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         /* Process pending alarms. */
  40         spin_lock_irqsave(&tmr->lock, flags);
  41         list_for_each_entry_safe(alarm, atemp, &tmr->alarms, head) {
  42                 /* Have we hit the earliest alarm that hasn't gone off? */
  43                 if (alarm->timestamp > nvkm_timer_read(tmr)) {
  44                         /* Schedule it.  If we didn't race, we're done. */
  45                         tmr->func->alarm_init(tmr, alarm->timestamp);
  46                         if (alarm->timestamp > nvkm_timer_read(tmr))
  47                                 break;
  48                 }
  49
  50                 /* Move to completed list.  We'll drop the lock before
  51                  * executing the callback so it can reschedule itself.
  52                  */
  53                 list_move_tail(&alarm->head, &exec);
  54         }
  55
  56         /* Shut down interrupt if no more pending alarms. */
  57         if (list_empty(&tmr->alarms))
  58                 tmr->func->alarm_fini(tmr);
  59         spin_unlock_irqrestore(&tmr->lock, flags);
  60
  61         /* Execute completed callbacks. */
  62         list_for_each_entry_safe(alarm, atemp, &exec, head) {
  63                 list_del_init(&alarm->head);
  64                 alarm->func(alarm);
  65         }
  66 }
  67
  68 void
  69 nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm)
  70 {
  71         struct nvkm_alarm *list;
  72         unsigned long flags;
  73
  74         /* Remove alarm from pending list.
  75          *
  76          * This both protects against the corruption of the list,
  77          * and implements alarm rescheduling/cancellation.
  78          */
  79         spin_lock_irqsave(&tmr->lock, flags);
  80         list_del_init(&alarm->head);
  81
  82         if (nsec) {
  83                 /* Insert into pending list, ordered earliest to latest. */
  84                 alarm->timestamp = nvkm_timer_read(tmr) + nsec;
  85                 list_for_each_entry(list, &tmr->alarms, head) {
  86                         if (list->timestamp > alarm->timestamp)
  87                                 break;
  88                 }
  89                 list_add_tail(&alarm->head, &list->head);
  90         }
  91         spin_unlock_irqrestore(&tmr->lock, flags);
  92
  93         /* process pending alarms */
  94         nvkm_timer_alarm_trigger(tmr);
  95 }
  96
  97 void
  98 nvkm_timer_alarm_cancel(struct nvkm_timer *tmr, struct nvkm_alarm *alarm)
  99 {
 100         unsigned long flags;
 101         spin_lock_irqsave(&tmr->lock, flags);
 102         list_del_init(&alarm->head);
 103         spin_unlock_irqrestore(&tmr->lock, flags);
 104 }
 105
 106 static void
 107 nvkm_timer_intr(struct nvkm_subdev *subdev)
 108 {
 109         struct nvkm_timer *tmr = nvkm_timer(subdev);
 110         tmr->func->intr(tmr);
 111 }
 112
 113 static int
 114 nvkm_timer_fini(struct nvkm_subdev *subdev, bool suspend)
 115 {
 116         struct nvkm_timer *tmr = nvkm_timer(subdev);
 117         tmr->func->alarm_fini(tmr);
 118         return 0;
 119 }
 120
 121 static int
 122 nvkm_timer_init(struct nvkm_subdev *subdev)
 123 {
 124         struct nvkm_timer *tmr = nvkm_timer(subdev);
 125         if (tmr->func->init)
 126                 tmr->func->init(tmr);
 127         tmr->func->time(tmr, ktime_to_ns(ktime_get()));
 128         nvkm_timer_alarm_trigger(tmr);
 129         return 0;
 130 }
 131
 132 static void *
 133 nvkm_timer_dtor(struct nvkm_subdev *subdev)
 134 {
 135         return nvkm_timer(subdev);
 136 }
 137
 138 static const struct nvkm_subdev_func
 139 nvkm_timer = {
 140         .dtor = nvkm_timer_dtor,
 141         .init = nvkm_timer_init,
 142         .fini = nvkm_timer_fini,
 143         .intr = nvkm_timer_intr,
 144 };
 145
 146 int
 147 nvkm_timer_new_(const struct nvkm_timer_func *func, struct nvkm_device *device,
 148                 int index, struct nvkm_timer **ptmr)
 149 {
 150         struct nvkm_timer *tmr;
 151
 152         if (!(tmr = *ptmr = kzalloc(sizeof(*tmr), GFP_KERNEL)))
 153                 return -ENOMEM;
 154
 155         nvkm_subdev_ctor(&nvkm_timer, device, index, &tmr->subdev);
 156         tmr->func = func;
 157         INIT_LIST_HEAD(&tmr->alarms);
 158         spin_lock_init(&tmr->lock);
 159         return 0;
 160 }