LXR uboot/arch/sandbox/include/asm/bitops.h

   1/*
   2 * Copyright (c) 2011 The Chromium OS Authors.
   3 *
   4 * Modified from Linux arch/arm/include/asm/bitops.h
   5 *
   6 * Copyright 1995, Russell King.
   7 * Various bits and pieces copyrights include:
   8 *  Linus Torvalds (test_bit).
   9 *
  10 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  11 *
  12 * Please note that the code in this file should never be included
  13 * from user space.  Many of these are not implemented in assembler
  14 * since they would be too costly.  Also, they require priviledged
  15 * instructions (which are not available from user mode) to ensure
  16 * that they are atomic.
  17 */
  18
  19#ifndef __ASM_SANDBOX_BITOPS_H
  20#define __ASM_SANDBOX_BITOPS_H
  21
  22#include <linux/compiler.h>
  23#include <asm/system.h>
  24#include <asm-generic/bitops/fls.h>
  25#include <asm-generic/bitops/__fls.h>
  26#include <asm-generic/bitops/fls64.h>
  27#include <asm-generic/bitops/__ffs.h>
  28
  29#ifdef __KERNEL__
  30
  31#define smp_mb__before_clear_bit()      do { } while (0)
  32#define smp_mb__after_clear_bit()       do { } while (0)
  33
  34/*
  35 * Function prototypes to keep gcc -Wall happy.
  36 */
  37extern void set_bit(int nr, void *addr);
  38
  39extern void clear_bit(int nr, void *addr);
  40
  41extern void change_bit(int nr, void *addr);
  42
  43static inline void __change_bit(int nr, void *addr)
  44{
  45        unsigned long mask = BIT_MASK(nr);
  46        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  47
  48        *p ^= mask;
  49}
  50
  51static inline int __test_and_set_bit(int nr, void *addr)
  52{
  53        unsigned long mask = BIT_MASK(nr);
  54        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  55        unsigned long old = *p;
  56
  57        *p = old | mask;
  58        return (old & mask) != 0;
  59}
  60
  61static inline int test_and_set_bit(int nr, void *addr)
  62{
  63        unsigned long __always_unused flags;
  64        int out;
  65
  66        local_irq_save(flags);
  67        out = __test_and_set_bit(nr, addr);
  68        local_irq_restore(flags);
  69
  70        return out;
  71}
  72
  73static inline int __test_and_clear_bit(int nr, void *addr)
  74{
  75        unsigned long mask = BIT_MASK(nr);
  76        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  77        unsigned long old = *p;
  78
  79        *p = old & ~mask;
  80        return (old & mask) != 0;
  81}
  82
  83static inline int test_and_clear_bit(int nr, void *addr)
  84{
  85        unsigned long __always_unused flags;
  86        int out;
  87
  88        local_irq_save(flags);
  89        out = __test_and_clear_bit(nr, addr);
  90        local_irq_restore(flags);
  91
  92        return out;
  93}
  94
  95extern int test_and_change_bit(int nr, void *addr);
  96
  97static inline int __test_and_change_bit(int nr, void *addr)
  98{
  99        unsigned long mask = BIT_MASK(nr);
 100        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
 101        unsigned long old = *p;
 102
 103        *p = old ^ mask;
 104        return (old & mask) != 0;
 105}
 106
 107extern int find_first_zero_bit(void *addr, unsigned size);
 108extern int find_next_zero_bit(void *addr, int size, int offset);
 109
 110/*
 111 * This routine doesn't need to be atomic.
 112 */
 113static inline int test_bit(int nr, const void *addr)
 114{
 115        return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
 116}
 117
 118/*
 119 * ffz = Find First Zero in word. Undefined if no zero exists,
 120 * so code should check against ~0UL first..
 121 */
 122static inline unsigned long ffz(unsigned long word)
 123{
 124        int k;
 125
 126        word = ~word;
 127        k = 31;
 128        if (word & 0x0000ffff) {
 129                k -= 16; word <<= 16;
 130        }
 131        if (word & 0x00ff0000) {
 132                k -= 8;  word <<= 8;
 133        }
 134        if (word & 0x0f000000) {
 135                k -= 4;  word <<= 4;
 136        }
 137        if (word & 0x30000000) {
 138                k -= 2;  word <<= 2;
 139        }
 140        if (word & 0x40000000)
 141                k -= 1;
 142        return k;
 143}
 144
 145/*
 146 * hweightN: returns the hamming weight (i.e. the number
 147 * of bits set) of a N-bit word
 148 */
 149
 150#define hweight32(x) generic_hweight32(x)
 151#define hweight16(x) generic_hweight16(x)
 152#define hweight8(x) generic_hweight8(x)
 153
 154#define ext2_set_bit                    test_and_set_bit
 155#define ext2_clear_bit                  test_and_clear_bit
 156#define ext2_test_bit                   test_bit
 157#define ext2_find_first_zero_bit        find_first_zero_bit
 158#define ext2_find_next_zero_bit         find_next_zero_bit
 159
 160/* Bitmap functions for the minix filesystem. */
 161#define minix_test_and_set_bit(nr, addr)        test_and_set_bit(nr, addr)
 162#define minix_set_bit(nr, addr)                 set_bit(nr, addr)
 163#define minix_test_and_clear_bit(nr, addr)      test_and_clear_bit(nr, addr)
 164#define minix_test_bit(nr, addr)                test_bit(nr, addr)
 165#define minix_find_first_zero_bit(addr, size)   find_first_zero_bit(addr, size)
 166
 167#endif /* __KERNEL__ */
 168
 169#endif /* _ARM_BITOPS_H */
 170