Commit 5eb2c72c authored by Russell King's avatar Russell King Committed by Gustavo Padovan
Browse files

dma-buf: fence debugging 



Add debugfs output to report shared and exclusive fences on a dma_buf
object.  This produces output such as:

Dma-buf Objects:
size    flags   mode    count   exp_name
08294400        00000000        00000005        00000005        drm
        Exclusive fence: etnaviv 134000.gpu signalled
        Attached Devices:
        gpu-subsystem
Total 1 devices attached

Total 1 objects, 8294400 bytes

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/E1cttMI-00068z-3X@rmk-PC.armlinux.org.uk
parent b121b051

drivers/dma-buf/dma-buf.c

+33 −1
Original line number Diff line number Diff line
@@ -1059,7 +1059,11 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) 
	int ret;

	struct dma_buf *buf_obj;

	struct dma_buf_attachment *attach_obj;

	int count = 0, attach_count;

	struct reservation_object *robj;

	struct reservation_object_list *fobj;

	struct dma_fence *fence;

	unsigned seq;

	int count = 0, attach_count, shared_count, i;

	size_t size = 0;



	ret = mutex_lock_interruptible(&db_list.lock);
@@ -1085,6 +1089,34 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) 
				file_count(buf_obj->file),

				buf_obj->exp_name);



		robj = buf_obj->resv;

		while (true) {

			seq = read_seqcount_begin(&robj->seq);

			rcu_read_lock();

			fobj = rcu_dereference(robj->fence);

			shared_count = fobj ? fobj->shared_count : 0;

			fence = rcu_dereference(robj->fence_excl);

			if (!read_seqcount_retry(&robj->seq, seq))

				break;

			rcu_read_unlock();

		}



		if (fence)

			seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n",

				   fence->ops->get_driver_name(fence),

				   fence->ops->get_timeline_name(fence),

				   dma_fence_is_signaled(fence) ? "" : "un");

		for (i = 0; i < shared_count; i++) {

			fence = rcu_dereference(fobj->shared[i]);

			if (!dma_fence_get_rcu(fence))

				continue;

			seq_printf(s, "\tShared fence: %s %s %ssignalled\n",

				   fence->ops->get_driver_name(fence),

				   fence->ops->get_timeline_name(fence),

				   dma_fence_is_signaled(fence) ? "" : "un");

		}

		rcu_read_unlock();



		seq_puts(s, "\tAttached Devices:\n");

		attach_count = 0;

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