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

#ifdef __KERNEL__

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>
#include <asm/synch.h>

#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
  __asm__ __volatile ( \
        PPC_ATOMIC_ENTRY_BARRIER \
"1:     lwarx   %0,0,%2\n" \
        insn \
"2:     stwcx.  %1,0,%2\n" \
        "bne-   1b\n" \
        PPC_ATOMIC_EXIT_BARRIER \
        "li     %1,0\n" \
"3:     .section .fixup,\"ax\"\n" \
"4:     li      %1,%3\n" \
        "b      3b\n" \
        ".previous\n" \
        EX_TABLE(1b, 4b) \
        EX_TABLE(2b, 4b) \
        : "=&r" (oldval), "=&r" (ret) \
        : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
        : "cr0", "memory")

static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
                u32 __user *uaddr)
{
        int oldval = 0, ret;

        if (!user_access_begin(uaddr, sizeof(u32)))
                return -EFAULT;

        switch (op) {
        case FUTEX_OP_SET:
                __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ADD:
                __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_OR:
                __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ANDN:
                __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_XOR:
                __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
                break;
        default:
                ret = -ENOSYS;
        }
        user_access_end();

        *oval = oldval;

        return ret;
}

static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
                              u32 oldval, u32 newval)
{
        int ret = 0;
        u32 prev;

        if (!user_access_begin(uaddr, sizeof(u32)))
                return -EFAULT;

        __asm__ __volatile__ (
        PPC_ATOMIC_ENTRY_BARRIER
"1:     lwarx   %1,0,%3         # futex_atomic_cmpxchg_inatomic\n\
        cmpw    0,%1,%4\n\
        bne-    3f\n"
"2:     stwcx.  %5,0,%3\n\
        bne-    1b\n"
        PPC_ATOMIC_EXIT_BARRIER
"3:     .section .fixup,\"ax\"\n\
4:      li      %0,%6\n\
        b       3b\n\
        .previous\n"
        EX_TABLE(1b, 4b)
        EX_TABLE(2b, 4b)
        : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
        : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
        : "cc", "memory");

        user_access_end();

        *uval = prev;

        return ret;
}

#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_FUTEX_H */