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/module.h> 26 #include <linux/sched.h> 27 #include <linux/slab.h> 28 #include <linux/wait.h> 29 30 #include <drm/gpu_scheduler.h> 31 32 static struct kmem_cache *sched_fence_slab; 33 34 static int __init drm_sched_fence_slab_init(void) 35 { 36 sched_fence_slab = kmem_cache_create( 37 "drm_sched_fence", sizeof(struct drm_sched_fence), 0, 38 SLAB_HWCACHE_ALIGN, NULL); 39 if (!sched_fence_slab) 40 return -ENOMEM; 41 42 return 0; 43 } 44 45 static void __exit drm_sched_fence_slab_fini(void) 46 { 47 rcu_barrier(); 48 kmem_cache_destroy(sched_fence_slab); 49 } 50 51 void drm_sched_fence_scheduled(struct drm_sched_fence *fence) 52 { 53 dma_fence_signal(&fence->scheduled); 54 } 55 56 void drm_sched_fence_finished(struct drm_sched_fence *fence) 57 { 58 dma_fence_signal(&fence->finished); 59 } 60 61 static const char *drm_sched_fence_get_driver_name(struct dma_fence *fence) 62 { 63 return "drm_sched"; 64 } 65 66 static const char *drm_sched_fence_get_timeline_name(struct dma_fence *f) 67 { 68 struct drm_sched_fence *fence = to_drm_sched_fence(f); 69 return (const char *)fence->sched->name; 70 } 71 72 /** 73 * drm_sched_fence_free - free up the fence memory 74 * 75 * @rcu: RCU callback head 76 * 77 * Free up the fence memory after the RCU grace period. 78 */ 79 void drm_sched_fence_free(struct rcu_head *rcu) 80 { 81 struct dma_fence *f = container_of(rcu, struct dma_fence, rcu); 82 struct drm_sched_fence *fence = to_drm_sched_fence(f); 83 84 kmem_cache_free(sched_fence_slab, fence); 85 } 86 87 /** 88 * drm_sched_fence_release_scheduled - callback that fence can be freed 89 * 90 * @f: fence 91 * 92 * This function is called when the reference count becomes zero. 93 * It just RCU schedules freeing up the fence. 94 */ 95 static void drm_sched_fence_release_scheduled(struct dma_fence *f) 96 { 97 struct drm_sched_fence *fence = to_drm_sched_fence(f); 98 99 dma_fence_put(fence->parent); 100 call_rcu(&fence->finished.rcu, drm_sched_fence_free); 101 } 102 103 /** 104 * drm_sched_fence_release_finished - drop extra reference 105 * 106 * @f: fence 107 * 108 * Drop the extra reference from the scheduled fence to the base fence. 109 */ 110 static void drm_sched_fence_release_finished(struct dma_fence *f) 111 { 112 struct drm_sched_fence *fence = to_drm_sched_fence(f); 113 114 dma_fence_put(&fence->scheduled); 115 } 116 117 static const struct dma_fence_ops drm_sched_fence_ops_scheduled = { 118 .get_driver_name = drm_sched_fence_get_driver_name, 119 .get_timeline_name = drm_sched_fence_get_timeline_name, 120 .release = drm_sched_fence_release_scheduled, 121 }; 122 123 static const struct dma_fence_ops drm_sched_fence_ops_finished = { 124 .get_driver_name = drm_sched_fence_get_driver_name, 125 .get_timeline_name = drm_sched_fence_get_timeline_name, 126 .release = drm_sched_fence_release_finished, 127 }; 128 129 struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f) 130 { 131 if (f->ops == &drm_sched_fence_ops_scheduled) 132 return container_of(f, struct drm_sched_fence, scheduled); 133 134 if (f->ops == &drm_sched_fence_ops_finished) 135 return container_of(f, struct drm_sched_fence, finished); 136 137 return NULL; 138 } 139 EXPORT_SYMBOL(to_drm_sched_fence); 140 141 struct drm_sched_fence *drm_sched_fence_alloc(struct drm_sched_entity *entity, 142 void *owner) 143 { 144 struct drm_sched_fence *fence = NULL; 145 146 fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL); 147 if (fence == NULL) 148 return NULL; 149 150 fence->owner = owner; 151 spin_lock_init(&fence->lock); 152 153 return fence; 154 } 155 156 void drm_sched_fence_init(struct drm_sched_fence *fence, 157 struct drm_sched_entity *entity) 158 { 159 unsigned seq; 160 161 fence->sched = entity->rq->sched; 162 seq = atomic_inc_return(&entity->fence_seq); 163 dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled, 164 &fence->lock, entity->fence_context, seq); 165 dma_fence_init(&fence->finished, &drm_sched_fence_ops_finished, 166 &fence->lock, entity->fence_context + 1, seq); 167 } 168 169 module_init(drm_sched_fence_slab_init); 170 module_exit(drm_sched_fence_slab_fini); 171 172 MODULE_DESCRIPTION("DRM GPU scheduler"); 173 MODULE_LICENSE("GPL and additional rights"); 174