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review.evervolv.com / android_kernel_htc_msm8960 / 1918e341383ab787d6c5b17200f4ed901b10c777 / . / include / asm-x86_64 / futex.h
blob: 8602c09bf89e8b7e6edc4cb956f832550378d460 [file] [log] [blame]
Jakub Jelinek4732efb2005-09-06 15:16:25 -0700[diff] [blame]1#ifndef _ASM_FUTEX_H
2#define _ASM_FUTEX_H
3
4#ifdef __KERNEL__
5
6#include <linux/futex.h>
7#include <asm/errno.h>
8#include <asm/system.h>
9#include <asm/uaccess.h>
10
11#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
12 __asm__ __volatile ( \
13"1: " insn "\n" \
14"2: .section .fixup,\"ax\"\n\
153: mov %3, %1\n\
16 jmp 2b\n\
17 .previous\n\
18 .section __ex_table,\"a\"\n\
19 .align 8\n\
20 .quad 1b,3b\n\
21 .previous" \
22 : "=r" (oldval), "=r" (ret), "=m" (*uaddr) \
23 : "i" (-EFAULT), "m" (*uaddr), "0" (oparg), "1" (0))
24
25#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
26 __asm__ __volatile ( \
27"1: movl %2, %0\n\
28 movl %0, %3\n" \
29 insn "\n" \
30"2: " LOCK_PREFIX "cmpxchgl %3, %2\n\
31 jnz 1b\n\
323: .section .fixup,\"ax\"\n\
334: mov %5, %1\n\
34 jmp 3b\n\
35 .previous\n\
36 .section __ex_table,\"a\"\n\
37 .align 8\n\
38 .quad 1b,4b,2b,4b\n\
39 .previous" \
40 : "=&a" (oldval), "=&r" (ret), "=m" (*uaddr), \
41 "=&r" (tem) \
42 : "r" (oparg), "i" (-EFAULT), "m" (*uaddr), "1" (0))
43
44static inline int
45futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
46{
47 int op = (encoded_op >> 28) & 7;
48 int cmp = (encoded_op >> 24) & 15;
49 int oparg = (encoded_op << 8) >> 20;
50 int cmparg = (encoded_op << 20) >> 20;
51 int oldval = 0, ret, tem;
52 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
53 oparg = 1 << oparg;
54
55 if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
56 return -EFAULT;
57
58 inc_preempt_count();
59
60 switch (op) {
61 case FUTEX_OP_SET:
62 __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
63 break;
64 case FUTEX_OP_ADD:
65 __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
66 uaddr, oparg);
67 break;
68 case FUTEX_OP_OR:
69 __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
70 break;
71 case FUTEX_OP_ANDN:
72 __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
73 break;
74 case FUTEX_OP_XOR:
75 __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg);
76 break;
77 default:
78 ret = -ENOSYS;
79 }
80
81 dec_preempt_count();
82
83 if (!ret) {
84 switch (cmp) {
85 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
86 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
87 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
88 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
89 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
90 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
91 default: ret = -ENOSYS;
92 }
93 }
94 return ret;
95}
96
97#endif
98#endif