Hi John, Suren,
On Wed, 20 Jan 2021 at 02:15, John Stultz john.stultz@linaro.org wrote:
We shouldn't vunmap more then we vmap, but if we do, make sure we complain loudly.
I was checking the general usage of vunmap in the kernel, and I couldn't find many instances where we need to WARN_ON for the vunmap count more than vmap count. Is there a specific need for this in the heaps?
Best, Sumit.
Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Liam Mark lmark@codeaurora.org Cc: Laura Abbott labbott@kernel.org Cc: Brian Starkey Brian.Starkey@arm.com Cc: Hridya Valsaraju hridya@google.com Cc: Suren Baghdasaryan surenb@google.com Cc: Sandeep Patil sspatil@google.com Cc: Daniel Mentz danielmentz@google.com Cc: Chris Goldsworthy cgoldswo@codeaurora.org Cc: Ørjan Eide orjan.eide@arm.com Cc: Robin Murphy robin.murphy@arm.com Cc: Ezequiel Garcia ezequiel@collabora.com Cc: Simon Ser contact@emersion.fr Cc: James Jones jajones@nvidia.com Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Suggested-by: Suren Baghdasaryan surenb@google.com Signed-off-by: John Stultz john.stultz@linaro.org
drivers/dma-buf/heaps/cma_heap.c | 1 + drivers/dma-buf/heaps/system_heap.c | 1 + 2 files changed, 2 insertions(+)
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c index 364fc2f3e499..0c76cbc3fb11 100644 --- a/drivers/dma-buf/heaps/cma_heap.c +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -232,6 +232,7 @@ static void cma_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) struct cma_heap_buffer *buffer = dmabuf->priv;
mutex_lock(&buffer->lock);
WARN_ON(buffer->vmap_cnt == 0); if (!--buffer->vmap_cnt) { vunmap(buffer->vaddr); buffer->vaddr = NULL;diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index 405351aad2a8..2321c91891f6 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -273,6 +273,7 @@ static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) struct system_heap_buffer *buffer = dmabuf->priv;
mutex_lock(&buffer->lock);
WARN_ON(buffer->vmap_cnt == 0); if (!--buffer->vmap_cnt) { vunmap(buffer->vaddr); buffer->vaddr = NULL;-- 2.17.1