On Tuesday 05 July 2011, Marek Szyprowski wrote:
The Contiguous Memory Allocator is a set of helper functions for DMA mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on system boot, marks it with CMA_MIGRATE_TYPE and gives back to the system. Kernel is allowed to allocate movable pages within CMA's managed memory so that it can be used for example for page cache when DMA mapping do not use it. On dma_alloc_from_contiguous() request such pages are migrated out of CMA area to free required contiguous block and fulfill the request. This allows to allocate large contiguous chunks of memory at any time assuming that there is enough free memory available in the system.
This code is heavily based on earlier works by Michal Nazarewicz.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com CC: Michal Nazarewicz mina86@mina86.com
Reviewed-by: Arnd Bergmann arnd@arndb.de, but I noticed two one-character mistakes:
+if CMA
+config CMA_DEBUG
- bool "CMA debug messages (DEVELOPEMENT)"
s/DEVELOPEMENT/DEVELOPMENT/
diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 4c5701c..be6aab4 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -5,6 +5,7 @@ obj-y := core.o sys.o bus.o dd.o syscore.o \ cpu.o firmware.o init.o map.o devres.o \ attribute_container.o transport_class.o obj-$(CONFIG_DEVTMPFS) += devtmpfs.o +obj-$(CONFIG_CMA) += dma-contiguous.o obj-y += power/ obj-$(CONFIG_HAS_DMA) += dma-mapping.o
Please add another tab to indent the line in the same way as the others.
Arnd