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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
22static struct host1x_syncpt_base *
23host1x_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
39static 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 */
57struct 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
98free_base:
99 host1x_syncpt_base_free(sp->base);
100 sp->base = NULL;
101unlock:
102 mutex_unlock(&host->syncpt_mutex);
103 return NULL;
104}
105EXPORT_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 */
115u32 host1x_syncpt_id(struct host1x_syncpt *sp)
116{
117 return sp->id;
118}
119EXPORT_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 */
126u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
127{
128 return (u32)atomic_add_return(incrs, &sp->max_val);
129}
130EXPORT_SYMBOL(host1x_syncpt_incr_max);
131
132 /*
133 * Write cached syncpoint and waitbase values to hardware.
134 */
135void 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 /*
142 * Unassign syncpt from channels for purposes of Tegra186
143 * syncpoint protection. This prevents any channel from
144 * accessing it until it is reassigned.
145 */
146 host1x_hw_syncpt_assign_to_channel(host, sp_base + i, NULL);
147 host1x_hw_syncpt_restore(host, sp_base + i);
148 }
149
150 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
151 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
152
153 host1x_hw_syncpt_enable_protection(host);
154
155 wmb();
156}
157
158/*
159 * Update the cached syncpoint and waitbase values by reading them
160 * from the registers.
161 */
162void host1x_syncpt_save(struct host1x *host)
163{
164 struct host1x_syncpt *sp_base = host->syncpt;
165 unsigned int i;
166
167 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
168 if (host1x_syncpt_client_managed(sp_base + i))
169 host1x_hw_syncpt_load(host, sp_base + i);
170 else
171 WARN_ON(!host1x_syncpt_idle(sp_base + i));
172 }
173
174 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
175 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
176}
177
178/*
179 * Updates the cached syncpoint value by reading a new value from the hardware
180 * register
181 */
182u32 host1x_syncpt_load(struct host1x_syncpt *sp)
183{
184 u32 val;
185
186 val = host1x_hw_syncpt_load(sp->host, sp);
187 trace_host1x_syncpt_load_min(sp->id, val);
188
189 return val;
190}
191
192/*
193 * Get the current syncpoint base
194 */
195u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
196{
197 host1x_hw_syncpt_load_wait_base(sp->host, sp);
198
199 return sp->base_val;
200}
201
202/**
203 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
204 * @sp: host1x syncpoint
205 */
206int host1x_syncpt_incr(struct host1x_syncpt *sp)
207{
208 return host1x_hw_syncpt_cpu_incr(sp->host, sp);
209}
210EXPORT_SYMBOL(host1x_syncpt_incr);
211
212/*
213 * Updated sync point form hardware, and returns true if syncpoint is expired,
214 * false if we may need to wait
215 */
216static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
217{
218 host1x_hw_syncpt_load(sp->host, sp);
219
220 return host1x_syncpt_is_expired(sp, thresh);
221}
222
223/**
224 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
225 * @sp: host1x syncpoint
226 * @thresh: threshold
227 * @timeout: maximum time to wait for the syncpoint to reach the given value
228 * @value: return location for the syncpoint value
229 */
230int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
231 u32 *value)
232{
233 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
234 void *ref;
235 struct host1x_waitlist *waiter;
236 int err = 0, check_count = 0;
237
238 if (value)
239 *value = host1x_syncpt_load(sp);
240
241 if (host1x_syncpt_is_expired(sp, thresh))
242 return 0;
243
244 if (!timeout) {
245 err = -EAGAIN;
246 goto done;
247 }
248
249 /* allocate a waiter */
250 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
251 if (!waiter) {
252 err = -ENOMEM;
253 goto done;
254 }
255
256 /* schedule a wakeup when the syncpoint value is reached */
257 err = host1x_intr_add_action(sp->host, sp, thresh,
258 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
259 &wq, waiter, &ref);
260 if (err)
261 goto done;
262
263 err = -EAGAIN;
264 /* Caller-specified timeout may be impractically low */
265 if (timeout < 0)
266 timeout = LONG_MAX;
267
268 /* wait for the syncpoint, or timeout, or signal */
269 while (timeout) {
270 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
271 int remain;
272
273 remain = wait_event_interruptible_timeout(wq,
274 syncpt_load_min_is_expired(sp, thresh),
275 check);
276 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
277 if (value)
278 *value = host1x_syncpt_load(sp);
279
280 err = 0;
281
282 break;
283 }
284
285 if (remain < 0) {
286 err = remain;
287 break;
288 }
289
290 timeout -= check;
291
292 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
293 dev_warn(sp->host->dev,
294 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
295 current->comm, sp->id, sp->name,
296 thresh, timeout);
297
298 host1x_debug_dump_syncpts(sp->host);
299
300 if (check_count == MAX_STUCK_CHECK_COUNT)
301 host1x_debug_dump(sp->host);
302
303 check_count++;
304 }
305 }
306
307 host1x_intr_put_ref(sp->host, sp->id, ref, true);
308
309done:
310 return err;
311}
312EXPORT_SYMBOL(host1x_syncpt_wait);
313
314/*
315 * Returns true if syncpoint is expired, false if we may need to wait
316 */
317bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
318{
319 u32 current_val;
320
321 smp_rmb();
322
323 current_val = (u32)atomic_read(&sp->min_val);
324
325 return ((current_val - thresh) & 0x80000000U) == 0U;
326}
327
328int host1x_syncpt_init(struct host1x *host)
329{
330 struct host1x_syncpt_base *bases;
331 struct host1x_syncpt *syncpt;
332 unsigned int i;
333
334 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
335 GFP_KERNEL);
336 if (!syncpt)
337 return -ENOMEM;
338
339 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
340 GFP_KERNEL);
341 if (!bases)
342 return -ENOMEM;
343
344 for (i = 0; i < host->info->nb_pts; i++) {
345 syncpt[i].id = i;
346 syncpt[i].host = host;
347 }
348
349 for (i = 0; i < host->info->nb_bases; i++)
350 bases[i].id = i;
351
352 mutex_init(&host->syncpt_mutex);
353 host->syncpt = syncpt;
354 host->bases = bases;
355
356 /* Allocate sync point to use for clearing waits for expired fences */
357 host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
358 if (!host->nop_sp)
359 return -ENOMEM;
360
361 if (host->info->reserve_vblank_syncpts) {
362 kref_init(&host->syncpt[26].ref);
363 kref_init(&host->syncpt[27].ref);
364 }
365
366 return 0;
367}
368
369/**
370 * host1x_syncpt_request() - request a syncpoint
371 * @client: client requesting the syncpoint
372 * @flags: flags
373 *
374 * host1x client drivers can use this function to allocate a syncpoint for
375 * subsequent use. A syncpoint returned by this function will be reserved for
376 * use by the client exclusively. When no longer using a syncpoint, a host1x
377 * client driver needs to release it using host1x_syncpt_put().
378 */
379struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
380 unsigned long flags)
381{
382 struct host1x *host = dev_get_drvdata(client->host->parent);
383
384 return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
385}
386EXPORT_SYMBOL(host1x_syncpt_request);
387
388static void syncpt_release(struct kref *ref)
389{
390 struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
391
392 atomic_set(&sp->max_val, host1x_syncpt_read(sp));
393
394 sp->locked = false;
395
396 mutex_lock(&sp->host->syncpt_mutex);
397
398 host1x_syncpt_base_free(sp->base);
399 kfree(sp->name);
400 sp->base = NULL;
401 sp->name = NULL;
402 sp->client_managed = false;
403
404 mutex_unlock(&sp->host->syncpt_mutex);
405}
406
407/**
408 * host1x_syncpt_put() - free a requested syncpoint
409 * @sp: host1x syncpoint
410 *
411 * Release a syncpoint previously allocated using host1x_syncpt_request(). A
412 * host1x client driver should call this when the syncpoint is no longer in
413 * use.
414 */
415void host1x_syncpt_put(struct host1x_syncpt *sp)
416{
417 if (!sp)
418 return;
419
420 kref_put(&sp->ref, syncpt_release);
421}
422EXPORT_SYMBOL(host1x_syncpt_put);
423
424void host1x_syncpt_deinit(struct host1x *host)
425{
426 struct host1x_syncpt *sp = host->syncpt;
427 unsigned int i;
428
429 for (i = 0; i < host->info->nb_pts; i++, sp++)
430 kfree(sp->name);
431}
432
433/**
434 * host1x_syncpt_read_max() - read maximum syncpoint value
435 * @sp: host1x syncpoint
436 *
437 * The maximum syncpoint value indicates how many operations there are in
438 * queue, either in channel or in a software thread.
439 */
440u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
441{
442 smp_rmb();
443
444 return (u32)atomic_read(&sp->max_val);
445}
446EXPORT_SYMBOL(host1x_syncpt_read_max);
447
448/**
449 * host1x_syncpt_read_min() - read minimum syncpoint value
450 * @sp: host1x syncpoint
451 *
452 * The minimum syncpoint value is a shadow of the current sync point value in
453 * hardware.
454 */
455u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
456{
457 smp_rmb();
458
459 return (u32)atomic_read(&sp->min_val);
460}
461EXPORT_SYMBOL(host1x_syncpt_read_min);
462
463/**
464 * host1x_syncpt_read() - read the current syncpoint value
465 * @sp: host1x syncpoint
466 */
467u32 host1x_syncpt_read(struct host1x_syncpt *sp)
468{
469 return host1x_syncpt_load(sp);
470}
471EXPORT_SYMBOL(host1x_syncpt_read);
472
473unsigned int host1x_syncpt_nb_pts(struct host1x *host)
474{
475 return host->info->nb_pts;
476}
477
478unsigned int host1x_syncpt_nb_bases(struct host1x *host)
479{
480 return host->info->nb_bases;
481}
482
483unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
484{
485 return host->info->nb_mlocks;
486}
487
488/**
489 * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
490 * @host: host1x controller
491 * @id: syncpoint ID
492 */
493struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
494 unsigned int id)
495{
496 if (id >= host->info->nb_pts)
497 return NULL;
498
499 if (kref_get_unless_zero(&host->syncpt[id].ref))
500 return &host->syncpt[id];
501 else
502 return NULL;
503}
504EXPORT_SYMBOL(host1x_syncpt_get_by_id);
505
506/**
507 * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
508 * increase the refcount.
509 * @host: host1x controller
510 * @id: syncpoint ID
511 */
512struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
513 unsigned int id)
514{
515 if (id >= host->info->nb_pts)
516 return NULL;
517
518 return &host->syncpt[id];
519}
520EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
521
522/**
523 * host1x_syncpt_get() - increment syncpoint refcount
524 * @sp: syncpoint
525 */
526struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
527{
528 kref_get(&sp->ref);
529
530 return sp;
531}
532EXPORT_SYMBOL(host1x_syncpt_get);
533
534/**
535 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
536 * @sp: host1x syncpoint
537 */
538struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
539{
540 return sp ? sp->base : NULL;
541}
542EXPORT_SYMBOL(host1x_syncpt_get_base);
543
544/**
545 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
546 * @base: host1x syncpoint wait base
547 */
548u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
549{
550 return base->id;
551}
552EXPORT_SYMBOL(host1x_syncpt_base_id);
553
554static void do_nothing(struct kref *ref)
555{
556}
557
558/**
559 * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
560 * available for allocation
561 *
562 * @client: host1x bus client
563 * @syncpt_id: syncpoint ID to make available
564 *
565 * Makes VBLANK<i> syncpoint available for allocatation if it was
566 * reserved at initialization time. This should be called by the display
567 * driver after it has ensured that any VBLANK increment programming configured
568 * by the boot chain has been disabled.
569 */
570void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
571 u32 syncpt_id)
572{
573 struct host1x *host = dev_get_drvdata(client->host->parent);
574
575 if (!host->info->reserve_vblank_syncpts)
576 return;
577
578 kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
579}
580EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);