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}