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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radeon_mn.c (3909B)

      1/*
      2 * Copyright 2014 Advanced Micro Devices, Inc.
      3 * All Rights Reserved.
      4 *
      5 * Permission is hereby granted, free of charge, to any person obtaining a
      6 * copy of this software and associated documentation files (the
      7 * "Software"), to deal in the Software without restriction, including
      8 * without limitation the rights to use, copy, modify, merge, publish,
      9 * distribute, sub license, and/or sell copies of the Software, and to
     10 * permit persons to whom the Software is furnished to do so, subject to
     11 * the following conditions:
     12 *
     13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     15 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
     16 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
     17 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
     18 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
     19 * USE OR OTHER DEALINGS IN THE SOFTWARE.
     20 *
     21 * The above copyright notice and this permission notice (including the
     22 * next paragraph) shall be included in all copies or substantial portions
     23 * of the Software.
     24 *
     25 */
     26/*
     27 * Authors:
     28 *    Christian König <christian.koenig@amd.com>
     29 */
     30
     31#include <linux/firmware.h>
     32#include <linux/module.h>
     33#include <linux/mmu_notifier.h>
     34
     35#include <drm/drm.h>
     36
     37#include "radeon.h"
     38
     39/**
     40 * radeon_mn_invalidate - callback to notify about mm change
     41 *
     42 * @mn: our notifier
     43 * @range: the VMA under invalidation
     44 * @cur_seq: Value to pass to mmu_interval_set_seq()
     45 *
     46 * We block for all BOs between start and end to be idle and
     47 * unmap them by move them into system domain again.
     48 */
     49static bool radeon_mn_invalidate(struct mmu_interval_notifier *mn,
     50				 const struct mmu_notifier_range *range,
     51				 unsigned long cur_seq)
     52{
     53	struct radeon_bo *bo = container_of(mn, struct radeon_bo, notifier);
     54	struct ttm_operation_ctx ctx = { false, false };
     55	long r;
     56
     57	if (!bo->tbo.ttm || !radeon_ttm_tt_is_bound(bo->tbo.bdev, bo->tbo.ttm))
     58		return true;
     59
     60	if (!mmu_notifier_range_blockable(range))
     61		return false;
     62
     63	r = radeon_bo_reserve(bo, true);
     64	if (r) {
     65		DRM_ERROR("(%ld) failed to reserve user bo\n", r);
     66		return true;
     67	}
     68
     69	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_BOOKKEEP,
     70				  false, MAX_SCHEDULE_TIMEOUT);
     71	if (r <= 0)
     72		DRM_ERROR("(%ld) failed to wait for user bo\n", r);
     73
     74	radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
     75	r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
     76	if (r)
     77		DRM_ERROR("(%ld) failed to validate user bo\n", r);
     78
     79	radeon_bo_unreserve(bo);
     80	return true;
     81}
     82
     83static const struct mmu_interval_notifier_ops radeon_mn_ops = {
     84	.invalidate = radeon_mn_invalidate,
     85};
     86
     87/**
     88 * radeon_mn_register - register a BO for notifier updates
     89 *
     90 * @bo: radeon buffer object
     91 * @addr: userptr addr we should monitor
     92 *
     93 * Registers an MMU notifier for the given BO at the specified address.
     94 * Returns 0 on success, -ERRNO if anything goes wrong.
     95 */
     96int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
     97{
     98	int ret;
     99
    100	ret = mmu_interval_notifier_insert(&bo->notifier, current->mm, addr,
    101					   radeon_bo_size(bo), &radeon_mn_ops);
    102	if (ret)
    103		return ret;
    104
    105	/*
    106	 * FIXME: radeon appears to allow get_user_pages to run during
    107	 * invalidate_range_start/end, which is not a safe way to read the
    108	 * PTEs. It should use the mmu_interval_read_begin() scheme around the
    109	 * get_user_pages to ensure that the PTEs are read properly
    110	 */
    111	mmu_interval_read_begin(&bo->notifier);
    112	return 0;
    113}
    114
    115/**
    116 * radeon_mn_unregister - unregister a BO for notifier updates
    117 *
    118 * @bo: radeon buffer object
    119 *
    120 * Remove any registration of MMU notifier updates from the buffer object.
    121 */
    122void radeon_mn_unregister(struct radeon_bo *bo)
    123{
    124	if (!bo->notifier.mm)
    125		return;
    126	mmu_interval_notifier_remove(&bo->notifier);
    127	bo->notifier.mm = NULL;
    128}