/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _PARISC_BITOPS_H
#define _PARISC_BITOPS_H

#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif

#include <linux/compiler.h>
#include <asm/types.h>
#include <asm/byteorder.h>
#include <asm/barrier.h>
#include <linux/atomic.h>

/* See http://marc.theaimsgroup.com/?t=108826637900003 for discussion
 * on use of volatile and __*_bit() (set/clear/change):
 *      *_bit() want use of volatile.
 *      __*_bit() are "relaxed" and don't use spinlock or volatile.
 */

static __inline__ void set_bit(int nr, volatile unsigned long * addr)
{
        unsigned long mask = BIT_MASK(nr);
        unsigned long flags;

        addr += BIT_WORD(nr);
        _atomic_spin_lock_irqsave(addr, flags);
        *addr |= mask;
        _atomic_spin_unlock_irqrestore(addr, flags);
}

static __inline__ void clear_bit(int nr, volatile unsigned long * addr)
{
        unsigned long mask = BIT_MASK(nr);
        unsigned long flags;

        addr += BIT_WORD(nr);
        _atomic_spin_lock_irqsave(addr, flags);
        *addr &= ~mask;
        _atomic_spin_unlock_irqrestore(addr, flags);
}

static __inline__ void change_bit(int nr, volatile unsigned long * addr)
{
        unsigned long mask = BIT_MASK(nr);
        unsigned long flags;

        addr += BIT_WORD(nr);
        _atomic_spin_lock_irqsave(addr, flags);
        *addr ^= mask;
        _atomic_spin_unlock_irqrestore(addr, flags);
}

static __inline__ int test_and_set_bit(int nr, volatile unsigned long * addr)
{
        unsigned long mask = BIT_MASK(nr);
        unsigned long old;
        unsigned long flags;
        int set;

        addr += BIT_WORD(nr);
        _atomic_spin_lock_irqsave(addr, flags);
        old = *addr;
        set = (old & mask) ? 1 : 0;
        if (!set)
                *addr = old | mask;
        _atomic_spin_unlock_irqrestore(addr, flags);

        return set;
}

static __inline__ int test_and_clear_bit(int nr, volatile unsigned long * addr)
{
        unsigned long mask = BIT_MASK(nr);
        unsigned long old;
        unsigned long flags;
        int set;

        addr += BIT_WORD(nr);
        _atomic_spin_lock_irqsave(addr, flags);
        old = *addr;
        set = (old & mask) ? 1 : 0;
        if (set)
                *addr = old & ~mask;
        _atomic_spin_unlock_irqrestore(addr, flags);

        return set;
}

static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)
{
        unsigned long mask = BIT_MASK(nr);
        unsigned long oldbit;
        unsigned long flags;

        addr += BIT_WORD(nr);
        _atomic_spin_lock_irqsave(addr, flags);
        oldbit = *addr;
        *addr = oldbit ^ mask;
        _atomic_spin_unlock_irqrestore(addr, flags);

        return (oldbit & mask) ? 1 : 0;
}

#include <asm-generic/bitops/non-atomic.h>

/**
 * __ffs - find first bit in word. returns 0 to "BITS_PER_LONG-1".
 * @word: The word to search
 *
 * __ffs() return is undefined if no bit is set.
 *
 * 32-bit fast __ffs by LaMont Jones "lamont At hp com".
 * 64-bit enhancement by Grant Grundler "grundler At parisc-linux org".
 * (with help from willy/jejb to get the semantics right)
 *
 * This algorithm avoids branches by making use of nullification.
 * One side effect of "extr" instructions is it sets PSW[N] bit.
 * How PSW[N] (nullify next insn) gets set is determined by the 
 * "condition" field (eg "<>" or "TR" below) in the extr* insn.
 * Only the 1st and one of either the 2cd or 3rd insn will get executed.
 * Each set of 3 insn will get executed in 2 cycles on PA8x00 vs 16 or so
 * cycles for each mispredicted branch.
 */

static __inline__ unsigned long __ffs(unsigned long x)
{
        unsigned long ret;

        __asm__(
#ifdef CONFIG_64BIT
                " ldi       63,%1\n"
                " extrd,u,*<>  %0,63,32,%%r0\n"
                " extrd,u,*TR  %0,31,32,%0\n"   /* move top 32-bits down */
                " addi    -32,%1,%1\n"
#else
                " ldi       31,%1\n"
#endif
                " extru,<>  %0,31,16,%%r0\n"
                " extru,TR  %0,15,16,%0\n"      /* xxxx0000 -> 0000xxxx */
                " addi    -16,%1,%1\n"
                " extru,<>  %0,31,8,%%r0\n"
                " extru,TR  %0,23,8,%0\n"       /* 0000xx00 -> 000000xx */
                " addi    -8,%1,%1\n"
                " extru,<>  %0,31,4,%%r0\n"
                " extru,TR  %0,27,4,%0\n"       /* 000000x0 -> 0000000x */
                " addi    -4,%1,%1\n"
                " extru,<>  %0,31,2,%%r0\n"
                " extru,TR  %0,29,2,%0\n"       /* 0000000y, 1100b -> 0011b */
                " addi    -2,%1,%1\n"
                " extru,=  %0,31,1,%%r0\n"      /* check last bit */
                " addi    -1,%1,%1\n"
                        : "+r" (x), "=r" (ret) );
        return ret;
}

#include <asm-generic/bitops/ffz.h>

/*
 * ffs: find first bit set. returns 1 to BITS_PER_LONG or 0 (if none set)
 * This is defined the same way as the libc and compiler builtin
 * ffs routines, therefore differs in spirit from the above ffz (man ffs).
 */
static __inline__ int ffs(int x)
{
        return x ? (__ffs((unsigned long)x) + 1) : 0;
}

/*
 * fls: find last (most significant) bit set.
 * fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 */

static __inline__ int fls(unsigned int x)
{
        int ret;
        if (!x)
                return 0;

        __asm__(
        "       ldi             1,%1\n"
        "       extru,<>        %0,15,16,%%r0\n"
        "       zdep,TR         %0,15,16,%0\n"          /* xxxx0000 */
        "       addi            16,%1,%1\n"
        "       extru,<>        %0,7,8,%%r0\n"
        "       zdep,TR         %0,23,24,%0\n"          /* xx000000 */
        "       addi            8,%1,%1\n"
        "       extru,<>        %0,3,4,%%r0\n"
        "       zdep,TR         %0,27,28,%0\n"          /* x0000000 */
        "       addi            4,%1,%1\n"
        "       extru,<>        %0,1,2,%%r0\n"
        "       zdep,TR         %0,29,30,%0\n"          /* y0000000 (y&3 = 0) */
        "       addi            2,%1,%1\n"
        "       extru,=         %0,0,1,%%r0\n"
        "       addi            1,%1,%1\n"              /* if y & 8, add 1 */
                : "+r" (x), "=r" (ret) );

        return ret;
}

#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic-setbit.h>

#endif /* _PARISC_BITOPS_H */