Re: [PATCH 5/6] RFC: dma-buf: Add an extra fence to dma_resv_get_singleton_unlocked

Am 10.06.21 um 23:09 schrieb Jason Ekstrand:

For dma-buf sync_file import, we want to get all the fences on a dma_resv plus one more. We could wrap the fence we get back in an array fence or we could make dma_resv_get_singleton_unlocked take "one more" to make this case easier.

Signed-off-by: Jason Ekstrand jason@jlekstrand.net Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch

Reviewed-by: Christian König christian.koenig@amd.com

Cc: Christian König christian.koenig@amd.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com

---

drivers/dma-buf/dma-buf.c | 2 +- drivers/dma-buf/dma-resv.c | 23 +++++++++++++++++++++-- include/linux/dma-resv.h | 3 ++- 3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 41b14b53cdda3..831828d71b646 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -389,7 +389,7 @@ static long dma_buf_export_sync_file(struct dma_buf *dmabuf, return fd;

if (arg.flags & DMA_BUF_SYNC_WRITE) {

• fence = dma_resv_get_singleton(dmabuf->resv);
  

• fence = dma_resv_get_singleton(dmabuf->resv, NULL);
  

  if (IS_ERR(fence)) { ret = PTR_ERR(fence); goto err_put_fd;

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 1b26aa7e5d81c..7c48c23239b4b 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -504,6 +504,7 @@ EXPORT_SYMBOL_GPL(dma_resv_get_fences); /**

• dma_resv_get_singleton - get a single fence for the dma_resv object
• @obj: the reservation object

• • @extra: extra fence to add to the resulting array
  • Get a single fence representing all unsignaled fences in the dma_resv object
  • plus the given extra fence. If we got only one fence return a new

@@ -512,7 +513,8 @@ EXPORT_SYMBOL_GPL(dma_resv_get_fences);

• RETURNS
• The singleton dma_fence on success or an ERR_PTR on failure

*/ -struct dma_fence *dma_resv_get_singleton(struct dma_resv *obj) +struct dma_fence *dma_resv_get_singleton(struct dma_resv *obj,

• 			 struct dma_fence *extra)
  

  { struct dma_fence *result, **resv_fences, *fence, *chain, **fences; struct dma_fence_array *array;

@@ -523,7 +525,7 @@ struct dma_fence *dma_resv_get_singleton(struct dma_resv *obj) if (err) return ERR_PTR(err);

• if (num_resv_fences == 0)

• if (num_resv_fences == 0 && !extra) return NULL;

  num_fences = 0;

@@ -539,6 +541,16 @@ struct dma_fence *dma_resv_get_singleton(struct dma_resv *obj) } }

• if (extra) {

• dma_fence_deep_dive_for_each(fence, chain, j, extra) {
  

• 	if (dma_fence_is_signaled(fence))
  

• 		continue;
  

• 	result = fence;
  

• 	++num_fences;
  

• }
  

• }
• if (num_fences <= 1) { result = dma_fence_get(result); goto put_resv_fences;

@@ -559,6 +571,13 @@ struct dma_fence *dma_resv_get_singleton(struct dma_resv *obj) } }

• if (extra) {

• dma_fence_deep_dive_for_each(fence, chain, j, extra) {
  

• 	if (dma_fence_is_signaled(fence))
  

• 		fences[num_fences++] = dma_fence_get(fence);
  

• }
  

• }
• if (num_fences <= 1) { result = num_fences ? fences[0] : NULL; kfree(fences);

diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index d60982975a786..f970e03fc1a08 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -275,7 +275,8 @@ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence); int dma_resv_get_fences(struct dma_resv *obj, struct dma_fence **pfence_excl, unsigned *pshared_count, struct dma_fence ***pshared); int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src); -struct dma_fence *dma_resv_get_singleton(struct dma_resv *obj); +struct dma_fence *dma_resv_get_singleton(struct dma_resv *obj,

• 			 struct dma_fence *extra);
  

  long dma_resv_wait_timeout(struct dma_resv *obj, bool wait_all, bool intr, unsigned long timeout); bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all);