diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt index f50309081ac78e0900c3ef5e5646abf998079657..e59480db9ee0acb6be2793a9e48ea4e55d1bf5e3 100644 --- a/Documentation/DMA-attributes.txt +++ b/Documentation/DMA-attributes.txt @@ -91,3 +91,12 @@ transferred to 'device' domain. This attribute can be also used for dma_unmap_{single,page,sg} functions family to force buffer to stay in device domain after releasing a mapping for it. Use this attribute with care! + +DMA_ATTR_FORCE_CONTIGUOUS +------------------------- + +By default DMA-mapping subsystem is allowed to assemble the buffer +allocated by dma_alloc_attrs() function from individual pages if it can +be mapped as contiguous chunk into device dma address space. By +specifing this attribute the allocated buffer is forced to be contiguous +also in physical memory. diff --git a/include/linux/dma-attrs.h b/include/linux/dma-attrs.h index f83f793223ff7491f59c44b3c3bd6d7440b51084..c8e1831d757232c7364ebb909cb77a6442bb4a8a 100644 --- a/include/linux/dma-attrs.h +++ b/include/linux/dma-attrs.h @@ -17,6 +17,7 @@ enum dma_attr { DMA_ATTR_NON_CONSISTENT, DMA_ATTR_NO_KERNEL_MAPPING, DMA_ATTR_SKIP_CPU_SYNC, + DMA_ATTR_FORCE_CONTIGUOUS, DMA_ATTR_MAX, };