1/* 2 * include/asm-xtensa/bitops.h 3 * 4 * Atomic operations that C can't guarantee us.Useful for resource counting etc. 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 * 10 * Copyright (C) 2001 - 2007 Tensilica Inc. 11 */ 12 13#ifndef _XTENSA_BITOPS_H 14#define _XTENSA_BITOPS_H 15 16#ifdef __KERNEL__ 17 18#ifndef _LINUX_BITOPS_H 19#error only <linux/bitops.h> can be included directly 20#endif 21 22#include <asm/processor.h> 23#include <asm/byteorder.h> 24#include <asm/system.h> 25 26#ifdef CONFIG_SMP 27# error SMP not supported on this architecture 28#endif 29 30#define smp_mb__before_clear_bit() barrier() 31#define smp_mb__after_clear_bit() barrier() 32 33#include <asm-generic/bitops/atomic.h> 34#include <asm-generic/bitops/non-atomic.h> 35 36#if XCHAL_HAVE_NSA 37 38static inline unsigned long __cntlz (unsigned long x) 39{ 40 int lz; 41 asm ("nsau %0, %1" : "=r" (lz) : "r" (x)); 42 return lz; 43} 44 45/* 46 * ffz: Find first zero in word. Undefined if no zero exists. 47 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). 48 */ 49 50static inline int ffz(unsigned long x) 51{ 52 return 31 - __cntlz(~x & -~x); 53} 54 55/* 56 * __ffs: Find first bit set in word. Return 0 for bit 0 57 */ 58 59static inline int __ffs(unsigned long x) 60{ 61 return 31 - __cntlz(x & -x); 62} 63 64/* 65 * ffs: Find first bit set in word. This is defined the same way as 66 * the libc and compiler builtin ffs routines, therefore 67 * differs in spirit from the above ffz (man ffs). 68 */ 69 70static inline int ffs(unsigned long x) 71{ 72 return 32 - __cntlz(x & -x); 73} 74 75/* 76 * fls: Find last (most-significant) bit set in word. 77 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 78 */ 79 80static inline int fls (unsigned int x) 81{ 82 return 32 - __cntlz(x); 83} 84 85/** 86 * __fls - find last (most-significant) set bit in a long word 87 * @word: the word to search 88 * 89 * Undefined if no set bit exists, so code should check against 0 first. 90 */ 91static inline unsigned long __fls(unsigned long word) 92{ 93 return 31 - __cntlz(word); 94} 95#else 96 97/* Use the generic implementation if we don't have the nsa/nsau instructions. */ 98 99# include <asm-generic/bitops/ffs.h> 100# include <asm-generic/bitops/__ffs.h> 101# include <asm-generic/bitops/ffz.h> 102# include <asm-generic/bitops/fls.h> 103# include <asm-generic/bitops/__fls.h> 104 105#endif 106 107#include <asm-generic/bitops/fls64.h> 108#include <asm-generic/bitops/find.h> 109#include <asm-generic/bitops/ext2-non-atomic.h> 110 111#ifdef __XTENSA_EL__ 112# define ext2_set_bit_atomic(lock,nr,addr) \ 113 test_and_set_bit((nr), (unsigned long*)(addr)) 114# define ext2_clear_bit_atomic(lock,nr,addr) \ 115 test_and_clear_bit((nr), (unsigned long*)(addr)) 116#elif defined(__XTENSA_EB__) 117# define ext2_set_bit_atomic(lock,nr,addr) \ 118 test_and_set_bit((nr) ^ 0x18, (unsigned long*)(addr)) 119# define ext2_clear_bit_atomic(lock,nr,addr) \ 120 test_and_clear_bit((nr) ^ 0x18, (unsigned long*)(addr)) 121#else 122# error processor byte order undefined! 123#endif 124 125#include <asm-generic/bitops/hweight.h> 126#include <asm-generic/bitops/lock.h> 127#include <asm-generic/bitops/sched.h> 128#include <asm-generic/bitops/minix.h> 129 130#endif /* __KERNEL__ */ 131 132#endif /* _XTENSA_BITOPS_H */ 133