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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#ifndef _ASM_FUTEX_H
#define _ASM_FUTEX_H
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/barrier.h>
#include <asm/compiler.h>
#include <asm/errno.h>
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
{ \
__asm__ __volatile__( \
"1: ll.w %1, %4 # __futex_atomic_op\n" \
" " insn " \n" \
"2: sc.w $t0, %2 \n" \
" beq $t0, $zero, 1b \n" \
"3: \n" \
" .section .fixup,\"ax\" \n" \
"4: li.w %0, %6 \n" \
" b 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" "__UA_ADDR "\t1b, 4b \n" \
" "__UA_ADDR "\t2b, 4b \n" \
" .previous \n" \
: "=r" (ret), "=&r" (oldval), \
"=ZC" (*uaddr) \
: "0" (0), "ZC" (*uaddr), "Jr" (oparg), \
"i" (-EFAULT) \
: "memory", "t0"); \
}
static inline int
arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret = 0;
pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("move $t0, %z5", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op("add.w $t0, %1, %z5", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op("or $t0, %1, %z5", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("and $t0, %1, %z5", ret, oldval, uaddr, ~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("xor $t0, %1, %z5", ret, oldval, uaddr, oparg);
break;
default:
ret = -ENOSYS;
}
pagefault_enable();
if (!ret)
*oval = oldval;
return ret;
}
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval)
{
int ret = 0;
u32 val = 0;
if (!access_ok(uaddr, sizeof(u32)))
return -EFAULT;
__asm__ __volatile__(
"# futex_atomic_cmpxchg_inatomic \n"
"1: ll.w %1, %3 \n"
" bne %1, %z4, 3f \n"
" or $t0, %z5, $zero \n"
"2: sc.w $t0, %2 \n"
" beq $zero, $t0, 1b \n"
"3: \n"
__WEAK_LLSC_MB
" .section .fixup,\"ax\" \n"
"4: li.d %0, %6 \n"
" b 3b \n"
" .previous \n"
" .section __ex_table,\"a\" \n"
" "__UA_ADDR "\t1b, 4b \n"
" "__UA_ADDR "\t2b, 4b \n"
" .previous \n"
: "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
: GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
"i" (-EFAULT)
: "memory", "t0");
*uval = val;
return ret;
}
#endif /* _ASM_FUTEX_H */
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