/* asm/bitops.h for Linux/CRIS * * TODO: asm versions if speed is needed * * All bit operations return 0 if the bit was cleared before the * operation and != 0 if it was not. * * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). */ #ifndef _CRIS_BITOPS_H #define _CRIS_BITOPS_H /* Currently this is unsuitable for consumption outside the kernel. */ #ifdef __KERNEL__ #ifndef _LINUX_BITOPS_H #error only can be included directly #endif #include #include #include #include /* * Some hacks to defeat gcc over-optimizations.. */ struct __dummy { unsigned long a[100]; }; #define ADDR (*(struct __dummy *) addr) #define CONST_ADDR (*(const struct __dummy *) addr) /* * set_bit - Atomically set a bit in memory * @nr: the bit to set * @addr: the address to start counting from * * This function is atomic and may not be reordered. See __set_bit() * if you do not require the atomic guarantees. * Note that @nr may be almost arbitrarily large; this function is not * restricted to acting on a single-word quantity. */ #define set_bit(nr, addr) (void)test_and_set_bit(nr, addr) /* * clear_bit - Clears a bit in memory * @nr: Bit to clear * @addr: Address to start counting from * * clear_bit() is atomic and may not be reordered. However, it does * not contain a memory barrier, so if it is used for locking purposes, * 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. */ #define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr) /* * change_bit - Toggle a bit in memory * @nr: Bit to change * @addr: Address to start counting from * * change_bit() is atomic and may not be reordered. * Note that @nr may be almost arbitrarily large; this function is not * restricted to acting on a single-word quantity. */ #define change_bit(nr, addr) (void)test_and_change_bit(nr, addr) /** * test_and_set_bit - Set a bit and return its old value * @nr: Bit to set * @addr: Address to count from * * This operation is atomic and cannot be reordered. * It also implies a memory barrier. */ static inline int test_and_set_bit(int nr, volatile unsigned long *addr) { unsigned int mask, retval; unsigned long flags; unsigned int *adr = (unsigned int *)addr; adr += nr >> 5; mask = 1 << (nr & 0x1f); cris_atomic_save(addr, flags); retval = (mask & *adr) != 0; *adr |= mask; cris_atomic_restore(addr, flags); return retval; } /* * clear_bit() doesn't provide any barrier for the compiler. */ #define smp_mb__before_clear_bit() barrier() #define smp_mb__after_clear_bit() barrier() /** * test_and_clear_bit - Clear a bit and return its old value * @nr: Bit to clear * @addr: Address to count from * * This operation is atomic and cannot be reordered. * It also implies a memory barrier. */ static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) { unsigned int mask, retval; unsigned long flags; unsigned int *adr = (unsigned int *)addr; adr += nr >> 5; mask = 1 << (nr & 0x1f); cris_atomic_save(addr, flags); retval = (mask & *adr) != 0; *adr &= ~mask; cris_atomic_restore(addr, flags); return retval; } /** * test_and_change_bit - Change a bit and return its old value * @nr: Bit to change * @addr: Address to count from * * This operation is atomic and cannot be reordered. * It also implies a memory barrier. */ static inline int test_and_change_bit(int nr, volatile unsigned long *addr) { unsigned int mask, retval; unsigned long flags; unsigned int *adr = (unsigned int *)addr; adr += nr >> 5; mask = 1 << (nr & 0x1f); cris_atomic_save(addr, flags); retval = (mask & *adr) != 0; *adr ^= mask; cris_atomic_restore(addr, flags); return retval; } #include /* * Since we define it "external", it collides with the built-in * definition, which doesn't have the same semantics. We don't want to * use -fno-builtin, so just hide the name ffs. */ #define ffs kernel_ffs #include #include #include #include #include #include #define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a) #define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a) #include #include #endif /* __KERNEL__ */ #endif /* _CRIS_BITOPS_H */