ARM: 7979/1: mm: Remove hugetlb warning from Coherent DMA allocator
authorSteven Capper <steve.capper@linaro.org>
Tue, 18 Feb 2014 15:56:55 +0000 (16:56 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Tue, 18 Feb 2014 19:42:47 +0000 (19:42 +0000)
commit6ea41c80115f49e7d8b80312ffc99973d283471f
tree5cfcabf9636bcd38229a3cf6357d693efe5747c8
parentea36d2ab1a04d38bb24145b2b8fa8c8109cbe64d
ARM: 7979/1: mm: Remove hugetlb warning from Coherent DMA allocator

The Coherant DMA allocator allocates pages of high order then splits
them up into smaller pages.

This splitting logic would run into problems if the allocator was
given compound pages. Thus the Coherant DMA allocator was originally
incompatible with compound pages existing and, by extension, huge
pages. A compile #error was put in place whenever huge pages were
enabled.

Compatibility with compound pages has since been introduced by the
following commit (which merely excludes GFP_COMP pages from being
requested by the coherant DMA allocator):
  ea2e705 ARM: 7172/1: dma: Drop GFP_COMP for DMA memory allocations

When huge page support was introduced to ARM, the compile #error in
dma-mapping.c was replaced by a #warning when it should have been
removed instead.

This patch removes the compile #warning in dma-mapping.c when huge
pages are enabled.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/mm/dma-mapping.c