[PATCH 6/8 RESEND] drivers: add Contiguous Memory Allocator

[Arnd Bergmann]

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 at samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> CC: Michal Nazarewicz <mina86 at mina86.com>

Reviewed-by: Arnd Bergmann <arnd at 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