Messages in this thread Patch in this message | | | From | Ard Biesheuvel <> | Subject | [RFC PATCH 2/2] ARM: memremap: implement arch_memremap_wb() | Date | Mon, 22 Feb 2016 15:02:08 +0100 |
| |
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 <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/include/asm/io.h | 3 +++ arch/arm/mm/ioremap.c | 11 +++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index 485982084fe9..7456638e6b3a 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -402,6 +402,9 @@ 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 66a978d05958..d3a2b028c614 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); @@ -414,6 +415,12 @@ __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 __arm_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); -- 2.5.0
| |