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Diffstat (limited to 'include/asm-cris/bitops.h')
| -rw-r--r-- | include/asm-cris/bitops.h | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/include/asm-cris/bitops.h b/include/asm-cris/bitops.h new file mode 100644 index 000000000..2d2c4df61 --- /dev/null +++ b/include/asm-cris/bitops.h @@ -0,0 +1,184 @@ +/* $Id: bitops.h,v 1.3 2000/10/17 14:56:27 bjornw Exp $ */ +/* all of these should probably be rewritten in assembler for speed. */ + +#ifndef _CRIS_BITOPS_H +#define _CRIS_BITOPS_H + +#include <asm/system.h> + +/* + * These have to be done with inline assembly: that way the bit-setting + * is guaranteed to be atomic. 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). + */ + +/* + * 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) + +#define set_bit(nr, addr) (void)test_and_set_bit(nr, addr) +#define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr) +#define change_bit(nr, addr) (void)test_and_change_bit(nr, addr) + +extern __inline__ int test_and_set_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned long flags; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + save_flags(flags); + cli(); + retval = (mask & *adr) != 0; + *adr |= mask; + restore_flags(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() + +extern __inline__ int test_and_clear_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned long flags; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + save_flags(flags); + cli(); + retval = (mask & *adr) != 0; + *adr &= ~mask; + restore_flags(flags); + return retval; +} + +extern __inline__ int test_and_change_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned long flags; + unsigned int *adr = (unsigned int *)addr; + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + save_flags(flags); + cli(); + retval = (mask & *adr) != 0; + *adr ^= mask; + restore_flags(flags); + return retval; +} + +/* + * This routine doesn't need to be atomic. + */ +extern __inline__ int test_bit(int nr, const void *addr) +{ + unsigned int mask; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + return ((mask & *adr) != 0); +} + +/* + * Find-bit routines.. + */ + +/* + * 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) +{ + unsigned long result = 0; + + while(word & 1) { + result++; + word >>= 1; + } + return result; +} + +/* + * Find first one in word. Undefined if no one exists, + * so code should check against 0UL first.. + */ +extern __inline__ unsigned long find_first_one(unsigned long word) +{ + unsigned long result = 0; + + while(!(word & 1)) { + result++; + word >>= 1; + } + return result; +} + +extern __inline__ int find_next_zero_bit (void * addr, int size, int offset) +{ + unsigned long *p = ((unsigned long *) addr) + (offset >> 5); + unsigned long result = offset & ~31UL; + unsigned long 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) + goto found_middle; + size -= 32; + result += 32; + } + while (size & ~31UL) { + if (~(tmp = *(p++))) + 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 find_first_zero_bit(addr, size) \ + find_next_zero_bit((addr), (size), 0) + +#ifdef __KERNEL__ + +#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_set_bit(nr,addr) test_and_set_bit(nr,addr) +#define minix_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) + +#endif /* __KERNEL__ */ + + +#endif /* _CRIS_BITOPS_H */ |