From 23759dc6430428897a36c4d493f611eca55c9481 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Sun, 2 Apr 2006 00:07:39 +0100 Subject: [ARM] 3439/2: xsc3: add I/O coherency support Patch from Lennert Buytenhek This patch adds support for the I/O coherent cache available on the xsc3. The approach is to provide a simple API to determine whether the chipset supports coherency by calling arch_is_coherent() and then setting the appropriate system memory PTE and PMD bits. In addition, we call this API on dma_alloc_coherent() and dma_map_single() calls. A generic version exists that will compile out all the coherency-related code that is not needed on the majority of ARM systems. Note that we do not check for coherency in the dma_alloc_writecombine() function as that still requires a special PTE setting. We also don't touch dma_mmap_coherent() as that is a special ARM-only API that is by definition only used on non-coherent system. Signed-off-by: Deepak Saxena Signed-off-by: Lennert Buytenhek Signed-off-by: Russell King --- include/asm-arm/pgtable-hwdef.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/asm-arm/pgtable-hwdef.h') diff --git a/include/asm-arm/pgtable-hwdef.h b/include/asm-arm/pgtable-hwdef.h index 1d033495cc75..1bc1f997bda2 100644 --- a/include/asm-arm/pgtable-hwdef.h +++ b/include/asm-arm/pgtable-hwdef.h @@ -73,6 +73,7 @@ #define PTE_EXT_AP_URW_SRW (PTE_EXT_AP1|PTE_EXT_AP0) #define PTE_EXT_TEX(x) ((x) << 6) /* v5 */ #define PTE_EXT_APX (1 << 9) /* v6 */ +#define PTE_EXT_COHERENT (1 << 9) /* XScale3 */ #define PTE_EXT_SHARED (1 << 10) /* v6 */ #define PTE_EXT_NG (1 << 11) /* v6 */ -- cgit v1.2.3