2 * Tegra host1x Syncpoints
4 * Copyright (c) 2010-2013, 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 *_host1x_syncpt_alloc(struct host1x *host,
38 struct host1x_syncpt *sp = host->syncpt;
41 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
44 if (i >= host->info->nb_pts)
47 name = kasprintf(GFP_KERNEL, "%02d-%s", sp->id,
48 dev ? dev_name(dev) : NULL);
54 sp->client_managed = client_managed;
59 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
65 * Updates the value sent to hardware.
67 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
69 return (u32)atomic_add_return(incrs, &sp->max_val);
73 * Write cached syncpoint and waitbase values to hardware.
75 void host1x_syncpt_restore(struct host1x *host)
77 struct host1x_syncpt *sp_base = host->syncpt;
80 for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
81 host1x_hw_syncpt_restore(host, sp_base + i);
82 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
83 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
88 * Update the cached syncpoint and waitbase values by reading them
91 void host1x_syncpt_save(struct host1x *host)
93 struct host1x_syncpt *sp_base = host->syncpt;
96 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
97 if (host1x_syncpt_client_managed(sp_base + i))
98 host1x_hw_syncpt_load(host, sp_base + i);
100 WARN_ON(!host1x_syncpt_idle(sp_base + i));
103 for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
104 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
108 * Updates the cached syncpoint value by reading a new value from the hardware
111 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
114 val = host1x_hw_syncpt_load(sp->host, sp);
115 trace_host1x_syncpt_load_min(sp->id, val);
121 * Get the current syncpoint base
123 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
126 host1x_hw_syncpt_load_wait_base(sp->host, sp);
132 * Increment syncpoint value from cpu, updating cache
134 int host1x_syncpt_incr(struct host1x_syncpt *sp)
136 return host1x_hw_syncpt_cpu_incr(sp->host, sp);
140 * Updated sync point form hardware, and returns true if syncpoint is expired,
141 * false if we may need to wait
143 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
145 host1x_hw_syncpt_load(sp->host, sp);
146 return host1x_syncpt_is_expired(sp, thresh);
150 * Main entrypoint for syncpoint value waits.
152 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
155 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
157 struct host1x_waitlist *waiter;
158 int err = 0, check_count = 0;
164 /* first check cache */
165 if (host1x_syncpt_is_expired(sp, thresh)) {
167 *value = host1x_syncpt_load(sp);
171 /* try to read from register */
172 val = host1x_hw_syncpt_load(sp->host, sp);
173 if (host1x_syncpt_is_expired(sp, thresh)) {
184 /* allocate a waiter */
185 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
191 /* schedule a wakeup when the syncpoint value is reached */
192 err = host1x_intr_add_action(sp->host, sp->id, thresh,
193 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
199 /* Caller-specified timeout may be impractically low */
203 /* wait for the syncpoint, or timeout, or signal */
205 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
206 int remain = wait_event_interruptible_timeout(wq,
207 syncpt_load_min_is_expired(sp, thresh),
209 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
211 *value = host1x_syncpt_load(sp);
220 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
221 dev_warn(sp->host->dev,
222 "%s: syncpoint id %d (%s) stuck waiting %d, timeout=%ld\n",
223 current->comm, sp->id, sp->name,
226 host1x_debug_dump_syncpts(sp->host);
227 if (check_count == MAX_STUCK_CHECK_COUNT)
228 host1x_debug_dump(sp->host);
232 host1x_intr_put_ref(sp->host, sp->id, ref);
237 EXPORT_SYMBOL(host1x_syncpt_wait);
240 * Returns true if syncpoint is expired, false if we may need to wait
242 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
247 current_val = (u32)atomic_read(&sp->min_val);
248 future_val = (u32)atomic_read(&sp->max_val);
250 /* Note the use of unsigned arithmetic here (mod 1<<32).
252 * c = current_val = min_val = the current value of the syncpoint.
253 * t = thresh = the value we are checking
254 * f = future_val = max_val = the value c will reach when all
255 * outstanding increments have completed.
257 * Note that c always chases f until it reaches f.
262 * Consider all cases:
264 * A) .....c..t..f..... Dtf < Dtc need to wait
265 * B) .....c.....f..t.. Dtf > Dtc expired
266 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large)
268 * Any case where f==c: always expired (for any t). Dtf == Dcf
269 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0)
270 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0,
275 * A) .....t..f..c..... Dtf < Dtc need to wait
276 * A) .....f..c..t..... Dtf < Dtc need to wait
277 * A) .....f..t..c..... Dtf > Dtc expired
280 * Dtf >= Dtc implies EXPIRED (return true)
281 * Dtf < Dtc implies WAIT (return false)
283 * Note: If t is expired then we *cannot* wait on it. We would wait
284 * forever (hang the system).
286 * Note: do NOT get clever and remove the -thresh from both sides. It
289 * If future valueis zero, we have a client managed sync point. In that
290 * case we do a direct comparison.
292 if (!host1x_syncpt_client_managed(sp))
293 return future_val - thresh >= current_val - thresh;
295 return (s32)(current_val - thresh) >= 0;
298 /* remove a wait pointed to by patch_addr */
299 int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr)
301 return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr);
304 int host1x_syncpt_init(struct host1x *host)
306 struct host1x_syncpt *syncpt;
309 syncpt = devm_kzalloc(host->dev, sizeof(*syncpt) * host->info->nb_pts,
314 for (i = 0; i < host->info->nb_pts; ++i) {
316 syncpt[i].host = host;
319 host->syncpt = syncpt;
321 host1x_syncpt_restore(host);
323 /* Allocate sync point to use for clearing waits for expired fences */
324 host->nop_sp = _host1x_syncpt_alloc(host, NULL, false);
331 struct host1x_syncpt *host1x_syncpt_request(struct device *dev,
334 struct host1x *host = dev_get_drvdata(dev->parent);
335 return _host1x_syncpt_alloc(host, dev, client_managed);
338 void host1x_syncpt_free(struct host1x_syncpt *sp)
346 sp->client_managed = false;
349 void host1x_syncpt_deinit(struct host1x *host)
352 struct host1x_syncpt *sp = host->syncpt;
353 for (i = 0; i < host->info->nb_pts; i++, sp++)
357 int host1x_syncpt_nb_pts(struct host1x *host)
359 return host->info->nb_pts;
362 int host1x_syncpt_nb_bases(struct host1x *host)
364 return host->info->nb_bases;
367 int host1x_syncpt_nb_mlocks(struct host1x *host)
369 return host->info->nb_mlocks;
372 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, u32 id)
374 if (host->info->nb_pts < id)
376 return host->syncpt + id;