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1/*2 * Copyright 2012 Red Hat Inc.3 *4 * Permission is hereby granted, free of charge, to any person obtaining a5 * copy of this software and associated documentation files (the "Software"),6 * to deal in the Software without restriction, including without limitation7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,8 * and/or sell copies of the Software, and to permit persons to whom the9 * Software is furnished to do so, subject to the following conditions:10 *11 * The above copyright notice and this permission notice shall be included in12 * all copies or substantial portions of the Software.13 *14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR20 * OTHER DEALINGS IN THE SOFTWARE.21 *22 * Authors: Ben Skeggs23 */24#include "priv.h"25 26s6427nvkm_timer_wait_test(struct nvkm_timer_wait *wait)28{29 struct nvkm_subdev *subdev = &wait->tmr->subdev;30 u64 time = nvkm_timer_read(wait->tmr);31 32 if (wait->reads == 0) {33 wait->time0 = time;34 wait->time1 = time;35 }36 37 if (wait->time1 == time) {38 if (wait->reads++ == 16) {39 nvkm_fatal(subdev, "stalled at %016llx\n", time);40 return -ETIMEDOUT;41 }42 } else {43 wait->time1 = time;44 wait->reads = 1;45 }46 47 if (wait->time1 - wait->time0 > wait->limit)48 return -ETIMEDOUT;49 50 return wait->time1 - wait->time0;51}52 53void54nvkm_timer_wait_init(struct nvkm_device *device, u64 nsec,55 struct nvkm_timer_wait *wait)56{57 wait->tmr = device->timer;58 wait->limit = nsec;59 wait->reads = 0;60}61 62u6463nvkm_timer_read(struct nvkm_timer *tmr)64{65 return tmr->func->read(tmr);66}67 68void69nvkm_timer_alarm_trigger(struct nvkm_timer *tmr)70{71 struct nvkm_alarm *alarm, *atemp;72 unsigned long flags;73 LIST_HEAD(exec);74 75 /* Process pending alarms. */76 spin_lock_irqsave(&tmr->lock, flags);77 list_for_each_entry_safe(alarm, atemp, &tmr->alarms, head) {78 /* Have we hit the earliest alarm that hasn't gone off? */79 if (alarm->timestamp > nvkm_timer_read(tmr)) {80 /* Schedule it. If we didn't race, we're done. */81 tmr->func->alarm_init(tmr, alarm->timestamp);82 if (alarm->timestamp > nvkm_timer_read(tmr))83 break;84 }85 86 /* Move to completed list. We'll drop the lock before87 * executing the callback so it can reschedule itself.88 */89 list_del_init(&alarm->head);90 list_add(&alarm->exec, &exec);91 }92 93 /* Shut down interrupt if no more pending alarms. */94 if (list_empty(&tmr->alarms))95 tmr->func->alarm_fini(tmr);96 spin_unlock_irqrestore(&tmr->lock, flags);97 98 /* Execute completed callbacks. */99 list_for_each_entry_safe(alarm, atemp, &exec, exec) {100 list_del(&alarm->exec);101 alarm->func(alarm);102 }103}104 105void106nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm)107{108 struct nvkm_alarm *list;109 unsigned long flags;110 111 /* Remove alarm from pending list.112 *113 * This both protects against the corruption of the list,114 * and implements alarm rescheduling/cancellation.115 */116 spin_lock_irqsave(&tmr->lock, flags);117 list_del_init(&alarm->head);118 119 if (nsec) {120 /* Insert into pending list, ordered earliest to latest. */121 alarm->timestamp = nvkm_timer_read(tmr) + nsec;122 list_for_each_entry(list, &tmr->alarms, head) {123 if (list->timestamp > alarm->timestamp)124 break;125 }126 127 list_add_tail(&alarm->head, &list->head);128 129 /* Update HW if this is now the earliest alarm. */130 list = list_first_entry(&tmr->alarms, typeof(*list), head);131 if (list == alarm) {132 tmr->func->alarm_init(tmr, alarm->timestamp);133 /* This shouldn't happen if callers aren't stupid.134 *135 * Worst case scenario is that it'll take roughly136 * 4 seconds for the next alarm to trigger.137 */138 WARN_ON(alarm->timestamp <= nvkm_timer_read(tmr));139 }140 }141 spin_unlock_irqrestore(&tmr->lock, flags);142}143 144static void145nvkm_timer_intr(struct nvkm_subdev *subdev)146{147 struct nvkm_timer *tmr = nvkm_timer(subdev);148 tmr->func->intr(tmr);149}150 151static int152nvkm_timer_fini(struct nvkm_subdev *subdev, bool suspend)153{154 struct nvkm_timer *tmr = nvkm_timer(subdev);155 tmr->func->alarm_fini(tmr);156 return 0;157}158 159static int160nvkm_timer_init(struct nvkm_subdev *subdev)161{162 struct nvkm_timer *tmr = nvkm_timer(subdev);163 if (tmr->func->init)164 tmr->func->init(tmr);165 tmr->func->time(tmr, ktime_to_ns(ktime_get()));166 nvkm_timer_alarm_trigger(tmr);167 return 0;168}169 170static void *171nvkm_timer_dtor(struct nvkm_subdev *subdev)172{173 return nvkm_timer(subdev);174}175 176static const struct nvkm_subdev_func177nvkm_timer = {178 .dtor = nvkm_timer_dtor,179 .init = nvkm_timer_init,180 .fini = nvkm_timer_fini,181 .intr = nvkm_timer_intr,182};183 184int185nvkm_timer_new_(const struct nvkm_timer_func *func, struct nvkm_device *device,186 enum nvkm_subdev_type type, int inst, struct nvkm_timer **ptmr)187{188 struct nvkm_timer *tmr;189 190 if (!(tmr = *ptmr = kzalloc(sizeof(*tmr), GFP_KERNEL)))191 return -ENOMEM;192 193 nvkm_subdev_ctor(&nvkm_timer, device, type, inst, &tmr->subdev);194 tmr->func = func;195 INIT_LIST_HEAD(&tmr->alarms);196 spin_lock_init(&tmr->lock);197 return 0;198}199