239 lines · c
1/*2 * Copyright 2015 Advanced Micro Devices, Inc.3 *4 * Permission is hereby granted, free of charge, to any person obtaining a5 * copy of this software and associated documentation files (the "Software"),6 * to deal in the Software without restriction, including without limitation7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,8 * and/or sell copies of the Software, and to permit persons to whom the9 * Software is furnished to do so, subject to the following conditions:10 *11 * The above copyright notice and this permission notice shall be included in12 * all copies or substantial portions of the Software.13 *14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR18 * 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 OR20 * 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 32static struct kmem_cache *sched_fence_slab;33 34static int __init drm_sched_fence_slab_init(void)35{36 sched_fence_slab = KMEM_CACHE(drm_sched_fence, SLAB_HWCACHE_ALIGN);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 49static void drm_sched_fence_set_parent(struct drm_sched_fence *s_fence,50 struct dma_fence *fence)51{52 /*53 * smp_store_release() to ensure another thread racing us54 * in drm_sched_fence_set_deadline_finished() sees the55 * fence's parent set before test_bit()56 */57 smp_store_release(&s_fence->parent, dma_fence_get(fence));58 if (test_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT,59 &s_fence->finished.flags))60 dma_fence_set_deadline(fence, s_fence->deadline);61}62 63void drm_sched_fence_scheduled(struct drm_sched_fence *fence,64 struct dma_fence *parent)65{66 /* Set the parent before signaling the scheduled fence, such that,67 * any waiter expecting the parent to be filled after the job has68 * been scheduled (which is the case for drivers delegating waits69 * to some firmware) doesn't have to busy wait for parent to show70 * up.71 */72 if (!IS_ERR_OR_NULL(parent))73 drm_sched_fence_set_parent(fence, parent);74 75 dma_fence_signal(&fence->scheduled);76}77 78void drm_sched_fence_finished(struct drm_sched_fence *fence, int result)79{80 if (result)81 dma_fence_set_error(&fence->finished, result);82 dma_fence_signal(&fence->finished);83}84 85static const char *drm_sched_fence_get_driver_name(struct dma_fence *fence)86{87 return "drm_sched";88}89 90static const char *drm_sched_fence_get_timeline_name(struct dma_fence *f)91{92 struct drm_sched_fence *fence = to_drm_sched_fence(f);93 return (const char *)fence->sched->name;94}95 96static void drm_sched_fence_free_rcu(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 if (!WARN_ON_ONCE(!fence))102 kmem_cache_free(sched_fence_slab, fence);103}104 105/**106 * drm_sched_fence_free - free up an uninitialized fence107 *108 * @fence: fence to free109 *110 * Free up the fence memory. Should only be used if drm_sched_fence_init()111 * has not been called yet.112 */113void drm_sched_fence_free(struct drm_sched_fence *fence)114{115 /* This function should not be called if the fence has been initialized. */116 if (!WARN_ON_ONCE(fence->sched))117 kmem_cache_free(sched_fence_slab, fence);118}119 120/**121 * drm_sched_fence_release_scheduled - callback that fence can be freed122 *123 * @f: fence124 *125 * This function is called when the reference count becomes zero.126 * It just RCU schedules freeing up the fence.127 */128static void drm_sched_fence_release_scheduled(struct dma_fence *f)129{130 struct drm_sched_fence *fence = to_drm_sched_fence(f);131 132 dma_fence_put(fence->parent);133 call_rcu(&fence->finished.rcu, drm_sched_fence_free_rcu);134}135 136/**137 * drm_sched_fence_release_finished - drop extra reference138 *139 * @f: fence140 *141 * Drop the extra reference from the scheduled fence to the base fence.142 */143static void drm_sched_fence_release_finished(struct dma_fence *f)144{145 struct drm_sched_fence *fence = to_drm_sched_fence(f);146 147 dma_fence_put(&fence->scheduled);148}149 150static void drm_sched_fence_set_deadline_finished(struct dma_fence *f,151 ktime_t deadline)152{153 struct drm_sched_fence *fence = to_drm_sched_fence(f);154 struct dma_fence *parent;155 unsigned long flags;156 157 spin_lock_irqsave(&fence->lock, flags);158 159 /* If we already have an earlier deadline, keep it: */160 if (test_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT, &f->flags) &&161 ktime_before(fence->deadline, deadline)) {162 spin_unlock_irqrestore(&fence->lock, flags);163 return;164 }165 166 fence->deadline = deadline;167 set_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT, &f->flags);168 169 spin_unlock_irqrestore(&fence->lock, flags);170 171 /*172 * smp_load_aquire() to ensure that if we are racing another173 * thread calling drm_sched_fence_set_parent(), that we see174 * the parent set before it calls test_bit(HAS_DEADLINE_BIT)175 */176 parent = smp_load_acquire(&fence->parent);177 if (parent)178 dma_fence_set_deadline(parent, deadline);179}180 181static const struct dma_fence_ops drm_sched_fence_ops_scheduled = {182 .get_driver_name = drm_sched_fence_get_driver_name,183 .get_timeline_name = drm_sched_fence_get_timeline_name,184 .release = drm_sched_fence_release_scheduled,185};186 187static const struct dma_fence_ops drm_sched_fence_ops_finished = {188 .get_driver_name = drm_sched_fence_get_driver_name,189 .get_timeline_name = drm_sched_fence_get_timeline_name,190 .release = drm_sched_fence_release_finished,191 .set_deadline = drm_sched_fence_set_deadline_finished,192};193 194struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f)195{196 if (f->ops == &drm_sched_fence_ops_scheduled)197 return container_of(f, struct drm_sched_fence, scheduled);198 199 if (f->ops == &drm_sched_fence_ops_finished)200 return container_of(f, struct drm_sched_fence, finished);201 202 return NULL;203}204EXPORT_SYMBOL(to_drm_sched_fence);205 206struct drm_sched_fence *drm_sched_fence_alloc(struct drm_sched_entity *entity,207 void *owner)208{209 struct drm_sched_fence *fence = NULL;210 211 fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL);212 if (fence == NULL)213 return NULL;214 215 fence->owner = owner;216 spin_lock_init(&fence->lock);217 218 return fence;219}220 221void drm_sched_fence_init(struct drm_sched_fence *fence,222 struct drm_sched_entity *entity)223{224 unsigned seq;225 226 fence->sched = entity->rq->sched;227 seq = atomic_inc_return(&entity->fence_seq);228 dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled,229 &fence->lock, entity->fence_context, seq);230 dma_fence_init(&fence->finished, &drm_sched_fence_ops_finished,231 &fence->lock, entity->fence_context + 1, seq);232}233 234module_init(drm_sched_fence_slab_init);235module_exit(drm_sched_fence_slab_fini);236 237MODULE_DESCRIPTION("DRM GPU scheduler");238MODULE_LICENSE("GPL and additional rights");239