From d5b59a71204b0a9a55eda633347b1214642bead3 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Tue, 26 Sep 2017 00:21:27 +0200 Subject: [PATCH] parisc: Convert MAP_TYPE to cover 4 bits on parisc On parisc we want to be as much as possible compatible to the major architectures like x86. Those architectures have MAP_TYPE defined as 0x0f which covers MAP_SHARED and MAP_PRIVATE and leaves two more bits unused. In contrast, on parisc we have MAP_TYPE defined to 0x03 which covers MAP_SHARED and MAP_PRIVATE only. But we don't have the 2 bits free as x86. Usually that's not a problem, but during the discussions for pmem+dax support the idea came up to use the two remaining bits of MAP_TYPE (on x86 and others) for the new MAP_DIRECT and MAP_SYNC flags. One requirement is, that an old kernel should correctly handle MAP_DIRECT and MAP_SYNC and fail on those if set. This only works if MAP_TYPE has 4 bits. Even though the pmem+dax people now choosed another solution via MAP_SHARED_VALIDATE, let's still proceed to be more compatible to x86 by adding two more bits for future usage. Signed-off-by: Helge Deller Signed-off-by: John David Anglin --- arch/parisc/include/uapi/asm/mman.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h index 80510ba44c08..a056a642bb31 100644 --- a/arch/parisc/include/uapi/asm/mman.h +++ b/arch/parisc/include/uapi/asm/mman.h @@ -13,7 +13,7 @@ #define MAP_SHARED 0x01 /* Share changes */ #define MAP_PRIVATE 0x02 /* Changes are private */ #define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */ -#define MAP_TYPE 0x03 /* Mask for type of mapping */ +#define MAP_TYPE 0x2b /* Mask for type of mapping, includes bits 0x08 and 0x20 */ #define MAP_FIXED 0x04 /* Interpret addr exactly */ #define MAP_ANONYMOUS 0x10 /* don't use a file */