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ARM: 7840/1: LPAE: don't reject mapping /dev/mem above 4GB

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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>
This commit is contained in:
Sergey Dyasly 2013-09-24 16:38:00 +01:00 committed by Russell King
parent 31d141e3a6
commit 3159f37235
1 changed files with 2 additions and 4 deletions
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6
arch/arm/mm/mmap.c
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@ -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