/* bitops.h: bit operations for the Fujitsu FR-V CPUs * * For an explanation of how atomic ops work in this arch, see: * Documentation/fujitsu/frv/atomic-ops.txt * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _ASM_BITOPS_H #define _ASM_BITOPS_H #include <linux/config.h> #include <linux/compiler.h> #include <asm/byteorder.h> #include <asm/system.h> #include <asm/atomic.h> #ifdef __KERNEL__ /* * ffz = Find First Zero in word. Undefined if no zero exists, * so code should check against ~0UL first.. */ static inline unsigned long ffz(unsigned long word) { unsigned long result = 0; while (word & 1) { result++; word >>= 1; } return result; } /* * 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 int test_and_clear_bit(int nr, volatile void *addr) { volatile unsigned long *ptr = addr; unsigned long mask = 1UL << (nr & 31); ptr += nr >> 5; return (atomic_test_and_ANDNOT_mask(mask, ptr) & mask) != 0; } static inline int test_and_set_bit(int nr, volatile void *addr) { volatile unsigned long *ptr = addr; unsigned long mask = 1UL << (nr & 31); ptr += nr >> 5; return (atomic_test_and_OR_mask(mask, ptr) & mask) != 0; } static inline int test_and_change_bit(int nr, volatile void *addr) { volatile unsigned long *ptr = addr; unsigned long mask = 1UL << (nr & 31); ptr += nr >> 5; return (atomic_test_and_XOR_mask(mask, ptr) & mask) != 0; } static inline void clear_bit(int nr, volatile void *addr) { test_and_clear_bit(nr, addr); } static inline void set_bit(int nr, volatile void *addr) { test_and_set_bit(nr, addr); } static inline void change_bit(int nr, volatile void * addr) { test_and_change_bit(nr, addr); } static inline void __clear_bit(int nr, volatile void * addr) { volatile unsigned long *a = addr; int mask; a += nr >> 5; mask = 1 << (nr & 31); *a &= ~mask; } static inline void __set_bit(int nr, volatile void * addr) { volatile unsigned long *a = addr; int mask; a += nr >> 5; mask = 1 << (nr & 31); *a |= mask; } static inline void __change_bit(int nr, volatile void *addr) { volatile unsigned long *a = addr; int mask; a += nr >> 5; mask = 1 << (nr & 31); *a ^= mask; } static inline int __test_and_clear_bit(int nr, volatile void * addr) { volatile unsigned long *a = addr; int mask, retval; a += nr >> 5; mask = 1 << (nr & 31); retval = (mask & *a) != 0; *a &= ~mask; return retval; } static inline int __test_and_set_bit(int nr, volatile void * addr) { volatile unsigned long *a = addr; int mask, retval; a += nr >> 5; mask = 1 << (nr & 31); retval = (mask & *a) != 0; *a |= mask; return retval; } static inline int __test_and_change_bit(int nr, volatile void * addr) { volatile unsigned long *a = addr; int mask, retval; a += nr >> 5; mask = 1 << (nr & 31); retval = (mask & *a) != 0; *a ^= mask; return retval; } /* * This routine doesn't need to be atomic. */ static inline int __constant_test_bit(int nr, const volatile void * addr) { return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0; } static inline int __test_bit(int nr, const volatile void * addr) { int * a = (int *) addr; int mask; a += nr >> 5; mask = 1 << (nr & 0x1f); return ((mask & *a) != 0); } #define test_bit(nr,addr) \ (__builtin_constant_p(nr) ? \ __constant_test_bit((nr),(addr)) : \ __test_bit((nr),(addr))) extern int find_next_bit(const unsigned long *addr, int size, int offset); #define find_first_bit(addr, size) find_next_bit(addr, size, 0) #define find_first_zero_bit(addr, size) \ find_next_zero_bit((addr), (size), 0) static inline int find_next_zero_bit(const void *addr, int size, int offset) { const unsigned long *p = ((const 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 ffs(x) generic_ffs(x) #define __ffs(x) (ffs(x) - 1) /* * fls: find last bit set. */ #define fls(x) \ ({ \ int bit; \ \ asm("scan %1,gr0,%0" : "=r"(bit) : "r"(x)); \ \ bit ? 33 - bit : bit; \ }) /* * Every architecture must define this function. It's the fastest * way of searching a 140-bit bitmap where the first 100 bits are * unlikely to be set. It's guaranteed that at least one of the 140 * bits is cleared. */ static inline int sched_find_first_bit(const unsigned long *b) { if (unlikely(b[0])) return __ffs(b[0]); if (unlikely(b[1])) return __ffs(b[1]) + 32; if (unlikely(b[2])) return __ffs(b[2]) + 64; if (b[3]) return __ffs(b[3]) + 96; return __ffs(b[4]) + 128; } /* * 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) #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)) #define ext2_set_bit_atomic(lock,nr,addr) ext2_set_bit((nr), addr) #define ext2_clear_bit_atomic(lock,nr,addr) ext2_clear_bit((nr), addr) static inline int ext2_test_bit(int nr, const volatile void * addr) { const volatile unsigned char *ADDR = (const unsigned char *) addr; int mask; ADDR += nr >> 3; mask = 1 << (nr & 0x07); return ((mask & *ADDR) != 0); } #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(const void *addr, unsigned long size, unsigned long offset) { const unsigned long *p = ((const unsigned long *) addr) + (offset >> 5); unsigned long result = offset & ~31UL; unsigned long tmp; if (offset >= size) return size; size -= result; offset &= 31UL; if(offset) { /* We hold the little endian value in tmp, but then the * shift is illegal. So we could keep a big endian value * in tmp, like this: * * tmp = __swab32(*(p++)); * tmp |= ~0UL >> (32-offset); * * but this would decrease preformance, so we change the * shift: */ tmp = *(p++); tmp |= __swab32(~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 is little endian, so we would have to swab the shift, * see above. But then we have to swab tmp below for ffz, so * we might as well do this here. */ return result + ffz(__swab32(tmp) | (~0UL << size)); found_middle: return result + ffz(__swab32(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) 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 /* __KERNEL__ */ #endif /* _ASM_BITOPS_H */