr != NULL;
392}
393
394static int guc_log_runtime_create(struct intel_guc *guc)
395{
396	struct drm_i915_private *dev_priv = guc_to_i915(guc);
397	void *vaddr;
398	int ret;
399
400	lockdep_assert_held(&dev_priv->drm.struct_mutex);
401
402	if (!guc->log.vma)
403		return -ENODEV;
404
405	GEM_BUG_ON(guc_log_has_runtime(guc));
406
407	ret = i915_gem_object_set_to_wc_domain(guc->log.vma->obj, true);
408	if (ret)
409		return ret;
410
411	/*
412	 * Create a WC (Uncached for read) vmalloc mapping of log
413	 * buffer pages, so that we can directly get the data
414	 * (up-to-date) from memory.
415	 */
416	vaddr = i915_gem_object_pin_map(guc->log.vma->obj, I915_MAP_WC);
417	if (IS_ERR(vaddr)) {
418		DRM_ERROR("Couldn't map log buffer pages %d\n", ret);
419		return PTR_ERR(vaddr);
420	}
421
422	guc->log.runtime.buf_addr = vaddr;
423
424	return 0;
425}
426
427static void guc_log_runtime_destroy(struct intel_guc *guc)
428{
429	/*
430	 * It's possible that the runtime stuff was never allocated because
431	 * GuC log was disabled at the boot time.
432	 */
433	if (!guc_log_has_runtime(guc))
434		return;
435
436	i915_gem_object_unpin_map(guc->log.vma->obj);
437	guc->log.runtime.buf_addr = NULL;
438}
439
440void intel_guc_log_init_early(struct intel_guc *guc)
441{
442	mutex_init(&guc->log.runtime.relay_lock);
443	INIT_WORK(&guc->log.runtime.flush_work, capture_logs_work);
444}
445
446int intel_guc_log_relay_create(struct intel_guc *guc)
447{
448	struct drm_i915_private *dev_priv = guc_to_i915(guc);
449	struct rchan *guc_log_relay_chan;
450	size_t n_subbufs, subbuf_size;
451	int ret;
452
453	if (!i915_modparams.guc_log_level)
454		return 0;
455
456	mutex_lock(&guc->log.runtime.relay_lock);
457
458	GEM_BUG_ON(guc_log_has_relay(guc));
459
460	 /* Keep the size of sub buffers same as shared log buffer */
461	subbuf_size = GUC_LOG_SIZE;
462
463	/*
464	 * Store up to 8 snapshots, which is large enough to buffer sufficient
465	 * boot time logs and provides enough leeway to User, in terms of
466	 * latency, for consuming the logs from relay. Also doesn't take
467	 * up too much memory.
468	 */
469	n_subbufs = 8;
470
471	/*
472	 * Create a relay channel, so that we have buffers for storing
473	 * the GuC firmware logs, the channel will be linked with a file
474	 * later on when debugfs is registered.
475	 */
476	guc_log_relay_chan = relay_open(NULL, NULL, subbuf_size,
477					n_subbufs, &relay_callbacks, dev_priv);
478	if (!guc_log_relay_chan) {
479		DRM_ERROR("Couldn't create relay chan for GuC logging\n");
480
481		ret = -ENOMEM;
482		goto err;
483	}
484
485	GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
486	guc->log.runtime.relay_chan = guc_log_relay_chan;
487
488	mutex_unlock(&guc->log.runtime.relay_lock);
489
490	return 0;
491
492err:
493	mutex_unlock(&guc->log.runtime.relay_lock);
494	/* logging will be off */
495	i915_modparams.guc_log_level = 0;
496	return ret;
497}
498
499void intel_guc_log_relay_destroy(struct intel_guc *guc)
500{
501	mutex_lock(&guc->log.runtime.relay_lock);
502
503	/*
504	 * It's possible that the relay was never allocated because
505	 * GuC log was disabled at the boot time.
506	 */
507	if (!guc_log_has_relay(guc))
508		goto out_unlock;
509
510	relay_close(guc->log.runtime.relay_chan);
511	guc->log.runtime.relay_chan = NULL;
512
513out_unlock:
514	mutex_unlock(&guc->log.runtime.relay_lock);
515}
516
517static int guc_log_late_setup(struct intel_guc *guc)
518{
519	struct drm_i915_private *dev_priv = guc_to_i915(guc);
520	int ret;
521
522	if (!guc_log_has_runtime(guc)) {
523		/*
524		 * If log was disabled at boot time, then setup needed to handle
525		 * log buffer flush interrupts would not have been done yet, so
526		 * do that now.
527		 */
528		ret = intel_guc_log_relay_create(guc);
529		if (ret)
530			goto err;
531
532		mutex_lock(&dev_priv->drm.struct_mutex);
533		intel_runtime_pm_get(dev_priv);
534		ret = guc_log_runtime_create(guc);
535		intel_runtime_pm_put(dev_priv);
536		mutex_unlock(&dev_priv->drm.struct_mutex);
537
538		if (ret)
539			goto err_relay;
540	}
541
542	ret = guc_log_relay_file_create(guc);
543	if (ret)
544		goto err_runtime;
545
546	return 0;
547
548err_runtime:
549	mutex_lock(&dev_priv->drm.struct_mutex);
550	guc_log_runtime_destroy(guc);
551	mutex_unlock(&dev_priv->drm.struct_mutex);
552err_relay:
553	intel_guc_log_relay_destroy(guc);
554err:
555	/* logging will remain off */
556	i915_modparams.guc_log_level = 0;
557	return ret;
558}
559
560static void guc_log_capture_logs(struct intel_guc *guc)
561{
562	struct drm_i915_private *dev_priv = guc_to_i915(guc);
563
564	guc_read_update_log_buffer(guc);
565
566	/*
567	 * Generally device is expected to be active only at this
568	 * time, so get/put should be really quick.
569	 */
570	intel_runtime_pm_get(dev_priv);
571	guc_log_flush_complete(guc);
572	intel_runtime_pm_put(dev_priv);
573}
574
575static void guc_flush_logs(struct intel_guc *guc)
576{
577	struct drm_i915_private *dev_priv = guc_to_i915(guc);
578
579	if (!USES_GUC_SUBMISSION(dev_priv) || !i915_modparams.guc_log_level)
580		return;
581
582	/* First disable the interrupts, will be renabled afterwards */
583	mutex_lock(&dev_priv->drm.struct_mutex);
584	intel_runtime_pm_get(dev_priv);
585	gen9_disable_guc_interrupts(dev_priv);
586	intel_runtime_pm_put(dev_priv);
587	mutex_unlock(&dev_priv->drm.struct_mutex);
588
589	/*
590	 * Before initiating the forceful flush, wait for any pending/ongoing
591	 * flush to complete otherwise forceful flush may not actually happen.
592	 */
593	flush_work(&guc->log.runtime.flush_work);
594
595	/* Ask GuC to update the log buffer state */
596	intel_runtime_pm_get(dev_priv);
597	guc_log_flush(guc);
598	intel_runtime_pm_put(dev_priv);
599
600	/* GuC would have updated log buffer by now, so capture it */
601	guc_log_capture_logs(guc);
602}
603
604int intel_guc_log_create(struct intel_guc *guc)
605{
606	struct i915_vma *vma;
607	unsigned long offset;
608	u32 flags;
609	int ret;
610
611	GEM_BUG_ON(guc->log.vma);
612
613	/*
614	 * We require SSE 4.1 for fast reads from the GuC log buffer and
615	 * it should be present on the chipsets supporting GuC based
616	 * submisssions.
617	 */
618	if (WARN_ON(!i915_has_memcpy_from_wc())) {
619		ret = -EINVAL;
620		goto err;
621	}
622
623	vma = intel_guc_allocate_vma(guc, GUC_LOG_SIZE);
624	if (IS_ERR(vma)) {
625		ret = PTR_ERR(vma);
626		goto err;
627	}
628
629	guc->log.vma = vma;
630
631	if (i915_modparams.guc_log_level) {
632		ret = guc_log_runtime_create(guc);
633		if (ret < 0)
634			goto err_vma;
635	}
636
637	/* each allocated unit is a page */
638	flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL |
639		(GUC_LOG_DPC_PAGES << GUC_LOG_DPC_SHIFT) |
640		(GUC_LOG_ISR_PAGES << GUC_LOG_ISR_SHIFT) |
641		(GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);
642
643	offset = guc_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
644	guc->log.flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
645
646	return 0;
647
648err_vma:
649	i915_vma_unpin_and_release(&guc->log.vma);
650err:
651	/* logging will be off */
652	i915_modparams.guc_log_level = 0;
653	return ret;
654}
655
656void intel_guc_log_destroy(struct intel_guc *guc)
657{
658	guc_log_runtime_destroy(guc);
659	i915_vma_unpin_and_release(&guc->log.vma);
660}
661
662int intel_guc_log_control(struct intel_guc *guc, u64 control_val)
663{
664	struct drm_i915_private *dev_priv = guc_to_i915(guc);
665	bool enable_logging = control_val > 0;
666	u32 verbosity;
667	int ret;
668
669	if (!guc->log.vma)
670		return -ENODEV;
671
672	BUILD_BUG_ON(GUC_LOG_VERBOSITY_MIN);
673	if (control_val > 1 + GUC_LOG_VERBOSITY_MAX)
674		return -EINVAL;
675
676	/* This combination doesn't make sense & won't have any effect */
677	if (!enable_logging && !i915_modparams.guc_log_level)
678		return 0;
679
680	verbosity = enable_logging ? control_val - 1 : 0;
681
682	ret = mutex_lock_interruptible(&dev_priv->drm.struct_mutex);
683	if (ret)
684		return ret;
685	intel_runtime_pm_get(dev_priv);
686	ret = guc_log_control(guc, enable_logging, verbosity);
687	intel_runtime_pm_put(dev_priv);
688	mutex_unlock(&dev_priv->drm.struct_mutex);
689
690	if (ret < 0) {
691		DRM_DEBUG_DRIVER("guc_logging_control action failed %d\n", ret);
692		return ret;
693	}
694
695	if (enable_logging) {
696		i915_modparams.guc_log_level = 1 + verbosity;
697
698		/*
699		 * If log was disabled at boot time, then the relay channel file
700		 * wouldn't have been created by now and interrupts also would
701		 * not have been enabled. Try again now, just in case.
702		 */
703		ret = guc_log_late_setup(guc);
704		if (ret < 0) {
705			DRM_DEBUG_DRIVER("GuC log late setup failed %d\n", ret);
706			return ret;
707		}
708
709		/* GuC logging is currently the only user of Guc2Host interrupts */
710		mutex_lock(&dev_priv->drm.struct_mutex);
711		intel_runtime_pm_get(dev_priv);
712		gen9_enable_guc_interrupts(dev_priv);
713		intel_runtime_pm_put(dev_priv);
714		mutex_unlock(&dev_priv->drm.struct_mutex);
715	} else {
716		/*
717		 * Once logging is disabled, GuC won't generate logs & send an
718		 * interrupt. But there could be some data in the log buffer
719		 * which is yet to be captured. So request GuC to update the log
720		 * buffer state and then collect the left over logs.
721		 */
722		guc_flush_logs(guc);
723
724		/* As logging is disabled, update log level to reflect that */
725		i915_modparams.guc_log_level = 0;
726	}
727
728	return ret;
729}
730
731void i915_guc_log_register(struct drm_i915_private *dev_priv)
732{
733	if (!USES_GUC_SUBMISSION(dev_priv) || !i915_modparams.guc_log_level)
734		return;
735
736	guc_log_late_setup(&dev_priv->guc);
737}
738
739void i915_guc_log_unregister(struct drm_i915_private *dev_priv)
740{
741	struct intel_guc *guc = &dev_priv->guc;
742
743	if (!USES_GUC_SUBMISSION(dev_priv))
744		return;
745
746	mutex_lock(&dev_priv->drm.struct_mutex);
747	/* GuC logging is currently the only user of Guc2Host interrupts */
748	intel_runtime_pm_get(dev_priv);
749	gen9_disable_guc_interrupts(dev_priv);
750	intel_runtime_pm_put(dev_priv);
751
752	guc_log_runtime_destroy(guc);
753	mutex_unlock(&dev_priv->drm.struct_mutex);
754
755	intel_guc_log_relay_destroy(guc);
756}