From 26a26d329688ab018e068b412b03d43d7c299f0a Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 20 Nov 2009 21:06:43 +0000 Subject: ARM: dma-mapping: switch ARMv7 DMA mappings to retain 'memory' attribute On ARMv7, it is invalid to map the same physical address multiple times with different memory types. Since system RAM is already mapped as 'memory', subsequent remapping of it must retain this attribute. However, DMA memory maps it as "strongly ordered". Fix this by introducing 'pgprot_dmacoherent()' which provides the necessary page table bits for DMA mappings. Signed-off-by: Russell King Acked-by: Greg Ungerer Reviewed-by: Catalin Marinas --- arch/arm/include/asm/pgtable.h | 14 ++++++++++++-- arch/arm/include/asm/system.h | 19 ++++++++++++------- 2 files changed, 24 insertions(+), 9 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index 201ccaa11f6..11397687f42 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -304,13 +304,23 @@ PTE_BIT_FUNC(mkyoung, |= L_PTE_YOUNG); static inline pte_t pte_mkspecial(pte_t pte) { return pte; } +#define __pgprot_modify(prot,mask,bits) \ + __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) + /* * Mark the prot value as uncacheable and unbufferable. */ #define pgprot_noncached(prot) \ - __pgprot((pgprot_val(prot) & ~L_PTE_MT_MASK) | L_PTE_MT_UNCACHED) + __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) #define pgprot_writecombine(prot) \ - __pgprot((pgprot_val(prot) & ~L_PTE_MT_MASK) | L_PTE_MT_BUFFERABLE) + __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE) +#if __LINUX_ARM_ARCH__ >= 7 +#define pgprot_dmacoherent(prot) \ + __pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_BUFFERABLE) +#else +#define pgprot_dmacoherent(prot) \ + __pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_UNCACHED) +#endif #define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_present(pmd) (pmd_val(pmd)) diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index d65b2f5bf41..058e7e90881 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -138,21 +138,26 @@ extern unsigned int user_debug; #define dmb() __asm__ __volatile__ ("" : : : "memory") #endif -#ifndef CONFIG_SMP +#if __LINUX_ARM_ARCH__ >= 7 || defined(CONFIG_SMP) +#define mb() dmb() +#define rmb() dmb() +#define wmb() dmb() +#else #define mb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) #define rmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) #define wmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) +#endif + +#ifndef CONFIG_SMP #define smp_mb() barrier() #define smp_rmb() barrier() #define smp_wmb() barrier() #else -#define mb() dmb() -#define rmb() dmb() -#define wmb() dmb() -#define smp_mb() dmb() -#define smp_rmb() dmb() -#define smp_wmb() dmb() +#define smp_mb() mb() +#define smp_rmb() rmb() +#define smp_wmb() wmb() #endif + #define read_barrier_depends() do { } while(0) #define smp_read_barrier_depends() do { } while(0) -- cgit v1.2.3-70-g09d2