diff options
Diffstat (limited to 'include/asm-i386/bitops.h')
| -rw-r--r-- | include/asm-i386/bitops.h | 105 |
1 files changed, 64 insertions, 41 deletions
diff --git a/include/asm-i386/bitops.h b/include/asm-i386/bitops.h index 18454e929..444f247c3 100644 --- a/include/asm-i386/bitops.h +++ b/include/asm-i386/bitops.h @@ -21,29 +21,9 @@ #define LOCK_PREFIX "" #endif -/* - * Function prototypes to keep gcc -Wall happy - */ -extern void set_bit(int nr, volatile void * addr); -extern void clear_bit(int nr, volatile void * addr); -extern void change_bit(int nr, volatile void * addr); -extern int test_and_set_bit(int nr, volatile void * addr); -extern int test_and_clear_bit(int nr, volatile void * addr); -extern int test_and_change_bit(int nr, volatile void * addr); -extern int __constant_test_bit(int nr, const volatile void * addr); -extern int __test_bit(int nr, volatile void * addr); -extern int find_first_zero_bit(void * addr, unsigned size); -extern int find_next_zero_bit (void * addr, int size, int offset); -extern unsigned long ffz(unsigned long word); - -/* - * Some hacks to defeat gcc over-optimizations.. - */ -struct __dummy { unsigned long a[100]; }; -#define ADDR (*(volatile struct __dummy *) addr) -#define CONST_ADDR (*(volatile const struct __dummy *) addr) +#define ADDR (*(volatile long *) addr) -extern __inline__ void set_bit(int nr, volatile void * addr) +static __inline__ void set_bit(int nr, volatile void * addr) { __asm__ __volatile__( LOCK_PREFIX "btsl %1,%0" @@ -51,7 +31,21 @@ extern __inline__ void set_bit(int nr, volatile void * addr) :"Ir" (nr)); } -extern __inline__ void clear_bit(int nr, volatile void * addr) +/* WARNING: non atomic and it can be reordered! */ +static __inline__ void __set_bit(int nr, volatile void * addr) +{ + __asm__( + "btsl %1,%0" + :"=m" (ADDR) + :"Ir" (nr)); +} + +/* + * clear_bit() doesn't provide any barrier for the compiler. + */ +#define smp_mb__before_clear_bit() barrier() +#define smp_mb__after_clear_bit() barrier() +static __inline__ void clear_bit(int nr, volatile void * addr) { __asm__ __volatile__( LOCK_PREFIX "btrl %1,%0" @@ -59,7 +53,7 @@ extern __inline__ void clear_bit(int nr, volatile void * addr) :"Ir" (nr)); } -extern __inline__ void change_bit(int nr, volatile void * addr) +static __inline__ void change_bit(int nr, volatile void * addr) { __asm__ __volatile__( LOCK_PREFIX "btcl %1,%0" @@ -67,48 +61,77 @@ extern __inline__ void change_bit(int nr, volatile void * addr) :"Ir" (nr)); } -extern __inline__ int test_and_set_bit(int nr, volatile void * addr) +/* + * It will also imply a memory barrier, thus it must clobber memory + * to make sure to reload anything that was cached into registers + * outside _this_ critical section. + */ +static __inline__ int test_and_set_bit(int nr, volatile void * addr) { int oldbit; __asm__ __volatile__( LOCK_PREFIX "btsl %2,%1\n\tsbbl %0,%0" :"=r" (oldbit),"=m" (ADDR) + :"Ir" (nr) : "memory"); + return oldbit; +} + +/* WARNING: non atomic and it can be reordered! */ +static __inline__ int __test_and_set_bit(int nr, volatile void * addr) +{ + int oldbit; + + __asm__( + "btsl %2,%1\n\tsbbl %0,%0" + :"=r" (oldbit),"=m" (ADDR) :"Ir" (nr)); return oldbit; } -extern __inline__ int test_and_clear_bit(int nr, volatile void * addr) +static __inline__ int test_and_clear_bit(int nr, volatile void * addr) { int oldbit; __asm__ __volatile__( LOCK_PREFIX "btrl %2,%1\n\tsbbl %0,%0" :"=r" (oldbit),"=m" (ADDR) + :"Ir" (nr) : "memory"); + return oldbit; +} + +/* WARNING: non atomic and it can be reordered! */ +static __inline__ int __test_and_clear_bit(int nr, volatile void * addr) +{ + int oldbit; + + __asm__( + "btrl %2,%1\n\tsbbl %0,%0" + :"=r" (oldbit),"=m" (ADDR) :"Ir" (nr)); return oldbit; } -extern __inline__ int test_and_change_bit(int nr, volatile void * addr) +static __inline__ int test_and_change_bit(int nr, volatile void * addr) { int oldbit; __asm__ __volatile__( LOCK_PREFIX "btcl %2,%1\n\tsbbl %0,%0" :"=r" (oldbit),"=m" (ADDR) - :"Ir" (nr)); + :"Ir" (nr) : "memory"); return oldbit; } /* * This routine doesn't need to be atomic. */ -extern __inline__ int __constant_test_bit(int nr, const volatile void * addr) +static __inline__ int constant_test_bit(int nr, const volatile void * addr) { return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0; } -extern __inline__ int __test_bit(int nr, volatile void * addr) +static __inline__ int variable_test_bit(int nr, volatile void * addr) { int oldbit; @@ -121,13 +144,13 @@ extern __inline__ int __test_bit(int nr, volatile void * addr) #define test_bit(nr,addr) \ (__builtin_constant_p(nr) ? \ - __constant_test_bit((nr),(addr)) : \ - __test_bit((nr),(addr))) + constant_test_bit((nr),(addr)) : \ + variable_test_bit((nr),(addr))) /* * Find-bit routines.. */ -extern __inline__ int find_first_zero_bit(void * addr, unsigned size) +static __inline__ int find_first_zero_bit(void * addr, unsigned size) { int d0, d1, d2; int res; @@ -151,7 +174,7 @@ extern __inline__ int find_first_zero_bit(void * addr, unsigned size) return res; } -extern __inline__ int find_next_zero_bit (void * addr, int size, int offset) +static __inline__ int find_next_zero_bit (void * addr, int size, int offset) { unsigned long * p = ((unsigned long *) addr) + (offset >> 5); int set = 0, bit = offset & 31, res; @@ -182,7 +205,7 @@ extern __inline__ int find_next_zero_bit (void * addr, int size, int offset) * ffz = Find First Zero in word. Undefined if no zero exists, * so code should check against ~0UL first.. */ -extern __inline__ unsigned long ffz(unsigned long word) +static __inline__ unsigned long ffz(unsigned long word) { __asm__("bsfl %1,%0" :"=r" (word) @@ -198,7 +221,7 @@ extern __inline__ unsigned long ffz(unsigned long word) * differs in spirit from the above ffz (man ffs). */ -extern __inline__ int ffs(int x) +static __inline__ int ffs(int x) { int r; @@ -222,16 +245,16 @@ extern __inline__ int ffs(int x) #ifdef __KERNEL__ -#define ext2_set_bit test_and_set_bit -#define ext2_clear_bit test_and_clear_bit +#define ext2_set_bit __test_and_set_bit +#define ext2_clear_bit __test_and_clear_bit #define ext2_test_bit test_bit #define ext2_find_first_zero_bit find_first_zero_bit #define ext2_find_next_zero_bit find_next_zero_bit /* Bitmap functions for the minix filesystem. */ -#define minix_test_and_set_bit(nr,addr) test_and_set_bit(nr,addr) -#define minix_set_bit(nr,addr) set_bit(nr,addr) -#define minix_test_and_clear_bit(nr,addr) test_and_clear_bit(nr,addr) +#define minix_test_and_set_bit(nr,addr) __test_and_set_bit(nr,addr) +#define minix_set_bit(nr,addr) __set_bit(nr,addr) +#define minix_test_and_clear_bit(nr,addr) __test_and_clear_bit(nr,addr) #define minix_test_bit(nr,addr) test_bit(nr,addr) #define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size) |