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: Russell King rmk+kernel@arm.linux.org.uk --- drivers/dma-buf/dma-buf.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletions(-)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 0007b792827b..f72aaacbe023 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -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 +1090,34 @@ 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;