arm64: Use Normal NonCacheable memory for writecombine

commit 4f00130b70 upstream.

This provides better performance compared to Device GRE and also allows
unaligned accesses. Such memory is intended to be used with standard RAM
(e.g. framebuffers) and not I/O.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

(cherry picked from commit 3655a197b1)
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Catalin Marinas
2013-11-29 10:56:14 +00:00
committed by Mark Brown
parent b67a42ee58
commit e850da006c

View File

@@ -184,7 +184,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
#define pgprot_noncached(prot) \
__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE))
#define pgprot_writecombine(prot) \
__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_GRE))
__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC))
#define pgprot_dmacoherent(prot) \
__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC))
#define __HAVE_PHYS_MEM_ACCESS_PROT