Commit 3159f372 authored Sep 24, 2013 by Sergey Dyasly Committed by Russell King Oct 29, 2013

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



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>

parent 31d141e3

arch/arm/mm/mmap.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -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

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