1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_OPENRISC_FUTEX_H
3#define __ASM_OPENRISC_FUTEX_H
4
5#ifdef __KERNEL__
6
7#include <linux/futex.h>
8#include <linux/uaccess.h>
9#include <asm/errno.h>
10
11#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
12({								\
13	__asm__ __volatile__ (					\
14		"1:	l.lwa	%0, %2			\n"	\
15			insn				"\n"	\
16		"2:	l.swa	%2, %1			\n"	\
17		"	l.bnf	1b			\n"	\
18		"	 l.ori	%1, r0, 0		\n"	\
19		"3:					\n"	\
20		".section .fixup,\"ax\"			\n"	\
21		"4:	l.j	3b			\n"	\
22		"	 l.addi	%1, r0, %3		\n"	\
23		".previous				\n"	\
24		".section __ex_table,\"a\"		\n"	\
25		".word	1b,4b,2b,4b			\n"	\
26		".previous				\n"	\
27		: "=&r" (oldval), "=&r" (ret), "+m" (*uaddr)	\
28		: "i" (-EFAULT), "r" (oparg)			\
29		: "cc", "memory"				\
30		);						\
31})
32
33static inline int
34arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
35{
36	int oldval = 0, ret;
37
38	if (!access_ok(uaddr, sizeof(u32)))
39		return -EFAULT;
40
41	switch (op) {
42	case FUTEX_OP_SET:
43		__futex_atomic_op("l.or %1,%4,%4", ret, oldval, uaddr, oparg);
44		break;
45	case FUTEX_OP_ADD:
46		__futex_atomic_op("l.add %1,%0,%4", ret, oldval, uaddr, oparg);
47		break;
48	case FUTEX_OP_OR:
49		__futex_atomic_op("l.or %1,%0,%4", ret, oldval, uaddr, oparg);
50		break;
51	case FUTEX_OP_ANDN:
52		__futex_atomic_op("l.and %1,%0,%4", ret, oldval, uaddr, ~oparg);
53		break;
54	case FUTEX_OP_XOR:
55		__futex_atomic_op("l.xor %1,%0,%4", ret, oldval, uaddr, oparg);
56		break;
57	default:
58		ret = -ENOSYS;
59	}
60
61	if (!ret)
62		*oval = oldval;
63
64	return ret;
65}
66
67static inline int
68futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
69			      u32 oldval, u32 newval)
70{
71	int ret = 0;
72	u32 prev;
73
74	if (!access_ok(uaddr, sizeof(u32)))
75		return -EFAULT;
76
77	__asm__ __volatile__ (				\
78		"1:	l.lwa	%1, %2		\n"	\
79		"	l.sfeq	%1, %3		\n"	\
80		"	l.bnf	3f		\n"	\
81		"	 l.nop			\n"	\
82		"2:	l.swa	%2, %4		\n"	\
83		"	l.bnf	1b		\n"	\
84		"	 l.nop			\n"	\
85		"3:				\n"	\
86		".section .fixup,\"ax\"		\n"	\
87		"4:	l.j	3b		\n"	\
88		"	 l.addi	%0, r0, %5	\n"	\
89		".previous			\n"	\
90		".section __ex_table,\"a\"	\n"	\
91		".word	1b,4b,2b,4b		\n"	\
92		".previous			\n"	\
93		: "+r" (ret), "=&r" (prev), "+m" (*uaddr) \
94		: "r" (oldval), "r" (newval), "i" (-EFAULT) \
95		: "cc",	"memory"			\
96		);
97
98	*uval = prev;
99	return ret;
100}
101
102#endif /* __KERNEL__ */
103
104#endif /* __ASM_OPENRISC_FUTEX_H */
105