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 30 static struct kmem_cache *sched_fence_slab; 31 32 static 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 43 static void __exit drm_sched_fence_slab_fini(void) 44 { 45 rcu_barrier(); 46 kmem_cache_destroy(sched_fence_slab); 47 } 48 49 void 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 61 void 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 73 static const char *drm_sched_fence_get_driver_name(struct dma_fence *fence) 74 { 75 return "drm_sched"; 76 } 77 78 static 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 */ 91 static 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 */ 107 static 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 */ 122 static 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 } 128 129 const 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 }; 134 135 const 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 }; 140 141 struct 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 } 151 EXPORT_SYMBOL(to_drm_sched_fence); 152 153 struct 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 = kzalloc(sizeof(struct drm_sched_fence), GFP_KERNEL); 160 if (fence == NULL) 161 return NULL; 162 163 fence->owner = owner; 164 fence->sched = entity->rq->sched; 165 lockinit(&fence->lock, "dscl", 0, LK_CANRECURSE); 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 } 175 176 module_init(drm_sched_fence_slab_init); 177 module_exit(drm_sched_fence_slab_fini); 178 179 MODULE_DESCRIPTION("DRM GPU scheduler"); 180 MODULE_LICENSE("GPL and additional rights"); 181