1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_MICROBLAZE_FUTEX_H
3 #define _ASM_MICROBLAZE_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:	lwx	%0, %2, r0; "			\
15 				insn					\
16 			"2:	swx	%1, %2, r0;			\
17 				addic	%1, r0, 0;			\
18 				bnei	%1, 1b;				\
19 			3:						\
20 			.section .fixup,\"ax\";				\
21 			4:	brid	3b;				\
22 				addik	%1, r0, %3;			\
23 			.previous;					\
24 			.section __ex_table,\"a\";			\
25 			.word	1b,4b,2b,4b;				\
26 			.previous;"					\
27 	: "=&r" (oldval), "=&r" (ret)					\
28 	: "r" (uaddr), "i" (-EFAULT), "r" (oparg)			\
29 	);								\
30 })
31 
32 static inline int
33 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
34 {
35 	int oldval = 0, ret;
36 
37 	pagefault_disable();
38 
39 	switch (op) {
40 	case FUTEX_OP_SET:
41 		__futex_atomic_op("or %1,%4,%4;", ret, oldval, uaddr, oparg);
42 		break;
43 	case FUTEX_OP_ADD:
44 		__futex_atomic_op("add %1,%0,%4;", ret, oldval, uaddr, oparg);
45 		break;
46 	case FUTEX_OP_OR:
47 		__futex_atomic_op("or %1,%0,%4;", ret, oldval, uaddr, oparg);
48 		break;
49 	case FUTEX_OP_ANDN:
50 		__futex_atomic_op("andn %1,%0,%4;", ret, oldval, uaddr, oparg);
51 		break;
52 	case FUTEX_OP_XOR:
53 		__futex_atomic_op("xor %1,%0,%4;", ret, oldval, uaddr, oparg);
54 		break;
55 	default:
56 		ret = -ENOSYS;
57 	}
58 
59 	pagefault_enable();
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, cmp;
72 	u32 prev;
73 
74 	if (!access_ok(uaddr, sizeof(u32)))
75 		return -EFAULT;
76 
77 	__asm__ __volatile__ ("1:	lwx	%1, %3, r0;		\
78 					cmp	%2, %1, %4;		\
79 					bnei	%2, 3f;			\
80 				2:	swx	%5, %3, r0;		\
81 					addic	%2, r0, 0;		\
82 					bnei	%2, 1b;			\
83 				3:					\
84 				.section .fixup,\"ax\";			\
85 				4:	brid	3b;			\
86 					addik	%0, r0, %6;		\
87 				.previous;				\
88 				.section __ex_table,\"a\";		\
89 				.word	1b,4b,2b,4b;			\
90 				.previous;"				\
91 		: "+r" (ret), "=&r" (prev), "=&r"(cmp)	\
92 		: "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT));
93 
94 	*uval = prev;
95 	return ret;
96 }
97 
98 #endif /* __KERNEL__ */
99 
100 #endif
101