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 *
 45 * We block for all BOs between start and end to be idle and
 46 * unmap them by move them into system domain again.
 47 */
 48static bool radeon_mn_invalidate(struct mmu_interval_notifier *mn,
 49				 const struct mmu_notifier_range *range,
 50				 unsigned long cur_seq)
 51{
 52	struct radeon_bo *bo = container_of(mn, struct radeon_bo, notifier);
 53	struct ttm_operation_ctx ctx = { false, false };
 54	long r;
 55
 56	if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
 57		return true;
 58
 59	if (!mmu_notifier_range_blockable(range))
 60		return false;
 61
 62	r = radeon_bo_reserve(bo, true);
 63	if (r) {
 64		DRM_ERROR("(%ld) failed to reserve user bo\n", r);
 65		return true;
 66	}
 67
 68	r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
 69				      MAX_SCHEDULE_TIMEOUT);
 70	if (r <= 0)
 71		DRM_ERROR("(%ld) failed to wait for user bo\n", r);
 72
 73	radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
 74	r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
 75	if (r)
 76		DRM_ERROR("(%ld) failed to validate user bo\n", r);
 77
 78	radeon_bo_unreserve(bo);
 79	return true;
 80}
 81
 82static const struct mmu_interval_notifier_ops radeon_mn_ops = {
 83	.invalidate = radeon_mn_invalidate,
 84};
 85
 86/**
 87 * radeon_mn_register - register a BO for notifier updates
 88 *
 89 * @bo: radeon buffer object
 90 * @addr: userptr addr we should monitor
 91 *
 92 * Registers an MMU notifier for the given BO at the specified address.
 93 * Returns 0 on success, -ERRNO if anything goes wrong.
 94 */
 95int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
 96{
 97	int ret;
 98
 99	ret = mmu_interval_notifier_insert(&bo->notifier, current->mm, addr,
100					   radeon_bo_size(bo), &radeon_mn_ops);
101	if (ret)
102		return ret;
103
104	/*
105	 * FIXME: radeon appears to allow get_user_pages to run during
106	 * invalidate_range_start/end, which is not a safe way to read the
107	 * PTEs. It should use the mmu_interval_read_begin() scheme around the
108	 * get_user_pages to ensure that the PTEs are read properly
109	 */
110	mmu_interval_read_begin(&bo->notifier);
111	return 0;
112}
113
114/**
115 * radeon_mn_unregister - unregister a BO for notifier updates
116 *
117 * @bo: radeon buffer object
118 *
119 * Remove any registration of MMU notifier updates from the buffer object.
120 */
121void radeon_mn_unregister(struct radeon_bo *bo)
122{
123	if (!bo->notifier.mm)
124		return;
125	mmu_interval_notifier_remove(&bo->notifier);
126	bo->notifier.mm = NULL;
127}