From 3aa91625007807bfca4155df1867a5c924a08662 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 29 Jun 2020 15:03:56 +0200 Subject: dma-mapping: Add a new dma_need_sync API Add a new API to check if calls to dma_sync_single_for_{device,cpu} are required for a given DMA streaming mapping. Signed-off-by: Christoph Hellwig Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200629130359.2690853-2-hch@lst.de --- Documentation/core-api/dma-api.rst | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation/core-api') diff --git a/Documentation/core-api/dma-api.rst b/Documentation/core-api/dma-api.rst index 2d8d2fed7317..f41620439ef3 100644 --- a/Documentation/core-api/dma-api.rst +++ b/Documentation/core-api/dma-api.rst @@ -204,6 +204,14 @@ Returns the maximum size of a mapping for the device. The size parameter of the mapping functions like dma_map_single(), dma_map_page() and others should not be larger than the returned value. +:: + + bool + dma_need_sync(struct device *dev, dma_addr_t dma_addr); + +Returns %true if dma_sync_single_for_{device,cpu} calls are required to +transfer memory ownership. Returns %false if those calls can be skipped. + :: unsigned long -- cgit v1.2.3