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1/*
2 * Tegra host1x Syncpoints
3 *
4 * Copyright (c) 2010-2015, NVIDIA Corporation.
5 *
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.
9 *
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
13 * more details.
14 *
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/>.
17 */
18
19#include <linux/module.h>
20#include <linux/device.h>
21#include <linux/slab.h>
22
23#include <trace/events/host1x.h>
24
25#include "syncpt.h"
26#include "dev.h"
27#include "intr.h"
28#include "debug.h"
29
30#define SYNCPT_CHECK_PERIOD (2 * HZ)
31#define MAX_STUCK_CHECK_COUNT 15
32
33static struct host1x_syncpt_base *
34host1x_syncpt_base_request(struct host1x *host)
35{
36 struct host1x_syncpt_base *bases = host->bases;
37 unsigned int i;
38
39 for (i = 0; i < host->info->nb_bases; i++)
40 if (!bases[i].requested)
41 break;
42
43 if (i >= host->info->nb_bases)
44 return NULL;
45
46 bases[i].requested = true;
47 return &bases[i];
48}
49
50static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
51{
52 if (base)
53 base->requested = false;
54}
55
56static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
57 struct host1x_client *client,
58 unsigned long flags)
59{
60 int i;
61 struct host1x_syncpt *sp = host->syncpt;
62 char *name;
63
64 mutex_lock(&host->syncpt_mutex);
65
66 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
67 ;
68
69 if (i >= host->info->nb_pts)
70 goto unlock;
71
72 if (flags & HOST1X_SYNCPT_HAS_BASE) {
73 sp->base = host1x_syncpt_base_request(host);
74 if (!sp->base)
75 goto unlock;
76 }
77
78 name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id,
79 client ? dev_name(client->dev) : NULL);
80 if (!name)
81 goto free_base;
82
83 sp->client = client;
84 sp->name = name;
85
86 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
87 sp->client_managed = true;
88 else
89 sp->client_managed = false;
90
91 mutex_unlock(&host->syncpt_mutex);
92 return sp;
93
94free_base:
95 host1x_syncpt_base_free(sp->base);
96 sp->base = NULL;
97unlock:
98 mutex_unlock(&host->syncpt_mutex);
99 return NULL;
100}
101
102/**
103 * host1x_syncpt_id() - retrieve syncpoint ID
104 * @sp: host1x syncpoint
105 *
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.
109 */
110u32 host1x_syncpt_id(struct host1x_syncpt *sp)
111{
112 return sp->id;
113}
114EXPORT_SYMBOL(host1x_syncpt_id);
115
116/**
117 * host1x_syncpt_incr_max() - update the value sent to hardware
118 * @sp: host1x syncpoint
119 * @incrs: number of increments
120 */
121u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
122{
123 return (u32)atomic_add_return(incrs, &sp->max_val);
124}
125EXPORT_SYMBOL(host1x_syncpt_incr_max);
126
127 /*
128 * Write cached syncpoint and waitbase values to hardware.
129 */
130void host1x_syncpt_restore(struct host1x *host)
131{
132 struct host1x_syncpt *sp_base = host->syncpt;
133 unsigned int i;
134
135 for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
136 host1x_hw_syncpt_restore(host, sp_base + i);
137
138 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
139 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
140
141 wmb();
142}
143
144/*
145 * Update the cached syncpoint and waitbase values by reading them
146 * from the registers.
147 */
148void host1x_syncpt_save(struct host1x *host)
149{
150 struct host1x_syncpt *sp_base = host->syncpt;
151 unsigned int i;
152
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);
156 else
157 WARN_ON(!host1x_syncpt_idle(sp_base + i));
158 }
159
160 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
161 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
162}
163
164/*
165 * Updates the cached syncpoint value by reading a new value from the hardware
166 * register
167 */
168u32 host1x_syncpt_load(struct host1x_syncpt *sp)
169{
170 u32 val;
171
172 val = host1x_hw_syncpt_load(sp->host, sp);
173 trace_host1x_syncpt_load_min(sp->id, val);
174
175 return val;
176}
177
178/*
179 * Get the current syncpoint base
180 */
181u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
182{
183 host1x_hw_syncpt_load_wait_base(sp->host, sp);
184
185 return sp->base_val;
186}
187
188/**
189 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
190 * @sp: host1x syncpoint
191 */
192int host1x_syncpt_incr(struct host1x_syncpt *sp)
193{
194 return host1x_hw_syncpt_cpu_incr(sp->host, sp);
195}
196EXPORT_SYMBOL(host1x_syncpt_incr);
197
198/*
199 * Updated sync point form hardware, and returns true if syncpoint is expired,
200 * false if we may need to wait
201 */
202static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
203{
204 host1x_hw_syncpt_load(sp->host, sp);
205
206 return host1x_syncpt_is_expired(sp, thresh);
207}
208
209/**
210 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
211 * @sp: host1x syncpoint
212 * @thresh: threshold
213 * @timeout: maximum time to wait for the syncpoint to reach the given value
214 * @value: return location for the syncpoint value
215 */
216int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
217 u32 *value)
218{
219 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
220 void *ref;
221 struct host1x_waitlist *waiter;
222 int err = 0, check_count = 0;
223 u32 val;
224
225 if (value)
226 *value = 0;
227
228 /* first check cache */
229 if (host1x_syncpt_is_expired(sp, thresh)) {
230 if (value)
231 *value = host1x_syncpt_load(sp);
232
233 return 0;
234 }
235
236 /* try to read from register */
237 val = host1x_hw_syncpt_load(sp->host, sp);
238 if (host1x_syncpt_is_expired(sp, thresh)) {
239 if (value)
240 *value = val;
241
242 goto done;
243 }
244
245 if (!timeout) {
246 err = -EAGAIN;
247 goto done;
248 }
249
250 /* allocate a waiter */
251 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
252 if (!waiter) {
253 err = -ENOMEM;
254 goto done;
255 }
256
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,
260 &wq, waiter, &ref);
261 if (err)
262 goto done;
263
264 err = -EAGAIN;
265 /* Caller-specified timeout may be impractically low */
266 if (timeout < 0)
267 timeout = LONG_MAX;
268
269 /* wait for the syncpoint, or timeout, or signal */
270 while (timeout) {
271 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
272 int remain;
273
274 remain = wait_event_interruptible_timeout(wq,
275 syncpt_load_min_is_expired(sp, thresh),
276 check);
277 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
278 if (value)
279 *value = host1x_syncpt_load(sp);
280
281 err = 0;
282
283 break;
284 }
285
286 if (remain < 0) {
287 err = remain;
288 break;
289 }
290
291 timeout -= check;
292
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,
297 thresh, timeout);
298
299 host1x_debug_dump_syncpts(sp->host);
300
301 if (check_count == MAX_STUCK_CHECK_COUNT)
302 host1x_debug_dump(sp->host);
303
304 check_count++;
305 }
306 }
307
308 host1x_intr_put_ref(sp->host, sp->id, ref);
309
310done:
311 return err;
312}
313EXPORT_SYMBOL(host1x_syncpt_wait);
314
315/*
316 * Returns true if syncpoint is expired, false if we may need to wait
317 */
318bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
319{
320 u32 current_val;
321 u32 future_val;
322
323 smp_rmb();
324
325 current_val = (u32)atomic_read(&sp->min_val);
326 future_val = (u32)atomic_read(&sp->max_val);
327
328 /* Note the use of unsigned arithmetic here (mod 1<<32).
329 *
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.
334 *
335 * Note that c always chases f until it reaches f.
336 *
337 * Dtf = (f - t)
338 * Dtc = (c - t)
339 *
340 * Consider all cases:
341 *
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)
345 *
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,
349 * Dtc!=0)
350 *
351 * Other cases:
352 *
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
356 *
357 * So:
358 * Dtf >= Dtc implies EXPIRED (return true)
359 * Dtf < Dtc implies WAIT (return false)
360 *
361 * Note: If t is expired then we *cannot* wait on it. We would wait
362 * forever (hang the system).
363 *
364 * Note: do NOT get clever and remove the -thresh from both sides. It
365 * is NOT the same.
366 *
367 * If future valueis zero, we have a client managed sync point. In that
368 * case we do a direct comparison.
369 */
370 if (!host1x_syncpt_client_managed(sp))
371 return future_val - thresh >= current_val - thresh;
372 else
373 return (s32)(current_val - thresh) >= 0;
374}
375
376/* remove a wait pointed to by patch_addr */
377int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr)
378{
379 return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr);
380}
381
382int host1x_syncpt_init(struct host1x *host)
383{
384 struct host1x_syncpt_base *bases;
385 struct host1x_syncpt *syncpt;
386 unsigned int i;
387
388 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
389 GFP_KERNEL);
390 if (!syncpt)
391 return -ENOMEM;
392
393 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
394 GFP_KERNEL);
395 if (!bases)
396 return -ENOMEM;
397
398 for (i = 0; i < host->info->nb_pts; i++) {
399 syncpt[i].id = i;
400 syncpt[i].host = host;
401
402 /*
403 * Unassign syncpt from channels for purposes of Tegra186
404 * syncpoint protection. This prevents any channel from
405 * accessing it until it is reassigned.
406 */
407 host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL);
408 }
409
410 for (i = 0; i < host->info->nb_bases; i++)
411 bases[i].id = i;
412
413 mutex_init(&host->syncpt_mutex);
414 host->syncpt = syncpt;
415 host->bases = bases;
416
417 host1x_syncpt_restore(host);
418 host1x_hw_syncpt_enable_protection(host);
419
420 /* Allocate sync point to use for clearing waits for expired fences */
421 host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
422 if (!host->nop_sp)
423 return -ENOMEM;
424
425 return 0;
426}
427
428/**
429 * host1x_syncpt_request() - request a syncpoint
430 * @client: client requesting the syncpoint
431 * @flags: flags
432 *
433 * host1x client drivers can use this function to allocate a syncpoint for
434 * subsequent use. A syncpoint returned by this function will be reserved for
435 * use by the client exclusively. When no longer using a syncpoint, a host1x
436 * client driver needs to release it using host1x_syncpt_free().
437 */
438struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
439 unsigned long flags)
440{
441 struct host1x *host = dev_get_drvdata(client->parent->parent);
442
443 return host1x_syncpt_alloc(host, client, flags);
444}
445EXPORT_SYMBOL(host1x_syncpt_request);
446
447/**
448 * host1x_syncpt_free() - free a requested syncpoint
449 * @sp: host1x syncpoint
450 *
451 * Release a syncpoint previously allocated using host1x_syncpt_request(). A
452 * host1x client driver should call this when the syncpoint is no longer in
453 * use. Note that client drivers must ensure that the syncpoint doesn't remain
454 * under the control of hardware after calling this function, otherwise two
455 * clients may end up trying to access the same syncpoint concurrently.
456 */
457void host1x_syncpt_free(struct host1x_syncpt *sp)
458{
459 if (!sp)
460 return;
461
462 mutex_lock(&sp->host->syncpt_mutex);
463
464 host1x_syncpt_base_free(sp->base);
465 kfree(sp->name);
466 sp->base = NULL;
467 sp->client = NULL;
468 sp->name = NULL;
469 sp->client_managed = false;
470
471 mutex_unlock(&sp->host->syncpt_mutex);
472}
473EXPORT_SYMBOL(host1x_syncpt_free);
474
475void host1x_syncpt_deinit(struct host1x *host)
476{
477 struct host1x_syncpt *sp = host->syncpt;
478 unsigned int i;
479
480 for (i = 0; i < host->info->nb_pts; i++, sp++)
481 kfree(sp->name);
482}
483
484/**
485 * host1x_syncpt_read_max() - read maximum syncpoint value
486 * @sp: host1x syncpoint
487 *
488 * The maximum syncpoint value indicates how many operations there are in
489 * queue, either in channel or in a software thread.
490 */
491u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
492{
493 smp_rmb();
494
495 return (u32)atomic_read(&sp->max_val);
496}
497EXPORT_SYMBOL(host1x_syncpt_read_max);
498
499/**
500 * host1x_syncpt_read_min() - read minimum syncpoint value
501 * @sp: host1x syncpoint
502 *
503 * The minimum syncpoint value is a shadow of the current sync point value in
504 * hardware.
505 */
506u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
507{
508 smp_rmb();
509
510 return (u32)atomic_read(&sp->min_val);
511}
512EXPORT_SYMBOL(host1x_syncpt_read_min);
513
514/**
515 * host1x_syncpt_read() - read the current syncpoint value
516 * @sp: host1x syncpoint
517 */
518u32 host1x_syncpt_read(struct host1x_syncpt *sp)
519{
520 return host1x_syncpt_load(sp);
521}
522EXPORT_SYMBOL(host1x_syncpt_read);
523
524unsigned int host1x_syncpt_nb_pts(struct host1x *host)
525{
526 return host->info->nb_pts;
527}
528
529unsigned int host1x_syncpt_nb_bases(struct host1x *host)
530{
531 return host->info->nb_bases;
532}
533
534unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
535{
536 return host->info->nb_mlocks;
537}
538
539/**
540 * host1x_syncpt_get() - obtain a syncpoint by ID
541 * @host: host1x controller
542 * @id: syncpoint ID
543 */
544struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id)
545{
546 if (id >= host->info->nb_pts)
547 return NULL;
548
549 return host->syncpt + id;
550}
551EXPORT_SYMBOL(host1x_syncpt_get);
552
553/**
554 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
555 * @sp: host1x syncpoint
556 */
557struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
558{
559 return sp ? sp->base : NULL;
560}
561EXPORT_SYMBOL(host1x_syncpt_get_base);
562
563/**
564 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
565 * @base: host1x syncpoint wait base
566 */
567u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
568{
569 return base->id;
570}
571EXPORT_SYMBOL(host1x_syncpt_base_id);