cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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timer.c (1758B)


      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}