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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
45static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
46 struct host1x_client *client,
47 unsigned long flags)
48{
49 struct host1x_syncpt *sp = host->syncpt;
50 unsigned int i;
51 char *name;
52
53 mutex_lock(&host->syncpt_mutex);
54
55 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
56 ;
57
58 if (i >= host->info->nb_pts)
59 goto unlock;
60
61 if (flags & HOST1X_SYNCPT_HAS_BASE) {
62 sp->base = host1x_syncpt_base_request(host);
63 if (!sp->base)
64 goto unlock;
65 }
66
67 name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id,
68 client ? dev_name(client->dev) : NULL);
69 if (!name)
70 goto free_base;
71
72 sp->client = client;
73 sp->name = name;
74
75 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
76 sp->client_managed = true;
77 else
78 sp->client_managed = false;
79
80 mutex_unlock(&host->syncpt_mutex);
81 return sp;
82
83free_base:
84 host1x_syncpt_base_free(sp->base);
85 sp->base = NULL;
86unlock:
87 mutex_unlock(&host->syncpt_mutex);
88 return NULL;
89}
90
91/**
92 * host1x_syncpt_id() - retrieve syncpoint ID
93 * @sp: host1x syncpoint
94 *
95 * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
96 * often used as a value to program into registers that control how hardware
97 * blocks interact with syncpoints.
98 */
99u32 host1x_syncpt_id(struct host1x_syncpt *sp)
100{
101 return sp->id;
102}
103EXPORT_SYMBOL(host1x_syncpt_id);
104
105/**
106 * host1x_syncpt_incr_max() - update the value sent to hardware
107 * @sp: host1x syncpoint
108 * @incrs: number of increments
109 */
110u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
111{
112 return (u32)atomic_add_return(incrs, &sp->max_val);
113}
114EXPORT_SYMBOL(host1x_syncpt_incr_max);
115
116 /*
117 * Write cached syncpoint and waitbase values to hardware.
118 */
119void host1x_syncpt_restore(struct host1x *host)
120{
121 struct host1x_syncpt *sp_base = host->syncpt;
122 unsigned int i;
123
124 for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
125 host1x_hw_syncpt_restore(host, sp_base + i);
126
127 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
128 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
129
130 wmb();
131}
132
133/*
134 * Update the cached syncpoint and waitbase values by reading them
135 * from the registers.
136 */
137void host1x_syncpt_save(struct host1x *host)
138{
139 struct host1x_syncpt *sp_base = host->syncpt;
140 unsigned int i;
141
142 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
143 if (host1x_syncpt_client_managed(sp_base + i))
144 host1x_hw_syncpt_load(host, sp_base + i);
145 else
146 WARN_ON(!host1x_syncpt_idle(sp_base + i));
147 }
148
149 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
150 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
151}
152
153/*
154 * Updates the cached syncpoint value by reading a new value from the hardware
155 * register
156 */
157u32 host1x_syncpt_load(struct host1x_syncpt *sp)
158{
159 u32 val;
160
161 val = host1x_hw_syncpt_load(sp->host, sp);
162 trace_host1x_syncpt_load_min(sp->id, val);
163
164 return val;
165}
166
167/*
168 * Get the current syncpoint base
169 */
170u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
171{
172 host1x_hw_syncpt_load_wait_base(sp->host, sp);
173
174 return sp->base_val;
175}
176
177/**
178 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
179 * @sp: host1x syncpoint
180 */
181int host1x_syncpt_incr(struct host1x_syncpt *sp)
182{
183 return host1x_hw_syncpt_cpu_incr(sp->host, sp);
184}
185EXPORT_SYMBOL(host1x_syncpt_incr);
186
187/*
188 * Updated sync point form hardware, and returns true if syncpoint is expired,
189 * false if we may need to wait
190 */
191static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
192{
193 host1x_hw_syncpt_load(sp->host, sp);
194
195 return host1x_syncpt_is_expired(sp, thresh);
196}
197
198/**
199 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
200 * @sp: host1x syncpoint
201 * @thresh: threshold
202 * @timeout: maximum time to wait for the syncpoint to reach the given value
203 * @value: return location for the syncpoint value
204 */
205int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
206 u32 *value)
207{
208 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
209 void *ref;
210 struct host1x_waitlist *waiter;
211 int err = 0, check_count = 0;
212 u32 val;
213
214 if (value)
215 *value = 0;
216
217 /* first check cache */
218 if (host1x_syncpt_is_expired(sp, thresh)) {
219 if (value)
220 *value = host1x_syncpt_load(sp);
221
222 return 0;
223 }
224
225 /* try to read from register */
226 val = host1x_hw_syncpt_load(sp->host, sp);
227 if (host1x_syncpt_is_expired(sp, thresh)) {
228 if (value)
229 *value = val;
230
231 goto done;
232 }
233
234 if (!timeout) {
235 err = -EAGAIN;
236 goto done;
237 }
238
239 /* allocate a waiter */
240 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
241 if (!waiter) {
242 err = -ENOMEM;
243 goto done;
244 }
245
246 /* schedule a wakeup when the syncpoint value is reached */
247 err = host1x_intr_add_action(sp->host, sp, thresh,
248 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
249 &wq, waiter, &ref);
250 if (err)
251 goto done;
252
253 err = -EAGAIN;
254 /* Caller-specified timeout may be impractically low */
255 if (timeout < 0)
256 timeout = LONG_MAX;
257
258 /* wait for the syncpoint, or timeout, or signal */
259 while (timeout) {
260 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
261 int remain;
262
263 remain = wait_event_interruptible_timeout(wq,
264 syncpt_load_min_is_expired(sp, thresh),
265 check);
266 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
267 if (value)
268 *value = host1x_syncpt_load(sp);
269
270 err = 0;
271
272 break;
273 }
274
275 if (remain < 0) {
276 err = remain;
277 break;
278 }
279
280 timeout -= check;
281
282 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
283 dev_warn(sp->host->dev,
284 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
285 current->comm, sp->id, sp->name,
286 thresh, timeout);
287
288 host1x_debug_dump_syncpts(sp->host);
289
290 if (check_count == MAX_STUCK_CHECK_COUNT)
291 host1x_debug_dump(sp->host);
292
293 check_count++;
294 }
295 }
296
297 host1x_intr_put_ref(sp->host, sp->id, ref);
298
299done:
300 return err;
301}
302EXPORT_SYMBOL(host1x_syncpt_wait);
303
304/*
305 * Returns true if syncpoint is expired, false if we may need to wait
306 */
307bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
308{
309 u32 current_val;
310 u32 future_val;
311
312 smp_rmb();
313
314 current_val = (u32)atomic_read(&sp->min_val);
315 future_val = (u32)atomic_read(&sp->max_val);
316
317 /* Note the use of unsigned arithmetic here (mod 1<<32).
318 *
319 * c = current_val = min_val = the current value of the syncpoint.
320 * t = thresh = the value we are checking
321 * f = future_val = max_val = the value c will reach when all
322 * outstanding increments have completed.
323 *
324 * Note that c always chases f until it reaches f.
325 *
326 * Dtf = (f - t)
327 * Dtc = (c - t)
328 *
329 * Consider all cases:
330 *
331 * A) .....c..t..f..... Dtf < Dtc need to wait
332 * B) .....c.....f..t.. Dtf > Dtc expired
333 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large)
334 *
335 * Any case where f==c: always expired (for any t). Dtf == Dcf
336 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0)
337 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0,
338 * Dtc!=0)
339 *
340 * Other cases:
341 *
342 * A) .....t..f..c..... Dtf < Dtc need to wait
343 * A) .....f..c..t..... Dtf < Dtc need to wait
344 * A) .....f..t..c..... Dtf > Dtc expired
345 *
346 * So:
347 * Dtf >= Dtc implies EXPIRED (return true)
348 * Dtf < Dtc implies WAIT (return false)
349 *
350 * Note: If t is expired then we *cannot* wait on it. We would wait
351 * forever (hang the system).
352 *
353 * Note: do NOT get clever and remove the -thresh from both sides. It
354 * is NOT the same.
355 *
356 * If future valueis zero, we have a client managed sync point. In that
357 * case we do a direct comparison.
358 */
359 if (!host1x_syncpt_client_managed(sp))
360 return future_val - thresh >= current_val - thresh;
361 else
362 return (s32)(current_val - thresh) >= 0;
363}
364
365int host1x_syncpt_init(struct host1x *host)
366{
367 struct host1x_syncpt_base *bases;
368 struct host1x_syncpt *syncpt;
369 unsigned int i;
370
371 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
372 GFP_KERNEL);
373 if (!syncpt)
374 return -ENOMEM;
375
376 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
377 GFP_KERNEL);
378 if (!bases)
379 return -ENOMEM;
380
381 for (i = 0; i < host->info->nb_pts; i++) {
382 syncpt[i].id = i;
383 syncpt[i].host = host;
384
385 /*
386 * Unassign syncpt from channels for purposes of Tegra186
387 * syncpoint protection. This prevents any channel from
388 * accessing it until it is reassigned.
389 */
390 host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL);
391 }
392
393 for (i = 0; i < host->info->nb_bases; i++)
394 bases[i].id = i;
395
396 mutex_init(&host->syncpt_mutex);
397 host->syncpt = syncpt;
398 host->bases = bases;
399
400 host1x_syncpt_restore(host);
401 host1x_hw_syncpt_enable_protection(host);
402
403 /* Allocate sync point to use for clearing waits for expired fences */
404 host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
405 if (!host->nop_sp)
406 return -ENOMEM;
407
408 return 0;
409}
410
411/**
412 * host1x_syncpt_request() - request a syncpoint
413 * @client: client requesting the syncpoint
414 * @flags: flags
415 *
416 * host1x client drivers can use this function to allocate a syncpoint for
417 * subsequent use. A syncpoint returned by this function will be reserved for
418 * use by the client exclusively. When no longer using a syncpoint, a host1x
419 * client driver needs to release it using host1x_syncpt_free().
420 */
421struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
422 unsigned long flags)
423{
424 struct host1x *host = dev_get_drvdata(client->host->parent);
425
426 return host1x_syncpt_alloc(host, client, flags);
427}
428EXPORT_SYMBOL(host1x_syncpt_request);
429
430/**
431 * host1x_syncpt_free() - free a requested syncpoint
432 * @sp: host1x syncpoint
433 *
434 * Release a syncpoint previously allocated using host1x_syncpt_request(). A
435 * host1x client driver should call this when the syncpoint is no longer in
436 * use. Note that client drivers must ensure that the syncpoint doesn't remain
437 * under the control of hardware after calling this function, otherwise two
438 * clients may end up trying to access the same syncpoint concurrently.
439 */
440void host1x_syncpt_free(struct host1x_syncpt *sp)
441{
442 if (!sp)
443 return;
444
445 mutex_lock(&sp->host->syncpt_mutex);
446
447 host1x_syncpt_base_free(sp->base);
448 kfree(sp->name);
449 sp->base = NULL;
450 sp->client = NULL;
451 sp->name = NULL;
452 sp->client_managed = false;
453
454 mutex_unlock(&sp->host->syncpt_mutex);
455}
456EXPORT_SYMBOL(host1x_syncpt_free);
457
458void host1x_syncpt_deinit(struct host1x *host)
459{
460 struct host1x_syncpt *sp = host->syncpt;
461 unsigned int i;
462
463 for (i = 0; i < host->info->nb_pts; i++, sp++)
464 kfree(sp->name);
465}
466
467/**
468 * host1x_syncpt_read_max() - read maximum syncpoint value
469 * @sp: host1x syncpoint
470 *
471 * The maximum syncpoint value indicates how many operations there are in
472 * queue, either in channel or in a software thread.
473 */
474u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
475{
476 smp_rmb();
477
478 return (u32)atomic_read(&sp->max_val);
479}
480EXPORT_SYMBOL(host1x_syncpt_read_max);
481
482/**
483 * host1x_syncpt_read_min() - read minimum syncpoint value
484 * @sp: host1x syncpoint
485 *
486 * The minimum syncpoint value is a shadow of the current sync point value in
487 * hardware.
488 */
489u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
490{
491 smp_rmb();
492
493 return (u32)atomic_read(&sp->min_val);
494}
495EXPORT_SYMBOL(host1x_syncpt_read_min);
496
497/**
498 * host1x_syncpt_read() - read the current syncpoint value
499 * @sp: host1x syncpoint
500 */
501u32 host1x_syncpt_read(struct host1x_syncpt *sp)
502{
503 return host1x_syncpt_load(sp);
504}
505EXPORT_SYMBOL(host1x_syncpt_read);
506
507unsigned int host1x_syncpt_nb_pts(struct host1x *host)
508{
509 return host->info->nb_pts;
510}
511
512unsigned int host1x_syncpt_nb_bases(struct host1x *host)
513{
514 return host->info->nb_bases;
515}
516
517unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
518{
519 return host->info->nb_mlocks;
520}
521
522/**
523 * host1x_syncpt_get() - obtain a syncpoint by ID
524 * @host: host1x controller
525 * @id: syncpoint ID
526 */
527struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id)
528{
529 if (id >= host->info->nb_pts)
530 return NULL;
531
532 return host->syncpt + id;
533}
534EXPORT_SYMBOL(host1x_syncpt_get);
535
536/**
537 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
538 * @sp: host1x syncpoint
539 */
540struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
541{
542 return sp ? sp->base : NULL;
543}
544EXPORT_SYMBOL(host1x_syncpt_get_base);
545
546/**
547 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
548 * @base: host1x syncpoint wait base
549 */
550u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
551{
552 return base->id;
553}
554EXPORT_SYMBOL(host1x_syncpt_base_id);
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
45static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
46 struct host1x_client *client,
47 unsigned long flags)
48{
49 struct host1x_syncpt *sp = host->syncpt;
50 unsigned int i;
51 char *name;
52
53 mutex_lock(&host->syncpt_mutex);
54
55 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
56 ;
57
58 if (i >= host->info->nb_pts)
59 goto unlock;
60
61 if (flags & HOST1X_SYNCPT_HAS_BASE) {
62 sp->base = host1x_syncpt_base_request(host);
63 if (!sp->base)
64 goto unlock;
65 }
66
67 name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id,
68 client ? dev_name(client->dev) : NULL);
69 if (!name)
70 goto free_base;
71
72 sp->client = client;
73 sp->name = name;
74
75 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
76 sp->client_managed = true;
77 else
78 sp->client_managed = false;
79
80 mutex_unlock(&host->syncpt_mutex);
81 return sp;
82
83free_base:
84 host1x_syncpt_base_free(sp->base);
85 sp->base = NULL;
86unlock:
87 mutex_unlock(&host->syncpt_mutex);
88 return NULL;
89}
90
91/**
92 * host1x_syncpt_id() - retrieve syncpoint ID
93 * @sp: host1x syncpoint
94 *
95 * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
96 * often used as a value to program into registers that control how hardware
97 * blocks interact with syncpoints.
98 */
99u32 host1x_syncpt_id(struct host1x_syncpt *sp)
100{
101 return sp->id;
102}
103EXPORT_SYMBOL(host1x_syncpt_id);
104
105/**
106 * host1x_syncpt_incr_max() - update the value sent to hardware
107 * @sp: host1x syncpoint
108 * @incrs: number of increments
109 */
110u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
111{
112 return (u32)atomic_add_return(incrs, &sp->max_val);
113}
114EXPORT_SYMBOL(host1x_syncpt_incr_max);
115
116 /*
117 * Write cached syncpoint and waitbase values to hardware.
118 */
119void host1x_syncpt_restore(struct host1x *host)
120{
121 struct host1x_syncpt *sp_base = host->syncpt;
122 unsigned int i;
123
124 for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
125 host1x_hw_syncpt_restore(host, sp_base + i);
126
127 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
128 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
129
130 wmb();
131}
132
133/*
134 * Update the cached syncpoint and waitbase values by reading them
135 * from the registers.
136 */
137void host1x_syncpt_save(struct host1x *host)
138{
139 struct host1x_syncpt *sp_base = host->syncpt;
140 unsigned int i;
141
142 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
143 if (host1x_syncpt_client_managed(sp_base + i))
144 host1x_hw_syncpt_load(host, sp_base + i);
145 else
146 WARN_ON(!host1x_syncpt_idle(sp_base + i));
147 }
148
149 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
150 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
151}
152
153/*
154 * Updates the cached syncpoint value by reading a new value from the hardware
155 * register
156 */
157u32 host1x_syncpt_load(struct host1x_syncpt *sp)
158{
159 u32 val;
160
161 val = host1x_hw_syncpt_load(sp->host, sp);
162 trace_host1x_syncpt_load_min(sp->id, val);
163
164 return val;
165}
166
167/*
168 * Get the current syncpoint base
169 */
170u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
171{
172 host1x_hw_syncpt_load_wait_base(sp->host, sp);
173
174 return sp->base_val;
175}
176
177/**
178 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
179 * @sp: host1x syncpoint
180 */
181int host1x_syncpt_incr(struct host1x_syncpt *sp)
182{
183 return host1x_hw_syncpt_cpu_incr(sp->host, sp);
184}
185EXPORT_SYMBOL(host1x_syncpt_incr);
186
187/*
188 * Updated sync point form hardware, and returns true if syncpoint is expired,
189 * false if we may need to wait
190 */
191static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
192{
193 host1x_hw_syncpt_load(sp->host, sp);
194
195 return host1x_syncpt_is_expired(sp, thresh);
196}
197
198/**
199 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
200 * @sp: host1x syncpoint
201 * @thresh: threshold
202 * @timeout: maximum time to wait for the syncpoint to reach the given value
203 * @value: return location for the syncpoint value
204 */
205int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
206 u32 *value)
207{
208 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
209 void *ref;
210 struct host1x_waitlist *waiter;
211 int err = 0, check_count = 0;
212 u32 val;
213
214 if (value)
215 *value = 0;
216
217 /* first check cache */
218 if (host1x_syncpt_is_expired(sp, thresh)) {
219 if (value)
220 *value = host1x_syncpt_load(sp);
221
222 return 0;
223 }
224
225 /* try to read from register */
226 val = host1x_hw_syncpt_load(sp->host, sp);
227 if (host1x_syncpt_is_expired(sp, thresh)) {
228 if (value)
229 *value = val;
230
231 goto done;
232 }
233
234 if (!timeout) {
235 err = -EAGAIN;
236 goto done;
237 }
238
239 /* allocate a waiter */
240 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
241 if (!waiter) {
242 err = -ENOMEM;
243 goto done;
244 }
245
246 /* schedule a wakeup when the syncpoint value is reached */
247 err = host1x_intr_add_action(sp->host, sp, thresh,
248 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
249 &wq, waiter, &ref);
250 if (err)
251 goto done;
252
253 err = -EAGAIN;
254 /* Caller-specified timeout may be impractically low */
255 if (timeout < 0)
256 timeout = LONG_MAX;
257
258 /* wait for the syncpoint, or timeout, or signal */
259 while (timeout) {
260 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
261 int remain;
262
263 remain = wait_event_interruptible_timeout(wq,
264 syncpt_load_min_is_expired(sp, thresh),
265 check);
266 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
267 if (value)
268 *value = host1x_syncpt_load(sp);
269
270 err = 0;
271
272 break;
273 }
274
275 if (remain < 0) {
276 err = remain;
277 break;
278 }
279
280 timeout -= check;
281
282 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
283 dev_warn(sp->host->dev,
284 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
285 current->comm, sp->id, sp->name,
286 thresh, timeout);
287
288 host1x_debug_dump_syncpts(sp->host);
289
290 if (check_count == MAX_STUCK_CHECK_COUNT)
291 host1x_debug_dump(sp->host);
292
293 check_count++;
294 }
295 }
296
297 host1x_intr_put_ref(sp->host, sp->id, ref);
298
299done:
300 return err;
301}
302EXPORT_SYMBOL(host1x_syncpt_wait);
303
304/*
305 * Returns true if syncpoint is expired, false if we may need to wait
306 */
307bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
308{
309 u32 current_val;
310 u32 future_val;
311
312 smp_rmb();
313
314 current_val = (u32)atomic_read(&sp->min_val);
315 future_val = (u32)atomic_read(&sp->max_val);
316
317 /* Note the use of unsigned arithmetic here (mod 1<<32).
318 *
319 * c = current_val = min_val = the current value of the syncpoint.
320 * t = thresh = the value we are checking
321 * f = future_val = max_val = the value c will reach when all
322 * outstanding increments have completed.
323 *
324 * Note that c always chases f until it reaches f.
325 *
326 * Dtf = (f - t)
327 * Dtc = (c - t)
328 *
329 * Consider all cases:
330 *
331 * A) .....c..t..f..... Dtf < Dtc need to wait
332 * B) .....c.....f..t.. Dtf > Dtc expired
333 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large)
334 *
335 * Any case where f==c: always expired (for any t). Dtf == Dcf
336 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0)
337 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0,
338 * Dtc!=0)
339 *
340 * Other cases:
341 *
342 * A) .....t..f..c..... Dtf < Dtc need to wait
343 * A) .....f..c..t..... Dtf < Dtc need to wait
344 * A) .....f..t..c..... Dtf > Dtc expired
345 *
346 * So:
347 * Dtf >= Dtc implies EXPIRED (return true)
348 * Dtf < Dtc implies WAIT (return false)
349 *
350 * Note: If t is expired then we *cannot* wait on it. We would wait
351 * forever (hang the system).
352 *
353 * Note: do NOT get clever and remove the -thresh from both sides. It
354 * is NOT the same.
355 *
356 * If future valueis zero, we have a client managed sync point. In that
357 * case we do a direct comparison.
358 */
359 if (!host1x_syncpt_client_managed(sp))
360 return future_val - thresh >= current_val - thresh;
361 else
362 return (s32)(current_val - thresh) >= 0;
363}
364
365int host1x_syncpt_init(struct host1x *host)
366{
367 struct host1x_syncpt_base *bases;
368 struct host1x_syncpt *syncpt;
369 unsigned int i;
370
371 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
372 GFP_KERNEL);
373 if (!syncpt)
374 return -ENOMEM;
375
376 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
377 GFP_KERNEL);
378 if (!bases)
379 return -ENOMEM;
380
381 for (i = 0; i < host->info->nb_pts; i++) {
382 syncpt[i].id = i;
383 syncpt[i].host = host;
384
385 /*
386 * Unassign syncpt from channels for purposes of Tegra186
387 * syncpoint protection. This prevents any channel from
388 * accessing it until it is reassigned.
389 */
390 host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL);
391 }
392
393 for (i = 0; i < host->info->nb_bases; i++)
394 bases[i].id = i;
395
396 mutex_init(&host->syncpt_mutex);
397 host->syncpt = syncpt;
398 host->bases = bases;
399
400 host1x_syncpt_restore(host);
401 host1x_hw_syncpt_enable_protection(host);
402
403 /* Allocate sync point to use for clearing waits for expired fences */
404 host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
405 if (!host->nop_sp)
406 return -ENOMEM;
407
408 return 0;
409}
410
411/**
412 * host1x_syncpt_request() - request a syncpoint
413 * @client: client requesting the syncpoint
414 * @flags: flags
415 *
416 * host1x client drivers can use this function to allocate a syncpoint for
417 * subsequent use. A syncpoint returned by this function will be reserved for
418 * use by the client exclusively. When no longer using a syncpoint, a host1x
419 * client driver needs to release it using host1x_syncpt_free().
420 */
421struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
422 unsigned long flags)
423{
424 struct host1x *host = dev_get_drvdata(client->parent->parent);
425
426 return host1x_syncpt_alloc(host, client, flags);
427}
428EXPORT_SYMBOL(host1x_syncpt_request);
429
430/**
431 * host1x_syncpt_free() - free a requested syncpoint
432 * @sp: host1x syncpoint
433 *
434 * Release a syncpoint previously allocated using host1x_syncpt_request(). A
435 * host1x client driver should call this when the syncpoint is no longer in
436 * use. Note that client drivers must ensure that the syncpoint doesn't remain
437 * under the control of hardware after calling this function, otherwise two
438 * clients may end up trying to access the same syncpoint concurrently.
439 */
440void host1x_syncpt_free(struct host1x_syncpt *sp)
441{
442 if (!sp)
443 return;
444
445 mutex_lock(&sp->host->syncpt_mutex);
446
447 host1x_syncpt_base_free(sp->base);
448 kfree(sp->name);
449 sp->base = NULL;
450 sp->client = NULL;
451 sp->name = NULL;
452 sp->client_managed = false;
453
454 mutex_unlock(&sp->host->syncpt_mutex);
455}
456EXPORT_SYMBOL(host1x_syncpt_free);
457
458void host1x_syncpt_deinit(struct host1x *host)
459{
460 struct host1x_syncpt *sp = host->syncpt;
461 unsigned int i;
462
463 for (i = 0; i < host->info->nb_pts; i++, sp++)
464 kfree(sp->name);
465}
466
467/**
468 * host1x_syncpt_read_max() - read maximum syncpoint value
469 * @sp: host1x syncpoint
470 *
471 * The maximum syncpoint value indicates how many operations there are in
472 * queue, either in channel or in a software thread.
473 */
474u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
475{
476 smp_rmb();
477
478 return (u32)atomic_read(&sp->max_val);
479}
480EXPORT_SYMBOL(host1x_syncpt_read_max);
481
482/**
483 * host1x_syncpt_read_min() - read minimum syncpoint value
484 * @sp: host1x syncpoint
485 *
486 * The minimum syncpoint value is a shadow of the current sync point value in
487 * hardware.
488 */
489u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
490{
491 smp_rmb();
492
493 return (u32)atomic_read(&sp->min_val);
494}
495EXPORT_SYMBOL(host1x_syncpt_read_min);
496
497/**
498 * host1x_syncpt_read() - read the current syncpoint value
499 * @sp: host1x syncpoint
500 */
501u32 host1x_syncpt_read(struct host1x_syncpt *sp)
502{
503 return host1x_syncpt_load(sp);
504}
505EXPORT_SYMBOL(host1x_syncpt_read);
506
507unsigned int host1x_syncpt_nb_pts(struct host1x *host)
508{
509 return host->info->nb_pts;
510}
511
512unsigned int host1x_syncpt_nb_bases(struct host1x *host)
513{
514 return host->info->nb_bases;
515}
516
517unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
518{
519 return host->info->nb_mlocks;
520}
521
522/**
523 * host1x_syncpt_get() - obtain a syncpoint by ID
524 * @host: host1x controller
525 * @id: syncpoint ID
526 */
527struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id)
528{
529 if (id >= host->info->nb_pts)
530 return NULL;
531
532 return host->syncpt + id;
533}
534EXPORT_SYMBOL(host1x_syncpt_get);
535
536/**
537 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
538 * @sp: host1x syncpoint
539 */
540struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
541{
542 return sp ? sp->base : NULL;
543}
544EXPORT_SYMBOL(host1x_syncpt_get_base);
545
546/**
547 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
548 * @base: host1x syncpoint wait base
549 */
550u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
551{
552 return base->id;
553}
554EXPORT_SYMBOL(host1x_syncpt_base_id);