tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright 2015 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 */
23
24#include <linux/kthread.h>
25#include <linux/wait.h>
26#include <linux/sched.h>
27#include <drm/drmP.h>
28#include <drm/gpu_scheduler.h>
29
30static struct kmem_cache *sched_fence_slab;
31
32static int __init drm_sched_fence_slab_init(void)
33{
34 sched_fence_slab = kmem_cache_create(
35 "drm_sched_fence", sizeof(struct drm_sched_fence), 0,
36 SLAB_HWCACHE_ALIGN, NULL);
37 if (!sched_fence_slab)
38 return -ENOMEM;
39
40 return 0;
41}
42
43static void __exit drm_sched_fence_slab_fini(void)
44{
45 rcu_barrier();
46 kmem_cache_destroy(sched_fence_slab);
47}
48
49void drm_sched_fence_scheduled(struct drm_sched_fence *fence)
50{
51 int ret = dma_fence_signal(&fence->scheduled);
52
53 if (!ret)
54 DMA_FENCE_TRACE(&fence->scheduled,
55 "signaled from irq context\n");
56 else
57 DMA_FENCE_TRACE(&fence->scheduled,
58 "was already signaled\n");
59}
60
61void drm_sched_fence_finished(struct drm_sched_fence *fence)
62{
63 int ret = dma_fence_signal(&fence->finished);
64
65 if (!ret)
66 DMA_FENCE_TRACE(&fence->finished,
67 "signaled from irq context\n");
68 else
69 DMA_FENCE_TRACE(&fence->finished,
70 "was already signaled\n");
71}
72
73static const char *drm_sched_fence_get_driver_name(struct dma_fence *fence)
74{
75 return "drm_sched";
76}
77
78static const char *drm_sched_fence_get_timeline_name(struct dma_fence *f)
79{
80 struct drm_sched_fence *fence = to_drm_sched_fence(f);
81 return (const char *)fence->sched->name;
82}
83
84/**
85 * drm_sched_fence_free - free up the fence memory
86 *
87 * @rcu: RCU callback head
88 *
89 * Free up the fence memory after the RCU grace period.
90 */
91static void drm_sched_fence_free(struct rcu_head *rcu)
92{
93 struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
94 struct drm_sched_fence *fence = to_drm_sched_fence(f);
95
96 kmem_cache_free(sched_fence_slab, fence);
97}
98
99/**
100 * drm_sched_fence_release_scheduled - callback that fence can be freed
101 *
102 * @fence: fence
103 *
104 * This function is called when the reference count becomes zero.
105 * It just RCU schedules freeing up the fence.
106 */
107static void drm_sched_fence_release_scheduled(struct dma_fence *f)
108{
109 struct drm_sched_fence *fence = to_drm_sched_fence(f);
110
111 dma_fence_put(fence->parent);
112 call_rcu(&fence->finished.rcu, drm_sched_fence_free);
113}
114
115/**
116 * drm_sched_fence_release_finished - drop extra reference
117 *
118 * @f: fence
119 *
120 * Drop the extra reference from the scheduled fence to the base fence.
121 */
122static void drm_sched_fence_release_finished(struct dma_fence *f)
123{
124 struct drm_sched_fence *fence = to_drm_sched_fence(f);
125
126 dma_fence_put(&fence->scheduled);
127}
128
129const struct dma_fence_ops drm_sched_fence_ops_scheduled = {
130 .get_driver_name = drm_sched_fence_get_driver_name,
131 .get_timeline_name = drm_sched_fence_get_timeline_name,
132 .release = drm_sched_fence_release_scheduled,
133};
134
135const struct dma_fence_ops drm_sched_fence_ops_finished = {
136 .get_driver_name = drm_sched_fence_get_driver_name,
137 .get_timeline_name = drm_sched_fence_get_timeline_name,
138 .release = drm_sched_fence_release_finished,
139};
140
141struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f)
142{
143 if (f->ops == &drm_sched_fence_ops_scheduled)
144 return container_of(f, struct drm_sched_fence, scheduled);
145
146 if (f->ops == &drm_sched_fence_ops_finished)
147 return container_of(f, struct drm_sched_fence, finished);
148
149 return NULL;
150}
151EXPORT_SYMBOL(to_drm_sched_fence);
152
153struct drm_sched_fence *drm_sched_fence_create(struct drm_sched_entity *entity,
154 void *owner)
155{
156 struct drm_sched_fence *fence = NULL;
157 unsigned seq;
158
159 fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL);
160 if (fence == NULL)
161 return NULL;
162
163 fence->owner = owner;
164 fence->sched = entity->rq->sched;
165 spin_lock_init(&fence->lock);
166
167 seq = atomic_inc_return(&entity->fence_seq);
168 dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled,
169 &fence->lock, entity->fence_context, seq);
170 dma_fence_init(&fence->finished, &drm_sched_fence_ops_finished,
171 &fence->lock, entity->fence_context + 1, seq);
172
173 return fence;
174}
175
176module_init(drm_sched_fence_slab_init);
177module_exit(drm_sched_fence_slab_fini);
178
179MODULE_DESCRIPTION("DRM GPU scheduler");
180MODULE_LICENSE("GPL and additional rights");