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1/*
2 * Tegra host1x Syncpoints
3 *
4 * Copyright (c) 2010-2013, 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 device *dev,
58 unsigned long flags)
59{
60 int i;
61 struct host1x_syncpt *sp = host->syncpt;
62 char *name;
63
64 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
65 ;
66
67 if (i >= host->info->nb_pts)
68 return NULL;
69
70 if (flags & HOST1X_SYNCPT_HAS_BASE) {
71 sp->base = host1x_syncpt_base_request(host);
72 if (!sp->base)
73 return NULL;
74 }
75
76 name = kasprintf(GFP_KERNEL, "%02d-%s", sp->id,
77 dev ? dev_name(dev) : NULL);
78 if (!name)
79 return NULL;
80
81 sp->dev = dev;
82 sp->name = name;
83
84 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
85 sp->client_managed = true;
86 else
87 sp->client_managed = false;
88
89 return sp;
90}
91
92u32 host1x_syncpt_id(struct host1x_syncpt *sp)
93{
94 return sp->id;
95}
96EXPORT_SYMBOL(host1x_syncpt_id);
97
98/*
99 * Updates the value sent to hardware.
100 */
101u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
102{
103 return (u32)atomic_add_return(incrs, &sp->max_val);
104}
105EXPORT_SYMBOL(host1x_syncpt_incr_max);
106
107 /*
108 * Write cached syncpoint and waitbase values to hardware.
109 */
110void host1x_syncpt_restore(struct host1x *host)
111{
112 struct host1x_syncpt *sp_base = host->syncpt;
113 u32 i;
114
115 for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
116 host1x_hw_syncpt_restore(host, sp_base + i);
117 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
118 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
119 wmb();
120}
121
122/*
123 * Update the cached syncpoint and waitbase values by reading them
124 * from the registers.
125 */
126void host1x_syncpt_save(struct host1x *host)
127{
128 struct host1x_syncpt *sp_base = host->syncpt;
129 u32 i;
130
131 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
132 if (host1x_syncpt_client_managed(sp_base + i))
133 host1x_hw_syncpt_load(host, sp_base + i);
134 else
135 WARN_ON(!host1x_syncpt_idle(sp_base + i));
136 }
137
138 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
139 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
140}
141
142/*
143 * Updates the cached syncpoint value by reading a new value from the hardware
144 * register
145 */
146u32 host1x_syncpt_load(struct host1x_syncpt *sp)
147{
148 u32 val;
149 val = host1x_hw_syncpt_load(sp->host, sp);
150 trace_host1x_syncpt_load_min(sp->id, val);
151
152 return val;
153}
154
155/*
156 * Get the current syncpoint base
157 */
158u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
159{
160 u32 val;
161 host1x_hw_syncpt_load_wait_base(sp->host, sp);
162 val = sp->base_val;
163 return val;
164}
165
166/*
167 * Increment syncpoint value from cpu, updating cache
168 */
169int host1x_syncpt_incr(struct host1x_syncpt *sp)
170{
171 return host1x_hw_syncpt_cpu_incr(sp->host, sp);
172}
173EXPORT_SYMBOL(host1x_syncpt_incr);
174
175/*
176 * Updated sync point form hardware, and returns true if syncpoint is expired,
177 * false if we may need to wait
178 */
179static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
180{
181 host1x_hw_syncpt_load(sp->host, sp);
182 return host1x_syncpt_is_expired(sp, thresh);
183}
184
185/*
186 * Main entrypoint for syncpoint value waits.
187 */
188int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
189 u32 *value)
190{
191 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
192 void *ref;
193 struct host1x_waitlist *waiter;
194 int err = 0, check_count = 0;
195 u32 val;
196
197 if (value)
198 *value = 0;
199
200 /* first check cache */
201 if (host1x_syncpt_is_expired(sp, thresh)) {
202 if (value)
203 *value = host1x_syncpt_load(sp);
204 return 0;
205 }
206
207 /* try to read from register */
208 val = host1x_hw_syncpt_load(sp->host, sp);
209 if (host1x_syncpt_is_expired(sp, thresh)) {
210 if (value)
211 *value = val;
212 goto done;
213 }
214
215 if (!timeout) {
216 err = -EAGAIN;
217 goto done;
218 }
219
220 /* allocate a waiter */
221 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
222 if (!waiter) {
223 err = -ENOMEM;
224 goto done;
225 }
226
227 /* schedule a wakeup when the syncpoint value is reached */
228 err = host1x_intr_add_action(sp->host, sp->id, thresh,
229 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
230 &wq, waiter, &ref);
231 if (err)
232 goto done;
233
234 err = -EAGAIN;
235 /* Caller-specified timeout may be impractically low */
236 if (timeout < 0)
237 timeout = LONG_MAX;
238
239 /* wait for the syncpoint, or timeout, or signal */
240 while (timeout) {
241 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
242 int remain = wait_event_interruptible_timeout(wq,
243 syncpt_load_min_is_expired(sp, thresh),
244 check);
245 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
246 if (value)
247 *value = host1x_syncpt_load(sp);
248 err = 0;
249 break;
250 }
251 if (remain < 0) {
252 err = remain;
253 break;
254 }
255 timeout -= check;
256 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
257 dev_warn(sp->host->dev,
258 "%s: syncpoint id %d (%s) stuck waiting %d, timeout=%ld\n",
259 current->comm, sp->id, sp->name,
260 thresh, timeout);
261
262 host1x_debug_dump_syncpts(sp->host);
263 if (check_count == MAX_STUCK_CHECK_COUNT)
264 host1x_debug_dump(sp->host);
265 check_count++;
266 }
267 }
268 host1x_intr_put_ref(sp->host, sp->id, ref);
269
270done:
271 return err;
272}
273EXPORT_SYMBOL(host1x_syncpt_wait);
274
275/*
276 * Returns true if syncpoint is expired, false if we may need to wait
277 */
278bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
279{
280 u32 current_val;
281 u32 future_val;
282 smp_rmb();
283 current_val = (u32)atomic_read(&sp->min_val);
284 future_val = (u32)atomic_read(&sp->max_val);
285
286 /* Note the use of unsigned arithmetic here (mod 1<<32).
287 *
288 * c = current_val = min_val = the current value of the syncpoint.
289 * t = thresh = the value we are checking
290 * f = future_val = max_val = the value c will reach when all
291 * outstanding increments have completed.
292 *
293 * Note that c always chases f until it reaches f.
294 *
295 * Dtf = (f - t)
296 * Dtc = (c - t)
297 *
298 * Consider all cases:
299 *
300 * A) .....c..t..f..... Dtf < Dtc need to wait
301 * B) .....c.....f..t.. Dtf > Dtc expired
302 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large)
303 *
304 * Any case where f==c: always expired (for any t). Dtf == Dcf
305 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0)
306 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0,
307 * Dtc!=0)
308 *
309 * Other cases:
310 *
311 * A) .....t..f..c..... Dtf < Dtc need to wait
312 * A) .....f..c..t..... Dtf < Dtc need to wait
313 * A) .....f..t..c..... Dtf > Dtc expired
314 *
315 * So:
316 * Dtf >= Dtc implies EXPIRED (return true)
317 * Dtf < Dtc implies WAIT (return false)
318 *
319 * Note: If t is expired then we *cannot* wait on it. We would wait
320 * forever (hang the system).
321 *
322 * Note: do NOT get clever and remove the -thresh from both sides. It
323 * is NOT the same.
324 *
325 * If future valueis zero, we have a client managed sync point. In that
326 * case we do a direct comparison.
327 */
328 if (!host1x_syncpt_client_managed(sp))
329 return future_val - thresh >= current_val - thresh;
330 else
331 return (s32)(current_val - thresh) >= 0;
332}
333
334/* remove a wait pointed to by patch_addr */
335int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr)
336{
337 return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr);
338}
339
340int host1x_syncpt_init(struct host1x *host)
341{
342 struct host1x_syncpt_base *bases;
343 struct host1x_syncpt *syncpt;
344 int i;
345
346 syncpt = devm_kzalloc(host->dev, sizeof(*syncpt) * host->info->nb_pts,
347 GFP_KERNEL);
348 if (!syncpt)
349 return -ENOMEM;
350
351 bases = devm_kzalloc(host->dev, sizeof(*bases) * host->info->nb_bases,
352 GFP_KERNEL);
353 if (!bases)
354 return -ENOMEM;
355
356 for (i = 0; i < host->info->nb_pts; i++) {
357 syncpt[i].id = i;
358 syncpt[i].host = host;
359 }
360
361 for (i = 0; i < host->info->nb_bases; i++)
362 bases[i].id = i;
363
364 host->syncpt = syncpt;
365 host->bases = bases;
366
367 host1x_syncpt_restore(host);
368
369 /* Allocate sync point to use for clearing waits for expired fences */
370 host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
371 if (!host->nop_sp)
372 return -ENOMEM;
373
374 return 0;
375}
376
377struct host1x_syncpt *host1x_syncpt_request(struct device *dev,
378 unsigned long flags)
379{
380 struct host1x *host = dev_get_drvdata(dev->parent);
381 return host1x_syncpt_alloc(host, dev, flags);
382}
383EXPORT_SYMBOL(host1x_syncpt_request);
384
385void host1x_syncpt_free(struct host1x_syncpt *sp)
386{
387 if (!sp)
388 return;
389
390 host1x_syncpt_base_free(sp->base);
391 kfree(sp->name);
392 sp->base = NULL;
393 sp->dev = NULL;
394 sp->name = NULL;
395 sp->client_managed = false;
396}
397EXPORT_SYMBOL(host1x_syncpt_free);
398
399void host1x_syncpt_deinit(struct host1x *host)
400{
401 int i;
402 struct host1x_syncpt *sp = host->syncpt;
403 for (i = 0; i < host->info->nb_pts; i++, sp++)
404 kfree(sp->name);
405}
406
407/*
408 * Read max. It indicates how many operations there are in queue, either in
409 * channel or in a software thread.
410 * */
411u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
412{
413 smp_rmb();
414 return (u32)atomic_read(&sp->max_val);
415}
416EXPORT_SYMBOL(host1x_syncpt_read_max);
417
418/*
419 * Read min, which is a shadow of the current sync point value in hardware.
420 */
421u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
422{
423 smp_rmb();
424 return (u32)atomic_read(&sp->min_val);
425}
426EXPORT_SYMBOL(host1x_syncpt_read_min);
427
428u32 host1x_syncpt_read(struct host1x_syncpt *sp)
429{
430 return host1x_syncpt_load(sp);
431}
432EXPORT_SYMBOL(host1x_syncpt_read);
433
434int host1x_syncpt_nb_pts(struct host1x *host)
435{
436 return host->info->nb_pts;
437}
438
439int host1x_syncpt_nb_bases(struct host1x *host)
440{
441 return host->info->nb_bases;
442}
443
444int host1x_syncpt_nb_mlocks(struct host1x *host)
445{
446 return host->info->nb_mlocks;
447}
448
449struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, u32 id)
450{
451 if (host->info->nb_pts < id)
452 return NULL;
453 return host->syncpt + id;
454}
455EXPORT_SYMBOL(host1x_syncpt_get);
456
457struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
458{
459 return sp ? sp->base : NULL;
460}
461EXPORT_SYMBOL(host1x_syncpt_get_base);
462
463u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
464{
465 return base->id;
466}
467EXPORT_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);