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>

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);