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 
41 static inline int
arch_futex_atomic_op_inuser(int op,int oparg,int * oval,u32 __user * uaddr)42 arch_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 
82 static inline int
futex_atomic_cmpxchg_inatomic(u32 * uval,u32 __user * uaddr,u32 oldval,u32 newval)83 futex_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