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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_FUTEX_H
#define _ASM_FUTEX_H
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>
#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
do { \
register unsigned long r8 __asm ("r8") = 0; \
__asm__ __volatile__( \
" mf;; \n" \
"[1:] " insn ";; \n" \
" .xdata4 \"__ex_table\", 1b-., 2f-. \n" \
"[2:]" \
: "+r" (r8), "=r" (oldval) \
: "r" (uaddr), "r" (oparg) \
: "memory"); \
ret = r8; \
} while (0)
#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
do { \
register unsigned long r8 __asm ("r8") = 0; \
int val, newval; \
do { \
__asm__ __volatile__( \
" mf;; \n" \
"[1:] ld4 %3=[%4];; \n" \
" mov %2=%3 \n" \
insn ";; \n" \
" mov ar.ccv=%2;; \n" \
"[2:] cmpxchg4.acq %1=[%4],%3,ar.ccv;; \n" \
" .xdata4 \"__ex_table\", 1b-., 3f-.\n" \
" .xdata4 \"__ex_table\", 2b-., 3f-.\n" \
"[3:]" \
: "+r" (r8), "=r" (val), "=&r" (oldval), \
"=&r" (newval) \
: "r" (uaddr), "r" (oparg) \
: "memory"); \
if (unlikely (r8)) \
break; \
} while (unlikely (val != oldval)); \
ret = r8; \
} while (0)
static inline int
arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret;
pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op1("xchg4 %1=[%2],%3", ret, oldval, uaddr,
oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op2("add %3=%3,%5", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op2("or %3=%3,%5", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op2("and %3=%3,%5", ret, oldval, uaddr,
~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op2("xor %3=%3,%5", 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)
{
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
{
register unsigned long r8 __asm ("r8") = 0;
unsigned long prev;
__asm__ __volatile__(
" mf;; \n"
" mov ar.ccv=%4;; \n"
"[1:] cmpxchg4.acq %1=[%2],%3,ar.ccv \n"
" .xdata4 \"__ex_table\", 1b-., 2f-. \n"
"[2:]"
: "+r" (r8), "=&r" (prev)
: "r" (uaddr), "r" (newval),
"rO" ((long) (unsigned) oldval)
: "memory");
*uval = prev;
return r8;
}
}
#endif /* _ASM_FUTEX_H */
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