drm/amd: add scheduler fence implementation (v2)

scheduler fence is based on kernel fence framework.

v2: squash in Christian's build fix

Signed-off-by: Chunming Zhou <[e-mail]>
Reviewed-by: Christian K?nig <[e-mail]>

drivers/gpu/drm/amd/amdgpu/Makefile

···
 # GPU scheduler
 amdgpu-y += \
 	../scheduler/gpu_scheduler.o \
+	../scheduler/sched_fence.o \
 	amdgpu_sched.o
 
 amdgpu-$(CONFIG_COMPAT) += amdgpu_ioc32.o

drivers/gpu/drm/amd/amdgpu/amdgpu.h

···
 	int (*prepare_job)(struct amdgpu_cs_parser *sched_job);
 	int (*run_job)(struct amdgpu_cs_parser *sched_job);
 	int (*free_job)(struct amdgpu_cs_parser *sched_job);
+	struct amd_sched_fence *s_fence;
 };
 
 static inline u32 amdgpu_get_ib_value(struct amdgpu_cs_parser *p, uint32_t ib_idx, int idx)

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

···
 	if (amdgpu_enable_scheduler && parser->num_ibs) {
 		struct amdgpu_ring * ring =
 			amdgpu_cs_parser_get_ring(adev, parser);
-		parser->ibs[parser->num_ibs - 1].sequence = atomic64_inc_return(
-			&parser->ctx->rings[ring->idx].entity.last_queued_v_seq);
 		if (ring->is_pte_ring || (parser->bo_list && parser->bo_list->has_userptr)) {
 			r = amdgpu_cs_parser_prepare_job(parser);
 			if (r)
···
 		parser->ring = ring;
 		parser->run_job = amdgpu_cs_parser_run_job;
 		parser->free_job = amdgpu_cs_parser_free_job;
-		amd_sched_push_job(ring->scheduler,
-				   &parser->ctx->rings[ring->idx].entity,
-				   parser);
-		cs->out.handle = parser->ibs[parser->num_ibs - 1].sequence;
+		mutex_lock(&parser->job_lock);
+		r = amd_sched_push_job(ring->scheduler,
+				       &parser->ctx->rings[ring->idx].entity,
+				       parser,
+				       &parser->s_fence);
+		if (r) {
+			mutex_unlock(&parser->job_lock);
+			goto out;
+		}
+		parser->ibs[parser->num_ibs - 1].sequence =
+			amdgpu_ctx_add_fence(parser->ctx, ring,
+					     &parser->s_fence->base,
+					     parser->s_fence->v_seq);
+		cs->out.handle = parser->s_fence->v_seq;
+		mutex_unlock(&parser->job_lock);
 		up_read(&adev->exclusive_lock);
 		return 0;
 	}

drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c

···
 	struct amdgpu_ctx_ring *cring = & ctx->rings[ring->idx];
 	struct fence *fence;
 	uint64_t queued_seq;
-	int r;
-
-	if (amdgpu_enable_scheduler) {
-		r = amd_sched_wait_emit(&cring->entity,
-					seq,
-					false,
-					-1);
-		if (r)
-			return NULL;
-	}
 
 	spin_lock(&ctx->ring_lock);
 	if (amdgpu_enable_scheduler)

drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c

···
 
 	sequence = amdgpu_enable_scheduler ? ib->sequence : 0;
 
-	if (ib->ctx)
+	if (!amdgpu_enable_scheduler && ib->ctx)
 		ib->sequence = amdgpu_ctx_add_fence(ib->ctx, ring,
 						    &ib->fence->base,
 						    sequence);

drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c

···
 {
 	int r = 0;
 	if (amdgpu_enable_scheduler) {
-		uint64_t v_seq;
 		struct amdgpu_cs_parser *sched_job =
 			amdgpu_cs_parser_create(adev, owner, &adev->kernel_ctx,
 						ibs, num_ibs);
···
 			return -ENOMEM;
 		}
 		sched_job->free_job = free_job;
-		v_seq = atomic64_inc_return(&adev->kernel_ctx.rings[ring->idx].entity.last_queued_v_seq);
-		ibs[num_ibs - 1].sequence = v_seq;
-		amd_sched_push_job(ring->scheduler,
-				   &adev->kernel_ctx.rings[ring->idx].entity,
-				   sched_job);
-		r = amd_sched_wait_emit(
-			&adev->kernel_ctx.rings[ring->idx].entity,
-			v_seq,
-			false,
-			-1);
-		if (r)
-			WARN(true, "emit timeout\n");
-	} else
+		mutex_lock(&sched_job->job_lock);
+		r = amd_sched_push_job(ring->scheduler,
+				       &adev->kernel_ctx.rings[ring->idx].entity,
+				       sched_job, &sched_job->s_fence);
+		if (r) {
+			mutex_unlock(&sched_job->job_lock);
+			kfree(sched_job);
+			return r;
+		}
+		ibs[num_ibs - 1].sequence = sched_job->s_fence->v_seq;
+		*f = &sched_job->s_fence->base;
+		mutex_unlock(&sched_job->job_lock);
+	} else {
 		r = amdgpu_ib_schedule(adev, num_ibs, ibs, owner);
-	if (r)
-		return r;
-	*f = &ibs[num_ibs - 1].fence->base;
+		if (r)
+			return r;
+		*f = &ibs[num_ibs - 1].fence->base;
+	}
 	return 0;
 }

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

···
 			  uint32_t jobs)
 {
 	uint64_t seq_ring = 0;
+	char name[20];
 
 	if (!(sched && entity && rq))
 		return -EINVAL;
···
 	entity->scheduler = sched;
 	init_waitqueue_head(&entity->wait_queue);
 	init_waitqueue_head(&entity->wait_emit);
+	entity->fence_context = fence_context_alloc(1);
+	snprintf(name, sizeof(name), "c_entity[%llu]", entity->fence_context);
+	memcpy(entity->name, name, 20);
+	INIT_LIST_HEAD(&entity->fence_list);
 	if(kfifo_alloc(&entity->job_queue,
 		       jobs * sizeof(void *),
 		       GFP_KERNEL))
···
 	spin_lock_init(&entity->queue_lock);
 	atomic64_set(&entity->last_emitted_v_seq, seq_ring);
 	atomic64_set(&entity->last_queued_v_seq, seq_ring);
+	atomic64_set(&entity->last_signaled_v_seq, seq_ring);
 
 	/* Add the entity to the run queue */
 	mutex_lock(&rq->lock);
···
 */
 int amd_sched_push_job(struct amd_gpu_scheduler *sched,
 		       struct amd_sched_entity *c_entity,
-		       void *data)
+		       void *data,
+		       struct amd_sched_fence **fence)
 {
-	struct amd_sched_job *job = kzalloc(sizeof(struct amd_sched_job),
-					    GFP_KERNEL);
+	struct amd_sched_job *job;
+
+	if (!fence)
+		return -EINVAL;
+	job = kzalloc(sizeof(struct amd_sched_job), GFP_KERNEL);
 	if (!job)
 		return -ENOMEM;
 	job->sched = sched;
 	job->s_entity = c_entity;
 	job->data = data;
+	*fence = amd_sched_fence_create(c_entity);
+	if ((*fence) == NULL) {
+		kfree(job);
+		return -EINVAL;
+	}
+	job->s_fence = *fence;
 	while (kfifo_in_spinlocked(&c_entity->job_queue, &job, sizeof(void *),
 				   &c_entity->queue_lock) != sizeof(void *)) {
 		/**
···
 	unsigned long flags;
 
 	sched = sched_job->sched;
+	atomic64_set(&sched_job->s_entity->last_signaled_v_seq,
+		     sched_job->s_fence->v_seq);
+	amd_sched_fence_signal(sched_job->s_fence);
 	spin_lock_irqsave(&sched->queue_lock, flags);
 	list_del(&sched_job->list);
 	atomic64_dec(&sched->hw_rq_count);
 	spin_unlock_irqrestore(&sched->queue_lock, flags);
 
 	sched->ops->process_job(sched, sched_job);
+	fence_put(&sched_job->s_fence->base);
 	kfree(sched_job);
 	wake_up_interruptible(&sched->wait_queue);
 }

drivers/gpu/drm/amd/scheduler/gpu_scheduler.h

···
 	/* the virtual_seq is unique per context per ring */
 	atomic64_t			last_queued_v_seq;
 	atomic64_t			last_emitted_v_seq;
+	atomic64_t			last_signaled_v_seq;
 	/* the job_queue maintains the jobs submitted by clients */
 	struct kfifo                    job_queue;
 	spinlock_t			queue_lock;
···
 	wait_queue_head_t		wait_queue;
 	wait_queue_head_t		wait_emit;
 	bool                            is_pending;
+	uint64_t                        fence_context;
+	struct list_head		fence_list;
+	char                            name[20];
 };
 
 /**
···
 	int (*check_entity_status)(struct amd_sched_entity *entity);
 };
 
+struct amd_sched_fence {
+	struct fence                    base;
+	struct fence_cb                 cb;
+	struct list_head		list;
+	struct amd_sched_entity	        *entity;
+	uint64_t			v_seq;
+	spinlock_t			lock;
+};
+
 struct amd_sched_job {
 	struct list_head		list;
 	struct fence_cb                 cb;
 	struct amd_gpu_scheduler        *sched;
 	struct amd_sched_entity         *s_entity;
 	void                            *data;
+	struct amd_sched_fence          *s_fence;
 };
+
+extern const struct fence_ops amd_sched_fence_ops;
+static inline struct amd_sched_fence *to_amd_sched_fence(struct fence *f)
+{
+	struct amd_sched_fence *__f = container_of(f, struct amd_sched_fence, base);
+
+	if (__f->base.ops == &amd_sched_fence_ops)
+		return __f;
+
+	return NULL;
+}
 
 /**
  * Define the backend operations called by the scheduler,
···
 
 int amd_sched_push_job(struct amd_gpu_scheduler *sched,
 		       struct amd_sched_entity *c_entity,
-		       void *data);
+		       void *data,
+		       struct amd_sched_fence **fence);
 
 int amd_sched_wait_emit(struct amd_sched_entity *c_entity,
 			uint64_t seq,
···
 void amd_sched_emit(struct amd_sched_entity *c_entity, uint64_t seq);
 
 uint64_t amd_sched_next_queued_seq(struct amd_sched_entity *c_entity);
+
+struct amd_sched_fence *amd_sched_fence_create(
+	struct amd_sched_entity *s_entity);
+void amd_sched_fence_signal(struct amd_sched_fence *fence);
+
 
 #endif

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

···
+/*
+ * 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/wait.h>
+#include <linux/sched.h>
+#include <drm/drmP.h>
+#include "gpu_scheduler.h"
+
+static void amd_sched_fence_wait_cb(struct fence *f, struct fence_cb *cb)
+{
+	struct amd_sched_fence *fence =
+		container_of(cb, struct amd_sched_fence, cb);
+	list_del_init(&fence->list);
+	fence_put(&fence->base);
+}
+
+struct amd_sched_fence *amd_sched_fence_create(
+	struct amd_sched_entity *s_entity)
+{
+	struct amd_sched_fence *fence = NULL;
+	fence = kzalloc(sizeof(struct amd_sched_fence), GFP_KERNEL);
+	if (fence == NULL)
+		return NULL;
+	fence->v_seq = atomic64_inc_return(&s_entity->last_queued_v_seq);
+	fence->entity = s_entity;
+	spin_lock_init(&fence->lock);
+	fence_init(&fence->base, &amd_sched_fence_ops,
+		&fence->lock,
+		s_entity->fence_context,
+		fence->v_seq);
+	fence_get(&fence->base);
+	list_add_tail(&fence->list, &s_entity->fence_list);
+	if (fence_add_callback(&fence->base,&fence->cb,
+			       amd_sched_fence_wait_cb)) {
+		fence_put(&fence->base);
+		kfree(fence);
+		return NULL;
+	}
+	return fence;
+}
+
+bool amd_sched_check_ts(struct amd_sched_entity *s_entity, uint64_t v_seq)
+{
+	return atomic64_read(&s_entity->last_signaled_v_seq) >= v_seq ? true : false;
+}
+
+void amd_sched_fence_signal(struct amd_sched_fence *fence)
+{
+	if (amd_sched_check_ts(fence->entity, fence->v_seq)) {
+		int ret = fence_signal_locked(&fence->base);
+		if (!ret)
+			FENCE_TRACE(&fence->base, "signaled from irq context\n");
+		else
+			FENCE_TRACE(&fence->base, "was already signaled\n");
+	} else
+		WARN(true, "fence process dismattch with job!\n");
+}
+
+static const char *amd_sched_fence_get_driver_name(struct fence *fence)
+{
+	return "amd_sched";
+}
+
+static const char *amd_sched_fence_get_timeline_name(struct fence *f)
+{
+	struct amd_sched_fence *fence = to_amd_sched_fence(f);
+	return (const char *)fence->entity->name;
+}
+
+static bool amd_sched_fence_enable_signaling(struct fence *f)
+{
+	struct amd_sched_fence *fence = to_amd_sched_fence(f);
+
+	return !amd_sched_check_ts(fence->entity, fence->v_seq);
+}
+
+static bool amd_sched_fence_is_signaled(struct fence *f)
+{
+	struct amd_sched_fence *fence = to_amd_sched_fence(f);
+
+	return amd_sched_check_ts(fence->entity, fence->v_seq);
+}
+
+const struct fence_ops amd_sched_fence_ops = {
+	.get_driver_name = amd_sched_fence_get_driver_name,
+	.get_timeline_name = amd_sched_fence_get_timeline_name,
+	.enable_signaling = amd_sched_fence_enable_signaling,
+	.signaled = amd_sched_fence_is_signaled,
+	.wait = fence_default_wait,
+	.release = NULL,
+};