1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Tegra host1x Syncpoints
4 *
5 * Copyright (c) 2010-2015, NVIDIA Corporation.
6 */
7
8 #include <linux/module.h>
9 #include <linux/device.h>
10 #include <linux/slab.h>
11
12 #include <trace/events/host1x.h>
13
14 #include "syncpt.h"
15 #include "dev.h"
16 #include "intr.h"
17 #include "debug.h"
18
19 #define SYNCPT_CHECK_PERIOD (2 * HZ)
20 #define MAX_STUCK_CHECK_COUNT 15
21
22 static struct host1x_syncpt_base *
host1x_syncpt_base_request(struct host1x * host)23 host1x_syncpt_base_request(struct host1x *host)
24 {
25 struct host1x_syncpt_base *bases = host->bases;
26 unsigned int i;
27
28 for (i = 0; i < host->info->nb_bases; i++)
29 if (!bases[i].requested)
30 break;
31
32 if (i >= host->info->nb_bases)
33 return NULL;
34
35 bases[i].requested = true;
36 return &bases[i];
37 }
38
host1x_syncpt_base_free(struct host1x_syncpt_base * base)39 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
40 {
41 if (base)
42 base->requested = false;
43 }
44
45 /**
46 * host1x_syncpt_alloc() - allocate a syncpoint
47 * @host: host1x device data
48 * @flags: bitfield of HOST1X_SYNCPT_* flags
49 * @name: name for the syncpoint for use in debug prints
50 *
51 * Allocates a hardware syncpoint for the caller's use. The caller then has
52 * the sole authority to mutate the syncpoint's value until it is freed again.
53 *
54 * If no free syncpoints are available, or a NULL name was specified, returns
55 * NULL.
56 */
host1x_syncpt_alloc(struct host1x * host,unsigned long flags,const char * name)57 struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
58 unsigned long flags,
59 const char *name)
60 {
61 struct host1x_syncpt *sp = host->syncpt;
62 char *full_name;
63 unsigned int i;
64
65 if (!name)
66 return NULL;
67
68 mutex_lock(&host->syncpt_mutex);
69
70 for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++)
71 ;
72
73 if (i >= host->info->nb_pts)
74 goto unlock;
75
76 if (flags & HOST1X_SYNCPT_HAS_BASE) {
77 sp->base = host1x_syncpt_base_request(host);
78 if (!sp->base)
79 goto unlock;
80 }
81
82 full_name = kasprintf(GFP_KERNEL, "%u-%s", sp->id, name);
83 if (!full_name)
84 goto free_base;
85
86 sp->name = full_name;
87
88 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
89 sp->client_managed = true;
90 else
91 sp->client_managed = false;
92
93 kref_init(&sp->ref);
94
95 mutex_unlock(&host->syncpt_mutex);
96 return sp;
97
98 free_base:
99 host1x_syncpt_base_free(sp->base);
100 sp->base = NULL;
101 unlock:
102 mutex_unlock(&host->syncpt_mutex);
103 return NULL;
104 }
105 EXPORT_SYMBOL(host1x_syncpt_alloc);
106
107 /**
108 * host1x_syncpt_id() - retrieve syncpoint ID
109 * @sp: host1x syncpoint
110 *
111 * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
112 * often used as a value to program into registers that control how hardware
113 * blocks interact with syncpoints.
114 */
host1x_syncpt_id(struct host1x_syncpt * sp)115 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
116 {
117 return sp->id;
118 }
119 EXPORT_SYMBOL(host1x_syncpt_id);
120
121 /**
122 * host1x_syncpt_incr_max() - update the value sent to hardware
123 * @sp: host1x syncpoint
124 * @incrs: number of increments
125 */
host1x_syncpt_incr_max(struct host1x_syncpt * sp,u32 incrs)126 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
127 {
128 return (u32)atomic_add_return(incrs, &sp->max_val);
129 }
130 EXPORT_SYMBOL(host1x_syncpt_incr_max);
131
132 /*
133 * Write cached syncpoint and waitbase values to hardware.
134 */
host1x_syncpt_restore(struct host1x * host)135 void host1x_syncpt_restore(struct host1x *host)
136 {
137 struct host1x_syncpt *sp_base = host->syncpt;
138 unsigned int i;
139
140 for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
141 host1x_hw_syncpt_restore(host, sp_base + i);
142
143 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
144 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
145
146 wmb();
147 }
148
149 /*
150 * Update the cached syncpoint and waitbase values by reading them
151 * from the registers.
152 */
host1x_syncpt_save(struct host1x * host)153 void host1x_syncpt_save(struct host1x *host)
154 {
155 struct host1x_syncpt *sp_base = host->syncpt;
156 unsigned int i;
157
158 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
159 if (host1x_syncpt_client_managed(sp_base + i))
160 host1x_hw_syncpt_load(host, sp_base + i);
161 else
162 WARN_ON(!host1x_syncpt_idle(sp_base + i));
163 }
164
165 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
166 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
167 }
168
169 /*
170 * Updates the cached syncpoint value by reading a new value from the hardware
171 * register
172 */
host1x_syncpt_load(struct host1x_syncpt * sp)173 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
174 {
175 u32 val;
176
177 val = host1x_hw_syncpt_load(sp->host, sp);
178 trace_host1x_syncpt_load_min(sp->id, val);
179
180 return val;
181 }
182
183 /*
184 * Get the current syncpoint base
185 */
host1x_syncpt_load_wait_base(struct host1x_syncpt * sp)186 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
187 {
188 host1x_hw_syncpt_load_wait_base(sp->host, sp);
189
190 return sp->base_val;
191 }
192
193 /**
194 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
195 * @sp: host1x syncpoint
196 */
host1x_syncpt_incr(struct host1x_syncpt * sp)197 int host1x_syncpt_incr(struct host1x_syncpt *sp)
198 {
199 return host1x_hw_syncpt_cpu_incr(sp->host, sp);
200 }
201 EXPORT_SYMBOL(host1x_syncpt_incr);
202
203 /*
204 * Updated sync point form hardware, and returns true if syncpoint is expired,
205 * false if we may need to wait
206 */
syncpt_load_min_is_expired(struct host1x_syncpt * sp,u32 thresh)207 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
208 {
209 host1x_hw_syncpt_load(sp->host, sp);
210
211 return host1x_syncpt_is_expired(sp, thresh);
212 }
213
214 /**
215 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
216 * @sp: host1x syncpoint
217 * @thresh: threshold
218 * @timeout: maximum time to wait for the syncpoint to reach the given value
219 * @value: return location for the syncpoint value
220 */
host1x_syncpt_wait(struct host1x_syncpt * sp,u32 thresh,long timeout,u32 * value)221 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
222 u32 *value)
223 {
224 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
225 void *ref;
226 struct host1x_waitlist *waiter;
227 int err = 0, check_count = 0;
228 u32 val;
229
230 if (value)
231 *value = 0;
232
233 /* first check cache */
234 if (host1x_syncpt_is_expired(sp, thresh)) {
235 if (value)
236 *value = host1x_syncpt_load(sp);
237
238 return 0;
239 }
240
241 /* try to read from register */
242 val = host1x_hw_syncpt_load(sp->host, sp);
243 if (host1x_syncpt_is_expired(sp, thresh)) {
244 if (value)
245 *value = val;
246
247 goto done;
248 }
249
250 if (!timeout) {
251 err = -EAGAIN;
252 goto done;
253 }
254
255 /* allocate a waiter */
256 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
257 if (!waiter) {
258 err = -ENOMEM;
259 goto done;
260 }
261
262 /* schedule a wakeup when the syncpoint value is reached */
263 err = host1x_intr_add_action(sp->host, sp, thresh,
264 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
265 &wq, waiter, &ref);
266 if (err)
267 goto done;
268
269 err = -EAGAIN;
270 /* Caller-specified timeout may be impractically low */
271 if (timeout < 0)
272 timeout = LONG_MAX;
273
274 /* wait for the syncpoint, or timeout, or signal */
275 while (timeout) {
276 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
277 int remain;
278
279 remain = wait_event_interruptible_timeout(wq,
280 syncpt_load_min_is_expired(sp, thresh),
281 check);
282 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
283 if (value)
284 *value = host1x_syncpt_load(sp);
285
286 err = 0;
287
288 break;
289 }
290
291 if (remain < 0) {
292 err = remain;
293 break;
294 }
295
296 timeout -= check;
297
298 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
299 dev_warn(sp->host->dev,
300 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
301 current->comm, sp->id, sp->name,
302 thresh, timeout);
303
304 host1x_debug_dump_syncpts(sp->host);
305
306 if (check_count == MAX_STUCK_CHECK_COUNT)
307 host1x_debug_dump(sp->host);
308
309 check_count++;
310 }
311 }
312
313 host1x_intr_put_ref(sp->host, sp->id, ref, true);
314
315 done:
316 return err;
317 }
318 EXPORT_SYMBOL(host1x_syncpt_wait);
319
320 /*
321 * Returns true if syncpoint is expired, false if we may need to wait
322 */
host1x_syncpt_is_expired(struct host1x_syncpt * sp,u32 thresh)323 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
324 {
325 u32 current_val;
326
327 smp_rmb();
328
329 current_val = (u32)atomic_read(&sp->min_val);
330
331 return ((current_val - thresh) & 0x80000000U) == 0U;
332 }
333
host1x_syncpt_init(struct host1x * host)334 int host1x_syncpt_init(struct host1x *host)
335 {
336 struct host1x_syncpt_base *bases;
337 struct host1x_syncpt *syncpt;
338 unsigned int i;
339
340 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
341 GFP_KERNEL);
342 if (!syncpt)
343 return -ENOMEM;
344
345 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
346 GFP_KERNEL);
347 if (!bases)
348 return -ENOMEM;
349
350 for (i = 0; i < host->info->nb_pts; i++) {
351 syncpt[i].id = i;
352 syncpt[i].host = host;
353
354 /*
355 * Unassign syncpt from channels for purposes of Tegra186
356 * syncpoint protection. This prevents any channel from
357 * accessing it until it is reassigned.
358 */
359 host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL);
360 }
361
362 for (i = 0; i < host->info->nb_bases; i++)
363 bases[i].id = i;
364
365 mutex_init(&host->syncpt_mutex);
366 host->syncpt = syncpt;
367 host->bases = bases;
368
369 host1x_syncpt_restore(host);
370 host1x_hw_syncpt_enable_protection(host);
371
372 /* Allocate sync point to use for clearing waits for expired fences */
373 host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
374 if (!host->nop_sp)
375 return -ENOMEM;
376
377 if (host->info->reserve_vblank_syncpts) {
378 kref_init(&host->syncpt[26].ref);
379 kref_init(&host->syncpt[27].ref);
380 }
381
382 return 0;
383 }
384
385 /**
386 * host1x_syncpt_request() - request a syncpoint
387 * @client: client requesting the syncpoint
388 * @flags: flags
389 *
390 * host1x client drivers can use this function to allocate a syncpoint for
391 * subsequent use. A syncpoint returned by this function will be reserved for
392 * use by the client exclusively. When no longer using a syncpoint, a host1x
393 * client driver needs to release it using host1x_syncpt_put().
394 */
host1x_syncpt_request(struct host1x_client * client,unsigned long flags)395 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
396 unsigned long flags)
397 {
398 struct host1x *host = dev_get_drvdata(client->host->parent);
399
400 return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
401 }
402 EXPORT_SYMBOL(host1x_syncpt_request);
403
syncpt_release(struct kref * ref)404 static void syncpt_release(struct kref *ref)
405 {
406 struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
407
408 atomic_set(&sp->max_val, host1x_syncpt_read(sp));
409
410 mutex_lock(&sp->host->syncpt_mutex);
411
412 host1x_syncpt_base_free(sp->base);
413 kfree(sp->name);
414 sp->base = NULL;
415 sp->name = NULL;
416 sp->client_managed = false;
417
418 mutex_unlock(&sp->host->syncpt_mutex);
419 }
420
421 /**
422 * host1x_syncpt_put() - free a requested syncpoint
423 * @sp: host1x syncpoint
424 *
425 * Release a syncpoint previously allocated using host1x_syncpt_request(). A
426 * host1x client driver should call this when the syncpoint is no longer in
427 * use.
428 */
host1x_syncpt_put(struct host1x_syncpt * sp)429 void host1x_syncpt_put(struct host1x_syncpt *sp)
430 {
431 if (!sp)
432 return;
433
434 kref_put(&sp->ref, syncpt_release);
435 }
436 EXPORT_SYMBOL(host1x_syncpt_put);
437
host1x_syncpt_deinit(struct host1x * host)438 void host1x_syncpt_deinit(struct host1x *host)
439 {
440 struct host1x_syncpt *sp = host->syncpt;
441 unsigned int i;
442
443 for (i = 0; i < host->info->nb_pts; i++, sp++)
444 kfree(sp->name);
445 }
446
447 /**
448 * host1x_syncpt_read_max() - read maximum syncpoint value
449 * @sp: host1x syncpoint
450 *
451 * The maximum syncpoint value indicates how many operations there are in
452 * queue, either in channel or in a software thread.
453 */
host1x_syncpt_read_max(struct host1x_syncpt * sp)454 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
455 {
456 smp_rmb();
457
458 return (u32)atomic_read(&sp->max_val);
459 }
460 EXPORT_SYMBOL(host1x_syncpt_read_max);
461
462 /**
463 * host1x_syncpt_read_min() - read minimum syncpoint value
464 * @sp: host1x syncpoint
465 *
466 * The minimum syncpoint value is a shadow of the current sync point value in
467 * hardware.
468 */
host1x_syncpt_read_min(struct host1x_syncpt * sp)469 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
470 {
471 smp_rmb();
472
473 return (u32)atomic_read(&sp->min_val);
474 }
475 EXPORT_SYMBOL(host1x_syncpt_read_min);
476
477 /**
478 * host1x_syncpt_read() - read the current syncpoint value
479 * @sp: host1x syncpoint
480 */
host1x_syncpt_read(struct host1x_syncpt * sp)481 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
482 {
483 return host1x_syncpt_load(sp);
484 }
485 EXPORT_SYMBOL(host1x_syncpt_read);
486
host1x_syncpt_nb_pts(struct host1x * host)487 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
488 {
489 return host->info->nb_pts;
490 }
491
host1x_syncpt_nb_bases(struct host1x * host)492 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
493 {
494 return host->info->nb_bases;
495 }
496
host1x_syncpt_nb_mlocks(struct host1x * host)497 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
498 {
499 return host->info->nb_mlocks;
500 }
501
502 /**
503 * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
504 * @host: host1x controller
505 * @id: syncpoint ID
506 */
host1x_syncpt_get_by_id(struct host1x * host,unsigned int id)507 struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
508 unsigned int id)
509 {
510 if (id >= host->info->nb_pts)
511 return NULL;
512
513 if (kref_get_unless_zero(&host->syncpt[id].ref))
514 return &host->syncpt[id];
515 else
516 return NULL;
517 }
518 EXPORT_SYMBOL(host1x_syncpt_get_by_id);
519
520 /**
521 * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
522 * increase the refcount.
523 * @host: host1x controller
524 * @id: syncpoint ID
525 */
host1x_syncpt_get_by_id_noref(struct host1x * host,unsigned int id)526 struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
527 unsigned int id)
528 {
529 if (id >= host->info->nb_pts)
530 return NULL;
531
532 return &host->syncpt[id];
533 }
534 EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
535
536 /**
537 * host1x_syncpt_get() - increment syncpoint refcount
538 * @sp: syncpoint
539 */
host1x_syncpt_get(struct host1x_syncpt * sp)540 struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
541 {
542 kref_get(&sp->ref);
543
544 return sp;
545 }
546 EXPORT_SYMBOL(host1x_syncpt_get);
547
548 /**
549 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
550 * @sp: host1x syncpoint
551 */
host1x_syncpt_get_base(struct host1x_syncpt * sp)552 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
553 {
554 return sp ? sp->base : NULL;
555 }
556 EXPORT_SYMBOL(host1x_syncpt_get_base);
557
558 /**
559 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
560 * @base: host1x syncpoint wait base
561 */
host1x_syncpt_base_id(struct host1x_syncpt_base * base)562 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
563 {
564 return base->id;
565 }
566 EXPORT_SYMBOL(host1x_syncpt_base_id);
567
do_nothing(struct kref * ref)568 static void do_nothing(struct kref *ref)
569 {
570 }
571
572 /**
573 * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
574 * available for allocation
575 *
576 * @client: host1x bus client
577 * @syncpt_id: syncpoint ID to make available
578 *
579 * Makes VBLANK<i> syncpoint available for allocatation if it was
580 * reserved at initialization time. This should be called by the display
581 * driver after it has ensured that any VBLANK increment programming configured
582 * by the boot chain has been disabled.
583 */
host1x_syncpt_release_vblank_reservation(struct host1x_client * client,u32 syncpt_id)584 void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
585 u32 syncpt_id)
586 {
587 struct host1x *host = dev_get_drvdata(client->host->parent);
588
589 if (!host->info->reserve_vblank_syncpts)
590 return;
591
592 kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
593 }
594 EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);
595