1 files changed, 18 insertions, 29 deletions

diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
index ad7b210aa3f6..8e790ec219a5 100644
--- a/arch/x86/include/asm/bitops.h
+++ b/arch/x86/include/asm/bitops.h
@@ -36,22 +36,17 @@
  * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  */
 
-#if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
-/* Technically wrong, but this avoids compilation errors on some gcc
-   versions. */
-#define BITOP_ADDR(x) "=m" (*(volatile long *) (x))
-#else
-#define BITOP_ADDR(x) "+m" (*(volatile long *) (x))
-#endif
+#define RLONG_ADDR(x)			 "m" (*(volatile long *) (x))
+#define WBYTE_ADDR(x)			"+m" (*(volatile char *) (x))
 
-#define ADDR				BITOP_ADDR(addr)
+#define ADDR				RLONG_ADDR(addr)
 
 /*
  * We do the locked ops that don't return the old value as
  * a mask operation on a byte.
  */
 #define IS_IMMEDIATE(nr)		(__builtin_constant_p(nr))
-#define CONST_MASK_ADDR(nr, addr)	BITOP_ADDR((void *)(addr) + ((nr)>>3))
+#define CONST_MASK_ADDR(nr, addr)	WBYTE_ADDR((void *)(addr) + ((nr)>>3))
 #define CONST_MASK(nr)			(1 << ((nr) & 7))
 
 /**
@@ -79,7 +74,7 @@ set_bit(long nr, volatile unsigned long *addr)
 			: "memory");
 	} else {
 		asm volatile(LOCK_PREFIX __ASM_SIZE(bts) " %1,%0"
-			: BITOP_ADDR(addr) : "Ir" (nr) : "memory");
+			: : RLONG_ADDR(addr), "Ir" (nr) : "memory");
 	}
 }
 
@@ -94,7 +89,7 @@ set_bit(long nr, volatile unsigned long *addr)
  */
 static __always_inline void __set_bit(long nr, volatile unsigned long *addr)
 {
-	asm volatile(__ASM_SIZE(bts) " %1,%0" : ADDR : "Ir" (nr) : "memory");
+	asm volatile(__ASM_SIZE(bts) " %1,%0" : : ADDR, "Ir" (nr) : "memory");
 }
 
 /**
@@ -116,8 +111,7 @@ clear_bit(long nr, volatile unsigned long *addr)
 			: "iq" ((u8)~CONST_MASK(nr)));
 	} else {
 		asm volatile(LOCK_PREFIX __ASM_SIZE(btr) " %1,%0"
-			: BITOP_ADDR(addr)
-			: "Ir" (nr));
+			: : RLONG_ADDR(addr), "Ir" (nr) : "memory");
 	}
 }
 
@@ -137,7 +131,7 @@ static __always_inline void clear_bit_unlock(long nr, volatile unsigned long *ad
 
 static __always_inline void __clear_bit(long nr, volatile unsigned long *addr)
 {
-	asm volatile(__ASM_SIZE(btr) " %1,%0" : ADDR : "Ir" (nr));
+	asm volatile(__ASM_SIZE(btr) " %1,%0" : : ADDR, "Ir" (nr) : "memory");
 }
 
 static __always_inline bool clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
@@ -145,7 +139,7 @@ static __always_inline bool clear_bit_unlock_is_negative_byte(long nr, volatile
 	bool negative;
 	asm volatile(LOCK_PREFIX "andb %2,%1"
 		CC_SET(s)
-		: CC_OUT(s) (negative), ADDR
+		: CC_OUT(s) (negative), WBYTE_ADDR(addr)
 		: "ir" ((char) ~(1 << nr)) : "memory");
 	return negative;
 }
@@ -161,13 +155,9 @@ static __always_inline bool clear_bit_unlock_is_negative_byte(long nr, volatile
  * __clear_bit() is non-atomic and implies release semantics before the memory
  * operation. It can be used for an unlock if no other CPUs can concurrently
  * modify other bits in the word.
- *
- * No memory barrier is required here, because x86 cannot reorder stores past
- * older loads. Same principle as spin_unlock.
  */
 static __always_inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
 {
-	barrier();
 	__clear_bit(nr, addr);
 }
 
@@ -182,7 +172,7 @@ static __always_inline void __clear_bit_unlock(long nr, volatile unsigned long *
  */
 static __always_inline void __change_bit(long nr, volatile unsigned long *addr)
 {
-	asm volatile(__ASM_SIZE(btc) " %1,%0" : ADDR : "Ir" (nr));
+	asm volatile(__ASM_SIZE(btc) " %1,%0" : : ADDR, "Ir" (nr) : "memory");
 }
 
 /**
@@ -202,8 +192,7 @@ static __always_inline void change_bit(long nr, volatile unsigned long *addr)
 			: "iq" ((u8)CONST_MASK(nr)));
 	} else {
 		asm volatile(LOCK_PREFIX __ASM_SIZE(btc) " %1,%0"
-			: BITOP_ADDR(addr)
-			: "Ir" (nr));
+			: : RLONG_ADDR(addr), "Ir" (nr) : "memory");
 	}
 }
 
@@ -248,8 +237,8 @@ static __always_inline bool __test_and_set_bit(long nr, volatile unsigned long *
 
 	asm(__ASM_SIZE(bts) " %2,%1"
 	    CC_SET(c)
-	    : CC_OUT(c) (oldbit), ADDR
-	    : "Ir" (nr));
+	    : CC_OUT(c) (oldbit)
+	    : ADDR, "Ir" (nr) : "memory");
 	return oldbit;
 }
 
@@ -288,8 +277,8 @@ static __always_inline bool __test_and_clear_bit(long nr, volatile unsigned long
 
 	asm volatile(__ASM_SIZE(btr) " %2,%1"
 		     CC_SET(c)
-		     : CC_OUT(c) (oldbit), ADDR
-		     : "Ir" (nr));
+		     : CC_OUT(c) (oldbit)
+		     : ADDR, "Ir" (nr) : "memory");
 	return oldbit;
 }
 
@@ -300,8 +289,8 @@ static __always_inline bool __test_and_change_bit(long nr, volatile unsigned lon
 
 	asm volatile(__ASM_SIZE(btc) " %2,%1"
 		     CC_SET(c)
-		     : CC_OUT(c) (oldbit), ADDR
-		     : "Ir" (nr) : "memory");
+		     : CC_OUT(c) (oldbit)
+		     : ADDR, "Ir" (nr) : "memory");
 
 	return oldbit;
 }
@@ -332,7 +321,7 @@ static __always_inline bool variable_test_bit(long nr, volatile const unsigned l
 	asm volatile(__ASM_SIZE(bt) " %2,%1"
 		     CC_SET(c)
 		     : CC_OUT(c) (oldbit)
-		     : "m" (*(unsigned long *)addr), "Ir" (nr));
+		     : "m" (*(unsigned long *)addr), "Ir" (nr) : "memory");
 
 	return oldbit;
 }