kernel/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c

   1 /*
   2  * Copyright 2012 Red Hat Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * 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 OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors: Ben Skeggs
  23  */
  24 #include "priv.h"
  25
  26 u64
  27 nvkm_timer_read(struct nvkm_timer *tmr)
  28 {
  29         return tmr->func->read(tmr);
  30 }
  31
  32 void
  33 nvkm_timer_alarm_trigger(struct nvkm_timer *tmr)
  34 {
  35         struct nvkm_alarm *alarm, *atemp;
  36         unsigned long flags;
  37         LIST_HEAD(exec);
  38
  39         /* move any due alarms off the pending list */
  40         spin_lock_irqsave(&tmr->lock, flags);
  41         list_for_each_entry_safe(alarm, atemp, &tmr->alarms, head) {
  42                 if (alarm->timestamp <= nvkm_timer_read(tmr))
  43                         list_move_tail(&alarm->head, &exec);
  44         }
  45
  46         /* reschedule interrupt for next alarm time */
  47         if (!list_empty(&tmr->alarms)) {
  48                 alarm = list_first_entry(&tmr->alarms, typeof(*alarm), head);
  49                 tmr->func->alarm_init(tmr, alarm->timestamp);
  50         } else {
  51                 tmr->func->alarm_fini(tmr);
  52         }
  53         spin_unlock_irqrestore(&tmr->lock, flags);
  54
  55         /* execute any pending alarm handlers */
  56         list_for_each_entry_safe(alarm, atemp, &exec, head) {
  57                 list_del_init(&alarm->head);
  58                 alarm->func(alarm);
  59         }
  60 }
  61
  62 void
  63 nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm)
  64 {
  65         struct nvkm_alarm *list;
  66         unsigned long flags;
  67
  68         alarm->timestamp = nvkm_timer_read(tmr) + nsec;
  69
  70         /* append new alarm to list, in soonest-alarm-first order */
  71         spin_lock_irqsave(&tmr->lock, flags);
  72         if (!nsec) {
  73                 if (!list_empty(&alarm->head))
  74                         list_del(&alarm->head);
  75         } else {
  76                 list_for_each_entry(list, &tmr->alarms, head) {
  77                         if (list->timestamp > alarm->timestamp)
  78                                 break;
  79                 }
  80                 list_add_tail(&alarm->head, &list->head);
  81         }
  82         spin_unlock_irqrestore(&tmr->lock, flags);
  83
  84         /* process pending alarms */
  85         nvkm_timer_alarm_trigger(tmr);
  86 }
  87
  88 void
  89 nvkm_timer_alarm_cancel(struct nvkm_timer *tmr, struct nvkm_alarm *alarm)
  90 {
  91         unsigned long flags;
  92         spin_lock_irqsave(&tmr->lock, flags);
  93         list_del_init(&alarm->head);
  94         spin_unlock_irqrestore(&tmr->lock, flags);
  95 }
  96
  97 static void
  98 nvkm_timer_intr(struct nvkm_subdev *subdev)
  99 {
 100         struct nvkm_timer *tmr = nvkm_timer(subdev);
 101         tmr->func->intr(tmr);
 102 }
 103
 104 static int
 105 nvkm_timer_fini(struct nvkm_subdev *subdev, bool suspend)
 106 {
 107         struct nvkm_timer *tmr = nvkm_timer(subdev);
 108         tmr->func->alarm_fini(tmr);
 109         return 0;
 110 }
 111
 112 static int
 113 nvkm_timer_init(struct nvkm_subdev *subdev)
 114 {
 115         struct nvkm_timer *tmr = nvkm_timer(subdev);
 116         if (tmr->func->init)
 117                 tmr->func->init(tmr);
 118         tmr->func->time(tmr, ktime_to_ns(ktime_get()));
 119         nvkm_timer_alarm_trigger(tmr);
 120         return 0;
 121 }
 122
 123 static void *
 124 nvkm_timer_dtor(struct nvkm_subdev *subdev)
 125 {
 126         return nvkm_timer(subdev);
 127 }
 128
 129 static const struct nvkm_subdev_func
 130 nvkm_timer = {
 131         .dtor = nvkm_timer_dtor,
 132         .init = nvkm_timer_init,
 133         .fini = nvkm_timer_fini,
 134         .intr = nvkm_timer_intr,
 135 };
 136
 137 int
 138 nvkm_timer_new_(const struct nvkm_timer_func *func, struct nvkm_device *device,
 139                 int index, struct nvkm_timer **ptmr)
 140 {
 141         struct nvkm_timer *tmr;
 142
 143         if (!(tmr = *ptmr = kzalloc(sizeof(*tmr), GFP_KERNEL)))
 144                 return -ENOMEM;
 145
 146         nvkm_subdev_ctor(&nvkm_timer, device, index, 0, &tmr->subdev);
 147         tmr->func = func;
 148         INIT_LIST_HEAD(&tmr->alarms);
 149         spin_lock_init(&tmr->lock);
 150         return 0;
 151 }