xref: /openbmc/linux/drivers/gpu/drm/radeon/radeon_mn.c (revision aeb64ff3)
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  */
48 static 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 
82 static 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  */
95 int 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  */
121 void 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 }
128