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Diffstat (limited to 'arch/powerpc/include/asm/bitops.h')
| -rw-r--r-- | arch/powerpc/include/asm/bitops.h | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/bitops.h b/arch/powerpc/include/asm/bitops.h new file mode 100644 index 00000000000..adaf0914921 --- /dev/null +++ b/arch/powerpc/include/asm/bitops.h @@ -0,0 +1,387 @@ +/* + * bitops.h: Bit string operations on the ppc + */ + +#ifndef _PPC_BITOPS_H +#define _PPC_BITOPS_H + +#include <linux/config.h> +#include <asm/byteorder.h> + +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); + +/* + * Arguably these bit operations don't imply any memory barrier or + * SMP ordering, but in fact a lot of drivers expect them to imply + * both, since they do on x86 cpus. + */ +#ifdef CONFIG_SMP +#define SMP_WMB "eieio\n" +#define SMP_MB "\nsync" +#else +#define SMP_WMB +#define SMP_MB +#endif /* CONFIG_SMP */ + +#define __INLINE_BITOPS 1 + +#if __INLINE_BITOPS +/* + * These used to be if'd out here because using : "cc" as a constraint + * resulted in errors from egcs. Things may be OK with gcc-2.95. + */ +extern __inline__ void set_bit(int nr, volatile void * addr) +{ + unsigned long old; + unsigned long mask = 1 << (nr & 0x1f); + unsigned long *p = ((unsigned long *)addr) + (nr >> 5); + + __asm__ __volatile__(SMP_WMB "\ +1: lwarx %0,0,%3\n\ + or %0,%0,%2\n\ + stwcx. %0,0,%3\n\ + bne 1b" + SMP_MB + : "=&r" (old), "=m" (*p) + : "r" (mask), "r" (p), "m" (*p) + : "cc" ); +} + +extern __inline__ void clear_bit(int nr, volatile void *addr) +{ + unsigned long old; + unsigned long mask = 1 << (nr & 0x1f); + unsigned long *p = ((unsigned long *)addr) + (nr >> 5); + + __asm__ __volatile__(SMP_WMB "\ +1: lwarx %0,0,%3\n\ + andc %0,%0,%2\n\ + stwcx. %0,0,%3\n\ + bne 1b" + SMP_MB + : "=&r" (old), "=m" (*p) + : "r" (mask), "r" (p), "m" (*p) + : "cc"); +} + +extern __inline__ void change_bit(int nr, volatile void *addr) +{ + unsigned long old; + unsigned long mask = 1 << (nr & 0x1f); + unsigned long *p = ((unsigned long *)addr) + (nr >> 5); + + __asm__ __volatile__(SMP_WMB "\ +1: lwarx %0,0,%3\n\ + xor %0,%0,%2\n\ + stwcx. %0,0,%3\n\ + bne 1b" + SMP_MB + : "=&r" (old), "=m" (*p) + : "r" (mask), "r" (p), "m" (*p) + : "cc"); +} + +extern __inline__ int test_and_set_bit(int nr, volatile void *addr) +{ + unsigned int old, t; + unsigned int mask = 1 << (nr & 0x1f); + volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); + + __asm__ __volatile__(SMP_WMB "\ +1: lwarx %0,0,%4\n\ + or %1,%0,%3\n\ + stwcx. %1,0,%4\n\ + bne 1b" + SMP_MB + : "=&r" (old), "=&r" (t), "=m" (*p) + : "r" (mask), "r" (p), "m" (*p) + : "cc"); + + return (old & mask) != 0; +} + +extern __inline__ int test_and_clear_bit(int nr, volatile void *addr) +{ + unsigned int old, t; + unsigned int mask = 1 << (nr & 0x1f); + volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); + + __asm__ __volatile__(SMP_WMB "\ +1: lwarx %0,0,%4\n\ + andc %1,%0,%3\n\ + stwcx. %1,0,%4\n\ + bne 1b" + SMP_MB + : "=&r" (old), "=&r" (t), "=m" (*p) + : "r" (mask), "r" (p), "m" (*p) + : "cc"); + + return (old & mask) != 0; +} + +extern __inline__ int test_and_change_bit(int nr, volatile void *addr) +{ + unsigned int old, t; + unsigned int mask = 1 << (nr & 0x1f); + volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); + + __asm__ __volatile__(SMP_WMB "\ +1: lwarx %0,0,%4\n\ + xor %1,%0,%3\n\ + stwcx. %1,0,%4\n\ + bne 1b" + SMP_MB + : "=&r" (old), "=&r" (t), "=m" (*p) + : "r" (mask), "r" (p), "m" (*p) + : "cc"); + + return (old & mask) != 0; +} +#endif /* __INLINE_BITOPS */ + +extern __inline__ int test_bit(int nr, __const__ volatile void *addr) +{ + __const__ unsigned int *p = (__const__ unsigned int *) addr; + + return ((p[nr >> 5] >> (nr & 0x1f)) & 1) != 0; +} + +/* Return the bit position of the most significant 1 bit in a word */ +/* - the result is undefined when x == 0 */ +extern __inline__ int __ilog2(unsigned int x) +{ + int lz; + + asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x)); + return 31 - lz; +} + +extern __inline__ int ffz(unsigned int x) +{ + if ((x = ~x) == 0) + return 32; + return __ilog2(x & -x); +} + +/* + * fls: find last (most-significant) bit set. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + * + * On powerpc, __ilog2(0) returns -1, but this is not safe in general + */ +static __inline__ int fls(unsigned int x) +{ + return __ilog2(x) + 1; +} +#define PLATFORM_FLS + +/** + * fls64 - find last set bit in a 64-bit word + * @x: the word to search + * + * This is defined in a similar way as the libc and compiler builtin + * ffsll, but returns the position of the most significant set bit. + * + * fls64(value) returns 0 if value is 0 or the position of the last + * set bit if value is nonzero. The last (most significant) bit is + * at position 64. + */ +#if BITS_PER_LONG == 32 +static inline int fls64(__u64 x) +{ + __u32 h = x >> 32; + if (h) + return fls(h) + 32; + return fls(x); +} +#elif BITS_PER_LONG == 64 +static inline int fls64(__u64 x) +{ + if (x == 0) + return 0; + return __ilog2(x) + 1; +} +#else +#error BITS_PER_LONG not 32 or 64 +#endif + +static inline int __ilog2_u64(u64 n) +{ + return fls64(n) - 1; +} + +static inline int ffs64(u64 x) +{ + return __ilog2_u64(x & -x) + 1ull; +} + +#ifdef __KERNEL__ + +/* + * ffs: find first bit set. This is defined the same way as + * the libc and compiler builtin ffs routines, therefore + * differs in spirit from the above ffz (man ffs). + */ +extern __inline__ int ffs(int x) +{ + return __ilog2(x & -x) + 1; +} +#define PLATFORM_FFS + +/* + * hweightN: returns the hamming weight (i.e. the number + * of bits set) of a N-bit word + */ + +#define hweight32(x) generic_hweight32(x) +#define hweight16(x) generic_hweight16(x) +#define hweight8(x) generic_hweight8(x) + +#endif /* __KERNEL__ */ + +/* + * This implementation of find_{first,next}_zero_bit was stolen from + * Linus' asm-alpha/bitops.h. + */ +#define find_first_zero_bit(addr, size) \ + find_next_zero_bit((addr), (size), 0) + +extern __inline__ unsigned long find_next_zero_bit(void * addr, + unsigned long size, unsigned long offset) +{ + unsigned int * p = ((unsigned int *) addr) + (offset >> 5); + unsigned int result = offset & ~31UL; + unsigned int tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 31UL; + if (offset) { + tmp = *p++; + tmp |= ~0UL >> (32-offset); + if (size < 32) + goto found_first; + if (tmp != ~0U) + goto found_middle; + size -= 32; + result += 32; + } + while (size >= 32) { + if ((tmp = *p++) != ~0U) + goto found_middle; + result += 32; + size -= 32; + } + if (!size) + return result; + tmp = *p; +found_first: + tmp |= ~0UL << size; +found_middle: + return result + ffz(tmp); +} + + +#define _EXT2_HAVE_ASM_BITOPS_ + +#ifdef __KERNEL__ +/* + * test_and_{set,clear}_bit guarantee atomicity without + * disabling interrupts. + */ +#define ext2_set_bit(nr, addr) test_and_set_bit((nr) ^ 0x18, addr) +#define ext2_clear_bit(nr, addr) test_and_clear_bit((nr) ^ 0x18, addr) + +#else +extern __inline__ int ext2_set_bit(int nr, void * addr) +{ + int mask; + unsigned char *ADDR = (unsigned char *) addr; + int oldbit; + + ADDR += nr >> 3; + mask = 1 << (nr & 0x07); + oldbit = (*ADDR & mask) ? 1 : 0; + *ADDR |= mask; + return oldbit; +} + +extern __inline__ int ext2_clear_bit(int nr, void * addr) +{ + int mask; + unsigned char *ADDR = (unsigned char *) addr; + int oldbit; + + ADDR += nr >> 3; + mask = 1 << (nr & 0x07); + oldbit = (*ADDR & mask) ? 1 : 0; + *ADDR = *ADDR & ~mask; + return oldbit; +} +#endif /* __KERNEL__ */ + +extern __inline__ int ext2_test_bit(int nr, __const__ void * addr) +{ + __const__ unsigned char *ADDR = (__const__ unsigned char *) addr; + + return (ADDR[nr >> 3] >> (nr & 7)) & 1; +} + +/* + * This implementation of ext2_find_{first,next}_zero_bit was stolen from + * Linus' asm-alpha/bitops.h and modified for a big-endian machine. + */ + +#define ext2_find_first_zero_bit(addr, size) \ + ext2_find_next_zero_bit((addr), (size), 0) + +static __inline__ unsigned long ext2_find_next_zero_bit(void *addr, + unsigned long size, unsigned long offset) +{ + unsigned int *p = ((unsigned int *) addr) + (offset >> 5); + unsigned int result = offset & ~31UL; + unsigned int tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 31UL; + if (offset) { + tmp = cpu_to_le32p(p++); + tmp |= ~0UL >> (32-offset); + if (size < 32) + goto found_first; + if (tmp != ~0U) + goto found_middle; + size -= 32; + result += 32; + } + while (size >= 32) { + if ((tmp = cpu_to_le32p(p++)) != ~0U) + goto found_middle; + result += 32; + size -= 32; + } + if (!size) + return result; + tmp = cpu_to_le32p(p); +found_first: + tmp |= ~0U << size; +found_middle: + return result + ffz(tmp); +} + +/* Bitmap functions for the minix filesystem. */ +#define minix_test_and_set_bit(nr,addr) ext2_set_bit(nr,addr) +#define minix_set_bit(nr,addr) ((void)ext2_set_bit(nr,addr)) +#define minix_test_and_clear_bit(nr,addr) ext2_clear_bit(nr,addr) +#define minix_test_bit(nr,addr) ext2_test_bit(nr,addr) +#define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size) + +#endif /* _PPC_BITOPS_H */ |