From 10ef6b0dffe404bcc54e94cb2ca1a5b18445a66b Mon Sep 17 00:00:00 2001 From: "Chen, Gong" Date: Fri, 18 Oct 2013 14:29:07 -0700 Subject: bitops: Introduce a more generic BITMASK macro GENMASK is used to create a contiguous bitmask([hi:lo]). It is implemented twice in current kernel. One is in EDAC driver, the other is in SiS/XGI FB driver. Move it to a more generic place for other usage. Signed-off-by: Chen, Gong Cc: Borislav Petkov Cc: Thomas Winischhofer Cc: Jean-Christophe Plagniol-Villard Cc: Tomi Valkeinen Acked-by: Borislav Petkov Acked-by: Mauro Carvalho Chehab Signed-off-by: Tony Luck --- include/linux/bitops.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/bitops.h') diff --git a/include/linux/bitops.h b/include/linux/bitops.h index a3b6b82108b9..bd0c4598d03b 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -10,6 +10,14 @@ #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) #endif +/* + * Create a contiguous bitmask starting at bit position @l and ending at + * position @h. For example + * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. + */ +#define GENMASK(h, l) (((U32_C(1) << ((h) - (l) + 1)) - 1) << (l)) +#define GENMASK_ULL(h, l) (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l)) + extern unsigned int __sw_hweight8(unsigned int w); extern unsigned int __sw_hweight16(unsigned int w); extern unsigned int __sw_hweight32(unsigned int w); -- cgit v1.2.3-59-g8ed1b