diff options
| author | Chen, Gong <gong.chen@linux.intel.com> | 2013-10-18 14:29:07 -0700 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2013-10-21 15:12:01 -0700 |
| commit | 10ef6b0dffe404bcc54e94cb2ca1a5b18445a66b (patch) | |
| tree | 6450859ffdc4494f2211442dd411b7f189cf326d /include/linux/bitops.h | |
| parent | 88f074f4871a8c212b212b725e4dcdcdb09613c1 (diff) | |
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 <gong.chen@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'include/linux/bitops.h')
| -rw-r--r-- | include/linux/bitops.h | 8 |
1 files changed, 8 insertions, 0 deletions
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); |