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 "gpu_scheduler.h"
29
30 static struct kmem_cache *sched_fence_slab;
31
amd_sched_fence_slab_init(void)32 int amd_sched_fence_slab_init(void)
33 {
34 sched_fence_slab = kmem_cache_create(
35 "amd_sched_fence", sizeof(struct amd_sched_fence), 0,
36 SLAB_HWCACHE_ALIGN, NULL);
37 if (!sched_fence_slab)
38 return -ENOMEM;
39
40 return 0;
41 }
42
amd_sched_fence_slab_fini(void)43 void amd_sched_fence_slab_fini(void)
44 {
45 rcu_barrier();
46 kmem_cache_destroy(sched_fence_slab);
47 }
48
amd_sched_fence_create(struct amd_sched_entity * entity,void * owner)49 struct amd_sched_fence *amd_sched_fence_create(struct amd_sched_entity *entity,
50 void *owner)
51 {
52 struct amd_sched_fence *fence = NULL;
53 unsigned seq;
54
55 fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL);
56 if (fence == NULL)
57 return NULL;
58
59 fence->owner = owner;
60 fence->sched = entity->sched;
61 spin_lock_init(&fence->lock);
62
63 seq = atomic_inc_return(&entity->fence_seq);
64 fence_init(&fence->scheduled, &amd_sched_fence_ops_scheduled,
65 &fence->lock, entity->fence_context, seq);
66 fence_init(&fence->finished, &amd_sched_fence_ops_finished,
67 &fence->lock, entity->fence_context + 1, seq);
68
69 return fence;
70 }
71
amd_sched_fence_scheduled(struct amd_sched_fence * fence)72 void amd_sched_fence_scheduled(struct amd_sched_fence *fence)
73 {
74 int ret = fence_signal(&fence->scheduled);
75
76 if (!ret)
77 FENCE_TRACE(&fence->scheduled, "signaled from irq context\n");
78 else
79 FENCE_TRACE(&fence->scheduled, "was already signaled\n");
80 }
81
amd_sched_fence_finished(struct amd_sched_fence * fence)82 void amd_sched_fence_finished(struct amd_sched_fence *fence)
83 {
84 int ret = fence_signal(&fence->finished);
85
86 if (!ret)
87 FENCE_TRACE(&fence->finished, "signaled from irq context\n");
88 else
89 FENCE_TRACE(&fence->finished, "was already signaled\n");
90 }
91
amd_sched_fence_get_driver_name(struct fence * fence)92 static const char *amd_sched_fence_get_driver_name(struct fence *fence)
93 {
94 return "amd_sched";
95 }
96
amd_sched_fence_get_timeline_name(struct fence * f)97 static const char *amd_sched_fence_get_timeline_name(struct fence *f)
98 {
99 struct amd_sched_fence *fence = to_amd_sched_fence(f);
100 return (const char *)fence->sched->name;
101 }
102
amd_sched_fence_enable_signaling(struct fence * f)103 static bool amd_sched_fence_enable_signaling(struct fence *f)
104 {
105 return true;
106 }
107
108 /**
109 * amd_sched_fence_free - free up the fence memory
110 *
111 * @rcu: RCU callback head
112 *
113 * Free up the fence memory after the RCU grace period.
114 */
amd_sched_fence_free(struct rcu_head * rcu)115 static void amd_sched_fence_free(struct rcu_head *rcu)
116 {
117 struct fence *f = container_of(rcu, struct fence, rcu);
118 struct amd_sched_fence *fence = to_amd_sched_fence(f);
119
120 fence_put(fence->parent);
121 kmem_cache_free(sched_fence_slab, fence);
122 }
123
124 /**
125 * amd_sched_fence_release_scheduled - callback that fence can be freed
126 *
127 * @fence: fence
128 *
129 * This function is called when the reference count becomes zero.
130 * It just RCU schedules freeing up the fence.
131 */
amd_sched_fence_release_scheduled(struct fence * f)132 static void amd_sched_fence_release_scheduled(struct fence *f)
133 {
134 struct amd_sched_fence *fence = to_amd_sched_fence(f);
135
136 call_rcu(&fence->finished.rcu, amd_sched_fence_free);
137 }
138
139 /**
140 * amd_sched_fence_release_finished - drop extra reference
141 *
142 * @f: fence
143 *
144 * Drop the extra reference from the scheduled fence to the base fence.
145 */
amd_sched_fence_release_finished(struct fence * f)146 static void amd_sched_fence_release_finished(struct fence *f)
147 {
148 struct amd_sched_fence *fence = to_amd_sched_fence(f);
149
150 fence_put(&fence->scheduled);
151 }
152
153 const struct fence_ops amd_sched_fence_ops_scheduled = {
154 .get_driver_name = amd_sched_fence_get_driver_name,
155 .get_timeline_name = amd_sched_fence_get_timeline_name,
156 .enable_signaling = amd_sched_fence_enable_signaling,
157 .signaled = NULL,
158 .wait = fence_default_wait,
159 .release = amd_sched_fence_release_scheduled,
160 };
161
162 const struct fence_ops amd_sched_fence_ops_finished = {
163 .get_driver_name = amd_sched_fence_get_driver_name,
164 .get_timeline_name = amd_sched_fence_get_timeline_name,
165 .enable_signaling = amd_sched_fence_enable_signaling,
166 .signaled = NULL,
167 .wait = fence_default_wait,
168 .release = amd_sched_fence_release_finished,
169 };
170