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
  45#define PLATFORM__SET_BIT
  46
  47static inline void __clear_bit(int nr, void *addr)
  48{
  49        int *a = (int *)addr;
  50        int mask;
  51
  52        a += nr >> 5;
  53        mask = 1 << (nr & 0x1f);
  54        *a &= ~mask;
  55}
  56
  57#define PLATFORM__CLEAR_BIT
  58
  59static inline void __change_bit(int nr, void *addr)
  60{
  61        int mask;
  62        unsigned long *ADDR = (unsigned long *)addr;
  63
  64        ADDR += nr >> 5;
  65        mask = 1 << (nr & 31);
  66        *ADDR ^= mask;
  67}
  68
  69static inline int __test_and_set_bit(int nr, void *addr)
  70{
  71        int mask, retval;
  72        unsigned int *a = (unsigned int *)addr;
  73
  74        a += nr >> 5;
  75        mask = 1 << (nr & 0x1f);
  76        retval = (mask & *a) != 0;
  77        *a |= mask;
  78        return retval;
  79}
  80
  81static inline int __test_and_clear_bit(int nr, void *addr)
  82{
  83        int mask, retval;
  84        unsigned int *a = (unsigned int *)addr;
  85
  86        a += nr >> 5;
  87        mask = 1 << (nr & 0x1f);
  88        retval = (mask & *a) != 0;
  89        *a &= ~mask;
  90        return retval;
  91}
  92
  93static inline int __test_and_change_bit(int nr, void *addr)
  94{
  95        int mask, retval;
  96        unsigned int *a = (unsigned int *)addr;
  97
  98        a += nr >> 5;
  99        mask = 1 << (nr & 0x1f);
 100        retval = (mask & *a) != 0;
 101        *a ^= mask;
 102        return retval;
 103}
 104
 105/*
 106 * This routine doesn't need to be atomic.
 107 */
 108static inline int test_bit(int nr, const void *addr)
 109{
 110        return ((unsigned char *)addr)[nr >> 3] & (1U << (nr & 7));
 111}
 112
 113/*
 114 * ffz = Find First Zero in word. Undefined if no zero exists,
 115 * so code should check against ~0UL first..
 116 */
 117static inline unsigned long ffz(unsigned long word)
 118{
 119        int k;
 120
 121        word = ~word;
 122        k = 31;
 123        if (word & 0x0000ffff) {
 124                k -= 16; word <<= 16;
 125        }
 126        if (word & 0x00ff0000) {
 127                k -= 8;  word <<= 8;
 128        }
 129        if (word & 0x0f000000) {
 130                k -= 4;  word <<= 4;
 131        }
 132        if (word & 0x30000000) {
 133                k -= 2;  word <<= 2;
 134        }
 135        if (word & 0x40000000)
 136                k -= 1;
 137
 138        return k;
 139}
 140
 141/*
 142 * ffs: find first bit set. This is defined the same way as
 143 * the libc and compiler builtin ffs routines, therefore
 144 * differs in spirit from the above ffz (man ffs).
 145 */
 146
 147/*
 148 * redefined in include/linux/bitops.h
 149 * #define ffs(x) generic_ffs(x)
 150 */
 151
 152/*
 153 * hweightN: returns the hamming weight (i.e. the number
 154 * of bits set) of a N-bit word
 155 */
 156
 157#define hweight32(x) generic_hweight32(x)
 158#define hweight16(x) generic_hweight16(x)
 159#define hweight8(x) generic_hweight8(x)
 160
 161#define ext2_set_bit                    test_and_set_bit
 162#define ext2_clear_bit                  test_and_clear_bit
 163#define ext2_test_bit                   test_bit
 164#define ext2_find_first_zero_bit        find_first_zero_bit
 165#define ext2_find_next_zero_bit         find_next_zero_bit
 166
 167/* Bitmap functions for the minix filesystem. */
 168#define minix_test_and_set_bit(nr, addr)        test_and_set_bit(nr, addr)
 169#define minix_set_bit(nr, addr)                 set_bit(nr, addr)
 170#define minix_test_and_clear_bit(nr, addr)      test_and_clear_bit(nr, addr)
 171#define minix_test_bit(nr, addr)                test_bit(nr, addr)
 172#define minix_find_first_zero_bit(addr, size)   find_first_zero_bit(addr, size)
 173
 174#endif /* __KERNEL__ */
 175
 176#endif /* __ASM_RISCV_BITOPS_H */
 177