1c54d77078
This unifies the set/clear/test bit functions of asm/bitops.h. I have not attempted to merge the bit-finding functions, since they rely on the machine word size and can't be easily restructured to work generically without a lot of #ifdefs. In particular, the 64-bit code can assume the presence of conditional move instructions, whereas 32-bit needs to be more careful. The inline assembly for the bit operations has been changed to remove explicit sizing hints on the instructions, so the assembler will pick the appropriate instruction forms depending on the architecture and the context. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Andi Kleen <ak@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
179 lines
4 KiB
C
179 lines
4 KiB
C
#ifndef _X86_64_BITOPS_H
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#define _X86_64_BITOPS_H
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/*
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* Copyright 1992, Linus Torvalds.
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*/
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extern long find_first_zero_bit(const unsigned long *addr, unsigned long size);
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extern long find_next_zero_bit(const unsigned long *addr, long size, long offset);
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extern long find_first_bit(const unsigned long *addr, unsigned long size);
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extern long find_next_bit(const unsigned long *addr, long size, long offset);
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/* return index of first bet set in val or max when no bit is set */
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static inline long __scanbit(unsigned long val, unsigned long max)
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{
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asm("bsfq %1,%0 ; cmovz %2,%0" : "=&r" (val) : "r" (val), "r" (max));
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return val;
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}
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#define find_first_bit(addr,size) \
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((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
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(__scanbit(*(unsigned long *)addr,(size))) : \
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find_first_bit(addr,size)))
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#define find_next_bit(addr,size,off) \
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((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
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((off) + (__scanbit((*(unsigned long *)addr) >> (off),(size)-(off)))) : \
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find_next_bit(addr,size,off)))
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#define find_first_zero_bit(addr,size) \
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((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
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(__scanbit(~*(unsigned long *)addr,(size))) : \
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find_first_zero_bit(addr,size)))
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#define find_next_zero_bit(addr,size,off) \
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((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
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((off)+(__scanbit(~(((*(unsigned long *)addr)) >> (off)),(size)-(off)))) : \
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find_next_zero_bit(addr,size,off)))
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/*
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* Find string of zero bits in a bitmap. -1 when not found.
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*/
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extern unsigned long
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find_next_zero_string(unsigned long *bitmap, long start, long nbits, int len);
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static inline void set_bit_string(unsigned long *bitmap, unsigned long i,
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int len)
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{
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unsigned long end = i + len;
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while (i < end) {
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__set_bit(i, bitmap);
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i++;
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}
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}
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static inline void __clear_bit_string(unsigned long *bitmap, unsigned long i,
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int len)
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{
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unsigned long end = i + len;
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while (i < end) {
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__clear_bit(i, bitmap);
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i++;
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}
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}
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/**
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* ffz - find first zero in word.
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* @word: The word to search
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*
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* Undefined if no zero exists, so code should check against ~0UL first.
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*/
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static inline unsigned long ffz(unsigned long word)
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{
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__asm__("bsfq %1,%0"
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:"=r" (word)
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:"r" (~word));
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return word;
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}
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/**
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* __ffs - find first bit in word.
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* @word: The word to search
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*
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* Undefined if no bit exists, so code should check against 0 first.
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*/
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static inline unsigned long __ffs(unsigned long word)
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{
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__asm__("bsfq %1,%0"
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:"=r" (word)
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:"rm" (word));
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return word;
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}
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/*
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* __fls: find last bit set.
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* @word: The word to search
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*
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* Undefined if no zero exists, so code should check against ~0UL first.
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*/
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static inline unsigned long __fls(unsigned long word)
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{
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__asm__("bsrq %1,%0"
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:"=r" (word)
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:"rm" (word));
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return word;
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}
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#ifdef __KERNEL__
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#include <asm-generic/bitops/sched.h>
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/**
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* ffs - find first bit set
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* @x: the word to search
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*
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* This is defined the same way as
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* the libc and compiler builtin ffs routines, therefore
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* differs in spirit from the above ffz (man ffs).
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*/
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static inline int ffs(int x)
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{
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int r;
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__asm__("bsfl %1,%0\n\t"
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"cmovzl %2,%0"
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: "=r" (r) : "rm" (x), "r" (-1));
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return r+1;
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}
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/**
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* fls64 - find last bit set in 64 bit word
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* @x: the word to search
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*
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* This is defined the same way as fls.
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*/
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static inline int fls64(__u64 x)
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{
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if (x == 0)
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return 0;
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return __fls(x) + 1;
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}
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/**
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* fls - find last bit set
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* @x: the word to search
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*
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* This is defined the same way as ffs.
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*/
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static inline int fls(int x)
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{
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int r;
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__asm__("bsrl %1,%0\n\t"
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"cmovzl %2,%0"
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: "=&r" (r) : "rm" (x), "rm" (-1));
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return r+1;
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}
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#define ARCH_HAS_FAST_MULTIPLIER 1
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#include <asm-generic/bitops/hweight.h>
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#endif /* __KERNEL__ */
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#ifdef __KERNEL__
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#include <asm-generic/bitops/ext2-non-atomic.h>
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#define ext2_set_bit_atomic(lock,nr,addr) \
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test_and_set_bit((nr),(unsigned long*)addr)
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#define ext2_clear_bit_atomic(lock,nr,addr) \
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test_and_clear_bit((nr),(unsigned long*)addr)
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#include <asm-generic/bitops/minix.h>
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#endif /* __KERNEL__ */
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#endif /* _X86_64_BITOPS_H */
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