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         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
  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
  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
  92 static const char *amd_sched_fence_get_driver_name(struct fence *fence)
  93 {
  94         return "amd_sched";
  95 }
  96
  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
 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  */
 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  */
 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  */
 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 };