bitops-op32.h

Go to the documentation of this file.

#ifndef __ASM_SH_BITOPS_OP32_H
#define __ASM_SH_BITOPS_OP32_H

/*
 * The bit modifying instructions on SH-2A are only capable of working
 * with a 3-bit immediate, which signifies the shift position for the bit
 * being worked on.
 */
#if defined(__BIG_ENDIAN)
#define BITOP_LE_SWIZZLE    ((BITS_PER_LONG-1) & ~0x7)
#define BYTE_NUMBER(nr)     ((nr ^ BITOP_LE_SWIZZLE) / BITS_PER_BYTE)
#define BYTE_OFFSET(nr)     ((nr ^ BITOP_LE_SWIZZLE) % BITS_PER_BYTE)
#else
#define BYTE_NUMBER(nr)     ((nr) / BITS_PER_BYTE)
#define BYTE_OFFSET(nr)     ((nr) % BITS_PER_BYTE)
#endif

#define IS_IMMEDIATE(nr)    (__builtin_constant_p(nr))

static inline void __set_bit(int nr, volatile unsigned long *addr)
{
    if (IS_IMMEDIATE(nr)) {
        __asm__ __volatile__ (
            "bset.b %1, @(%O2,%0)       ! __set_bit\n\t"
            : "+r" (addr)
            : "i" (BYTE_OFFSET(nr)), "i" (BYTE_NUMBER(nr))
            : "t", "memory"
        );
    } else {
        unsigned long mask = BIT_MASK(nr);
        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);

        *p |= mask;
    }
}

static inline void __clear_bit(int nr, volatile unsigned long *addr)
{
    if (IS_IMMEDIATE(nr)) {
        __asm__ __volatile__ (
            "bclr.b %1, @(%O2,%0)       ! __clear_bit\n\t"
            : "+r" (addr)
            : "i" (BYTE_OFFSET(nr)),
              "i" (BYTE_NUMBER(nr))
            : "t", "memory"
        );
    } else {
        unsigned long mask = BIT_MASK(nr);
        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);

        *p &= ~mask;
    }
}

static inline void __change_bit(int nr, volatile unsigned long *addr)
{
    if (IS_IMMEDIATE(nr)) {
        __asm__ __volatile__ (
            "bxor.b %1, @(%O2,%0)       ! __change_bit\n\t"
            : "+r" (addr)
            : "i" (BYTE_OFFSET(nr)),
              "i" (BYTE_NUMBER(nr))
            : "t", "memory"
        );
    } else {
        unsigned long mask = BIT_MASK(nr);
        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);

        *p ^= mask;
    }
}

static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
{
    unsigned long mask = BIT_MASK(nr);
    unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
    unsigned long old = *p;

    *p = old | mask;
    return (old & mask) != 0;
}

static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
{
    unsigned long mask = BIT_MASK(nr);
    unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
    unsigned long old = *p;

    *p = old & ~mask;
    return (old & mask) != 0;
}

/* WARNING: non atomic and it can be reordered! */
static inline int __test_and_change_bit(int nr,
                        volatile unsigned long *addr)
{
    unsigned long mask = BIT_MASK(nr);
    unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
    unsigned long old = *p;

    *p = old ^ mask;
    return (old & mask) != 0;
}

static inline int test_bit(int nr, const volatile unsigned long *addr)
{
    return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
}

#endif /* __ASM_SH_BITOPS_OP32_H */