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/dma-fence.h>
11#include <linux/slab.h>
12
13#include <trace/events/host1x.h>
14
15#include "syncpt.h"
16#include "dev.h"
17#include "intr.h"
18#include "debug.h"
19
20#define SYNCPT_CHECK_PERIOD (2 * HZ)
21#define MAX_STUCK_CHECK_COUNT 15
22
23static struct host1x_syncpt_base *
24host1x_syncpt_base_request(struct host1x *host)
25{
26 struct host1x_syncpt_base *bases = host->bases;
27 unsigned int i;
28
29 for (i = 0; i < host->info->nb_bases; i++)
30 if (!bases[i].requested)
31 break;
32
33 if (i >= host->info->nb_bases)
34 return NULL;
35
36 bases[i].requested = true;
37 return &bases[i];
38}
39
40static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
41{
42 if (base)
43 base->requested = false;
44}
45
46/**
47 * host1x_syncpt_alloc() - allocate a syncpoint
48 * @host: host1x device data
49 * @flags: bitfield of HOST1X_SYNCPT_* flags
50 * @name: name for the syncpoint for use in debug prints
51 *
52 * Allocates a hardware syncpoint for the caller's use. The caller then has
53 * the sole authority to mutate the syncpoint's value until it is freed again.
54 *
55 * If no free syncpoints are available, or a NULL name was specified, returns
56 * NULL.
57 */
58struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
59 unsigned long flags,
60 const char *name)
61{
62 struct host1x_syncpt *sp = host->syncpt;
63 char *full_name;
64 unsigned int i;
65
66 if (!name)
67 return NULL;
68
69 mutex_lock(&host->syncpt_mutex);
70
71 for (i = 0; i < host->info->nb_pts && kref_read(kref: &sp->ref); i++, sp++)
72 ;
73
74 if (i >= host->info->nb_pts)
75 goto unlock;
76
77 if (flags & HOST1X_SYNCPT_HAS_BASE) {
78 sp->base = host1x_syncpt_base_request(host);
79 if (!sp->base)
80 goto unlock;
81 }
82
83 full_name = kasprintf(GFP_KERNEL, fmt: "%u-%s", sp->id, name);
84 if (!full_name)
85 goto free_base;
86
87 sp->name = full_name;
88
89 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
90 sp->client_managed = true;
91 else
92 sp->client_managed = false;
93
94 kref_init(kref: &sp->ref);
95
96 mutex_unlock(lock: &host->syncpt_mutex);
97 return sp;
98
99free_base:
100 host1x_syncpt_base_free(base: sp->base);
101 sp->base = NULL;
102unlock:
103 mutex_unlock(lock: &host->syncpt_mutex);
104 return NULL;
105}
106EXPORT_SYMBOL(host1x_syncpt_alloc);
107
108/**
109 * host1x_syncpt_id() - retrieve syncpoint ID
110 * @sp: host1x syncpoint
111 *
112 * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
113 * often used as a value to program into registers that control how hardware
114 * blocks interact with syncpoints.
115 */
116u32 host1x_syncpt_id(struct host1x_syncpt *sp)
117{
118 return sp->id;
119}
120EXPORT_SYMBOL(host1x_syncpt_id);
121
122/**
123 * host1x_syncpt_incr_max() - update the value sent to hardware
124 * @sp: host1x syncpoint
125 * @incrs: number of increments
126 */
127u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
128{
129 return (u32)atomic_add_return(i: incrs, v: &sp->max_val);
130}
131EXPORT_SYMBOL(host1x_syncpt_incr_max);
132
133 /*
134 * Write cached syncpoint and waitbase values to hardware.
135 */
136void host1x_syncpt_restore(struct host1x *host)
137{
138 struct host1x_syncpt *sp_base = host->syncpt;
139 unsigned int i;
140
141 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
142 /*
143 * Unassign syncpt from channels for purposes of Tegra186
144 * syncpoint protection. This prevents any channel from
145 * accessing it until it is reassigned.
146 */
147 host1x_hw_syncpt_assign_to_channel(host, sp: sp_base + i, NULL);
148 host1x_hw_syncpt_restore(host, sp: sp_base + i);
149 }
150
151 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
152 host1x_hw_syncpt_restore_wait_base(host, sp: sp_base + i);
153
154 host1x_hw_syncpt_enable_protection(host);
155
156 wmb();
157}
158
159/*
160 * Update the cached syncpoint and waitbase values by reading them
161 * from the registers.
162 */
163void host1x_syncpt_save(struct host1x *host)
164{
165 struct host1x_syncpt *sp_base = host->syncpt;
166 unsigned int i;
167
168 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
169 if (host1x_syncpt_client_managed(sp: sp_base + i))
170 host1x_hw_syncpt_load(host, sp: sp_base + i);
171 else
172 WARN_ON(!host1x_syncpt_idle(sp_base + i));
173 }
174
175 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
176 host1x_hw_syncpt_load_wait_base(host, sp: sp_base + i);
177}
178
179/*
180 * Updates the cached syncpoint value by reading a new value from the hardware
181 * register
182 */
183u32 host1x_syncpt_load(struct host1x_syncpt *sp)
184{
185 u32 val;
186
187 val = host1x_hw_syncpt_load(host: sp->host, sp);
188 trace_host1x_syncpt_load_min(id: sp->id, val);
189
190 return val;
191}
192
193/*
194 * Get the current syncpoint base
195 */
196u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
197{
198 host1x_hw_syncpt_load_wait_base(host: sp->host, sp);
199
200 return sp->base_val;
201}
202
203/**
204 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
205 * @sp: host1x syncpoint
206 */
207int host1x_syncpt_incr(struct host1x_syncpt *sp)
208{
209 return host1x_hw_syncpt_cpu_incr(host: sp->host, sp);
210}
211EXPORT_SYMBOL(host1x_syncpt_incr);
212
213/**
214 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
215 * @sp: host1x syncpoint
216 * @thresh: threshold
217 * @timeout: maximum time to wait for the syncpoint to reach the given value
218 * @value: return location for the syncpoint value
219 */
220int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
221 u32 *value)
222{
223 struct dma_fence *fence;
224 long wait_err;
225
226 host1x_hw_syncpt_load(host: sp->host, sp);
227
228 if (value)
229 *value = host1x_syncpt_load(sp);
230
231 if (host1x_syncpt_is_expired(sp, thresh))
232 return 0;
233
234 if (timeout < 0)
235 timeout = LONG_MAX;
236 else if (timeout == 0)
237 return -EAGAIN;
238
239 fence = host1x_fence_create(sp, threshold: thresh, timeout: false);
240 if (IS_ERR(ptr: fence))
241 return PTR_ERR(ptr: fence);
242
243 wait_err = dma_fence_wait_timeout(fence, intr: true, timeout);
244 if (wait_err == 0)
245 host1x_fence_cancel(fence);
246 dma_fence_put(fence);
247
248 if (value)
249 *value = host1x_syncpt_load(sp);
250
251 /*
252 * Don't rely on dma_fence_wait_timeout return value,
253 * since it returns zero both on timeout and if the
254 * wait completed with 0 jiffies left.
255 */
256 host1x_hw_syncpt_load(host: sp->host, sp);
257 if (wait_err == 0 && !host1x_syncpt_is_expired(sp, thresh))
258 return -EAGAIN;
259 else if (wait_err < 0)
260 return wait_err;
261 else
262 return 0;
263}
264EXPORT_SYMBOL(host1x_syncpt_wait);
265
266/*
267 * Returns true if syncpoint is expired, false if we may need to wait
268 */
269bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
270{
271 u32 current_val;
272
273 smp_rmb();
274
275 current_val = (u32)atomic_read(v: &sp->min_val);
276
277 return ((current_val - thresh) & 0x80000000U) == 0U;
278}
279
280int host1x_syncpt_init(struct host1x *host)
281{
282 struct host1x_syncpt_base *bases;
283 struct host1x_syncpt *syncpt;
284 unsigned int i;
285
286 syncpt = devm_kcalloc(dev: host->dev, n: host->info->nb_pts, size: sizeof(*syncpt),
287 GFP_KERNEL);
288 if (!syncpt)
289 return -ENOMEM;
290
291 bases = devm_kcalloc(dev: host->dev, n: host->info->nb_bases, size: sizeof(*bases),
292 GFP_KERNEL);
293 if (!bases)
294 return -ENOMEM;
295
296 for (i = 0; i < host->info->nb_pts; i++) {
297 syncpt[i].id = i;
298 syncpt[i].host = host;
299 }
300
301 for (i = 0; i < host->info->nb_bases; i++)
302 bases[i].id = i;
303
304 mutex_init(&host->syncpt_mutex);
305 host->syncpt = syncpt;
306 host->bases = bases;
307
308 /* Allocate sync point to use for clearing waits for expired fences */
309 host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
310 if (!host->nop_sp)
311 return -ENOMEM;
312
313 if (host->info->reserve_vblank_syncpts) {
314 kref_init(kref: &host->syncpt[26].ref);
315 kref_init(kref: &host->syncpt[27].ref);
316 }
317
318 return 0;
319}
320
321/**
322 * host1x_syncpt_request() - request a syncpoint
323 * @client: client requesting the syncpoint
324 * @flags: flags
325 *
326 * host1x client drivers can use this function to allocate a syncpoint for
327 * subsequent use. A syncpoint returned by this function will be reserved for
328 * use by the client exclusively. When no longer using a syncpoint, a host1x
329 * client driver needs to release it using host1x_syncpt_put().
330 */
331struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
332 unsigned long flags)
333{
334 struct host1x *host = dev_get_drvdata(dev: client->host->parent);
335
336 return host1x_syncpt_alloc(host, flags, dev_name(dev: client->dev));
337}
338EXPORT_SYMBOL(host1x_syncpt_request);
339
340static void syncpt_release(struct kref *ref)
341{
342 struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
343
344 atomic_set(v: &sp->max_val, i: host1x_syncpt_read(sp));
345
346 sp->locked = false;
347
348 mutex_lock(&sp->host->syncpt_mutex);
349
350 host1x_syncpt_base_free(base: sp->base);
351 kfree(objp: sp->name);
352 sp->base = NULL;
353 sp->name = NULL;
354 sp->client_managed = false;
355
356 mutex_unlock(lock: &sp->host->syncpt_mutex);
357}
358
359/**
360 * host1x_syncpt_put() - free a requested syncpoint
361 * @sp: host1x syncpoint
362 *
363 * Release a syncpoint previously allocated using host1x_syncpt_request(). A
364 * host1x client driver should call this when the syncpoint is no longer in
365 * use.
366 */
367void host1x_syncpt_put(struct host1x_syncpt *sp)
368{
369 if (!sp)
370 return;
371
372 kref_put(kref: &sp->ref, release: syncpt_release);
373}
374EXPORT_SYMBOL(host1x_syncpt_put);
375
376void host1x_syncpt_deinit(struct host1x *host)
377{
378 struct host1x_syncpt *sp = host->syncpt;
379 unsigned int i;
380
381 for (i = 0; i < host->info->nb_pts; i++, sp++)
382 kfree(objp: sp->name);
383}
384
385/**
386 * host1x_syncpt_read_max() - read maximum syncpoint value
387 * @sp: host1x syncpoint
388 *
389 * The maximum syncpoint value indicates how many operations there are in
390 * queue, either in channel or in a software thread.
391 */
392u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
393{
394 smp_rmb();
395
396 return (u32)atomic_read(v: &sp->max_val);
397}
398EXPORT_SYMBOL(host1x_syncpt_read_max);
399
400/**
401 * host1x_syncpt_read_min() - read minimum syncpoint value
402 * @sp: host1x syncpoint
403 *
404 * The minimum syncpoint value is a shadow of the current sync point value in
405 * hardware.
406 */
407u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
408{
409 smp_rmb();
410
411 return (u32)atomic_read(v: &sp->min_val);
412}
413EXPORT_SYMBOL(host1x_syncpt_read_min);
414
415/**
416 * host1x_syncpt_read() - read the current syncpoint value
417 * @sp: host1x syncpoint
418 */
419u32 host1x_syncpt_read(struct host1x_syncpt *sp)
420{
421 return host1x_syncpt_load(sp);
422}
423EXPORT_SYMBOL(host1x_syncpt_read);
424
425unsigned int host1x_syncpt_nb_pts(struct host1x *host)
426{
427 return host->info->nb_pts;
428}
429
430unsigned int host1x_syncpt_nb_bases(struct host1x *host)
431{
432 return host->info->nb_bases;
433}
434
435unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
436{
437 return host->info->nb_mlocks;
438}
439
440/**
441 * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
442 * @host: host1x controller
443 * @id: syncpoint ID
444 */
445struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
446 unsigned int id)
447{
448 if (id >= host->info->nb_pts)
449 return NULL;
450
451 if (kref_get_unless_zero(kref: &host->syncpt[id].ref))
452 return &host->syncpt[id];
453 else
454 return NULL;
455}
456EXPORT_SYMBOL(host1x_syncpt_get_by_id);
457
458/**
459 * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
460 * increase the refcount.
461 * @host: host1x controller
462 * @id: syncpoint ID
463 */
464struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
465 unsigned int id)
466{
467 if (id >= host->info->nb_pts)
468 return NULL;
469
470 return &host->syncpt[id];
471}
472EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
473
474/**
475 * host1x_syncpt_get() - increment syncpoint refcount
476 * @sp: syncpoint
477 */
478struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
479{
480 kref_get(kref: &sp->ref);
481
482 return sp;
483}
484EXPORT_SYMBOL(host1x_syncpt_get);
485
486/**
487 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
488 * @sp: host1x syncpoint
489 */
490struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
491{
492 return sp ? sp->base : NULL;
493}
494EXPORT_SYMBOL(host1x_syncpt_get_base);
495
496/**
497 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
498 * @base: host1x syncpoint wait base
499 */
500u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
501{
502 return base->id;
503}
504EXPORT_SYMBOL(host1x_syncpt_base_id);
505
506static void do_nothing(struct kref *ref)
507{
508}
509
510/**
511 * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
512 * available for allocation
513 *
514 * @client: host1x bus client
515 * @syncpt_id: syncpoint ID to make available
516 *
517 * Makes VBLANK<i> syncpoint available for allocatation if it was
518 * reserved at initialization time. This should be called by the display
519 * driver after it has ensured that any VBLANK increment programming configured
520 * by the boot chain has been disabled.
521 */
522void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
523 u32 syncpt_id)
524{
525 struct host1x *host = dev_get_drvdata(dev: client->host->parent);
526
527 if (!host->info->reserve_vblank_syncpts)
528 return;
529
530 kref_put(kref: &host->syncpt[syncpt_id].ref, release: do_nothing);
531}
532EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);
533

source code of linux/drivers/gpu/host1x/syncpt.c