diff options
| author | Sergey Dyasly <dserrg@gmail.com> | 2013-09-24 16:38:00 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-05-05 11:44:20 +0200 |
| commit | 4aeced5ed3e351ffad601615a11305b6e2eb16e1 (patch) | |
| tree | e8b1e391ba251205b4ae51524bba195f7bd3aa94 /arch | |
| parent | 3da1d25c3849e8a02d4f70feeae16711ad458eaf (diff) | |
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 <av1474@comtv.ru>
Signed-off-by: Sergey Dyasly <dserrg@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mm/mmap.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 304661d21369..5e85ed371364 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -202,13 +202,11 @@ 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 |