1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_FUTEX_H
3#define _ASM_FUTEX_H
4
5#include <linux/futex.h>
6#include <linux/uaccess.h>
7#include <asm/errno.h>
8
9#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
10do {									\
11	register unsigned long r8 __asm ("r8") = 0;			\
12	__asm__ __volatile__(						\
13		"	mf;;					\n"	\
14		"[1:] "	insn ";;				\n"	\
15		"	.xdata4 \"__ex_table\", 1b-., 2f-.	\n"	\
16		"[2:]"							\
17		: "+r" (r8), "=r" (oldval)				\
18		: "r" (uaddr), "r" (oparg)				\
19		: "memory");						\
20	ret = r8;							\
21} while (0)
22
23#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
24do {									\
25	register unsigned long r8 __asm ("r8") = 0;			\
26	int val, newval;						\
27	do {								\
28		__asm__ __volatile__(					\
29			"	mf;;				  \n"	\
30			"[1:]	ld4 %3=[%4];;			  \n"	\
31			"	mov %2=%3			  \n"	\
32				insn	";;			  \n"	\
33			"	mov ar.ccv=%2;;			  \n"	\
34			"[2:]	cmpxchg4.acq %1=[%4],%3,ar.ccv;;  \n"	\
35			"	.xdata4 \"__ex_table\", 1b-., 3f-.\n"	\
36			"	.xdata4 \"__ex_table\", 2b-., 3f-.\n"	\
37			"[3:]"						\
38			: "+r" (r8), "=r" (val), "=&r" (oldval),	\
39			   "=&r" (newval)				\
40			: "r" (uaddr), "r" (oparg)			\
41			: "memory");					\
42		if (unlikely (r8))					\
43			break;						\
44	} while (unlikely (val != oldval));				\
45	ret = r8;							\
46} while (0)
47
48static inline int
49arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
50{
51	int oldval = 0, ret;
52
53	if (!access_ok(uaddr, sizeof(u32)))
54		return -EFAULT;
55
56	switch (op) {
57	case FUTEX_OP_SET:
58		__futex_atomic_op1("xchg4 %1=[%2],%3", ret, oldval, uaddr,
59				   oparg);
60		break;
61	case FUTEX_OP_ADD:
62		__futex_atomic_op2("add %3=%3,%5", ret, oldval, uaddr, oparg);
63		break;
64	case FUTEX_OP_OR:
65		__futex_atomic_op2("or %3=%3,%5", ret, oldval, uaddr, oparg);
66		break;
67	case FUTEX_OP_ANDN:
68		__futex_atomic_op2("and %3=%3,%5", ret, oldval, uaddr,
69				   ~oparg);
70		break;
71	case FUTEX_OP_XOR:
72		__futex_atomic_op2("xor %3=%3,%5", ret, oldval, uaddr, oparg);
73		break;
74	default:
75		ret = -ENOSYS;
76	}
77
78	if (!ret)
79		*oval = oldval;
80
81	return ret;
82}
83
84static inline int
85futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
86			      u32 oldval, u32 newval)
87{
88	if (!access_ok(uaddr, sizeof(u32)))
89		return -EFAULT;
90
91	{
92		register unsigned long r8 __asm ("r8") = 0;
93		unsigned long prev;
94		__asm__ __volatile__(
95			"	mf;;					\n"
96			"	mov ar.ccv=%4;;				\n"
97			"[1:]	cmpxchg4.acq %1=[%2],%3,ar.ccv		\n"
98			"	.xdata4 \"__ex_table\", 1b-., 2f-.	\n"
99			"[2:]"
100			: "+r" (r8), "=&r" (prev)
101			: "r" (uaddr), "r" (newval),
102			  "rO" ((long) (unsigned) oldval)
103			: "memory");
104		*uval = prev;
105		return r8;
106	}
107}
108
109#endif /* _ASM_FUTEX_H */
110