Commit 1f70b8b8 authored by Chris Wilson's avatar Chris Wilson
Browse files

dma-fence: Propagate errors to dma-fence-array container 



When one of the array of fences is signaled, propagate its errors to the
parent fence-array (keeping the first error to be raised).

v2: Opencode cmpxchg_local to avoid compiler freakout.
v3: Be careful not to flag an error if we race against signal-on-any.
v4: Same applies to installing the signal cb.
v5: Use cmpxchg to only set the error once before using a nifty idea by
Christian to avoid changing the status after emitting the signal.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Christian König <christian.koenig@amd.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190811210902.22112-1-chris@chris-wilson.co.uk
parent e0d409ff

drivers/dma-buf/dma-fence-array.c

+31 −1
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ 
#include <linux/slab.h>

#include <linux/dma-fence-array.h>



#define PENDING_ERROR 1



static const char *dma_fence_array_get_driver_name(struct dma_fence *fence)

{

	return "dma_fence_array";
@@ -23,10 +25,29 @@ static const char *dma_fence_array_get_timeline_name(struct dma_fence *fence) 
	return "unbound";

}



static void dma_fence_array_set_pending_error(struct dma_fence_array *array,

					      int error)

{

	/*

	 * Propagate the first error reported by any of our fences, but only

	 * before we ourselves are signaled.

	 */

	if (error)

		cmpxchg(&array->base.error, PENDING_ERROR, error);

}



static void dma_fence_array_clear_pending_error(struct dma_fence_array *array)

{

	/* Clear the error flag if not actually set. */

	cmpxchg(&array->base.error, PENDING_ERROR, 0);

}



static void irq_dma_fence_array_work(struct irq_work *wrk)

{

	struct dma_fence_array *array = container_of(wrk, typeof(*array), work);



	dma_fence_array_clear_pending_error(array);



	dma_fence_signal(&array->base);

	dma_fence_put(&array->base);

}
@@ -38,6 +59,8 @@ static void dma_fence_array_cb_func(struct dma_fence *f, 
		container_of(cb, struct dma_fence_array_cb, cb);

	struct dma_fence_array *array = array_cb->array;



	dma_fence_array_set_pending_error(array, f->error);



	if (atomic_dec_and_test(&array->num_pending))

		irq_work_queue(&array->work);

	else
@@ -63,11 +86,16 @@ static bool dma_fence_array_enable_signaling(struct dma_fence *fence) 
		dma_fence_get(&array->base);

		if (dma_fence_add_callback(array->fences[i], &cb[i].cb,

					   dma_fence_array_cb_func)) {

			int error = array->fences[i]->error;



			dma_fence_array_set_pending_error(array, error);

			dma_fence_put(&array->base);

			if (atomic_dec_and_test(&array->num_pending))

			if (atomic_dec_and_test(&array->num_pending)) {

				dma_fence_array_clear_pending_error(array);

				return false;

			}

		}

	}



	return true;

}
@@ -142,6 +170,8 @@ struct dma_fence_array *dma_fence_array_create(int num_fences, 
	atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);

	array->fences = fences;



	array->base.error = PENDING_ERROR;



	return array;

}

EXPORT_SYMBOL(dma_fence_array_create);

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