c5fb2d6d918ae52d3e8734c27ced258a98076b6d
[linux-2.6.git] / include / asm-mips / futex.h
1 #ifndef _ASM_FUTEX_H
2 #define _ASM_FUTEX_H
3
4 #ifdef __KERNEL__
5
6 #include <linux/config.h>
7 #include <linux/futex.h>
8 #include <asm/errno.h>
9 #include <asm/uaccess.h>
10
11 #ifdef CONFIG_SMP
12 #define __FUTEX_SMP_SYNC "      sync                                    \n"
13 #else
14 #define __FUTEX_SMP_SYNC
15 #endif
16
17 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)              \
18 {                                                                       \
19         __asm__ __volatile__(                                           \
20         "       .set    push                                    \n"     \
21         "       .set    noat                                    \n"     \
22         "       .set    mips3                                   \n"     \
23         "1:     ll      %1, (%3)        # __futex_atomic_op1    \n"     \
24         "       .set    mips0                                   \n"     \
25         "       " insn  "                                       \n"     \
26         "       .set    mips3                                   \n"     \
27         "2:     sc      $1, (%3)                                \n"     \
28         "       beqzl   $1, 1b                                  \n"     \
29         __FUTEX_SMP_SYNC                                                \
30         "3:                                                     \n"     \
31         "       .set    pop                                     \n"     \
32         "       .set    mips0                                   \n"     \
33         "       .section .fixup,\"ax\"                          \n"     \
34         "4:     li      %0, %5                                  \n"     \
35         "       j       2b                                      \n"     \
36         "       .previous                                       \n"     \
37         "       .section __ex_table,\"a\"                       \n"     \
38         "       "__UA_ADDR "\t1b, 4b                            \n"     \
39         "       "__UA_ADDR "\t2b, 4b                            \n"     \
40         "       .previous                                       \n"     \
41         : "=r" (ret), "=r" (oldval)                                     \
42         : "0" (0), "r" (uaddr), "Jr" (oparg), "i" (-EFAULT));           \
43 }
44
45 static inline int
46 futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
47 {
48         int op = (encoded_op >> 28) & 7;
49         int cmp = (encoded_op >> 24) & 15;
50         int oparg = (encoded_op << 8) >> 20;
51         int cmparg = (encoded_op << 20) >> 20;
52         int oldval = 0, ret;
53         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
54                 oparg = 1 << oparg;
55
56         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
57                 return -EFAULT;
58
59         inc_preempt_count();
60
61         switch (op) {
62         case FUTEX_OP_SET:
63                 __futex_atomic_op("move $1, %z4", ret, oldval, uaddr, oparg);
64                 break;
65
66         case FUTEX_OP_ADD:
67                 __futex_atomic_op("addu $1, %1, %z4",
68                                   ret, oldval, uaddr, oparg);
69                 break;
70         case FUTEX_OP_OR:
71                 __futex_atomic_op("or   $1, %1, %z4",
72                                   ret, oldval, uaddr, oparg);
73                 break;
74         case FUTEX_OP_ANDN:
75                 __futex_atomic_op("and  $1, %1, %z4",
76                                   ret, oldval, uaddr, ~oparg);
77                 break;
78         case FUTEX_OP_XOR:
79                 __futex_atomic_op("xor  $1, %1, %z4",
80                                   ret, oldval, uaddr, oparg);
81                 break;
82         default:
83                 ret = -ENOSYS;
84         }
85
86         dec_preempt_count();
87
88         if (!ret) {
89                 switch (cmp) {
90                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
91                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
92                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
93                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
94                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
95                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
96                 default: ret = -ENOSYS;
97                 }
98         }
99         return ret;
100 }
101
102 static inline int
103 futex_atomic_cmpxchg_inuser(int __user *uaddr, int oldval, int newval)
104 {
105         return -ENOSYS;
106 }
107
108 #endif
109 #endif