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gerrit-public.fairphone.software / kernel / msm-4.19 / 40ef06f1120bcc0a2ad483b5cd42f58c4df78a5b / . / arch / alpha / include / asm / futex.h
blob: 945de222ab91a3409836ce070a4bcd9f525061cb [file] [log] [blame]
Ivan Kokshaysky77b4cf52009-04-30 15:08:48 -0700[diff] [blame]1#ifndef _ASM_ALPHA_FUTEX_H
2#define _ASM_ALPHA_FUTEX_H
Jakub Jelinek4732efb2005-09-06 15:16:25 -0700[diff] [blame]3
Ivan Kokshaysky77b4cf52009-04-30 15:08:48 -0700[diff] [blame]4#ifdef __KERNEL__
Jakub Jelinek4732efb2005-09-06 15:16:25 -0700[diff] [blame]5
Ivan Kokshaysky77b4cf52009-04-30 15:08:48 -0700[diff] [blame]6#include <linux/futex.h>
7#include <linux/uaccess.h>
8#include <asm/errno.h>
9#include <asm/barrier.h>
10
11#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
12 __asm__ __volatile__( \
13 __ASM_SMP_MB \
14 "1: ldl_l %0,0(%2)\n" \
15 insn \
16 "2: stl_c %1,0(%2)\n" \
17 " beq %1,4f\n" \
18 " mov $31,%1\n" \
19 "3: .subsection 2\n" \
20 "4: br 1b\n" \
21 " .previous\n" \
22 " .section __ex_table,\"a\"\n" \
23 " .long 1b-.\n" \
24 " lda $31,3b-1b(%1)\n" \
25 " .long 2b-.\n" \
26 " lda $31,3b-2b(%1)\n" \
27 " .previous\n" \
28 : "=&r" (oldval), "=&r"(ret) \
29 : "r" (uaddr), "r"(oparg) \
30 : "memory")
31
32static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
33{
34 int op = (encoded_op >> 28) & 7;
35 int cmp = (encoded_op >> 24) & 15;
36 int oparg = (encoded_op << 8) >> 20;
37 int cmparg = (encoded_op << 20) >> 20;
38 int oldval = 0, ret;
39 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
40 oparg = 1 << oparg;
41
42 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
43 return -EFAULT;
44
45 pagefault_disable();
46
47 switch (op) {
48 case FUTEX_OP_SET:
49 __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
50 break;
51 case FUTEX_OP_ADD:
52 __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
53 break;
54 case FUTEX_OP_OR:
55 __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
56 break;
57 case FUTEX_OP_ANDN:
58 __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
59 break;
60 case FUTEX_OP_XOR:
61 __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
62 break;
63 default:
64 ret = -ENOSYS;
65 }
66
67 pagefault_enable();
68
69 if (!ret) {
70 switch (cmp) {
71 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
72 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
73 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
74 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
75 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
76 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
77 default: ret = -ENOSYS;
78 }
79 }
80 return ret;
81}
82
83static inline int
84futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
85{
86 int prev, cmp;
87
88 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
89 return -EFAULT;
90
91 __asm__ __volatile__ (
92 __ASM_SMP_MB
93 "1: ldl_l %0,0(%2)\n"
94 " cmpeq %0,%3,%1\n"
95 " beq %1,3f\n"
96 " mov %4,%1\n"
97 "2: stl_c %1,0(%2)\n"
98 " beq %1,4f\n"
99 "3: .subsection 2\n"
100 "4: br 1b\n"
101 " .previous\n"
102 " .section __ex_table,\"a\"\n"
103 " .long 1b-.\n"
104 " lda $31,3b-1b(%0)\n"
105 " .long 2b-.\n"
106 " lda $31,3b-2b(%0)\n"
107 " .previous\n"
108 : "=&r"(prev), "=&r"(cmp)
109 : "r"(uaddr), "r"((long)oldval), "r"(newval)
110 : "memory");
111
112 return prev;
113}
114
115#endif /* __KERNEL__ */
116#endif /* _ASM_ALPHA_FUTEX_H */