From 9ab9e4fce45379cb6a7dbf87cf8f8e6ba01853c2 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 22 Feb 2016 15:02:08 +0100 Subject: [PATCH] ARM: memremap: implement arch_memremap_wb() The generic memremap() falls back to using ioremap_cache() to create MEMREMAP_WB mappings if the requested region is not already covered by the linear mapping, unless the architecture provides an implementation of arch_memremap_wb(). Since ioremap_cache() is not appropriate on ARM to map memory with the same attributes used for the linear mapping, implement arch_memremap_wb() which does exactly that. Also, relax the WARN() check to allow MT_MEMORY_RW mappings of pfn_valid() pages. Cc: Russell King Acked-by: Dan Williams Signed-off-by: Ard Biesheuvel --- arch/arm/include/asm/io.h | 6 ++++++ arch/arm/mm/ioremap.c | 12 ++++++++++-- arch/arm/mm/nommu.c | 5 +++++ 3 files changed, 21 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index fb94de290edd..781ef5fe235d 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -392,6 +392,9 @@ void __iomem *ioremap(resource_size_t res_cookie, size_t size); #define ioremap ioremap #define ioremap_nocache ioremap +/* + * Do not use ioremap_cache for mapping memory. Use memremap instead. + */ void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size); #define ioremap_cache ioremap_cache @@ -408,6 +411,9 @@ void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size); void iounmap(volatile void __iomem *iomem_cookie); #define iounmap iounmap +void *arch_memremap_wb(phys_addr_t phys_addr, size_t size); +#define arch_memremap_wb arch_memremap_wb + /* * io{read,write}{16,32}be() macros */ diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c index d5350f6af089..ff0eed23ddf1 100644 --- a/arch/arm/mm/ioremap.c +++ b/arch/arm/mm/ioremap.c @@ -297,9 +297,10 @@ static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn, } /* - * Don't allow RAM to be mapped - this causes problems with ARMv6+ + * Don't allow RAM to be mapped with mismatched attributes - this + * causes problems with ARMv6+ */ - if (WARN_ON(pfn_valid(pfn))) + if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW)) return NULL; area = get_vm_area_caller(size, VM_IOREMAP, caller); @@ -418,6 +419,13 @@ __arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached) __builtin_return_address(0)); } +void *arch_memremap_wb(phys_addr_t phys_addr, size_t size) +{ + return (__force void *)arch_ioremap_caller(phys_addr, size, + MT_MEMORY_RW, + __builtin_return_address(0)); +} + void __iounmap(volatile void __iomem *io_addr) { void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c index f24967e8ff7f..ca6d8e8ca1f8 100644 --- a/arch/arm/mm/nommu.c +++ b/arch/arm/mm/nommu.c @@ -384,6 +384,11 @@ void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size) } EXPORT_SYMBOL(ioremap_wc); +void *arch_memremap_wb(phys_addr_t phys_addr, size_t size) +{ + return (void *)phys_addr; +} + void __iounmap(volatile void __iomem *addr) { } -- 2.39.2