drivers/gpu/drm/nouveau/nvif/timer.c

   1 /*
   2  * Copyright 2020 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 #include <nvif/timer.h>
  23 #include <nvif/device.h>
  24
  25 s64
  26 nvif_timer_wait_test(struct nvif_timer_wait *wait)
  27 {
  28         u64 time = nvif_device_time(wait->device);
  29
  30         if (wait->reads == 0) {
  31                 wait->time0 = time;
  32                 wait->time1 = time;
  33         }
  34
  35         if (wait->time1 == time) {
  36                 if (WARN_ON(wait->reads++ == 16))
  37                         return -ETIMEDOUT;
  38         } else {
  39                 wait->time1 = time;
  40                 wait->reads = 1;
  41         }
  42
  43         if (wait->time1 - wait->time0 > wait->limit)
  44                 return -ETIMEDOUT;
  45
  46         return wait->time1 - wait->time0;
  47 }
  48
  49 void
  50 nvif_timer_wait_init(struct nvif_device *device, u64 nsec,
  51                      struct nvif_timer_wait *wait)
  52 {
  53         wait->device = device;
  54         wait->limit = nsec;
  55         wait->reads = 0;
  56 }