From d0a65199908110f3d4efb732363144e9b9436ea5 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 18 Aug 2015 10:34:42 +0100 Subject: [PATCH] arm64: set MAX_MEMBLOCK_ADDR according to linear region size commit 34ba2c4247e5c4b1542b1106e156af324660c4f0 upstream. The linear region size of a 39-bit VA kernel is only 256 GB, which may be insufficient to cover all of system RAM, even on platforms that have much less than 256 GB of memory but which is laid out very sparsely. So make sure we clip the memory we will not be able to map before installing it into the memblock memory table, by setting MAX_MEMBLOCK_ADDR accordingly. Reviewed-by: Catalin Marinas Tested-by: Stuart Yoder Signed-off-by: Ard Biesheuvel Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/memory.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index f800d45ea2265..44a59c20e7735 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -113,6 +113,14 @@ extern phys_addr_t memstart_addr; /* PHYS_OFFSET - the physical address of the start of memory. */ #define PHYS_OFFSET ({ memstart_addr; }) +/* + * The maximum physical address that the linear direct mapping + * of system RAM can cover. (PAGE_OFFSET can be interpreted as + * a 2's complement signed quantity and negated to derive the + * maximum size of the linear mapping.) + */ +#define MAX_MEMBLOCK_ADDR ({ memstart_addr - PAGE_OFFSET - 1; }) + /* * PFNs are used to describe any physical page; this means * PFN 0 == physical address 0. -- 2.47.2