/*
* Copyright 2015 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
*/
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <drm/gpu_scheduler.h>
static struct kmem_cache *sched_fence_slab;
static int __init drm_sched_fence_slab_init(void)
{
sched_fence_slab = KMEM_CACHE(drm_sched_fence, SLAB_HWCACHE_ALIGN);
if (!sched_fence_slab)
return -ENOMEM;
return 0;
}
static void __exit drm_sched_fence_slab_fini(void)
{
rcu_barrier();
kmem_cache_destroy(sched_fence_slab);
}
static void drm_sched_fence_set_parent(struct drm_sched_fence *s_fence,
struct dma_fence *fence)
{
/*
* smp_store_release() to ensure another thread racing us
* in drm_sched_fence_set_deadline_finished() sees the
* fence's parent set before test_bit()
*/
smp_store_release(&s_fence->parent, dma_fence_get(fence));
if (test_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT,
&s_fence->finished.flags))
dma_fence_set_deadline(fence, s_fence->deadline);
}
void drm_sched_fence_scheduled(struct drm_sched_fence *fence,
struct dma_fence *parent)
{
/* Set the parent before signaling the scheduled fence, such that,
* any waiter expecting the parent to be filled after the job has
* been scheduled (which is the case for drivers delegating waits
* to some firmware) doesn't have to busy wait for parent to show
* up.
*/
if (!IS_ERR_OR_NULL(parent))
drm_sched_fence_set_parent(fence, parent);
dma_fence_signal(&fence->scheduled);
}
void drm_sched_fence_finished(struct drm_sched_fence *fence, int result)
{
if (result)
dma_fence_set_error(&fence->finished, result);
dma_fence_signal(&fence->finished);
}
static const char *drm_sched_fence_get_driver_name(struct dma_fence *fence)
{
return "drm_sched";
}
static const char *drm_sched_fence_get_timeline_name(struct dma_fence *f)
{
struct drm_sched_fence *fence = to_drm_sched_fence(f);
return (const char *)fence->sched->name;
}
static void drm_sched_fence_free_rcu(struct rcu_head *rcu)
{
struct dma_fence *f = container_of(rcu, struct dma_fence, rcu);
struct drm_sched_fence *fence = to_drm_sched_fence(f);
if (!WARN_ON_ONCE(!fence))
kmem_cache_free(sched_fence_slab, fence);
}
/**
* drm_sched_fence_free - free up an uninitialized fence
*
* @fence: fence to free
*
* Free up the fence memory. Should only be used if drm_sched_fence_init()
* has not been called yet.
*/
void drm_sched_fence_free(struct drm_sched_fence *fence)
{
/* This function should not be called if the fence has been initialized. */
if (!WARN_ON_ONCE(fence->sched))
kmem_cache_free(sched_fence_slab, fence);
}
/**
* drm_sched_fence_release_scheduled - callback that fence can be freed
*
* @f: fence
*
* This function is called when the reference count becomes zero.
* It just RCU schedules freeing up the fence.
*/
static void drm_sched_fence_release_scheduled(struct dma_fence *f)
{
struct drm_sched_fence *fence = to_drm_sched_fence(f);
dma_fence_put(fence->parent);
call_rcu(&fence->finished.rcu, drm_sched_fence_free_rcu);
}
/**
* drm_sched_fence_release_finished - drop extra reference
*
* @f: fence
*
* Drop the extra reference from the scheduled fence to the base fence.
*/
static void drm_sched_fence_release_finished(struct dma_fence *f)
{
struct drm_sched_fence *fence = to_drm_sched_fence(f);
dma_fence_put(&fence->scheduled);
}
static void drm_sched_fence_set_deadline_finished(struct dma_fence *f,
ktime_t deadline)
{
struct drm_sched_fence *fence = to_drm_sched_fence(f);
struct dma_fence *parent;
unsigned long flags;
spin_lock_irqsave(&fence->lock, flags);
/* If we already have an earlier deadline, keep it: */
if (test_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT, &f->flags) &&
ktime_before(fence->deadline, deadline)) {
spin_unlock_irqrestore(&fence->lock, flags);
return;
}
fence->deadline = deadline;
set_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT, &f->flags);
spin_unlock_irqrestore(&fence->lock, flags);
/*
* smp_load_aquire() to ensure that if we are racing another
* thread calling drm_sched_fence_set_parent(), that we see
* the parent set before it calls test_bit(HAS_DEADLINE_BIT)
*/
parent = smp_load_acquire(&fence->parent);
if (parent)
dma_fence_set_deadline(parent, deadline);
}
static const struct dma_fence_ops drm_sched_fence_ops_scheduled = {
.get_driver_name = drm_sched_fence_get_driver_name,
.get_timeline_name = drm_sched_fence_get_timeline_name,
.release = drm_sched_fence_release_scheduled,
};
static const struct dma_fence_ops drm_sched_fence_ops_finished = {
.get_driver_name = drm_sched_fence_get_driver_name,
.get_timeline_name = drm_sched_fence_get_timeline_name,
.release = drm_sched_fence_release_finished,
.set_deadline = drm_sched_fence_set_deadline_finished,
};
struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f)
{
if (f->ops == &drm_sched_fence_ops_scheduled)
return container_of(f, struct drm_sched_fence, scheduled);
if (f->ops == &drm_sched_fence_ops_finished)
return container_of(f, struct drm_sched_fence, finished);
return NULL;
}
EXPORT_SYMBOL(to_drm_sched_fence);
struct drm_sched_fence *drm_sched_fence_alloc(struct drm_sched_entity *entity,
void *owner)
{
struct drm_sched_fence *fence = NULL;
fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL);
if (fence == NULL)
return NULL;
fence->owner = owner;
spin_lock_init(&fence->lock);
return fence;
}
void drm_sched_fence_init(struct drm_sched_fence *fence,
struct drm_sched_entity *entity)
{
unsigned seq;
fence->sched = entity->rq->sched;
seq = atomic_inc_return(&entity->fence_seq);
dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled,
&fence->lock, entity->fence_context, seq);
dma_fence_init(&fence->finished, &drm_sched_fence_ops_finished,
&fence->lock, entity->fence_context + 1, seq);
}
module_init(drm_sched_fence_slab_init);
module_exit(drm_sched_fence_slab_fini);
MODULE_DESCRIPTION("DRM GPU scheduler");
MODULE_LICENSE("GPL and additional rights");
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