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
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_FUTEX_H
#define _ASM_POWERPC_FUTEX_H
#ifdef __KERNEL__
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>
#include <asm/synch.h>
#include <asm/asm-405.h>
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
__asm__ __volatile ( \
PPC_ATOMIC_ENTRY_BARRIER \
"1: lwarx %0,0,%2\n" \
insn \
PPC405_ERR77(0, %2) \
"2: stwcx. %1,0,%2\n" \
"bne- 1b\n" \
PPC_ATOMIC_EXIT_BARRIER \
"li %1,0\n" \
"3: .section .fixup,\"ax\"\n" \
"4: li %1,%3\n" \
"b 3b\n" \
".previous\n" \
EX_TABLE(1b, 4b) \
EX_TABLE(2b, 4b) \
: "=&r" (oldval), "=&r" (ret) \
: "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
: "cr0", "memory")
static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
u32 __user *uaddr)
{
int oldval = 0, ret;
if (!access_ok(uaddr, sizeof(u32)))
return -EFAULT;
allow_read_write_user(uaddr, uaddr, sizeof(*uaddr));
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
break;
default:
ret = -ENOSYS;
}
*oval = oldval;
prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr));
return ret;
}
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
int ret = 0;
u32 prev;
if (!access_ok(uaddr, sizeof(u32)))
return -EFAULT;
allow_read_write_user(uaddr, uaddr, sizeof(*uaddr));
__asm__ __volatile__ (
PPC_ATOMIC_ENTRY_BARRIER
"1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\
cmpw 0,%1,%4\n\
bne- 3f\n"
PPC405_ERR77(0,%3)
"2: stwcx. %5,0,%3\n\
bne- 1b\n"
PPC_ATOMIC_EXIT_BARRIER
"3: .section .fixup,\"ax\"\n\
4: li %0,%6\n\
b 3b\n\
.previous\n"
EX_TABLE(1b, 4b)
EX_TABLE(2b, 4b)
: "+r" (ret), "=&r" (prev), "+m" (*uaddr)
: "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
: "cc", "memory");
*uval = prev;
prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr));
return ret;
}
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_FUTEX_H */
|
