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
arch_futex_atomic_op_inuser(int op,int oparg,int * oval,u32 __user * uaddr)33 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
34 {
35 	int oldval = 0, ret;
36 
37 	if (!access_ok(uaddr, sizeof(u32)))
38 		return -EFAULT;
39 
40 	switch (op) {
41 	case FUTEX_OP_SET:
42 		__futex_atomic_op("or %1,%4,%4;", ret, oldval, uaddr, oparg);
43 		break;
44 	case FUTEX_OP_ADD:
45 		__futex_atomic_op("add %1,%0,%4;", ret, oldval, uaddr, oparg);
46 		break;
47 	case FUTEX_OP_OR:
48 		__futex_atomic_op("or %1,%0,%4;", ret, oldval, uaddr, oparg);
49 		break;
50 	case FUTEX_OP_ANDN:
51 		__futex_atomic_op("andn %1,%0,%4;", ret, oldval, uaddr, oparg);
52 		break;
53 	case FUTEX_OP_XOR:
54 		__futex_atomic_op("xor %1,%0,%4;", ret, oldval, uaddr, oparg);
55 		break;
56 	default:
57 		ret = -ENOSYS;
58 	}
59 
60 	if (!ret)
61 		*oval = oldval;
62 
63 	return ret;
64 }
65 
66 static inline int
futex_atomic_cmpxchg_inatomic(u32 * uval,u32 __user * uaddr,u32 oldval,u32 newval)67 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
68 			      u32 oldval, u32 newval)
69 {
70 	int ret = 0, cmp;
71 	u32 prev;
72 
73 	if (!access_ok(uaddr, sizeof(u32)))
74 		return -EFAULT;
75 
76 	__asm__ __volatile__ ("1:	lwx	%1, %3, r0;		\
77 					cmp	%2, %1, %4;		\
78 					bnei	%2, 3f;			\
79 				2:	swx	%5, %3, r0;		\
80 					addic	%2, r0, 0;		\
81 					bnei	%2, 1b;			\
82 				3:					\
83 				.section .fixup,\"ax\";			\
84 				4:	brid	3b;			\
85 					addik	%0, r0, %6;		\
86 				.previous;				\
87 				.section __ex_table,\"a\";		\
88 				.word	1b,4b,2b,4b;			\
89 				.previous;"				\
90 		: "+r" (ret), "=&r" (prev), "=&r"(cmp)	\
91 		: "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT));
92 
93 	*uval = prev;
94 	return ret;
95 }
96 
97 #endif /* __KERNEL__ */
98 
99 #endif
100