blob: 9feff4ce1424bc390608326240be369eb13aa648 [file] [log] [blame]
Jakub Jelinek4732efb2005-09-06 15:16:25 -07001#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/uaccess.h>
9
10static inline int
11futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
12{
13 int op = (encoded_op >> 28) & 7;
14 int cmp = (encoded_op >> 24) & 15;
15 int oparg = (encoded_op << 8) >> 20;
16 int cmparg = (encoded_op << 20) >> 20;
Russell King7f8c0fd2005-09-18 21:11:08 +010017 int oldval = 0, ret;
Jakub Jelinek4732efb2005-09-06 15:16:25 -070018 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
19 oparg = 1 << oparg;
20
21 if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
22 return -EFAULT;
23
24 inc_preempt_count();
25
26 switch (op) {
27 case FUTEX_OP_SET:
28 case FUTEX_OP_ADD:
29 case FUTEX_OP_OR:
30 case FUTEX_OP_ANDN:
31 case FUTEX_OP_XOR:
32 default:
33 ret = -ENOSYS;
34 }
35
36 dec_preempt_count();
37
38 if (!ret) {
39 switch (cmp) {
40 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
41 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
42 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
43 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
44 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
45 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
46 default: ret = -ENOSYS;
47 }
48 }
49 return ret;
50}
51
52#endif
53#endif