1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_ALPHA_FUTEX_H
3 #define _ASM_ALPHA_FUTEX_H
4
5 #ifdef __KERNEL__
6
7 #include <linux/futex.h>
8 #include <linux/uaccess.h>
9 #include <asm/errno.h>
10 #include <asm/barrier.h>
11
12 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
13 __asm__ __volatile__( \
14 __ASM_SMP_MB \
15 "1: ldl_l %0,0(%2)\n" \
16 insn \
17 "2: stl_c %1,0(%2)\n" \
18 " beq %1,4f\n" \
19 " mov $31,%1\n" \
20 "3: .subsection 2\n" \
21 "4: br 1b\n" \
22 " .previous\n" \
23 EXC(1b,3b,$31,%1) \
24 EXC(2b,3b,$31,%1) \
25 : "=&r" (oldval), "=&r"(ret) \
26 : "r" (uaddr), "r"(oparg) \
27 : "memory")
28
29 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
30 u32 __user *uaddr)
31 {
32 int oldval = 0, ret;
33
34 if (!access_ok(uaddr, sizeof(u32)))
35 return -EFAULT;
36
37 switch (op) {
38 case FUTEX_OP_SET:
39 __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
40 break;
41 case FUTEX_OP_ADD:
42 __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
43 break;
44 case FUTEX_OP_OR:
45 __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
46 break;
47 case FUTEX_OP_ANDN:
48 __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
49 break;
50 case FUTEX_OP_XOR:
51 __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
52 break;
53 default:
54 ret = -ENOSYS;
55 }
56
57 if (!ret)
58 *oval = oldval;
59
60 return ret;
61 }
62
63 static inline int
64 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
65 u32 oldval, u32 newval)
66 {
67 int ret = 0, cmp;
68 u32 prev;
69
70 if (!access_ok(uaddr, sizeof(u32)))
71 return -EFAULT;
72
73 __asm__ __volatile__ (
74 __ASM_SMP_MB
75 "1: ldl_l %1,0(%3)\n"
76 " cmpeq %1,%4,%2\n"
77 " beq %2,3f\n"
78 " mov %5,%2\n"
79 "2: stl_c %2,0(%3)\n"
80 " beq %2,4f\n"
81 "3: .subsection 2\n"
82 "4: br 1b\n"
83 " .previous\n"
84 EXC(1b,3b,$31,%0)
85 EXC(2b,3b,$31,%0)
86 : "+r"(ret), "=&r"(prev), "=&r"(cmp)
87 : "r"(uaddr), "r"((long)(int)oldval), "r"(newval)
88 : "memory");
89
90 *uval = prev;
91 return ret;
92 }
93
94 #endif /* __KERNEL__ */
95 #endif /* _ASM_ALPHA_FUTEX_H */
96
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