drm/v3d: Use scheduler dependency handling

With the prep work out of the way this isn't tricky anymore.

Aside: The chaining of the various jobs is a bit awkward, with the
possibility of failure in bad places. I think with the
drm_sched_job_init/arm split and maybe preloading the
job->dependencies xarray this should be fixable.

v2: Rebase over renamed function names for adding dependencies.

Reviewed-by: Melissa Wen <mwen@igalia.com> (v1)
Acked-by: Emma Anholt <emma@anholt.net>
Cc: Melissa Wen <melissa.srw@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Emma Anholt <emma@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20210805104705.862416-11-daniel.vetter@ffwll.ch

drivers/gpu/drm/v3d/v3d_drv.h

@@ -234,11 +234,6 @@ struct v3d_job {
 	struct drm_gem_object **bo;
 	u32 bo_count;
 
-	/* Array of struct dma_fence * to block on before submitting this job.
-	 */
-	struct xarray deps;
-	unsigned long last_dep;
-
 	/* v3d fence to be signaled by IRQ handler when the job is complete. */
 	struct dma_fence *irq_fence;
 

drivers/gpu/drm/v3d/v3d_gem.c

@@ -259,8 +259,8 @@ v3d_lock_bo_reservations(struct v3d_job *job,
 		return ret;
 
 	for (i = 0; i < job->bo_count; i++) {
-		ret = drm_gem_fence_array_add_implicit(&job->deps,
-						       job->bo[i], true);
+		ret = drm_sched_job_add_implicit_dependencies(&job->base,
+							      job->bo[i], true);
 		if (ret) {
 			drm_gem_unlock_reservations(job->bo, job->bo_count,
 						    acquire_ctx);
@@ -356,8 +356,6 @@ static void
 v3d_job_free(struct kref *ref)
 {
 	struct v3d_job *job = container_of(ref, struct v3d_job, refcount);
-	unsigned long index;
-	struct dma_fence *fence;
 	int i;
 
 	for (i = 0; i < job->bo_count; i++) {
@@ -366,11 +364,6 @@ v3d_job_free(struct kref *ref)
 	}
 	kvfree(job->bo);
 
-	xa_for_each(&job->deps, index, fence) {
-		dma_fence_put(fence);
-	}
-	xa_destroy(&job->deps);
-
 	dma_fence_put(job->irq_fence);
 	dma_fence_put(job->done_fence);
 
@@ -457,7 +450,6 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
 	if (ret < 0)
 		return ret;
 
-	xa_init_flags(&job->deps, XA_FLAGS_ALLOC);
 	ret = drm_sched_job_init(&job->base, &v3d_priv->sched_entity[queue],
 				 v3d_priv);
 	if (ret)
@@ -467,7 +459,7 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
 	if (ret == -EINVAL)
 		goto fail_job;
 
-	ret = drm_gem_fence_array_add(&job->deps, in_fence);
+	ret = drm_sched_job_add_dependency(&job->base, in_fence);
 	if (ret)
 		goto fail_job;
 
@@ -477,7 +469,6 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
 fail_job:
 	drm_sched_job_cleanup(&job->base);
 fail:
-	xa_destroy(&job->deps);
 	pm_runtime_put_autosuspend(v3d->drm.dev);
 	return ret;
 }
@@ -640,8 +631,8 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 		v3d_perfmon_get(bin->base.perfmon);
 		v3d_push_job(&bin->base);
 
-		ret = drm_gem_fence_array_add(&render->base.deps,
-					      dma_fence_get(bin->base.done_fence));
+		ret = drm_sched_job_add_dependency(&render->base.base,
+						   dma_fence_get(bin->base.done_fence));
 		if (ret)
 			goto fail_unreserve;
 	}
@@ -651,7 +642,8 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 	if (clean_job) {
 		struct dma_fence *render_fence =
 			dma_fence_get(render->base.done_fence);
-		ret = drm_gem_fence_array_add(&clean_job->deps, render_fence);
+		ret = drm_sched_job_add_dependency(&clean_job->base,
+						   render_fence);
 		if (ret)
 			goto fail_unreserve;
 		clean_job->perfmon = render->base.perfmon;
@@ -853,8 +845,8 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data,
 	mutex_lock(&v3d->sched_lock);
 	v3d_push_job(&job->base);
 
-	ret = drm_gem_fence_array_add(&clean_job->deps,
-				      dma_fence_get(job->base.done_fence));
+	ret = drm_sched_job_add_dependency(&clean_job->base,
+					   dma_fence_get(job->base.done_fence));
 	if (ret)
 		goto fail_unreserve;
 

drivers/gpu/drm/v3d/v3d_sched.c

@@ -13,7 +13,7 @@
  * jobs when bulk background jobs are queued up, we submit a new job
  * to the HW only when it has completed the last one, instead of
  * filling up the CT[01]Q FIFOs with jobs.  Similarly, we use
- * v3d_job_dependency() to manage the dependency between bin and
+ * drm_sched_job_add_dependency() to manage the dependency between bin and
  * render, instead of having the clients submit jobs using the HW's
  * semaphores to interlock between them.
  */
@@ -72,28 +72,6 @@ v3d_switch_perfmon(struct v3d_dev *v3d, struct v3d_job *job)
 		v3d_perfmon_start(v3d, job->perfmon);
 }
 
-/*
- * Returns the fences that the job depends on, one by one.
- *
- * If placed in the scheduler's .dependency method, the corresponding
- * .run_job won't be called until all of them have been signaled.
- */
-static struct dma_fence *
-v3d_job_dependency(struct drm_sched_job *sched_job,
-		   struct drm_sched_entity *s_entity)
-{
-	struct v3d_job *job = to_v3d_job(sched_job);
-
-	/* XXX: Wait on a fence for switching the GMP if necessary,
-	 * and then do so.
-	 */
-
-	if (!xa_empty(&job->deps))
-		return xa_erase(&job->deps, job->last_dep++);
-
-	return NULL;
-}
-
 static struct dma_fence *v3d_bin_job_run(struct drm_sched_job *sched_job)
 {
 	struct v3d_bin_job *job = to_bin_job(sched_job);
@@ -372,35 +350,30 @@ v3d_csd_job_timedout(struct drm_sched_job *sched_job)
 }
 
 static const struct drm_sched_backend_ops v3d_bin_sched_ops = {
-	.dependency = v3d_job_dependency,
 	.run_job = v3d_bin_job_run,
 	.timedout_job = v3d_bin_job_timedout,
 	.free_job = v3d_sched_job_free,
 };
 
 static const struct drm_sched_backend_ops v3d_render_sched_ops = {
-	.dependency = v3d_job_dependency,
 	.run_job = v3d_render_job_run,
 	.timedout_job = v3d_render_job_timedout,
 	.free_job = v3d_sched_job_free,
 };
 
 static const struct drm_sched_backend_ops v3d_tfu_sched_ops = {
-	.dependency = v3d_job_dependency,
 	.run_job = v3d_tfu_job_run,
 	.timedout_job = v3d_generic_job_timedout,
 	.free_job = v3d_sched_job_free,
 };
 
 static const struct drm_sched_backend_ops v3d_csd_sched_ops = {
-	.dependency = v3d_job_dependency,
 	.run_job = v3d_csd_job_run,
 	.timedout_job = v3d_csd_job_timedout,
 	.free_job = v3d_sched_job_free
 };
 
 static const struct drm_sched_backend_ops v3d_cache_clean_sched_ops = {
-	.dependency = v3d_job_dependency,
 	.run_job = v3d_cache_clean_job_run,
 	.timedout_job = v3d_generic_job_timedout,
 	.free_job = v3d_sched_job_free