2 * Tegra host1x Syncpoints
4 * Copyright (c) 2010-2015, NVIDIA Corporation.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #include <linux/module.h>
20 #include <linux/device.h>
21 #include <linux/slab.h>
23 #include <trace/events/host1x.h>
30 #define SYNCPT_CHECK_PERIOD (2 * HZ)
31 #define MAX_STUCK_CHECK_COUNT 15
33 static struct host1x_syncpt_base *
34 host1x_syncpt_base_request(struct host1x *host)
36 struct host1x_syncpt_base *bases = host->bases;
39 for (i = 0; i < host->info->nb_bases; i++)
40 if (!bases[i].requested)
43 if (i >= host->info->nb_bases)
46 bases[i].requested = true;
50 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
53 base->requested = false;
56 static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
61 struct host1x_syncpt *sp = host->syncpt;
64 mutex_lock(&host->syncpt_mutex);
66 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
69 if (i >= host->info->nb_pts)
72 if (flags & HOST1X_SYNCPT_HAS_BASE) {
73 sp->base = host1x_syncpt_base_request(host);
78 name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id,
79 dev ? dev_name(dev) : NULL);
86 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
87 sp->client_managed = true;
89 sp->client_managed = false;
91 mutex_unlock(&host->syncpt_mutex);
95 host1x_syncpt_base_free(sp->base);
98 mutex_unlock(&host->syncpt_mutex);
103 * host1x_syncpt_id() - retrieve syncpoint ID
104 * @sp: host1x syncpoint
106 * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
107 * often used as a value to program into registers that control how hardware
108 * blocks interact with syncpoints.
110 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
114 EXPORT_SYMBOL(host1x_syncpt_id);
117 * host1x_syncpt_incr_max() - update the value sent to hardware
118 * @sp: host1x syncpoint
119 * @incrs: number of increments
121 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
123 return (u32)atomic_add_return(incrs, &sp->max_val);
125 EXPORT_SYMBOL(host1x_syncpt_incr_max);
128 * Write cached syncpoint and waitbase values to hardware.
130 void host1x_syncpt_restore(struct host1x *host)
132 struct host1x_syncpt *sp_base = host->syncpt;
135 for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
136 host1x_hw_syncpt_restore(host, sp_base + i);
138 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
139 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
145 * Update the cached syncpoint and waitbase values by reading them
146 * from the registers.
148 void host1x_syncpt_save(struct host1x *host)
150 struct host1x_syncpt *sp_base = host->syncpt;
153 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
154 if (host1x_syncpt_client_managed(sp_base + i))
155 host1x_hw_syncpt_load(host, sp_base + i);
157 WARN_ON(!host1x_syncpt_idle(sp_base + i));
160 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
161 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
165 * Updates the cached syncpoint value by reading a new value from the hardware
168 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
172 val = host1x_hw_syncpt_load(sp->host, sp);
173 trace_host1x_syncpt_load_min(sp->id, val);
179 * Get the current syncpoint base
181 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
183 host1x_hw_syncpt_load_wait_base(sp->host, sp);
189 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
190 * @sp: host1x syncpoint
192 int host1x_syncpt_incr(struct host1x_syncpt *sp)
194 return host1x_hw_syncpt_cpu_incr(sp->host, sp);
196 EXPORT_SYMBOL(host1x_syncpt_incr);
199 * Updated sync point form hardware, and returns true if syncpoint is expired,
200 * false if we may need to wait
202 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
204 host1x_hw_syncpt_load(sp->host, sp);
206 return host1x_syncpt_is_expired(sp, thresh);
210 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
211 * @sp: host1x syncpoint
213 * @timeout: maximum time to wait for the syncpoint to reach the given value
214 * @value: return location for the syncpoint value
216 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
219 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
221 struct host1x_waitlist *waiter;
222 int err = 0, check_count = 0;
228 /* first check cache */
229 if (host1x_syncpt_is_expired(sp, thresh)) {
231 *value = host1x_syncpt_load(sp);
236 /* try to read from register */
237 val = host1x_hw_syncpt_load(sp->host, sp);
238 if (host1x_syncpt_is_expired(sp, thresh)) {
250 /* allocate a waiter */
251 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
257 /* schedule a wakeup when the syncpoint value is reached */
258 err = host1x_intr_add_action(sp->host, sp->id, thresh,
259 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
265 /* Caller-specified timeout may be impractically low */
269 /* wait for the syncpoint, or timeout, or signal */
271 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
274 remain = wait_event_interruptible_timeout(wq,
275 syncpt_load_min_is_expired(sp, thresh),
277 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
279 *value = host1x_syncpt_load(sp);
293 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
294 dev_warn(sp->host->dev,
295 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
296 current->comm, sp->id, sp->name,
299 host1x_debug_dump_syncpts(sp->host);
301 if (check_count == MAX_STUCK_CHECK_COUNT)
302 host1x_debug_dump(sp->host);
308 host1x_intr_put_ref(sp->host, sp->id, ref);
313 EXPORT_SYMBOL(host1x_syncpt_wait);
316 * Returns true if syncpoint is expired, false if we may need to wait
318 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
325 current_val = (u32)atomic_read(&sp->min_val);
326 future_val = (u32)atomic_read(&sp->max_val);
328 /* Note the use of unsigned arithmetic here (mod 1<<32).
330 * c = current_val = min_val = the current value of the syncpoint.
331 * t = thresh = the value we are checking
332 * f = future_val = max_val = the value c will reach when all
333 * outstanding increments have completed.
335 * Note that c always chases f until it reaches f.
340 * Consider all cases:
342 * A) .....c..t..f..... Dtf < Dtc need to wait
343 * B) .....c.....f..t.. Dtf > Dtc expired
344 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large)
346 * Any case where f==c: always expired (for any t). Dtf == Dcf
347 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0)
348 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0,
353 * A) .....t..f..c..... Dtf < Dtc need to wait
354 * A) .....f..c..t..... Dtf < Dtc need to wait
355 * A) .....f..t..c..... Dtf > Dtc expired
358 * Dtf >= Dtc implies EXPIRED (return true)
359 * Dtf < Dtc implies WAIT (return false)
361 * Note: If t is expired then we *cannot* wait on it. We would wait
362 * forever (hang the system).
364 * Note: do NOT get clever and remove the -thresh from both sides. It
367 * If future valueis zero, we have a client managed sync point. In that
368 * case we do a direct comparison.
370 if (!host1x_syncpt_client_managed(sp))
371 return future_val - thresh >= current_val - thresh;
373 return (s32)(current_val - thresh) >= 0;
376 /* remove a wait pointed to by patch_addr */
377 int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr)
379 return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr);
382 int host1x_syncpt_init(struct host1x *host)
384 struct host1x_syncpt_base *bases;
385 struct host1x_syncpt *syncpt;
388 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
393 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
398 for (i = 0; i < host->info->nb_pts; i++) {
400 syncpt[i].host = host;
403 for (i = 0; i < host->info->nb_bases; i++)
406 mutex_init(&host->syncpt_mutex);
407 host->syncpt = syncpt;
410 host1x_syncpt_restore(host);
412 /* Allocate sync point to use for clearing waits for expired fences */
413 host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
421 * host1x_syncpt_request() - request a syncpoint
422 * @dev: device requesting the syncpoint
425 * host1x client drivers can use this function to allocate a syncpoint for
426 * subsequent use. A syncpoint returned by this function will be reserved for
427 * use by the client exclusively. When no longer using a syncpoint, a host1x
428 * client driver needs to release it using host1x_syncpt_free().
430 struct host1x_syncpt *host1x_syncpt_request(struct device *dev,
433 struct host1x *host = dev_get_drvdata(dev->parent);
435 return host1x_syncpt_alloc(host, dev, flags);
437 EXPORT_SYMBOL(host1x_syncpt_request);
440 * host1x_syncpt_free() - free a requested syncpoint
441 * @sp: host1x syncpoint
443 * Release a syncpoint previously allocated using host1x_syncpt_request(). A
444 * host1x client driver should call this when the syncpoint is no longer in
445 * use. Note that client drivers must ensure that the syncpoint doesn't remain
446 * under the control of hardware after calling this function, otherwise two
447 * clients may end up trying to access the same syncpoint concurrently.
449 void host1x_syncpt_free(struct host1x_syncpt *sp)
454 mutex_lock(&sp->host->syncpt_mutex);
456 host1x_syncpt_base_free(sp->base);
461 sp->client_managed = false;
463 mutex_unlock(&sp->host->syncpt_mutex);
465 EXPORT_SYMBOL(host1x_syncpt_free);
467 void host1x_syncpt_deinit(struct host1x *host)
469 struct host1x_syncpt *sp = host->syncpt;
472 for (i = 0; i < host->info->nb_pts; i++, sp++)
477 * host1x_syncpt_read_max() - read maximum syncpoint value
478 * @sp: host1x syncpoint
480 * The maximum syncpoint value indicates how many operations there are in
481 * queue, either in channel or in a software thread.
483 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
487 return (u32)atomic_read(&sp->max_val);
489 EXPORT_SYMBOL(host1x_syncpt_read_max);
492 * host1x_syncpt_read_min() - read minimum syncpoint value
493 * @sp: host1x syncpoint
495 * The minimum syncpoint value is a shadow of the current sync point value in
498 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
502 return (u32)atomic_read(&sp->min_val);
504 EXPORT_SYMBOL(host1x_syncpt_read_min);
507 * host1x_syncpt_read() - read the current syncpoint value
508 * @sp: host1x syncpoint
510 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
512 return host1x_syncpt_load(sp);
514 EXPORT_SYMBOL(host1x_syncpt_read);
516 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
518 return host->info->nb_pts;
521 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
523 return host->info->nb_bases;
526 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
528 return host->info->nb_mlocks;
532 * host1x_syncpt_get() - obtain a syncpoint by ID
533 * @host: host1x controller
536 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id)
538 if (id >= host->info->nb_pts)
541 return host->syncpt + id;
543 EXPORT_SYMBOL(host1x_syncpt_get);
546 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
547 * @sp: host1x syncpoint
549 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
551 return sp ? sp->base : NULL;
553 EXPORT_SYMBOL(host1x_syncpt_get_base);
556 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
557 * @base: host1x syncpoint wait base
559 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
563 EXPORT_SYMBOL(host1x_syncpt_base_id);