ARM: dts: imx6qdl: add support for Ka-Ro TX6 modules

[karo-tx-linux.git] / Documentation / DMA-attributes.txt

diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt
index f50309081ac78e0900c3ef5e5646abf998079657..cc2450d80310a5b8b0d979a23bd469c2d22ec130 100644 (file)
--- a/Documentation/DMA-attributes.txt
+++ b/Documentation/DMA-attributes.txt
@@ -13,7 +13,7 @@ all pending DMA writes to complete, and thus provides a mechanism to
 strictly order DMA from a device across all intervening busses and
 bridges.  This barrier is not specific to a particular type of
 interconnect, it applies to the system as a whole, and so its
-implementation must account for the idiosyncracies of the system all
+implementation must account for the idiosyncrasies of the system all
 the way from the DMA device to memory.
 
 As an example of a situation where DMA_ATTR_WRITE_BARRIER would be
@@ -60,7 +60,7 @@ such mapping is non-trivial task and consumes very limited resources
 Buffers allocated with this attribute can be only passed to user space
 by calling dma_mmap_attrs(). By using this API, you are guaranteeing
 that you won't dereference the pointer returned by dma_alloc_attr(). You
-can threat it as a cookie that must be passed to dma_mmap_attrs() and
+can treat it as a cookie that must be passed to dma_mmap_attrs() and
 dma_free_attrs(). Make sure that both of these also get this attribute
 set on each call.
 
@@ -82,7 +82,7 @@ to 'device' domain, what synchronizes CPU caches for the given region
 (usually it means that the cache has been flushed or invalidated
 depending on the dma direction). However, next calls to
 dma_map_{single,page,sg}() for other devices will perform exactly the
-same sychronization operation on the CPU cache. CPU cache sychronization
+same synchronization operation on the CPU cache. CPU cache synchronization
 might be a time consuming operation, especially if the buffers are
 large, so it is highly recommended to avoid it if possible.
 DMA_ATTR_SKIP_CPU_SYNC allows platform code to skip synchronization of
@@ -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.