drivers/gpu/drm/amd/scheduler/sched_fence.c

   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
  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
  43 void amd_sched_fence_slab_fini(void)
  44 {
  45         rcu_barrier();
  46         kmem_cache_destroy(sched_fence_slab);
  47 }
  48
  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         dma_fence_init(&fence->scheduled, &amd_sched_fence_ops_scheduled,
  65                        &fence->lock, entity->fence_context, seq);
  66         dma_fence_init(&fence->finished, &amd_sched_fence_ops_finished,
  67                        &fence->lock, entity->fence_context + 1, seq);
  68
  69         return fence;
  70 }
  71
  72 void amd_sched_fence_scheduled(struct amd_sched_fence *fence)
  73 {
  74         int ret = dma_fence_signal(&fence->scheduled);
  75
  76         if (!ret)
  77                 DMA_FENCE_TRACE(&fence->scheduled,
  78                                 "signaled from irq context\n");
  79         else
  80                 DMA_FENCE_TRACE(&fence->scheduled,
  81                                 "was already signaled\n");
  82 }
  83
  84 void amd_sched_fence_finished(struct amd_sched_fence *fence)
  85 {
  86         int ret = dma_fence_signal(&fence->finished);
  87
  88         if (!ret)
  89                 DMA_FENCE_TRACE(&fence->finished,
  90                                 "signaled from irq context\n");
  91         else
  92                 DMA_FENCE_TRACE(&fence->finished,
  93                                 "was already signaled\n");
  94 }
  95
  96 static const char *amd_sched_fence_get_driver_name(struct dma_fence *fence)
  97 {
  98         return "amd_sched";
  99 }
 100
 101 static const char *amd_sched_fence_get_timeline_name(struct dma_fence *f)
 102 {
 103         struct amd_sched_fence *fence = to_amd_sched_fence(f);
 104         return (const char *)fence->sched->name;
 105 }
 106
 107 static bool amd_sched_fence_enable_signaling(struct dma_fence *f)
 108 {
 109         return true;
 110 }
 111
 112 /**
 113  * amd_sched_fence_free - free up the fence memory
 114  *
 115  * @rcu: RCU callback head
 116  *
 117  * Free up the fence memory after the RCU grace period.
 118  */
 119 static void amd_sched_fence_free(struct rcu_head *rcu)
 120 {
 121         struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
 122         struct amd_sched_fence *fence = to_amd_sched_fence(f);
 123
 124         dma_fence_put(fence->parent);
 125         kmem_cache_free(sched_fence_slab, fence);
 126 }
 127
 128 /**
 129  * amd_sched_fence_release_scheduled - callback that fence can be freed
 130  *
 131  * @fence: fence
 132  *
 133  * This function is called when the reference count becomes zero.
 134  * It just RCU schedules freeing up the fence.
 135  */
 136 static void amd_sched_fence_release_scheduled(struct dma_fence *f)
 137 {
 138         struct amd_sched_fence *fence = to_amd_sched_fence(f);
 139
 140         call_rcu(&fence->finished.rcu, amd_sched_fence_free);
 141 }
 142
 143 /**
 144  * amd_sched_fence_release_finished - drop extra reference
 145  *
 146  * @f: fence
 147  *
 148  * Drop the extra reference from the scheduled fence to the base fence.
 149  */
 150 static void amd_sched_fence_release_finished(struct dma_fence *f)
 151 {
 152         struct amd_sched_fence *fence = to_amd_sched_fence(f);
 153
 154         dma_fence_put(&fence->scheduled);
 155 }
 156
 157 const struct dma_fence_ops amd_sched_fence_ops_scheduled = {
 158         .get_driver_name = amd_sched_fence_get_driver_name,
 159         .get_timeline_name = amd_sched_fence_get_timeline_name,
 160         .enable_signaling = amd_sched_fence_enable_signaling,
 161         .signaled = NULL,
 162         .wait = dma_fence_default_wait,
 163         .release = amd_sched_fence_release_scheduled,
 164 };
 165
 166 const struct dma_fence_ops amd_sched_fence_ops_finished = {
 167         .get_driver_name = amd_sched_fence_get_driver_name,
 168         .get_timeline_name = amd_sched_fence_get_timeline_name,
 169         .enable_signaling = amd_sched_fence_enable_signaling,
 170         .signaled = NULL,
 171         .wait = dma_fence_default_wait,
 172         .release = amd_sched_fence_release_finished,
 173 };