1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef __ASM_CSKY_FUTEX_H
4#define __ASM_CSKY_FUTEX_H
5
6#ifndef CONFIG_SMP
7#include <asm-generic/futex.h>
8#else
9#include <linux/atomic.h>
10#include <linux/futex.h>
11#include <linux/uaccess.h>
12#include <linux/errno.h>
13
14#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)		\
15{									\
16	u32 tmp;							\
17									\
18	__atomic_pre_full_fence();					\
19									\
20	__asm__ __volatile__ (						\
21	"1:	ldex.w	%[ov], %[u]			\n"		\
22	"	"insn"					\n"		\
23	"2:	stex.w	%[t], %[u]			\n"		\
24	"	bez	%[t], 1b			\n"		\
25	"	br	4f				\n"		\
26	"3:	mov	%[r], %[e]			\n"		\
27	"4:						\n"		\
28	"	.section __ex_table,\"a\"		\n"		\
29	"	.balign 4				\n"		\
30	"	.long	1b, 3b				\n"		\
31	"	.long	2b, 3b				\n"		\
32	"	.previous				\n"		\
33	: [r] "+r" (ret), [ov] "=&r" (oldval),				\
34	  [u] "+m" (*uaddr), [t] "=&r" (tmp)				\
35	: [op] "Jr" (oparg), [e] "jr" (-EFAULT)				\
36	: "memory");							\
37									\
38	__atomic_post_full_fence();					\
39}
40
41static inline int
42arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
43{
44	int oldval = 0, ret = 0;
45
46	if (!access_ok(uaddr, sizeof(u32)))
47		return -EFAULT;
48
49	switch (op) {
50	case FUTEX_OP_SET:
51		__futex_atomic_op("mov %[t], %[ov]",
52				  ret, oldval, uaddr, oparg);
53		break;
54	case FUTEX_OP_ADD:
55		__futex_atomic_op("add %[t], %[ov], %[op]",
56				  ret, oldval, uaddr, oparg);
57		break;
58	case FUTEX_OP_OR:
59		__futex_atomic_op("or %[t], %[ov], %[op]",
60				  ret, oldval, uaddr, oparg);
61		break;
62	case FUTEX_OP_ANDN:
63		__futex_atomic_op("and %[t], %[ov], %[op]",
64				  ret, oldval, uaddr, ~oparg);
65		break;
66	case FUTEX_OP_XOR:
67		__futex_atomic_op("xor %[t], %[ov], %[op]",
68				  ret, oldval, uaddr, oparg);
69		break;
70	default:
71		ret = -ENOSYS;
72	}
73
74	if (!ret)
75		*oval = oldval;
76
77	return ret;
78}
79
80
81
82static inline int
83futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
84			      u32 oldval, u32 newval)
85{
86	int ret = 0;
87	u32 val, tmp;
88
89	if (!access_ok(uaddr, sizeof(u32)))
90		return -EFAULT;
91
92	__atomic_pre_full_fence();
93
94	__asm__ __volatile__ (
95	"1:	ldex.w	%[v], %[u]			\n"
96	"	cmpne	%[v], %[ov]			\n"
97	"	bt	4f				\n"
98	"	mov	%[t], %[nv]			\n"
99	"2:	stex.w	%[t], %[u]			\n"
100	"	bez	%[t], 1b			\n"
101	"	br	4f				\n"
102	"3:	mov	%[r], %[e]			\n"
103	"4:						\n"
104	"	.section __ex_table,\"a\"		\n"
105	"	.balign 4				\n"
106	"	.long	1b, 3b				\n"
107	"	.long	2b, 3b				\n"
108	"	.previous				\n"
109	: [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr),
110	  [t] "=&r" (tmp)
111	: [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "Jr" (-EFAULT)
112	: "memory");
113
114	__atomic_post_full_fence();
115
116	*uval = val;
117	return ret;
118}
119
120#endif /* CONFIG_SMP */
121#endif /* __ASM_CSKY_FUTEX_H */
122