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75471687 TB |
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" | |
7ede0b0b TB |
27 | #include "intr.h" |
28 | ||
29 | #define SYNCPT_CHECK_PERIOD (2 * HZ) | |
30 | #define MAX_STUCK_CHECK_COUNT 15 | |
75471687 TB |
31 | |
32 | static struct host1x_syncpt *_host1x_syncpt_alloc(struct host1x *host, | |
33 | struct device *dev, | |
34 | int client_managed) | |
35 | { | |
36 | int i; | |
37 | struct host1x_syncpt *sp = host->syncpt; | |
38 | char *name; | |
39 | ||
40 | for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++) | |
41 | ; | |
42 | if (sp->dev) | |
43 | return NULL; | |
44 | ||
45 | name = kasprintf(GFP_KERNEL, "%02d-%s", sp->id, | |
46 | dev ? dev_name(dev) : NULL); | |
47 | if (!name) | |
48 | return NULL; | |
49 | ||
50 | sp->dev = dev; | |
51 | sp->name = name; | |
52 | sp->client_managed = client_managed; | |
53 | ||
54 | return sp; | |
55 | } | |
56 | ||
57 | u32 host1x_syncpt_id(struct host1x_syncpt *sp) | |
58 | { | |
59 | return sp->id; | |
60 | } | |
61 | ||
62 | /* | |
63 | * Updates the value sent to hardware. | |
64 | */ | |
65 | u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs) | |
66 | { | |
67 | return (u32)atomic_add_return(incrs, &sp->max_val); | |
68 | } | |
69 | ||
70 | /* | |
71 | * Write cached syncpoint and waitbase values to hardware. | |
72 | */ | |
73 | void host1x_syncpt_restore(struct host1x *host) | |
74 | { | |
75 | struct host1x_syncpt *sp_base = host->syncpt; | |
76 | u32 i; | |
77 | ||
78 | for (i = 0; i < host1x_syncpt_nb_pts(host); i++) | |
79 | host1x_hw_syncpt_restore(host, sp_base + i); | |
80 | for (i = 0; i < host1x_syncpt_nb_bases(host); i++) | |
81 | host1x_hw_syncpt_restore_wait_base(host, sp_base + i); | |
82 | wmb(); | |
83 | } | |
84 | ||
85 | /* | |
86 | * Update the cached syncpoint and waitbase values by reading them | |
87 | * from the registers. | |
88 | */ | |
89 | void host1x_syncpt_save(struct host1x *host) | |
90 | { | |
91 | struct host1x_syncpt *sp_base = host->syncpt; | |
92 | u32 i; | |
93 | ||
94 | for (i = 0; i < host1x_syncpt_nb_pts(host); i++) { | |
95 | if (host1x_syncpt_client_managed(sp_base + i)) | |
96 | host1x_hw_syncpt_load(host, sp_base + i); | |
97 | else | |
98 | WARN_ON(!host1x_syncpt_idle(sp_base + i)); | |
99 | } | |
100 | ||
101 | for (i = 0; i < host1x_syncpt_nb_bases(host); i++) | |
102 | host1x_hw_syncpt_load_wait_base(host, sp_base + i); | |
103 | } | |
104 | ||
105 | /* | |
106 | * Updates the cached syncpoint value by reading a new value from the hardware | |
107 | * register | |
108 | */ | |
109 | u32 host1x_syncpt_load(struct host1x_syncpt *sp) | |
110 | { | |
111 | u32 val; | |
112 | val = host1x_hw_syncpt_load(sp->host, sp); | |
113 | trace_host1x_syncpt_load_min(sp->id, val); | |
114 | ||
115 | return val; | |
116 | } | |
117 | ||
118 | /* | |
119 | * Get the current syncpoint base | |
120 | */ | |
121 | u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp) | |
122 | { | |
123 | u32 val; | |
124 | host1x_hw_syncpt_load_wait_base(sp->host, sp); | |
125 | val = sp->base_val; | |
126 | return val; | |
127 | } | |
128 | ||
129 | /* | |
130 | * Write a cpu syncpoint increment to the hardware, without touching | |
131 | * the cache. Caller is responsible for host being powered. | |
132 | */ | |
133 | void host1x_syncpt_cpu_incr(struct host1x_syncpt *sp) | |
134 | { | |
135 | host1x_hw_syncpt_cpu_incr(sp->host, sp); | |
136 | } | |
137 | ||
138 | /* | |
139 | * Increment syncpoint value from cpu, updating cache | |
140 | */ | |
141 | void host1x_syncpt_incr(struct host1x_syncpt *sp) | |
142 | { | |
143 | if (host1x_syncpt_client_managed(sp)) | |
144 | host1x_syncpt_incr_max(sp, 1); | |
145 | host1x_syncpt_cpu_incr(sp); | |
146 | } | |
147 | ||
7ede0b0b TB |
148 | /* |
149 | * Updated sync point form hardware, and returns true if syncpoint is expired, | |
150 | * false if we may need to wait | |
151 | */ | |
152 | static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh) | |
153 | { | |
154 | host1x_hw_syncpt_load(sp->host, sp); | |
155 | return host1x_syncpt_is_expired(sp, thresh); | |
156 | } | |
157 | ||
158 | /* | |
159 | * Main entrypoint for syncpoint value waits. | |
160 | */ | |
161 | int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout, | |
162 | u32 *value) | |
163 | { | |
164 | DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); | |
165 | void *ref; | |
166 | struct host1x_waitlist *waiter; | |
167 | int err = 0, check_count = 0; | |
168 | u32 val; | |
169 | ||
170 | if (value) | |
171 | *value = 0; | |
172 | ||
173 | /* first check cache */ | |
174 | if (host1x_syncpt_is_expired(sp, thresh)) { | |
175 | if (value) | |
176 | *value = host1x_syncpt_load(sp); | |
177 | return 0; | |
178 | } | |
179 | ||
180 | /* try to read from register */ | |
181 | val = host1x_hw_syncpt_load(sp->host, sp); | |
182 | if (host1x_syncpt_is_expired(sp, thresh)) { | |
183 | if (value) | |
184 | *value = val; | |
185 | goto done; | |
186 | } | |
187 | ||
188 | if (!timeout) { | |
189 | err = -EAGAIN; | |
190 | goto done; | |
191 | } | |
192 | ||
193 | /* allocate a waiter */ | |
194 | waiter = kzalloc(sizeof(*waiter), GFP_KERNEL); | |
195 | if (!waiter) { | |
196 | err = -ENOMEM; | |
197 | goto done; | |
198 | } | |
199 | ||
200 | /* schedule a wakeup when the syncpoint value is reached */ | |
201 | err = host1x_intr_add_action(sp->host, sp->id, thresh, | |
202 | HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE, | |
203 | &wq, waiter, &ref); | |
204 | if (err) | |
205 | goto done; | |
206 | ||
207 | err = -EAGAIN; | |
208 | /* Caller-specified timeout may be impractically low */ | |
209 | if (timeout < 0) | |
210 | timeout = LONG_MAX; | |
211 | ||
212 | /* wait for the syncpoint, or timeout, or signal */ | |
213 | while (timeout) { | |
214 | long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout); | |
215 | int remain = wait_event_interruptible_timeout(wq, | |
216 | syncpt_load_min_is_expired(sp, thresh), | |
217 | check); | |
218 | if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) { | |
219 | if (value) | |
220 | *value = host1x_syncpt_load(sp); | |
221 | err = 0; | |
222 | break; | |
223 | } | |
224 | if (remain < 0) { | |
225 | err = remain; | |
226 | break; | |
227 | } | |
228 | timeout -= check; | |
229 | if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) { | |
230 | dev_warn(sp->host->dev, | |
231 | "%s: syncpoint id %d (%s) stuck waiting %d, timeout=%ld\n", | |
232 | current->comm, sp->id, sp->name, | |
233 | thresh, timeout); | |
234 | check_count++; | |
235 | } | |
236 | } | |
237 | host1x_intr_put_ref(sp->host, sp->id, ref); | |
238 | ||
239 | done: | |
240 | return err; | |
241 | } | |
242 | EXPORT_SYMBOL(host1x_syncpt_wait); | |
243 | ||
244 | /* | |
245 | * Returns true if syncpoint is expired, false if we may need to wait | |
246 | */ | |
247 | bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh) | |
248 | { | |
249 | u32 current_val; | |
250 | u32 future_val; | |
251 | smp_rmb(); | |
252 | current_val = (u32)atomic_read(&sp->min_val); | |
253 | future_val = (u32)atomic_read(&sp->max_val); | |
254 | ||
255 | /* Note the use of unsigned arithmetic here (mod 1<<32). | |
256 | * | |
257 | * c = current_val = min_val = the current value of the syncpoint. | |
258 | * t = thresh = the value we are checking | |
259 | * f = future_val = max_val = the value c will reach when all | |
260 | * outstanding increments have completed. | |
261 | * | |
262 | * Note that c always chases f until it reaches f. | |
263 | * | |
264 | * Dtf = (f - t) | |
265 | * Dtc = (c - t) | |
266 | * | |
267 | * Consider all cases: | |
268 | * | |
269 | * A) .....c..t..f..... Dtf < Dtc need to wait | |
270 | * B) .....c.....f..t.. Dtf > Dtc expired | |
271 | * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large) | |
272 | * | |
273 | * Any case where f==c: always expired (for any t). Dtf == Dcf | |
274 | * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0) | |
275 | * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0, | |
276 | * Dtc!=0) | |
277 | * | |
278 | * Other cases: | |
279 | * | |
280 | * A) .....t..f..c..... Dtf < Dtc need to wait | |
281 | * A) .....f..c..t..... Dtf < Dtc need to wait | |
282 | * A) .....f..t..c..... Dtf > Dtc expired | |
283 | * | |
284 | * So: | |
285 | * Dtf >= Dtc implies EXPIRED (return true) | |
286 | * Dtf < Dtc implies WAIT (return false) | |
287 | * | |
288 | * Note: If t is expired then we *cannot* wait on it. We would wait | |
289 | * forever (hang the system). | |
290 | * | |
291 | * Note: do NOT get clever and remove the -thresh from both sides. It | |
292 | * is NOT the same. | |
293 | * | |
294 | * If future valueis zero, we have a client managed sync point. In that | |
295 | * case we do a direct comparison. | |
296 | */ | |
297 | if (!host1x_syncpt_client_managed(sp)) | |
298 | return future_val - thresh >= current_val - thresh; | |
299 | else | |
300 | return (s32)(current_val - thresh) >= 0; | |
301 | } | |
302 | ||
6579324a TB |
303 | /* remove a wait pointed to by patch_addr */ |
304 | int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr) | |
305 | { | |
306 | return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr); | |
307 | } | |
308 | ||
75471687 TB |
309 | int host1x_syncpt_init(struct host1x *host) |
310 | { | |
311 | struct host1x_syncpt *syncpt; | |
312 | int i; | |
313 | ||
314 | syncpt = devm_kzalloc(host->dev, sizeof(*syncpt) * host->info->nb_pts, | |
315 | GFP_KERNEL); | |
316 | if (!syncpt) | |
317 | return -ENOMEM; | |
318 | ||
319 | for (i = 0; i < host->info->nb_pts; ++i) { | |
320 | syncpt[i].id = i; | |
321 | syncpt[i].host = host; | |
322 | } | |
323 | ||
324 | host->syncpt = syncpt; | |
325 | ||
326 | host1x_syncpt_restore(host); | |
327 | ||
6579324a TB |
328 | /* Allocate sync point to use for clearing waits for expired fences */ |
329 | host->nop_sp = _host1x_syncpt_alloc(host, NULL, 0); | |
330 | if (!host->nop_sp) | |
331 | return -ENOMEM; | |
332 | ||
75471687 TB |
333 | return 0; |
334 | } | |
335 | ||
336 | struct host1x_syncpt *host1x_syncpt_request(struct device *dev, | |
337 | int client_managed) | |
338 | { | |
339 | struct host1x *host = dev_get_drvdata(dev->parent); | |
340 | return _host1x_syncpt_alloc(host, dev, client_managed); | |
341 | } | |
342 | ||
343 | void host1x_syncpt_free(struct host1x_syncpt *sp) | |
344 | { | |
345 | if (!sp) | |
346 | return; | |
347 | ||
348 | kfree(sp->name); | |
349 | sp->dev = NULL; | |
350 | sp->name = NULL; | |
351 | sp->client_managed = 0; | |
352 | } | |
353 | ||
354 | void host1x_syncpt_deinit(struct host1x *host) | |
355 | { | |
356 | int i; | |
357 | struct host1x_syncpt *sp = host->syncpt; | |
358 | for (i = 0; i < host->info->nb_pts; i++, sp++) | |
359 | kfree(sp->name); | |
360 | } | |
361 | ||
362 | int host1x_syncpt_nb_pts(struct host1x *host) | |
363 | { | |
364 | return host->info->nb_pts; | |
365 | } | |
366 | ||
367 | int host1x_syncpt_nb_bases(struct host1x *host) | |
368 | { | |
369 | return host->info->nb_bases; | |
370 | } | |
371 | ||
372 | int host1x_syncpt_nb_mlocks(struct host1x *host) | |
373 | { | |
374 | return host->info->nb_mlocks; | |
375 | } | |
376 | ||
377 | struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, u32 id) | |
378 | { | |
379 | if (host->info->nb_pts < id) | |
380 | return NULL; | |
381 | return host->syncpt + id; | |
382 | } |