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

   1/*
   2 * Copyright 1995, Russell King.
   3 * Various bits and pieces copyrights include:
   4 * Linus Torvalds (test_bit).
   5 *
   6 * Copyright (C) 2017 Andes Technology Corporation
   7 * Rick Chen, Andes Technology Corporation <rick@andestech.com>
   8 *
   9 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  10 *
  11 * Please note that the code in this file should never be included
  12 * from user space.  Many of these are not implemented in assembler
  13 * since they would be too costly.  Also, they require priviledged
  14 * instructions (which are not available from user mode) to ensure
  15 * that they are atomic.
  16 */
  17
  18#ifndef __ASM_RISCV_BITOPS_H
  19#define __ASM_RISCV_BITOPS_H
  20
  21#ifdef __KERNEL__
  22
  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#define smp_mb__before_clear_bit()      do { } while (0)
  30#define smp_mb__after_clear_bit()       do { } while (0)
  31
  32/*
  33 * Function prototypes to keep gcc -Wall happy.
  34 */
  35static inline void __set_bit(int nr, void *addr)
  36{
  37        int *a = (int *)addr;
  38        int mask;
  39
  40        a += nr >> 5;
  41        mask = 1 << (nr & 0x1f);
  42        *a |= mask;
  43}
  44
  45static inline void __clear_bit(int nr, void *addr)
  46{
  47        int *a = (int *)addr;
  48        int mask;
  49
  50        a += nr >> 5;
  51        mask = 1 << (nr & 0x1f);
  52        *a &= ~mask;
  53}
  54
  55static inline void __change_bit(int nr, void *addr)
  56{
  57        int mask;
  58        unsigned long *ADDR = (unsigned long *)addr;
  59
  60        ADDR += nr >> 5;
  61        mask = 1 << (nr & 31);
  62        *ADDR ^= mask;
  63}
  64
  65static inline int __test_and_set_bit(int nr, void *addr)
  66{
  67        int mask, retval;
  68        unsigned int *a = (unsigned int *)addr;
  69
  70        a += nr >> 5;
  71        mask = 1 << (nr & 0x1f);
  72        retval = (mask & *a) != 0;
  73        *a |= mask;
  74        return retval;
  75}
  76
  77static inline int __test_and_clear_bit(int nr, void *addr)
  78{
  79        int mask, retval;
  80        unsigned int *a = (unsigned int *)addr;
  81
  82        a += nr >> 5;
  83        mask = 1 << (nr & 0x1f);
  84        retval = (mask & *a) != 0;
  85        *a &= ~mask;
  86        return retval;
  87}
  88
  89static inline int __test_and_change_bit(int nr, void *addr)
  90{
  91        int mask, retval;
  92        unsigned int *a = (unsigned int *)addr;
  93
  94        a += nr >> 5;
  95        mask = 1 << (nr & 0x1f);
  96        retval = (mask & *a) != 0;
  97        *a ^= mask;
  98        return retval;
  99}
 100
 101/*
 102 * This routine doesn't need to be atomic.
 103 */
 104static inline int test_bit(int nr, const void *addr)
 105{
 106        return ((unsigned char *)addr)[nr >> 3] & (1U << (nr & 7));
 107}
 108
 109/*
 110 * ffz = Find First Zero in word. Undefined if no zero exists,
 111 * so code should check against ~0UL first..
 112 */
 113static inline unsigned long ffz(unsigned long word)
 114{
 115        int k;
 116
 117        word = ~word;
 118        k = 31;
 119        if (word & 0x0000ffff) {
 120                k -= 16; word <<= 16;
 121        }
 122        if (word & 0x00ff0000) {
 123                k -= 8;  word <<= 8;
 124        }
 125        if (word & 0x0f000000) {
 126                k -= 4;  word <<= 4;
 127        }
 128        if (word & 0x30000000) {
 129                k -= 2;  word <<= 2;
 130        }
 131        if (word & 0x40000000)
 132                k -= 1;
 133
 134        return k;
 135}
 136
 137/*
 138 * ffs: find first bit set. This is defined the same way as
 139 * the libc and compiler builtin ffs routines, therefore
 140 * differs in spirit from the above ffz (man ffs).
 141 */
 142
 143/*
 144 * redefined in include/linux/bitops.h
 145 * #define ffs(x) generic_ffs(x)
 146 */
 147
 148/*
 149 * hweightN: returns the hamming weight (i.e. the number
 150 * of bits set) of a N-bit word
 151 */
 152
 153#define hweight32(x) generic_hweight32(x)
 154#define hweight16(x) generic_hweight16(x)
 155#define hweight8(x) generic_hweight8(x)
 156
 157#define ext2_set_bit                    test_and_set_bit
 158#define ext2_clear_bit                  test_and_clear_bit
 159#define ext2_test_bit                   test_bit
 160#define ext2_find_first_zero_bit        find_first_zero_bit
 161#define ext2_find_next_zero_bit         find_next_zero_bit
 162
 163/* Bitmap functions for the minix filesystem. */
 164#define minix_test_and_set_bit(nr, addr)        test_and_set_bit(nr, addr)
 165#define minix_set_bit(nr, addr)                 set_bit(nr, addr)
 166#define minix_test_and_clear_bit(nr, addr)      test_and_clear_bit(nr, addr)
 167#define minix_test_bit(nr, addr)                test_bit(nr, addr)
 168#define minix_find_first_zero_bit(addr, size)   find_first_zero_bit(addr, size)
 169
 170#endif /* __KERNEL__ */
 171
 172#endif /* __ASM_RISCV_BITOPS_H */
 173