xref: /openbmc/linux/arch/openrisc/include/asm/futex.h (revision 2cf1c348)
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 
33 static inline int
34 arch_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 
67 static inline int
68 futex_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