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 "radeon.h"
32#include "radeon_trace.h"
33
34/**
35 * radeon_sync_create - zero init sync object
36 *
37 * @sync: sync object to initialize
38 *
39 * Just clear the sync object for now.
40 */
41void radeon_sync_create(struct radeon_sync *sync)
42{
43 unsigned i;
44
45 for (i = 0; i < RADEON_NUM_SYNCS; ++i)
46 sync->semaphores[i] = NULL;
47
48 for (i = 0; i < RADEON_NUM_RINGS; ++i)
49 sync->sync_to[i] = NULL;
50
51 sync->last_vm_update = NULL;
52}
53
54/**
55 * radeon_sync_fence - use the semaphore to sync to a fence
56 *
57 * @sync: sync object to add fence to
58 * @fence: fence to sync to
59 *
60 * Sync to the fence using the semaphore objects
61 */
62void radeon_sync_fence(struct radeon_sync *sync,
63 struct radeon_fence *fence)
64{
65 struct radeon_fence *other;
66
67 if (!fence)
68 return;
69
70 other = sync->sync_to[fence->ring];
71 sync->sync_to[fence->ring] = radeon_fence_later(a: fence, b: other);
72
73 if (fence->is_vm_update) {
74 other = sync->last_vm_update;
75 sync->last_vm_update = radeon_fence_later(a: fence, b: other);
76 }
77}
78
79/**
80 * radeon_sync_resv - use the semaphores to sync to a reservation object
81 *
82 * @rdev: radeon_device pointer
83 * @sync: sync object to add fences from reservation object to
84 * @resv: reservation object with embedded fence
85 * @shared: true if we should only sync to the exclusive fence
86 *
87 * Sync to the fence using the semaphore objects
88 */
89int radeon_sync_resv(struct radeon_device *rdev,
90 struct radeon_sync *sync,
91 struct dma_resv *resv,
92 bool shared)
93{
94 struct dma_resv_iter cursor;
95 struct radeon_fence *fence;
96 struct dma_fence *f;
97 int r = 0;
98
99 dma_resv_for_each_fence(&cursor, resv, dma_resv_usage_rw(!shared), f) {
100 fence = to_radeon_fence(f);
101 if (fence && fence->rdev == rdev)
102 radeon_sync_fence(sync, fence);
103 else
104 r = dma_fence_wait(fence: f, intr: true);
105 if (r)
106 break;
107 }
108 return r;
109}
110
111/**
112 * radeon_sync_rings - sync ring to all registered fences
113 *
114 * @rdev: radeon_device pointer
115 * @sync: sync object to use
116 * @ring: ring that needs sync
117 *
118 * Ensure that all registered fences are signaled before letting
119 * the ring continue. The caller must hold the ring lock.
120 */
121int radeon_sync_rings(struct radeon_device *rdev,
122 struct radeon_sync *sync,
123 int ring)
124{
125 unsigned count = 0;
126 int i, r;
127
128 for (i = 0; i < RADEON_NUM_RINGS; ++i) {
129 struct radeon_fence *fence = sync->sync_to[i];
130 struct radeon_semaphore *semaphore;
131
132 /* check if we really need to sync */
133 if (!radeon_fence_need_sync(fence, ring))
134 continue;
135
136 /* prevent GPU deadlocks */
137 if (!rdev->ring[i].ready) {
138 dev_err(rdev->dev, "Syncing to a disabled ring!");
139 return -EINVAL;
140 }
141
142 if (count >= RADEON_NUM_SYNCS) {
143 /* not enough room, wait manually */
144 r = radeon_fence_wait(fence, interruptible: false);
145 if (r)
146 return r;
147 continue;
148 }
149 r = radeon_semaphore_create(rdev, semaphore: &semaphore);
150 if (r)
151 return r;
152
153 sync->semaphores[count++] = semaphore;
154
155 /* allocate enough space for sync command */
156 r = radeon_ring_alloc(rdev, cp: &rdev->ring[i], ndw: 16);
157 if (r)
158 return r;
159
160 /* emit the signal semaphore */
161 if (!radeon_semaphore_emit_signal(rdev, ring: i, semaphore)) {
162 /* signaling wasn't successful wait manually */
163 radeon_ring_undo(ring: &rdev->ring[i]);
164 r = radeon_fence_wait(fence, interruptible: false);
165 if (r)
166 return r;
167 continue;
168 }
169
170 /* we assume caller has already allocated space on waiters ring */
171 if (!radeon_semaphore_emit_wait(rdev, ring, semaphore)) {
172 /* waiting wasn't successful wait manually */
173 radeon_ring_undo(ring: &rdev->ring[i]);
174 r = radeon_fence_wait(fence, interruptible: false);
175 if (r)
176 return r;
177 continue;
178 }
179
180 radeon_ring_commit(rdev, cp: &rdev->ring[i], hdp_flush: false);
181 radeon_fence_note_sync(fence, ring);
182 }
183
184 return 0;
185}
186
187/**
188 * radeon_sync_free - free the sync object
189 *
190 * @rdev: radeon_device pointer
191 * @sync: sync object to use
192 * @fence: fence to use for the free
193 *
194 * Free the sync object by freeing all semaphores in it.
195 */
196void radeon_sync_free(struct radeon_device *rdev,
197 struct radeon_sync *sync,
198 struct radeon_fence *fence)
199{
200 unsigned i;
201
202 for (i = 0; i < RADEON_NUM_SYNCS; ++i)
203 radeon_semaphore_free(rdev, semaphore: &sync->semaphores[i], fence);
204}
205

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