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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_HEXAGON_FUTEX_H
#define _ASM_HEXAGON_FUTEX_H
#ifdef __KERNEL__
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>
/* XXX TODO-- need to add sync barriers! */
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
__asm__ __volatile( \
"1: %0 = memw_locked(%3);\n" \
/* For example: %1 = %4 */ \
insn \
"2: memw_locked(%3,p2) = %1;\n" \
" if !p2 jump 1b;\n" \
" %1 = #0;\n" \
"3:\n" \
".section .fixup,\"ax\"\n" \
"4: %1 = #%5;\n" \
" jump 3b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
".long 1b,4b,2b,4b\n" \
".previous\n" \
: "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \
: "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
: "p2", "memory")
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_op("%1 = %4\n", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr,
oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr,
oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret,
oldval, uaddr, oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("%1 = xor(%0,%4)\n", 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 prev;
int ret;
if (!access_ok(uaddr, sizeof(u32)))
return -EFAULT;
__asm__ __volatile__ (
"1: %1 = memw_locked(%3)\n"
" {\n"
" p2 = cmp.eq(%1,%4)\n"
" if !p2.new jump:NT 3f\n"
" }\n"
"2: memw_locked(%3,p2) = %5\n"
" if !p2 jump 1b\n"
"3:\n"
".section .fixup,\"ax\"\n"
"4: %0 = #%6\n"
" jump 3b\n"
".previous\n"
".section __ex_table,\"a\"\n"
".long 1b,4b,2b,4b\n"
".previous\n"
: "+r" (ret), "=&r" (prev), "+m" (*uaddr)
: "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT)
: "p2", "memory");
*uval = prev;
return ret;
}
#endif /* __KERNEL__ */
#endif /* _ASM_HEXAGON_FUTEX_H */
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