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
84static bool drm_sched_fence_enable_signaling(struct dma_fence *f)
85{
86 return true;
87}
88
89/**
90 * amd_sched_fence_free - free up the fence memory
91 *
92 * @rcu: RCU callback head
93 *
94 * Free up the fence memory after the RCU grace period.
95 */
96static void drm_sched_fence_free(struct rcu_head *rcu)
97{
98 struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
99 struct drm_sched_fence *fence = to_drm_sched_fence(f);
100
101 dma_fence_put(fence->parent);
102 kmem_cache_free(sched_fence_slab, fence);
103}
104
105/**
106 * amd_sched_fence_release_scheduled - callback that fence can be freed
107 *
108 * @fence: fence
109 *
110 * This function is called when the reference count becomes zero.
111 * It just RCU schedules freeing up the fence.
112 */
113static void drm_sched_fence_release_scheduled(struct dma_fence *f)
114{
115 struct drm_sched_fence *fence = to_drm_sched_fence(f);
116
117 call_rcu(&fence->finished.rcu, drm_sched_fence_free);
118}
119
120/**
121 * amd_sched_fence_release_finished - drop extra reference
122 *
123 * @f: fence
124 *
125 * Drop the extra reference from the scheduled fence to the base fence.
126 */
127static void drm_sched_fence_release_finished(struct dma_fence *f)
128{
129 struct drm_sched_fence *fence = to_drm_sched_fence(f);
130
131 dma_fence_put(&fence->scheduled);
132}
133
134const struct dma_fence_ops drm_sched_fence_ops_scheduled = {
135 .get_driver_name = drm_sched_fence_get_driver_name,
136 .get_timeline_name = drm_sched_fence_get_timeline_name,
137 .enable_signaling = drm_sched_fence_enable_signaling,
138 .signaled = NULL,
139 .wait = dma_fence_default_wait,
140 .release = drm_sched_fence_release_scheduled,
141};
142
143const struct dma_fence_ops drm_sched_fence_ops_finished = {
144 .get_driver_name = drm_sched_fence_get_driver_name,
145 .get_timeline_name = drm_sched_fence_get_timeline_name,
146 .enable_signaling = drm_sched_fence_enable_signaling,
147 .signaled = NULL,
148 .wait = dma_fence_default_wait,
149 .release = drm_sched_fence_release_finished,
150};
151
152struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f)
153{
154 if (f->ops == &drm_sched_fence_ops_scheduled)
155 return container_of(f, struct drm_sched_fence, scheduled);
156
157 if (f->ops == &drm_sched_fence_ops_finished)
158 return container_of(f, struct drm_sched_fence, finished);
159
160 return NULL;
161}
162EXPORT_SYMBOL(to_drm_sched_fence);
163
164struct drm_sched_fence *drm_sched_fence_create(struct drm_sched_entity *entity,
165 void *owner)
166{
167 struct drm_sched_fence *fence = NULL;
168 unsigned seq;
169
170 fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL);
171 if (fence == NULL)
172 return NULL;
173
174 fence->owner = owner;
175 fence->sched = entity->sched;
176 spin_lock_init(&fence->lock);
177
178 seq = atomic_inc_return(&entity->fence_seq);
179 dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled,
180 &fence->lock, entity->fence_context, seq);
181 dma_fence_init(&fence->finished, &drm_sched_fence_ops_finished,
182 &fence->lock, entity->fence_context + 1, seq);
183
184 return fence;
185}
186
187module_init(drm_sched_fence_slab_init);
188module_exit(drm_sched_fence_slab_fini);
189
190MODULE_DESCRIPTION("DRM GPU scheduler");
191MODULE_LICENSE("GPL and additional rights");