/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_BITOPS_H
#define _ASM_X86_BITOPS_H

/*
 * Copyright 1992, Linus Torvalds.
 *
 * Note: inlines with more than a single statement should be marked
 * __always_inline to avoid problems with older gcc's inlining heuristics.
 */

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

#include <linux/compiler.h>
#include <asm/alternative.h>
#include <asm/rmwcc.h>
#include <asm/barrier.h>

#if BITS_PER_LONG == 32
# define _BITOPS_LONG_SHIFT 5
#elif BITS_PER_LONG == 64
# define _BITOPS_LONG_SHIFT 6
#else
# error "Unexpected BITS_PER_LONG"
#endif

#define BIT_64(n)                       (U64_C(1) << (n))

/*
 * These have to be done with inline assembly: that way the bit-setting
 * is guaranteed to be atomic. All bit operations return 0 if the bit
 * was cleared before the operation and != 0 if it was not.
 *
 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
 */

#define RLONG_ADDR(x)                    "m" (*(volatile long *) (x))
#define WBYTE_ADDR(x)                   "+m" (*(volatile char *) (x))

#define ADDR                            RLONG_ADDR(addr)

/*
 * We do the locked ops that don't return the old value as
 * a mask operation on a byte.
 */
#define CONST_MASK_ADDR(nr, addr)       WBYTE_ADDR((void *)(addr) + ((nr)>>3))
#define CONST_MASK(nr)                  (1 << ((nr) & 7))

static __always_inline void
arch_set_bit(long nr, volatile unsigned long *addr)
{
        if (__builtin_constant_p(nr)) {
                asm volatile(LOCK_PREFIX "orb %b1,%0"
                        : CONST_MASK_ADDR(nr, addr)
                        : "iq" (CONST_MASK(nr))
                        : "memory");
        } else {
                asm volatile(LOCK_PREFIX __ASM_SIZE(bts) " %1,%0"
                        : : RLONG_ADDR(addr), "Ir" (nr) : "memory");
        }
}

static __always_inline void
arch___set_bit(long nr, volatile unsigned long *addr)
{
        asm volatile(__ASM_SIZE(bts) " %1,%0" : : ADDR, "Ir" (nr) : "memory");
}

static __always_inline void
arch_clear_bit(long nr, volatile unsigned long *addr)
{
        if (__builtin_constant_p(nr)) {
                asm volatile(LOCK_PREFIX "andb %b1,%0"
                        : CONST_MASK_ADDR(nr, addr)
                        : "iq" (~CONST_MASK(nr)));
        } else {
                asm volatile(LOCK_PREFIX __ASM_SIZE(btr) " %1,%0"
                        : : RLONG_ADDR(addr), "Ir" (nr) : "memory");
        }
}

static __always_inline void
arch_clear_bit_unlock(long nr, volatile unsigned long *addr)
{
        barrier();
        arch_clear_bit(nr, addr);
}

static __always_inline void
arch___clear_bit(long nr, volatile unsigned long *addr)
{
        asm volatile(__ASM_SIZE(btr) " %1,%0" : : ADDR, "Ir" (nr) : "memory");
}

static __always_inline bool
arch_clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
{
        bool negative;
        asm volatile(LOCK_PREFIX "andb %2,%1"
                CC_SET(s)
                : CC_OUT(s) (negative), WBYTE_ADDR(addr)
                : "ir" ((char) ~(1 << nr)) : "memory");
        return negative;
}
#define arch_clear_bit_unlock_is_negative_byte                                 \
        arch_clear_bit_unlock_is_negative_byte

static __always_inline void
arch___clear_bit_unlock(long nr, volatile unsigned long *addr)
{
        arch___clear_bit(nr, addr);
}

static __always_inline void
arch___change_bit(long nr, volatile unsigned long *addr)
{
        asm volatile(__ASM_SIZE(btc) " %1,%0" : : ADDR, "Ir" (nr) : "memory");
}

static __always_inline void
arch_change_bit(long nr, volatile unsigned long *addr)
{
        if (__builtin_constant_p(nr)) {
                asm volatile(LOCK_PREFIX "xorb %b1,%0"
                        : CONST_MASK_ADDR(nr, addr)
                        : "iq" (CONST_MASK(nr)));
        } else {
                asm volatile(LOCK_PREFIX __ASM_SIZE(btc) " %1,%0"
                        : : RLONG_ADDR(addr), "Ir" (nr) : "memory");
        }
}

static __always_inline bool
arch_test_and_set_bit(long nr, volatile unsigned long *addr)
{
        return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(bts), *addr, c, "Ir", nr);
}

static __always_inline bool
arch_test_and_set_bit_lock(long nr, volatile unsigned long *addr)
{
        return arch_test_and_set_bit(nr, addr);
}

static __always_inline bool
arch___test_and_set_bit(long nr, volatile unsigned long *addr)
{
        bool oldbit;

        asm(__ASM_SIZE(bts) " %2,%1"
            CC_SET(c)
            : CC_OUT(c) (oldbit)
            : ADDR, "Ir" (nr) : "memory");
        return oldbit;
}

static __always_inline bool
arch_test_and_clear_bit(long nr, volatile unsigned long *addr)
{
        return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(btr), *addr, c, "Ir", nr);
}

/*
 * Note: the operation is performed atomically with respect to
 * the local CPU, but not other CPUs. Portable code should not
 * rely on this behaviour.
 * KVM relies on this behaviour on x86 for modifying memory that is also
 * accessed from a hypervisor on the same CPU if running in a VM: don't change
 * this without also updating arch/x86/kernel/kvm.c
 */
static __always_inline bool
arch___test_and_clear_bit(long nr, volatile unsigned long *addr)
{
        bool oldbit;

        asm volatile(__ASM_SIZE(btr) " %2,%1"
                     CC_SET(c)
                     : CC_OUT(c) (oldbit)
                     : ADDR, "Ir" (nr) : "memory");
        return oldbit;
}

static __always_inline bool
arch___test_and_change_bit(long nr, volatile unsigned long *addr)
{
        bool oldbit;

        asm volatile(__ASM_SIZE(btc) " %2,%1"
                     CC_SET(c)
                     : CC_OUT(c) (oldbit)
                     : ADDR, "Ir" (nr) : "memory");

        return oldbit;
}

static __always_inline bool
arch_test_and_change_bit(long nr, volatile unsigned long *addr)
{
        return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(btc), *addr, c, "Ir", nr);
}

static __always_inline bool constant_test_bit(long nr, const volatile unsigned long *addr)
{
        return ((1UL << (nr & (BITS_PER_LONG-1))) &
                (addr[nr >> _BITOPS_LONG_SHIFT])) != 0;
}

static __always_inline bool variable_test_bit(long nr, volatile const unsigned long *addr)
{
        bool oldbit;

        asm volatile(__ASM_SIZE(bt) " %2,%1"
                     CC_SET(c)
                     : CC_OUT(c) (oldbit)
                     : "m" (*(unsigned long *)addr), "Ir" (nr) : "memory");

        return oldbit;
}

#define arch_test_bit(nr, addr)                 \
        (__builtin_constant_p((nr))             \
         ? constant_test_bit((nr), (addr))      \
         : variable_test_bit((nr), (addr)))

/**
 * __ffs - find first set bit in word
 * @word: The word to search
 *
 * Undefined if no bit exists, so code should check against 0 first.
 */
static __always_inline unsigned long __ffs(unsigned long word)
{
        asm("rep; bsf %1,%0"
                : "=r" (word)
                : "rm" (word));
        return word;
}

/**
 * ffz - find first zero bit in word
 * @word: The word to search
 *
 * Undefined if no zero exists, so code should check against ~0UL first.
 */
static __always_inline unsigned long ffz(unsigned long word)
{
        asm("rep; bsf %1,%0"
                : "=r" (word)
                : "r" (~word));
        return word;
}

/*
 * __fls: find last set bit in word
 * @word: The word to search
 *
 * Undefined if no set bit exists, so code should check against 0 first.
 */
static __always_inline unsigned long __fls(unsigned long word)
{
        asm("bsr %1,%0"
            : "=r" (word)
            : "rm" (word));
        return word;
}

#undef ADDR

#ifdef __KERNEL__
/**
 * ffs - find first set bit in word
 * @x: the word to search
 *
 * This is defined the same way as the libc and compiler builtin ffs
 * routines, therefore differs in spirit from the other bitops.
 *
 * ffs(value) returns 0 if value is 0 or the position of the first
 * set bit if value is nonzero. The first (least significant) bit
 * is at position 1.
 */
static __always_inline int ffs(int x)
{
        int r;

#ifdef CONFIG_X86_64
        /*
         * AMD64 says BSFL won't clobber the dest reg if x==0; Intel64 says the
         * dest reg is undefined if x==0, but their CPU architect says its
         * value is written to set it to the same as before, except that the
         * top 32 bits will be cleared.
         *
         * We cannot do this on 32 bits because at the very least some
         * 486 CPUs did not behave this way.
         */
        asm("bsfl %1,%0"
            : "=r" (r)
            : "rm" (x), "0" (-1));
#elif defined(CONFIG_X86_CMOV)
        asm("bsfl %1,%0\n\t"
            "cmovzl %2,%0"
            : "=&r" (r) : "rm" (x), "r" (-1));
#else
        asm("bsfl %1,%0\n\t"
            "jnz 1f\n\t"
            "movl $-1,%0\n"
            "1:" : "=r" (r) : "rm" (x));
#endif
        return r + 1;
}

/**
 * fls - find last set bit in word
 * @x: the word to search
 *
 * This is defined in a similar way as the libc and compiler builtin
 * ffs, but returns the position of the most significant set bit.
 *
 * fls(value) returns 0 if value is 0 or the position of the last
 * set bit if value is nonzero. The last (most significant) bit is
 * at position 32.
 */
static __always_inline int fls(unsigned int x)
{
        int r;

#ifdef CONFIG_X86_64
        /*
         * AMD64 says BSRL won't clobber the dest reg if x==0; Intel64 says the
         * dest reg is undefined if x==0, but their CPU architect says its
         * value is written to set it to the same as before, except that the
         * top 32 bits will be cleared.
         *
         * We cannot do this on 32 bits because at the very least some
         * 486 CPUs did not behave this way.
         */
        asm("bsrl %1,%0"
            : "=r" (r)
            : "rm" (x), "0" (-1));
#elif defined(CONFIG_X86_CMOV)
        asm("bsrl %1,%0\n\t"
            "cmovzl %2,%0"
            : "=&r" (r) : "rm" (x), "rm" (-1));
#else
        asm("bsrl %1,%0\n\t"
            "jnz 1f\n\t"
            "movl $-1,%0\n"
            "1:" : "=r" (r) : "rm" (x));
#endif
        return r + 1;
}

/**
 * fls64 - find last set bit in a 64-bit word
 * @x: the word to search
 *
 * This is defined in a similar way as the libc and compiler builtin
 * ffsll, but returns the position of the most significant set bit.
 *
 * fls64(value) returns 0 if value is 0 or the position of the last
 * set bit if value is nonzero. The last (most significant) bit is
 * at position 64.
 */
#ifdef CONFIG_X86_64
static __always_inline int fls64(__u64 x)
{
        int bitpos = -1;
        /*
         * AMD64 says BSRQ won't clobber the dest reg if x==0; Intel64 says the
         * dest reg is undefined if x==0, but their CPU architect says its
         * value is written to set it to the same as before.
         */
        asm("bsrq %1,%q0"
            : "+r" (bitpos)
            : "rm" (x));
        return bitpos + 1;
}
#else
#include <asm-generic/bitops/fls64.h>
#endif

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

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

#include <asm/arch_hweight.h>

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

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

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

#include <asm-generic/bitops/ext2-atomic-setbit.h>

#endif /* __KERNEL__ */
#endif /* _ASM_X86_BITOPS_H */