1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/*
* linux/arch/unicore32/include/asm/futex.h
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __UNICORE_FUTEX_H__
#define __UNICORE_FUTEX_H__
#ifdef __KERNEL__
#include <linux/futex.h>
#include <linux/preempt.h>
#include <linux/uaccess.h>
#include <linux/errno.h>
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
__asm__ __volatile__( \
"1: ldw.u %1, [%2]\n" \
" " insn "\n" \
"2: stw.u %0, [%2]\n" \
" mov %0, #0\n" \
"3:\n" \
" .pushsection __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4f, 2b, 4f\n" \
" .popsection\n" \
" .pushsection .fixup,\"ax\"\n" \
"4: mov %0, %4\n" \
" b 3b\n" \
" .popsection" \
: "=&r" (ret), "=&r" (oldval) \
: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
: "cc", "memory")
static inline int
futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
{
int op = (encoded_op >> 28) & 7;
int cmp = (encoded_op >> 24) & 15;
int oparg = (encoded_op << 8) >> 20;
int cmparg = (encoded_op << 20) >> 20;
int oldval = 0, ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
pagefault_disable(); /* implies preempt_disable() */
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op("or %0, %1, %3", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("and %0, %1, %3",
ret, oldval, uaddr, ~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("xor %0, %1, %3", ret, oldval, uaddr, oparg);
break;
default:
ret = -ENOSYS;
}
pagefault_enable(); /* subsumes preempt_enable() */
if (!ret) {
switch (cmp) {
case FUTEX_OP_CMP_EQ:
ret = (oldval == cmparg);
break;
case FUTEX_OP_CMP_NE:
ret = (oldval != cmparg);
break;
case FUTEX_OP_CMP_LT:
ret = (oldval < cmparg);
break;
case FUTEX_OP_CMP_GE:
ret = (oldval >= cmparg);
break;
case FUTEX_OP_CMP_LE:
ret = (oldval <= cmparg);
break;
case FUTEX_OP_CMP_GT:
ret = (oldval > cmparg);
break;
default:
ret = -ENOSYS;
}
}
return ret;
}
static inline int
futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
{
int val;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
pagefault_disable(); /* implies preempt_disable() */
__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
"1: ldw.u %0, [%3]\n"
" cmpxor.a %0, %1\n"
" bne 3f\n"
"2: stw.u %2, [%3]\n"
"3:\n"
" .pushsection __ex_table,\"a\"\n"
" .align 3\n"
" .long 1b, 4f, 2b, 4f\n"
" .popsection\n"
" .pushsection .fixup,\"ax\"\n"
"4: mov %0, %4\n"
" b 3b\n"
" .popsection"
: "=&r" (val)
: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
: "cc", "memory");
pagefault_enable(); /* subsumes preempt_enable() */
return val;
}
#endif /* __KERNEL__ */
#endif /* __UNICORE_FUTEX_H__ */
|
