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 s64
  27 nvkm_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
  53 void
  54 nvkm_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
  62 u64
  63 nvkm_timer_read(struct nvkm_timer *tmr)
  64 {
  65         return tmr->func->read(tmr);
  66 }
  67
  68 void
  69 nvkm_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 before
  87                  * 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
 105 void
 106 nvkm_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 roughly
 136                          * 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
 144 static void
 145 nvkm_timer_intr(struct nvkm_subdev *subdev)
 146 {
 147         struct nvkm_timer *tmr = nvkm_timer(subdev);
 148         tmr->func->intr(tmr);
 149 }
 150
 151 static int
 152 nvkm_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
 159 static int
 160 nvkm_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
 170 static void *
 171 nvkm_timer_dtor(struct nvkm_subdev *subdev)
 172 {
 173         return nvkm_timer(subdev);
 174 }
 175
 176 static const struct nvkm_subdev_func
 177 nvkm_timer = {
 178         .dtor = nvkm_timer_dtor,
 179         .init = nvkm_timer_init,
 180         .fini = nvkm_timer_fini,
 181         .intr = nvkm_timer_intr,
 182 };
 183
 184 int
 185 nvkm_timer_new_(const struct nvkm_timer_func *func, struct nvkm_device *device,
 186                 int index, 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, index, &tmr->subdev);
 194         tmr->func = func;
 195         INIT_LIST_HEAD(&tmr->alarms);
 196         spin_lock_init(&tmr->lock);
 197         return 0;
 198 }