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 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
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
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