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/*
* Copyright 2012 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: Ben Skeggs
*/
#include "priv.h"
u64
nvkm_timer_read(struct nvkm_timer *tmr)
{
return tmr->func->read(tmr);
}
void
nvkm_timer_alarm_trigger(struct nvkm_timer *tmr)
{
struct nvkm_alarm *alarm, *atemp;
unsigned long flags;
LIST_HEAD(exec);
/* Process pending alarms. */
spin_lock_irqsave(&tmr->lock, flags);
list_for_each_entry_safe(alarm, atemp, &tmr->alarms, head) {
/* Have we hit the earliest alarm that hasn't gone off? */
if (alarm->timestamp > nvkm_timer_read(tmr)) {
/* Schedule it. If we didn't race, we're done. */
tmr->func->alarm_init(tmr, alarm->timestamp);
if (alarm->timestamp > nvkm_timer_read(tmr))
break;
}
/* Move to completed list. We'll drop the lock before
* executing the callback so it can reschedule itself.
*/
list_del_init(&alarm->head);
list_add(&alarm->exec, &exec);
}
/* Shut down interrupt if no more pending alarms. */
if (list_empty(&tmr->alarms))
tmr->func->alarm_fini(tmr);
spin_unlock_irqrestore(&tmr->lock, flags);
/* Execute completed callbacks. */
list_for_each_entry_safe(alarm, atemp, &exec, exec) {
list_del(&alarm->exec);
alarm->func(alarm);
}
}
void
nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm)
{
struct nvkm_alarm *list;
unsigned long flags;
/* Remove alarm from pending list.
*
* This both protects against the corruption of the list,
* and implements alarm rescheduling/cancellation.
*/
spin_lock_irqsave(&tmr->lock, flags);
list_del_init(&alarm->head);
if (nsec) {
/* Insert into pending list, ordered earliest to latest. */
alarm->timestamp = nvkm_timer_read(tmr) + nsec;
list_for_each_entry(list, &tmr->alarms, head) {
if (list->timestamp > alarm->timestamp)
break;
}
list_add_tail(&alarm->head, &list->head);
/* Update HW if this is now the earliest alarm. */
list = list_first_entry(&tmr->alarms, typeof(*list), head);
if (list == alarm) {
tmr->func->alarm_init(tmr, alarm->timestamp);
/* This shouldn't happen if callers aren't stupid.
*
* Worst case scenario is that it'll take roughly
* 4 seconds for the next alarm to trigger.
*/
WARN_ON(alarm->timestamp <= nvkm_timer_read(tmr));
}
}
spin_unlock_irqrestore(&tmr->lock, flags);
}
void
nvkm_timer_alarm_cancel(struct nvkm_timer *tmr, struct nvkm_alarm *alarm)
{
unsigned long flags;
spin_lock_irqsave(&tmr->lock, flags);
list_del_init(&alarm->head);
spin_unlock_irqrestore(&tmr->lock, flags);
}
static void
nvkm_timer_intr(struct nvkm_subdev *subdev)
{
struct nvkm_timer *tmr = nvkm_timer(subdev);
tmr->func->intr(tmr);
}
static int
nvkm_timer_fini(struct nvkm_subdev *subdev, bool suspend)
{
struct nvkm_timer *tmr = nvkm_timer(subdev);
tmr->func->alarm_fini(tmr);
return 0;
}
static int
nvkm_timer_init(struct nvkm_subdev *subdev)
{
struct nvkm_timer *tmr = nvkm_timer(subdev);
if (tmr->func->init)
tmr->func->init(tmr);
tmr->func->time(tmr, ktime_to_ns(ktime_get()));
nvkm_timer_alarm_trigger(tmr);
return 0;
}
static void *
nvkm_timer_dtor(struct nvkm_subdev *subdev)
{
return nvkm_timer(subdev);
}
static const struct nvkm_subdev_func
nvkm_timer = {
.dtor = nvkm_timer_dtor,
.init = nvkm_timer_init,
.fini = nvkm_timer_fini,
.intr = nvkm_timer_intr,
};
int
nvkm_timer_new_(const struct nvkm_timer_func *func, struct nvkm_device *device,
int index, struct nvkm_timer **ptmr)
{
struct nvkm_timer *tmr;
if (!(tmr = *ptmr = kzalloc(sizeof(*tmr), GFP_KERNEL)))
return -ENOMEM;
nvkm_subdev_ctor(&nvkm_timer, device, index, 0, &tmr->subdev);
tmr->func = func;
INIT_LIST_HEAD(&tmr->alarms);
spin_lock_init(&tmr->lock);
return 0;
}
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