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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Tegra host1x Command DMA
4 *
5 * Copyright (c) 2010-2013, NVIDIA Corporation.
6 */
7
8
9#include <asm/cacheflush.h>
10#include <linux/device.h>
11#include <linux/dma-mapping.h>
12#include <linux/host1x.h>
13#include <linux/interrupt.h>
14#include <linux/kernel.h>
15#include <linux/kfifo.h>
16#include <linux/slab.h>
17#include <trace/events/host1x.h>
18
19#include "cdma.h"
20#include "channel.h"
21#include "dev.h"
22#include "debug.h"
23#include "job.h"
24
25/*
26 * push_buffer
27 *
28 * The push buffer is a circular array of words to be fetched by command DMA.
29 * Note that it works slightly differently to the sync queue; fence == pos
30 * means that the push buffer is full, not empty.
31 */
32
33/*
34 * Typically the commands written into the push buffer are a pair of words. We
35 * use slots to represent each of these pairs and to simplify things. Note the
36 * strange number of slots allocated here. 512 slots will fit exactly within a
37 * single memory page. We also need one additional word at the end of the push
38 * buffer for the RESTART opcode that will instruct the CDMA to jump back to
39 * the beginning of the push buffer. With 512 slots, this means that we'll use
40 * 2 memory pages and waste 4092 bytes of the second page that will never be
41 * used.
42 */
43#define HOST1X_PUSHBUFFER_SLOTS 511
44
45/*
46 * Clean up push buffer resources
47 */
48static void host1x_pushbuffer_destroy(struct push_buffer *pb)
49{
50 struct host1x_cdma *cdma = pb_to_cdma(pb);
51 struct host1x *host1x = cdma_to_host1x(cdma);
52
53 if (!pb->mapped)
54 return;
55
56 if (host1x->domain) {
57 iommu_unmap(host1x->domain, pb->dma, pb->alloc_size);
58 free_iova(&host1x->iova, iova_pfn(&host1x->iova, pb->dma));
59 }
60
61 dma_free_wc(host1x->dev, pb->alloc_size, pb->mapped, pb->phys);
62
63 pb->mapped = NULL;
64 pb->phys = 0;
65}
66
67/*
68 * Init push buffer resources
69 */
70static int host1x_pushbuffer_init(struct push_buffer *pb)
71{
72 struct host1x_cdma *cdma = pb_to_cdma(pb);
73 struct host1x *host1x = cdma_to_host1x(cdma);
74 struct iova *alloc;
75 u32 size;
76 int err;
77
78 pb->mapped = NULL;
79 pb->phys = 0;
80 pb->size = HOST1X_PUSHBUFFER_SLOTS * 8;
81
82 size = pb->size + 4;
83
84 /* initialize buffer pointers */
85 pb->fence = pb->size - 8;
86 pb->pos = 0;
87
88 if (host1x->domain) {
89 unsigned long shift;
90
91 size = iova_align(&host1x->iova, size);
92
93 pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys,
94 GFP_KERNEL);
95 if (!pb->mapped)
96 return -ENOMEM;
97
98 shift = iova_shift(&host1x->iova);
99 alloc = alloc_iova(&host1x->iova, size >> shift,
100 host1x->iova_end >> shift, true);
101 if (!alloc) {
102 err = -ENOMEM;
103 goto iommu_free_mem;
104 }
105
106 pb->dma = iova_dma_addr(&host1x->iova, alloc);
107 err = iommu_map(host1x->domain, pb->dma, pb->phys, size,
108 IOMMU_READ);
109 if (err)
110 goto iommu_free_iova;
111 } else {
112 pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys,
113 GFP_KERNEL);
114 if (!pb->mapped)
115 return -ENOMEM;
116
117 pb->dma = pb->phys;
118 }
119
120 pb->alloc_size = size;
121
122 host1x_hw_pushbuffer_init(host1x, pb);
123
124 return 0;
125
126iommu_free_iova:
127 __free_iova(&host1x->iova, alloc);
128iommu_free_mem:
129 dma_free_wc(host1x->dev, size, pb->mapped, pb->phys);
130
131 return err;
132}
133
134/*
135 * Push two words to the push buffer
136 * Caller must ensure push buffer is not full
137 */
138static void host1x_pushbuffer_push(struct push_buffer *pb, u32 op1, u32 op2)
139{
140 u32 *p = (u32 *)((void *)pb->mapped + pb->pos);
141
142 WARN_ON(pb->pos == pb->fence);
143 *(p++) = op1;
144 *(p++) = op2;
145 pb->pos += 8;
146
147 if (pb->pos >= pb->size)
148 pb->pos -= pb->size;
149}
150
151/*
152 * Pop a number of two word slots from the push buffer
153 * Caller must ensure push buffer is not empty
154 */
155static void host1x_pushbuffer_pop(struct push_buffer *pb, unsigned int slots)
156{
157 /* Advance the next write position */
158 pb->fence += slots * 8;
159
160 if (pb->fence >= pb->size)
161 pb->fence -= pb->size;
162}
163
164/*
165 * Return the number of two word slots free in the push buffer
166 */
167static u32 host1x_pushbuffer_space(struct push_buffer *pb)
168{
169 unsigned int fence = pb->fence;
170
171 if (pb->fence < pb->pos)
172 fence += pb->size;
173
174 return (fence - pb->pos) / 8;
175}
176
177/*
178 * Sleep (if necessary) until the requested event happens
179 * - CDMA_EVENT_SYNC_QUEUE_EMPTY : sync queue is completely empty.
180 * - Returns 1
181 * - CDMA_EVENT_PUSH_BUFFER_SPACE : there is space in the push buffer
182 * - Return the amount of space (> 0)
183 * Must be called with the cdma lock held.
184 */
185unsigned int host1x_cdma_wait_locked(struct host1x_cdma *cdma,
186 enum cdma_event event)
187{
188 for (;;) {
189 struct push_buffer *pb = &cdma->push_buffer;
190 unsigned int space;
191
192 switch (event) {
193 case CDMA_EVENT_SYNC_QUEUE_EMPTY:
194 space = list_empty(&cdma->sync_queue) ? 1 : 0;
195 break;
196
197 case CDMA_EVENT_PUSH_BUFFER_SPACE:
198 space = host1x_pushbuffer_space(pb);
199 break;
200
201 default:
202 WARN_ON(1);
203 return -EINVAL;
204 }
205
206 if (space)
207 return space;
208
209 trace_host1x_wait_cdma(dev_name(cdma_to_channel(cdma)->dev),
210 event);
211
212 /* If somebody has managed to already start waiting, yield */
213 if (cdma->event != CDMA_EVENT_NONE) {
214 mutex_unlock(&cdma->lock);
215 schedule();
216 mutex_lock(&cdma->lock);
217 continue;
218 }
219
220 cdma->event = event;
221
222 mutex_unlock(&cdma->lock);
223 wait_for_completion(&cdma->complete);
224 mutex_lock(&cdma->lock);
225 }
226
227 return 0;
228}
229
230/*
231 * Sleep (if necessary) until the push buffer has enough free space.
232 *
233 * Must be called with the cdma lock held.
234 */
235static int host1x_cdma_wait_pushbuffer_space(struct host1x *host1x,
236 struct host1x_cdma *cdma,
237 unsigned int needed)
238{
239 while (true) {
240 struct push_buffer *pb = &cdma->push_buffer;
241 unsigned int space;
242
243 space = host1x_pushbuffer_space(pb);
244 if (space >= needed)
245 break;
246
247 trace_host1x_wait_cdma(dev_name(cdma_to_channel(cdma)->dev),
248 CDMA_EVENT_PUSH_BUFFER_SPACE);
249
250 host1x_hw_cdma_flush(host1x, cdma);
251
252 /* If somebody has managed to already start waiting, yield */
253 if (cdma->event != CDMA_EVENT_NONE) {
254 mutex_unlock(&cdma->lock);
255 schedule();
256 mutex_lock(&cdma->lock);
257 continue;
258 }
259
260 cdma->event = CDMA_EVENT_PUSH_BUFFER_SPACE;
261
262 mutex_unlock(&cdma->lock);
263 wait_for_completion(&cdma->complete);
264 mutex_lock(&cdma->lock);
265 }
266
267 return 0;
268}
269/*
270 * Start timer that tracks the time spent by the job.
271 * Must be called with the cdma lock held.
272 */
273static void cdma_start_timer_locked(struct host1x_cdma *cdma,
274 struct host1x_job *job)
275{
276 if (cdma->timeout.client) {
277 /* timer already started */
278 return;
279 }
280
281 cdma->timeout.client = job->client;
282 cdma->timeout.syncpt = job->syncpt;
283 cdma->timeout.syncpt_val = job->syncpt_end;
284 cdma->timeout.start_ktime = ktime_get();
285
286 schedule_delayed_work(&cdma->timeout.wq,
287 msecs_to_jiffies(job->timeout));
288}
289
290/*
291 * Stop timer when a buffer submission completes.
292 * Must be called with the cdma lock held.
293 */
294static void stop_cdma_timer_locked(struct host1x_cdma *cdma)
295{
296 cancel_delayed_work(&cdma->timeout.wq);
297 cdma->timeout.client = NULL;
298}
299
300/*
301 * For all sync queue entries that have already finished according to the
302 * current sync point registers:
303 * - unpin & unref their mems
304 * - pop their push buffer slots
305 * - remove them from the sync queue
306 * This is normally called from the host code's worker thread, but can be
307 * called manually if necessary.
308 * Must be called with the cdma lock held.
309 */
310static void update_cdma_locked(struct host1x_cdma *cdma)
311{
312 bool signal = false;
313 struct host1x_job *job, *n;
314
315 /*
316 * Walk the sync queue, reading the sync point registers as necessary,
317 * to consume as many sync queue entries as possible without blocking
318 */
319 list_for_each_entry_safe(job, n, &cdma->sync_queue, list) {
320 struct host1x_syncpt *sp = job->syncpt;
321
322 /* Check whether this syncpt has completed, and bail if not */
323 if (!host1x_syncpt_is_expired(sp, job->syncpt_end) &&
324 !job->cancelled) {
325 /* Start timer on next pending syncpt */
326 if (job->timeout)
327 cdma_start_timer_locked(cdma, job);
328
329 break;
330 }
331
332 /* Cancel timeout, when a buffer completes */
333 if (cdma->timeout.client)
334 stop_cdma_timer_locked(cdma);
335
336 /* Unpin the memory */
337 host1x_job_unpin(job);
338
339 /* Pop push buffer slots */
340 if (job->num_slots) {
341 struct push_buffer *pb = &cdma->push_buffer;
342
343 host1x_pushbuffer_pop(pb, job->num_slots);
344
345 if (cdma->event == CDMA_EVENT_PUSH_BUFFER_SPACE)
346 signal = true;
347 }
348
349 list_del(&job->list);
350 host1x_job_put(job);
351 }
352
353 if (cdma->event == CDMA_EVENT_SYNC_QUEUE_EMPTY &&
354 list_empty(&cdma->sync_queue))
355 signal = true;
356
357 if (signal) {
358 cdma->event = CDMA_EVENT_NONE;
359 complete(&cdma->complete);
360 }
361}
362
363void host1x_cdma_update_sync_queue(struct host1x_cdma *cdma,
364 struct device *dev)
365{
366 struct host1x *host1x = cdma_to_host1x(cdma);
367 u32 restart_addr, syncpt_incrs, syncpt_val;
368 struct host1x_job *job, *next_job = NULL;
369
370 syncpt_val = host1x_syncpt_load(cdma->timeout.syncpt);
371
372 dev_dbg(dev, "%s: starting cleanup (thresh %d)\n",
373 __func__, syncpt_val);
374
375 /*
376 * Move the sync_queue read pointer to the first entry that hasn't
377 * completed based on the current HW syncpt value. It's likely there
378 * won't be any (i.e. we're still at the head), but covers the case
379 * where a syncpt incr happens just prior/during the teardown.
380 */
381
382 dev_dbg(dev, "%s: skip completed buffers still in sync_queue\n",
383 __func__);
384
385 list_for_each_entry(job, &cdma->sync_queue, list) {
386 if (syncpt_val < job->syncpt_end) {
387
388 if (!list_is_last(&job->list, &cdma->sync_queue))
389 next_job = list_next_entry(job, list);
390
391 goto syncpt_incr;
392 }
393
394 host1x_job_dump(dev, job);
395 }
396
397 /* all jobs have been completed */
398 job = NULL;
399
400syncpt_incr:
401
402 /*
403 * Increment with CPU the remaining syncpts of a partially executed job.
404 *
405 * CDMA will continue execution starting with the next job or will get
406 * into idle state.
407 */
408 if (next_job)
409 restart_addr = next_job->first_get;
410 else
411 restart_addr = cdma->last_pos;
412
413 if (!job)
414 goto resume;
415
416 /* do CPU increments for the remaining syncpts */
417 if (job->syncpt_recovery) {
418 dev_dbg(dev, "%s: perform CPU incr on pending buffers\n",
419 __func__);
420
421 /* won't need a timeout when replayed */
422 job->timeout = 0;
423
424 syncpt_incrs = job->syncpt_end - syncpt_val;
425 dev_dbg(dev, "%s: CPU incr (%d)\n", __func__, syncpt_incrs);
426
427 host1x_job_dump(dev, job);
428
429 /* safe to use CPU to incr syncpts */
430 host1x_hw_cdma_timeout_cpu_incr(host1x, cdma, job->first_get,
431 syncpt_incrs, job->syncpt_end,
432 job->num_slots);
433
434 dev_dbg(dev, "%s: finished sync_queue modification\n",
435 __func__);
436 } else {
437 struct host1x_job *failed_job = job;
438
439 host1x_job_dump(dev, job);
440
441 host1x_syncpt_set_locked(job->syncpt);
442 failed_job->cancelled = true;
443
444 list_for_each_entry_continue(job, &cdma->sync_queue, list) {
445 unsigned int i;
446
447 if (job->syncpt != failed_job->syncpt)
448 continue;
449
450 for (i = 0; i < job->num_slots; i++) {
451 unsigned int slot = (job->first_get/8 + i) %
452 HOST1X_PUSHBUFFER_SLOTS;
453 u32 *mapped = cdma->push_buffer.mapped;
454
455 /*
456 * Overwrite opcodes with 0 word writes
457 * to offset 0xbad. This does nothing but
458 * has a easily detected signature in debug
459 * traces.
460 *
461 * On systems with MLOCK enforcement enabled,
462 * the above 0 word writes would fall foul of
463 * the enforcement. As such, in the first slot
464 * put a RESTART_W opcode to the beginning
465 * of the next job. We don't use this for older
466 * chips since those only support the RESTART
467 * opcode with inconvenient alignment requirements.
468 */
469 if (i == 0 && host1x->info->has_wide_gather) {
470 unsigned int next_job = (job->first_get/8 + job->num_slots)
471 % HOST1X_PUSHBUFFER_SLOTS;
472 mapped[2*slot+0] = (0xd << 28) | (next_job * 2);
473 mapped[2*slot+1] = 0x0;
474 } else {
475 mapped[2*slot+0] = 0x1bad0000;
476 mapped[2*slot+1] = 0x1bad0000;
477 }
478 }
479
480 job->cancelled = true;
481 }
482
483 wmb();
484
485 update_cdma_locked(cdma);
486 }
487
488resume:
489 /* roll back DMAGET and start up channel again */
490 host1x_hw_cdma_resume(host1x, cdma, restart_addr);
491}
492
493/*
494 * Create a cdma
495 */
496int host1x_cdma_init(struct host1x_cdma *cdma)
497{
498 int err;
499
500 mutex_init(&cdma->lock);
501 init_completion(&cdma->complete);
502
503 INIT_LIST_HEAD(&cdma->sync_queue);
504
505 cdma->event = CDMA_EVENT_NONE;
506 cdma->running = false;
507 cdma->torndown = false;
508
509 err = host1x_pushbuffer_init(&cdma->push_buffer);
510 if (err)
511 return err;
512
513 return 0;
514}
515
516/*
517 * Destroy a cdma
518 */
519int host1x_cdma_deinit(struct host1x_cdma *cdma)
520{
521 struct push_buffer *pb = &cdma->push_buffer;
522 struct host1x *host1x = cdma_to_host1x(cdma);
523
524 if (cdma->running) {
525 pr_warn("%s: CDMA still running\n", __func__);
526 return -EBUSY;
527 }
528
529 host1x_pushbuffer_destroy(pb);
530 host1x_hw_cdma_timeout_destroy(host1x, cdma);
531
532 return 0;
533}
534
535/*
536 * Begin a cdma submit
537 */
538int host1x_cdma_begin(struct host1x_cdma *cdma, struct host1x_job *job)
539{
540 struct host1x *host1x = cdma_to_host1x(cdma);
541
542 mutex_lock(&cdma->lock);
543
544 /*
545 * Check if syncpoint was locked due to previous job timeout.
546 * This needs to be done within the cdma lock to avoid a race
547 * with the timeout handler.
548 */
549 if (job->syncpt->locked) {
550 mutex_unlock(&cdma->lock);
551 return -EPERM;
552 }
553
554 if (job->timeout) {
555 /* init state on first submit with timeout value */
556 if (!cdma->timeout.initialized) {
557 int err;
558
559 err = host1x_hw_cdma_timeout_init(host1x, cdma);
560 if (err) {
561 mutex_unlock(&cdma->lock);
562 return err;
563 }
564 }
565 }
566
567 if (!cdma->running)
568 host1x_hw_cdma_start(host1x, cdma);
569
570 cdma->slots_free = 0;
571 cdma->slots_used = 0;
572 cdma->first_get = cdma->push_buffer.pos;
573
574 trace_host1x_cdma_begin(dev_name(job->channel->dev));
575 return 0;
576}
577
578/*
579 * Push two words into a push buffer slot
580 * Blocks as necessary if the push buffer is full.
581 */
582void host1x_cdma_push(struct host1x_cdma *cdma, u32 op1, u32 op2)
583{
584 struct host1x *host1x = cdma_to_host1x(cdma);
585 struct push_buffer *pb = &cdma->push_buffer;
586 u32 slots_free = cdma->slots_free;
587
588 if (host1x_debug_trace_cmdbuf)
589 trace_host1x_cdma_push(dev_name(cdma_to_channel(cdma)->dev),
590 op1, op2);
591
592 if (slots_free == 0) {
593 host1x_hw_cdma_flush(host1x, cdma);
594 slots_free = host1x_cdma_wait_locked(cdma,
595 CDMA_EVENT_PUSH_BUFFER_SPACE);
596 }
597
598 cdma->slots_free = slots_free - 1;
599 cdma->slots_used++;
600 host1x_pushbuffer_push(pb, op1, op2);
601}
602
603/*
604 * Push four words into two consecutive push buffer slots. Note that extra
605 * care needs to be taken not to split the two slots across the end of the
606 * push buffer. Otherwise the RESTART opcode at the end of the push buffer
607 * that ensures processing will restart at the beginning will break up the
608 * four words.
609 *
610 * Blocks as necessary if the push buffer is full.
611 */
612void host1x_cdma_push_wide(struct host1x_cdma *cdma, u32 op1, u32 op2,
613 u32 op3, u32 op4)
614{
615 struct host1x_channel *channel = cdma_to_channel(cdma);
616 struct host1x *host1x = cdma_to_host1x(cdma);
617 struct push_buffer *pb = &cdma->push_buffer;
618 unsigned int space = cdma->slots_free;
619 unsigned int needed = 2, extra = 0;
620
621 if (host1x_debug_trace_cmdbuf)
622 trace_host1x_cdma_push_wide(dev_name(channel->dev), op1, op2,
623 op3, op4);
624
625 /* compute number of extra slots needed for padding */
626 if (pb->pos + 16 > pb->size) {
627 extra = (pb->size - pb->pos) / 8;
628 needed += extra;
629 }
630
631 host1x_cdma_wait_pushbuffer_space(host1x, cdma, needed);
632 space = host1x_pushbuffer_space(pb);
633
634 cdma->slots_free = space - needed;
635 cdma->slots_used += needed;
636
637 if (extra > 0) {
638 /*
639 * If there isn't enough space at the tail of the pushbuffer,
640 * insert a RESTART(0) here to go back to the beginning.
641 * The code above adjusted the indexes appropriately.
642 */
643 host1x_pushbuffer_push(pb, (0x5 << 28), 0xdead0000);
644 }
645
646 host1x_pushbuffer_push(pb, op1, op2);
647 host1x_pushbuffer_push(pb, op3, op4);
648}
649
650/*
651 * End a cdma submit
652 * Kick off DMA, add job to the sync queue, and a number of slots to be freed
653 * from the pushbuffer. The handles for a submit must all be pinned at the same
654 * time, but they can be unpinned in smaller chunks.
655 */
656void host1x_cdma_end(struct host1x_cdma *cdma,
657 struct host1x_job *job)
658{
659 struct host1x *host1x = cdma_to_host1x(cdma);
660 bool idle = list_empty(&cdma->sync_queue);
661
662 host1x_hw_cdma_flush(host1x, cdma);
663
664 job->first_get = cdma->first_get;
665 job->num_slots = cdma->slots_used;
666 host1x_job_get(job);
667 list_add_tail(&job->list, &cdma->sync_queue);
668
669 /* start timer on idle -> active transitions */
670 if (job->timeout && idle)
671 cdma_start_timer_locked(cdma, job);
672
673 trace_host1x_cdma_end(dev_name(job->channel->dev));
674 mutex_unlock(&cdma->lock);
675}
676
677/*
678 * Update cdma state according to current sync point values
679 */
680void host1x_cdma_update(struct host1x_cdma *cdma)
681{
682 mutex_lock(&cdma->lock);
683 update_cdma_locked(cdma);
684 mutex_unlock(&cdma->lock);
685}