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
 30struct amd_sched_fence *amd_sched_fence_create(struct amd_sched_entity *s_entity, void *owner)
 31{
 32	struct amd_sched_fence *fence = NULL;
 33	unsigned seq;
 34
 35	fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL);
 36	if (fence == NULL)
 37		return NULL;
 38
 39	INIT_LIST_HEAD(&fence->scheduled_cb);
 40	fence->owner = owner;
 41	fence->sched = s_entity->sched;
 42	spin_lock_init(&fence->lock);
 43
 44	seq = atomic_inc_return(&s_entity->fence_seq);
 45	fence_init(&fence->base, &amd_sched_fence_ops, &fence->lock,
 46		   s_entity->fence_context, seq);
 47
 48	return fence;
 49}
 50
 51void amd_sched_fence_signal(struct amd_sched_fence *fence)
 52{
 53	int ret = fence_signal(&fence->base);
 54	if (!ret)
 55		FENCE_TRACE(&fence->base, "signaled from irq context\n");
 56	else
 57		FENCE_TRACE(&fence->base, "was already signaled\n");
 58}
 59
 60void amd_sched_fence_scheduled(struct amd_sched_fence *s_fence)
 61{
 62	struct fence_cb *cur, *tmp;
 63
 64	set_bit(AMD_SCHED_FENCE_SCHEDULED_BIT, &s_fence->base.flags);
 65	list_for_each_entry_safe(cur, tmp, &s_fence->scheduled_cb, node) {
 66		list_del_init(&cur->node);
 67		cur->func(&s_fence->base, cur);
 68	}
 69}
 70
 71static const char *amd_sched_fence_get_driver_name(struct fence *fence)
 72{
 73	return "amd_sched";
 74}
 75
 76static const char *amd_sched_fence_get_timeline_name(struct fence *f)
 77{
 78	struct amd_sched_fence *fence = to_amd_sched_fence(f);
 79	return (const char *)fence->sched->name;
 80}
 81
 82static bool amd_sched_fence_enable_signaling(struct fence *f)
 83{
 84	return true;
 85}
 86
 87/**
 88 * amd_sched_fence_free - free up the fence memory
 89 *
 90 * @rcu: RCU callback head
 91 *
 92 * Free up the fence memory after the RCU grace period.
 93 */
 94static void amd_sched_fence_free(struct rcu_head *rcu)
 95{
 96	struct fence *f = container_of(rcu, struct fence, rcu);
 97	struct amd_sched_fence *fence = to_amd_sched_fence(f);
 98	kmem_cache_free(sched_fence_slab, fence);
 99}
100
101/**
102 * amd_sched_fence_release - callback that fence can be freed
103 *
104 * @fence: fence
105 *
106 * This function is called when the reference count becomes zero.
107 * It just RCU schedules freeing up the fence.
108 */
109static void amd_sched_fence_release(struct fence *f)
110{
111	call_rcu(&f->rcu, amd_sched_fence_free);
112}
113
114const struct fence_ops amd_sched_fence_ops = {
115	.get_driver_name = amd_sched_fence_get_driver_name,
116	.get_timeline_name = amd_sched_fence_get_timeline_name,
117	.enable_signaling = amd_sched_fence_enable_signaling,
118	.signaled = NULL,
119	.wait = fence_default_wait,
120	.release = amd_sched_fence_release,
121};