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(bdev: bo->tbo.bdev, ttm: bo->tbo.ttm))
58 return true;
59
60 if (!mmu_notifier_range_blockable(range))
61 return false;
62
63 r = radeon_bo_reserve(bo, no_intr: 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(obj: bo->tbo.base.resv, usage: DMA_RESV_USAGE_BOOKKEEP,
70 intr: 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(rbo: bo, RADEON_GEM_DOMAIN_CPU);
75 r = ttm_bo_validate(bo: &bo->tbo, placement: &bo->placement, ctx: &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(interval_sub: &bo->notifier, current->mm, start: addr,
101 length: radeon_bo_size(bo), ops: &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(interval_sub: &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(interval_sub: &bo->notifier);
127 bo->notifier.mm = NULL;
128}
129

source code of linux/drivers/gpu/drm/radeon/radeon_mn.c