X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=include%2Flinux%2Fbitops.h;h=be5fd38bd5a05d83eaac250055defcccacafe054;hb=00a1a053ebe5febcfc2ec498bd894f035ad2aa06;hp=abc9ca7784568ba5737add4fce84577348428eac;hpb=7acd71879ce408af2d2ca3cd3ec3a86d0667ceae;p=~andy%2Flinux

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index abc9ca77845..be5fd38bd5a 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -196,6 +196,21 @@ static inline unsigned long __ffs64(u64 word)
 
 #ifdef __KERNEL__
 
+#ifndef set_mask_bits
+#define set_mask_bits(ptr, _mask, _bits)	\
+({								\
+	const typeof(*ptr) mask = (_mask), bits = (_bits);	\
+	typeof(*ptr) old, new;					\
+								\
+	do {							\
+		old = ACCESS_ONCE(*ptr);			\
+		new = (old & ~mask) | bits;			\
+	} while (cmpxchg(ptr, old, new) != old);		\
+								\
+	new;							\
+})
+#endif
+
 #ifndef find_last_bit
 /**
  * find_last_bit - find the last set bit in a memory region