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