LXR linux/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
  25s64
  26nvif_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
  49void
  50nvif_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}
  57