summaryrefslogtreecommitdiff
path: root/drivers/gpu/host1x/cdma.c
blob: 765e5aa64eb6886dab9400413c71452589f7f082 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Tegra host1x Command DMA
 *
 * Copyright (c) 2010-2013, NVIDIA Corporation.
 */


#include <asm/cacheflush.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/host1x.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/kfifo.h>
#include <linux/slab.h>
#include <trace/events/host1x.h>

#include "cdma.h"
#include "channel.h"
#include "dev.h"
#include "debug.h"
#include "job.h"

/*
 * push_buffer
 *
 * The push buffer is a circular array of words to be fetched by command DMA.
 * Note that it works slightly differently to the sync queue; fence == pos
 * means that the push buffer is full, not empty.
 */

/*
 * Typically the commands written into the push buffer are a pair of words. We
 * use slots to represent each of these pairs and to simplify things. Note the
 * strange number of slots allocated here. 512 slots will fit exactly within a
 * single memory page. We also need one additional word at the end of the push
 * buffer for the RESTART opcode that will instruct the CDMA to jump back to
 * the beginning of the push buffer. With 512 slots, this means that we'll use
 * 2 memory pages and waste 4092 bytes of the second page that will never be
 * used.
 */
#define HOST1X_PUSHBUFFER_SLOTS	511

/*
 * Clean up push buffer resources
 */
static void host1x_pushbuffer_destroy(struct push_buffer *pb)
{
	struct host1x_cdma *cdma = pb_to_cdma(pb);
	struct host1x *host1x = cdma_to_host1x(cdma);

	if (!pb->mapped)
		return;

	if (host1x->domain) {
		iommu_unmap(host1x->domain, pb->dma, pb->alloc_size);
		free_iova(&host1x->iova, iova_pfn(&host1x->iova, pb->dma));
	}

	dma_free_wc(host1x->dev, pb->alloc_size, pb->mapped, pb->phys);

	pb->mapped = NULL;
	pb->phys = 0;
}

/*
 * Init push buffer resources
 */
static int host1x_pushbuffer_init(struct push_buffer *pb)
{
	struct host1x_cdma *cdma = pb_to_cdma(pb);
	struct host1x *host1x = cdma_to_host1x(cdma);
	struct iova *alloc;
	u32 size;
	int err;

	pb->mapped = NULL;
	pb->phys = 0;
	pb->size = HOST1X_PUSHBUFFER_SLOTS * 8;

	size = pb->size + 4;

	/* initialize buffer pointers */
	pb->fence = pb->size - 8;
	pb->pos = 0;

	if (host1x->domain) {
		unsigned long shift;

		size = iova_align(&host1x->iova, size);

		pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys,
					  GFP_KERNEL);
		if (!pb->mapped)
			return -ENOMEM;

		shift = iova_shift(&host1x->iova);
		alloc = alloc_iova(&host1x->iova, size >> shift,
				   host1x->iova_end >> shift, true);
		if (!alloc) {
			err = -ENOMEM;
			goto iommu_free_mem;
		}

		pb->dma = iova_dma_addr(&host1x->iova, alloc);
		err = iommu_map(host1x->domain, pb->dma, pb->phys, size,
				IOMMU_READ);
		if (err)
			goto iommu_free_iova;
	} else {
		pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys,
					  GFP_KERNEL);
		if (!pb->mapped)
			return -ENOMEM;

		pb->dma = pb->phys;
	}

	pb->alloc_size = size;

	host1x_hw_pushbuffer_init(host1x, pb);

	return 0;

iommu_free_iova:
	__free_iova(&host1x->iova, alloc);
iommu_free_mem:
	dma_free_wc(host1x->dev, size, pb->mapped, pb->phys);

	return err;
}

/*
 * Push two words to the push buffer
 * Caller must ensure push buffer is not full
 */
static void host1x_pushbuffer_push(struct push_buffer *pb, u32 op1, u32 op2)
{
	u32 *p = (u32 *)((void *)pb->mapped + pb->pos);

	WARN_ON(pb->pos == pb->fence);
	*(p++) = op1;
	*(p++) = op2;
	pb->pos += 8;

	if (pb->pos >= pb->size)
		pb->pos -= pb->size;
}

/*
 * Pop a number of two word slots from the push buffer
 * Caller must ensure push buffer is not empty
 */
static void host1x_pushbuffer_pop(struct push_buffer *pb, unsigned int slots)
{
	/* Advance the next write position */
	pb->fence += slots * 8;

	if (pb->fence >= pb->size)
		pb->fence -= pb->size;
}

/*
 * Return the number of two word slots free in the push buffer
 */
static u32 host1x_pushbuffer_space(struct push_buffer *pb)
{
	unsigned int fence = pb->fence;

	if (pb->fence < pb->pos)
		fence += pb->size;

	return (fence - pb->pos) / 8;
}

/*
 * Sleep (if necessary) until the requested event happens
 *   - CDMA_EVENT_SYNC_QUEUE_EMPTY : sync queue is completely empty.
 *     - Returns 1
 *   - CDMA_EVENT_PUSH_BUFFER_SPACE : there is space in the push buffer
 *     - Return the amount of space (> 0)
 * Must be called with the cdma lock held.
 */
unsigned int host1x_cdma_wait_locked(struct host1x_cdma *cdma,
				     enum cdma_event event)
{
	for (;;) {
		struct push_buffer *pb = &cdma->push_buffer;
		unsigned int space;

		switch (event) {
		case CDMA_EVENT_SYNC_QUEUE_EMPTY:
			space = list_empty(&cdma->sync_queue) ? 1 : 0;
			break;

		case CDMA_EVENT_PUSH_BUFFER_SPACE:
			space = host1x_pushbuffer_space(pb);
			break;

		default:
			WARN_ON(1);
			return -EINVAL;
		}

		if (space)
			return space;

		trace_host1x_wait_cdma(dev_name(cdma_to_channel(cdma)->dev),
				       event);

		/* If somebody has managed to already start waiting, yield */
		if (cdma->event != CDMA_EVENT_NONE) {
			mutex_unlock(&cdma->lock);
			schedule();
			mutex_lock(&cdma->lock);
			continue;
		}

		cdma->event = event;

		mutex_unlock(&cdma->lock);
		wait_for_completion(&cdma->complete);
		mutex_lock(&cdma->lock);
	}

	return 0;
}

/*
 * Sleep (if necessary) until the push buffer has enough free space.
 *
 * Must be called with the cdma lock held.
 */
static int host1x_cdma_wait_pushbuffer_space(struct host1x *host1x,
					     struct host1x_cdma *cdma,
					     unsigned int needed)
{
	while (true) {
		struct push_buffer *pb = &cdma->push_buffer;
		unsigned int space;

		space = host1x_pushbuffer_space(pb);
		if (space >= needed)
			break;

		trace_host1x_wait_cdma(dev_name(cdma_to_channel(cdma)->dev),
				       CDMA_EVENT_PUSH_BUFFER_SPACE);

		host1x_hw_cdma_flush(host1x, cdma);

		/* If somebody has managed to already start waiting, yield */
		if (cdma->event != CDMA_EVENT_NONE) {
			mutex_unlock(&cdma->lock);
			schedule();
			mutex_lock(&cdma->lock);
			continue;
		}

		cdma->event = CDMA_EVENT_PUSH_BUFFER_SPACE;

		mutex_unlock(&cdma->lock);
		wait_for_completion(&cdma->complete);
		mutex_lock(&cdma->lock);
	}

	return 0;
}
/*
 * Start timer that tracks the time spent by the job.
 * Must be called with the cdma lock held.
 */
static void cdma_start_timer_locked(struct host1x_cdma *cdma,
				    struct host1x_job *job)
{
	if (cdma->timeout.client) {
		/* timer already started */
		return;
	}

	cdma->timeout.client = job->client;
	cdma->timeout.syncpt = job->syncpt;
	cdma->timeout.syncpt_val = job->syncpt_end;
	cdma->timeout.start_ktime = ktime_get();

	schedule_delayed_work(&cdma->timeout.wq,
			      msecs_to_jiffies(job->timeout));
}

/*
 * Stop timer when a buffer submission completes.
 * Must be called with the cdma lock held.
 */
static void stop_cdma_timer_locked(struct host1x_cdma *cdma)
{
	cancel_delayed_work(&cdma->timeout.wq);
	cdma->timeout.client = NULL;
}

/*
 * For all sync queue entries that have already finished according to the
 * current sync point registers:
 *  - unpin & unref their mems
 *  - pop their push buffer slots
 *  - remove them from the sync queue
 * This is normally called from the host code's worker thread, but can be
 * called manually if necessary.
 * Must be called with the cdma lock held.
 */
static void update_cdma_locked(struct host1x_cdma *cdma)
{
	bool signal = false;
	struct host1x_job *job, *n;

	/*
	 * Walk the sync queue, reading the sync point registers as necessary,
	 * to consume as many sync queue entries as possible without blocking
	 */
	list_for_each_entry_safe(job, n, &cdma->sync_queue, list) {
		struct host1x_syncpt *sp = job->syncpt;

		/* Check whether this syncpt has completed, and bail if not */
		if (!host1x_syncpt_is_expired(sp, job->syncpt_end) &&
		    !job->cancelled) {
			/* Start timer on next pending syncpt */
			if (job->timeout)
				cdma_start_timer_locked(cdma, job);

			break;
		}

		/* Cancel timeout, when a buffer completes */
		if (cdma->timeout.client)
			stop_cdma_timer_locked(cdma);

		/* Unpin the memory */
		host1x_job_unpin(job);

		/* Pop push buffer slots */
		if (job->num_slots) {
			struct push_buffer *pb = &cdma->push_buffer;

			host1x_pushbuffer_pop(pb, job->num_slots);

			if (cdma->event == CDMA_EVENT_PUSH_BUFFER_SPACE)
				signal = true;
		}

		list_del(&job->list);
		host1x_job_put(job);
	}

	if (cdma->event == CDMA_EVENT_SYNC_QUEUE_EMPTY &&
	    list_empty(&cdma->sync_queue))
		signal = true;

	if (signal) {
		cdma->event = CDMA_EVENT_NONE;
		complete(&cdma->complete);
	}
}

void host1x_cdma_update_sync_queue(struct host1x_cdma *cdma,
				   struct device *dev)
{
	struct host1x *host1x = cdma_to_host1x(cdma);
	u32 restart_addr, syncpt_incrs, syncpt_val;
	struct host1x_job *job, *next_job = NULL;

	syncpt_val = host1x_syncpt_load(cdma->timeout.syncpt);

	dev_dbg(dev, "%s: starting cleanup (thresh %d)\n",
		__func__, syncpt_val);

	/*
	 * Move the sync_queue read pointer to the first entry that hasn't
	 * completed based on the current HW syncpt value. It's likely there
	 * won't be any (i.e. we're still at the head), but covers the case
	 * where a syncpt incr happens just prior/during the teardown.
	 */

	dev_dbg(dev, "%s: skip completed buffers still in sync_queue\n",
		__func__);

	list_for_each_entry(job, &cdma->sync_queue, list) {
		if (syncpt_val < job->syncpt_end) {

			if (!list_is_last(&job->list, &cdma->sync_queue))
				next_job = list_next_entry(job, list);

			goto syncpt_incr;
		}

		host1x_job_dump(dev, job);
	}

	/* all jobs have been completed */
	job = NULL;

syncpt_incr:

	/*
	 * Increment with CPU the remaining syncpts of a partially executed job.
	 *
	 * CDMA will continue execution starting with the next job or will get
	 * into idle state.
	 */
	if (next_job)
		restart_addr = next_job->first_get;
	else
		restart_addr = cdma->last_pos;

	if (!job)
		goto resume;

	/* do CPU increments for the remaining syncpts */
	if (job->syncpt_recovery) {
		dev_dbg(dev, "%s: perform CPU incr on pending buffers\n",
			__func__);

		/* won't need a timeout when replayed */
		job->timeout = 0;

		syncpt_incrs = job->syncpt_end - syncpt_val;
		dev_dbg(dev, "%s: CPU incr (%d)\n", __func__, syncpt_incrs);

		host1x_job_dump(dev, job);

		/* safe to use CPU to incr syncpts */
		host1x_hw_cdma_timeout_cpu_incr(host1x, cdma, job->first_get,
						syncpt_incrs, job->syncpt_end,
						job->num_slots);

		dev_dbg(dev, "%s: finished sync_queue modification\n",
			__func__);
	} else {
		struct host1x_job *failed_job = job;

		host1x_job_dump(dev, job);

		host1x_syncpt_set_locked(job->syncpt);
		failed_job->cancelled = true;

		list_for_each_entry_continue(job, &cdma->sync_queue, list) {
			unsigned int i;

			if (job->syncpt != failed_job->syncpt)
				continue;

			for (i = 0; i < job->num_slots; i++) {
				unsigned int slot = (job->first_get/8 + i) %
						    HOST1X_PUSHBUFFER_SLOTS;
				u32 *mapped = cdma->push_buffer.mapped;

				/*
				 * Overwrite opcodes with 0 word writes
				 * to offset 0xbad. This does nothing but
				 * has a easily detected signature in debug
				 * traces.
				 */
				mapped[2*slot+0] = 0x1bad0000;
				mapped[2*slot+1] = 0x1bad0000;
			}

			job->cancelled = true;
		}

		wmb();

		update_cdma_locked(cdma);
	}

resume:
	/* roll back DMAGET and start up channel again */
	host1x_hw_cdma_resume(host1x, cdma, restart_addr);
}

/*
 * Create a cdma
 */
int host1x_cdma_init(struct host1x_cdma *cdma)
{
	int err;

	mutex_init(&cdma->lock);
	init_completion(&cdma->complete);

	INIT_LIST_HEAD(&cdma->sync_queue);

	cdma->event = CDMA_EVENT_NONE;
	cdma->running = false;
	cdma->torndown = false;

	err = host1x_pushbuffer_init(&cdma->push_buffer);
	if (err)
		return err;

	return 0;
}

/*
 * Destroy a cdma
 */
int host1x_cdma_deinit(struct host1x_cdma *cdma)
{
	struct push_buffer *pb = &cdma->push_buffer;
	struct host1x *host1x = cdma_to_host1x(cdma);

	if (cdma->running) {
		pr_warn("%s: CDMA still running\n", __func__);
		return -EBUSY;
	}

	host1x_pushbuffer_destroy(pb);
	host1x_hw_cdma_timeout_destroy(host1x, cdma);

	return 0;
}

/*
 * Begin a cdma submit
 */
int host1x_cdma_begin(struct host1x_cdma *cdma, struct host1x_job *job)
{
	struct host1x *host1x = cdma_to_host1x(cdma);

	mutex_lock(&cdma->lock);

	/*
	 * Check if syncpoint was locked due to previous job timeout.
	 * This needs to be done within the cdma lock to avoid a race
	 * with the timeout handler.
	 */
	if (job->syncpt->locked) {
		mutex_unlock(&cdma->lock);
		return -EPERM;
	}

	if (job->timeout) {
		/* init state on first submit with timeout value */
		if (!cdma->timeout.initialized) {
			int err;

			err = host1x_hw_cdma_timeout_init(host1x, cdma);
			if (err) {
				mutex_unlock(&cdma->lock);
				return err;
			}
		}
	}

	if (!cdma->running)
		host1x_hw_cdma_start(host1x, cdma);

	cdma->slots_free = 0;
	cdma->slots_used = 0;
	cdma->first_get = cdma->push_buffer.pos;

	trace_host1x_cdma_begin(dev_name(job->channel->dev));
	return 0;
}

/*
 * Push two words into a push buffer slot
 * Blocks as necessary if the push buffer is full.
 */
void host1x_cdma_push(struct host1x_cdma *cdma, u32 op1, u32 op2)
{
	struct host1x *host1x = cdma_to_host1x(cdma);
	struct push_buffer *pb = &cdma->push_buffer;
	u32 slots_free = cdma->slots_free;

	if (host1x_debug_trace_cmdbuf)
		trace_host1x_cdma_push(dev_name(cdma_to_channel(cdma)->dev),
				       op1, op2);

	if (slots_free == 0) {
		host1x_hw_cdma_flush(host1x, cdma);
		slots_free = host1x_cdma_wait_locked(cdma,
						CDMA_EVENT_PUSH_BUFFER_SPACE);
	}

	cdma->slots_free = slots_free - 1;
	cdma->slots_used++;
	host1x_pushbuffer_push(pb, op1, op2);
}

/*
 * Push four words into two consecutive push buffer slots. Note that extra
 * care needs to be taken not to split the two slots across the end of the
 * push buffer. Otherwise the RESTART opcode at the end of the push buffer
 * that ensures processing will restart at the beginning will break up the
 * four words.
 *
 * Blocks as necessary if the push buffer is full.
 */
void host1x_cdma_push_wide(struct host1x_cdma *cdma, u32 op1, u32 op2,
			   u32 op3, u32 op4)
{
	struct host1x_channel *channel = cdma_to_channel(cdma);
	struct host1x *host1x = cdma_to_host1x(cdma);
	struct push_buffer *pb = &cdma->push_buffer;
	unsigned int needed = 2, extra = 0, i;
	unsigned int space = cdma->slots_free;

	if (host1x_debug_trace_cmdbuf)
		trace_host1x_cdma_push_wide(dev_name(channel->dev), op1, op2,
					    op3, op4);

	/* compute number of extra slots needed for padding */
	if (pb->pos + 16 > pb->size) {
		extra = (pb->size - pb->pos) / 8;
		needed += extra;
	}

	host1x_cdma_wait_pushbuffer_space(host1x, cdma, needed);
	space = host1x_pushbuffer_space(pb);

	cdma->slots_free = space - needed;
	cdma->slots_used += needed;

	/*
	 * Note that we rely on the fact that this is only used to submit wide
	 * gather opcodes, which consist of 3 words, and they are padded with
	 * a NOP to avoid having to deal with fractional slots (a slot always
	 * represents 2 words). The fourth opcode passed to this function will
	 * therefore always be a NOP.
	 *
	 * This works around a slight ambiguity when it comes to opcodes. For
	 * all current host1x incarnations the NOP opcode uses the exact same
	 * encoding (0x20000000), so we could hard-code the value here, but a
	 * new incarnation may change it and break that assumption.
	 */
	for (i = 0; i < extra; i++)
		host1x_pushbuffer_push(pb, op4, op4);

	host1x_pushbuffer_push(pb, op1, op2);
	host1x_pushbuffer_push(pb, op3, op4);
}

/*
 * End a cdma submit
 * Kick off DMA, add job to the sync queue, and a number of slots to be freed
 * from the pushbuffer. The handles for a submit must all be pinned at the same
 * time, but they can be unpinned in smaller chunks.
 */
void host1x_cdma_end(struct host1x_cdma *cdma,
		     struct host1x_job *job)
{
	struct host1x *host1x = cdma_to_host1x(cdma);
	bool idle = list_empty(&cdma->sync_queue);

	host1x_hw_cdma_flush(host1x, cdma);

	job->first_get = cdma->first_get;
	job->num_slots = cdma->slots_used;
	host1x_job_get(job);
	list_add_tail(&job->list, &cdma->sync_queue);

	/* start timer on idle -> active transitions */
	if (job->timeout && idle)
		cdma_start_timer_locked(cdma, job);

	trace_host1x_cdma_end(dev_name(job->channel->dev));
	mutex_unlock(&cdma->lock);
}

/*
 * Update cdma state according to current sync point values
 */
void host1x_cdma_update(struct host1x_cdma *cdma)
{
	mutex_lock(&cdma->lock);
	update_cdma_locked(cdma);
	mutex_unlock(&cdma->lock);
}