From b6b461e90f8fbebb8fa46f363999ed5023be7d3c Mon Sep 17 00:00:00 2001 From: Sergey Dyasly Date: Tue, 24 Sep 2013 16:38:00 +0100 Subject: ARM: 7840/1: LPAE: don't reject mapping /dev/mem above 4GB commit 3159f372354e8e1f5dee714663d705dd2c7e0759 upstream. With LPAE enabled, physical address space is larger than 4GB. Allow mapping any part of it via /dev/mem by using PHYS_MASK to determine valid range. PHYS_MASK covers 40 bits with LPAE enabled and 32 bits otherwise. Reported-by: Vassili Karpov Signed-off-by: Sergey Dyasly Acked-by: Catalin Marinas Signed-off-by: Russell King Cc: hujianyang Signed-off-by: Greg Kroah-Hartman --- arch/arm/mm/mmap.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index f0ef2f7d4ad..5ef506c6f49 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -204,13 +204,11 @@ int valid_phys_addr_range(phys_addr_t addr, size_t size) } /* - * We don't use supersection mappings for mmap() on /dev/mem, which - * means that we can't map the memory area above the 4G barrier into - * userspace. + * Do not allow /dev/mem mappings beyond the supported physical range. */ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) { - return !(pfn + (size >> PAGE_SHIFT) > 0x00100000); + return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT)); } #ifdef CONFIG_STRICT_DEVMEM -- cgit v1.2.3