aboutsummaryrefslogtreecommitdiff
path: root/include/asm-x86/bitops.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-x86/bitops.h')
-rw-r--r--include/asm-x86/bitops.h70
1 files changed, 48 insertions, 22 deletions
diff --git a/include/asm-x86/bitops.h b/include/asm-x86/bitops.h
index ee4b3ead6a4..cfb2b64f76e 100644
--- a/include/asm-x86/bitops.h
+++ b/include/asm-x86/bitops.h
@@ -23,11 +23,21 @@
#if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
/* Technically wrong, but this avoids compilation errors on some gcc
versions. */
-#define ADDR "=m" (*(volatile long *) addr)
+#define BITOP_ADDR(x) "=m" (*(volatile long *) (x))
#else
-#define ADDR "+m" (*(volatile long *) addr)
+#define BITOP_ADDR(x) "+m" (*(volatile long *) (x))
#endif
+#define ADDR BITOP_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(nr) (1 << ((nr) & 7))
+
/**
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
@@ -43,9 +53,17 @@
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
-static inline void set_bit(int nr, volatile void *addr)
+static inline void set_bit(unsigned int nr, volatile unsigned long *addr)
{
- asm volatile(LOCK_PREFIX "bts %1,%0" : ADDR : "Ir" (nr) : "memory");
+ if (IS_IMMEDIATE(nr)) {
+ asm volatile(LOCK_PREFIX "orb %1,%0"
+ : CONST_MASK_ADDR(nr, addr)
+ : "iq" ((u8)CONST_MASK(nr))
+ : "memory");
+ } else {
+ asm volatile(LOCK_PREFIX "bts %1,%0"
+ : BITOP_ADDR(addr) : "Ir" (nr) : "memory");
+ }
}
/**
@@ -57,7 +75,7 @@ static inline void set_bit(int nr, volatile void *addr)
* If it's called on the same region of memory simultaneously, the effect
* may be that only one operation succeeds.
*/
-static inline void __set_bit(int nr, volatile void *addr)
+static inline void __set_bit(int nr, volatile unsigned long *addr)
{
asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory");
}
@@ -72,9 +90,17 @@ static inline void __set_bit(int nr, volatile void *addr)
* you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
* in order to ensure changes are visible on other processors.
*/
-static inline void clear_bit(int nr, volatile void *addr)
+static inline void clear_bit(int nr, volatile unsigned long *addr)
{
- asm volatile(LOCK_PREFIX "btr %1,%0" : ADDR : "Ir" (nr));
+ if (IS_IMMEDIATE(nr)) {
+ asm volatile(LOCK_PREFIX "andb %1,%0"
+ : CONST_MASK_ADDR(nr, addr)
+ : "iq" ((u8)~CONST_MASK(nr)));
+ } else {
+ asm volatile(LOCK_PREFIX "btr %1,%0"
+ : BITOP_ADDR(addr)
+ : "Ir" (nr));
+ }
}
/*
@@ -85,13 +111,13 @@ static inline void clear_bit(int nr, volatile void *addr)
* clear_bit() is atomic and implies release semantics before the memory
* operation. It can be used for an unlock.
*/
-static inline void clear_bit_unlock(unsigned nr, volatile void *addr)
+static inline void clear_bit_unlock(unsigned nr, volatile unsigned long *addr)
{
barrier();
clear_bit(nr, addr);
}
-static inline void __clear_bit(int nr, volatile void *addr)
+static inline void __clear_bit(int nr, volatile unsigned long *addr)
{
asm volatile("btr %1,%0" : ADDR : "Ir" (nr));
}
@@ -108,7 +134,7 @@ static inline void __clear_bit(int nr, volatile void *addr)
* No memory barrier is required here, because x86 cannot reorder stores past
* older loads. Same principle as spin_unlock.
*/
-static inline void __clear_bit_unlock(unsigned nr, volatile void *addr)
+static inline void __clear_bit_unlock(unsigned nr, volatile unsigned long *addr)
{
barrier();
__clear_bit(nr, addr);
@@ -126,7 +152,7 @@ static inline void __clear_bit_unlock(unsigned nr, volatile void *addr)
* If it's called on the same region of memory simultaneously, the effect
* may be that only one operation succeeds.
*/
-static inline void __change_bit(int nr, volatile void *addr)
+static inline void __change_bit(int nr, volatile unsigned long *addr)
{
asm volatile("btc %1,%0" : ADDR : "Ir" (nr));
}
@@ -140,7 +166,7 @@ static inline void __change_bit(int nr, volatile void *addr)
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
-static inline void change_bit(int nr, volatile void *addr)
+static inline void change_bit(int nr, volatile unsigned long *addr)
{
asm volatile(LOCK_PREFIX "btc %1,%0" : ADDR : "Ir" (nr));
}
@@ -153,7 +179,7 @@ static inline void change_bit(int nr, volatile void *addr)
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
-static inline int test_and_set_bit(int nr, volatile void *addr)
+static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
{
int oldbit;
@@ -170,7 +196,7 @@ static inline int test_and_set_bit(int nr, volatile void *addr)
*
* This is the same as test_and_set_bit on x86.
*/
-static inline int test_and_set_bit_lock(int nr, volatile void *addr)
+static inline int test_and_set_bit_lock(int nr, volatile unsigned long *addr)
{
return test_and_set_bit(nr, addr);
}
@@ -184,7 +210,7 @@ static inline int test_and_set_bit_lock(int nr, volatile void *addr)
* If two examples of this operation race, one can appear to succeed
* but actually fail. You must protect multiple accesses with a lock.
*/
-static inline int __test_and_set_bit(int nr, volatile void *addr)
+static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
{
int oldbit;
@@ -203,7 +229,7 @@ static inline int __test_and_set_bit(int nr, volatile void *addr)
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
-static inline int test_and_clear_bit(int nr, volatile void *addr)
+static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
{
int oldbit;
@@ -223,7 +249,7 @@ static inline int test_and_clear_bit(int nr, volatile void *addr)
* If two examples of this operation race, one can appear to succeed
* but actually fail. You must protect multiple accesses with a lock.
*/
-static inline int __test_and_clear_bit(int nr, volatile void *addr)
+static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
{
int oldbit;
@@ -235,7 +261,7 @@ static inline int __test_and_clear_bit(int nr, volatile void *addr)
}
/* WARNING: non atomic and it can be reordered! */
-static inline int __test_and_change_bit(int nr, volatile void *addr)
+static inline int __test_and_change_bit(int nr, volatile unsigned long *addr)
{
int oldbit;
@@ -255,7 +281,7 @@ static inline int __test_and_change_bit(int nr, volatile void *addr)
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
-static inline int test_and_change_bit(int nr, volatile void *addr)
+static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
{
int oldbit;
@@ -266,13 +292,13 @@ static inline int test_and_change_bit(int nr, volatile void *addr)
return oldbit;
}
-static inline int constant_test_bit(int nr, const volatile void *addr)
+static inline int constant_test_bit(int nr, const volatile unsigned long *addr)
{
return ((1UL << (nr % BITS_PER_LONG)) &
(((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0;
}
-static inline int variable_test_bit(int nr, volatile const void *addr)
+static inline int variable_test_bit(int nr, volatile const unsigned long *addr)
{
int oldbit;
@@ -330,7 +356,7 @@ static inline unsigned long ffz(unsigned long word)
* __fls: find last set bit in word
* @word: The word to search
*
- * Undefined if no zero exists, so code should check against ~0UL first.
+ * Undefined if no set bit exists, so code should check against 0 first.
*/
static inline unsigned long __fls(unsigned long word)
{