x86: replace LOCK_PREFIX in futex.h
[linux-2.6.git] / include / asm-x86 / futex.h
1 #ifndef _ASM_X86_FUTEX_H
2 #define _ASM_X86_FUTEX_H
3
4 #ifdef __KERNEL__
5
6 #include <linux/futex.h>
7
8 #include <asm/asm.h>
9 #include <asm/errno.h>
10 #include <asm/processor.h>
11 #include <asm/system.h>
12 #include <asm/uaccess.h>
13
14 #define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg)     \
15   __asm__ __volatile(                                           \
16 "1:     " insn "\n"                                             \
17 "2:     .section .fixup,\"ax\"\n                                \
18 3:      mov     %3, %1\n                                        \
19         jmp     2b\n                                            \
20         .previous\n                                             \
21         .section __ex_table,\"a\"\n                             \
22         .align  8\n"                                            \
23         _ASM_PTR "1b,3b\n                                       \
24         .previous"                                              \
25         : "=r" (oldval), "=r" (ret), "+m" (*uaddr)              \
26         : "i" (-EFAULT), "0" (oparg), "1" (0))
27
28 #define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg)     \
29   __asm__ __volatile(                                           \
30 "1:     movl    %2, %0\n                                        \
31         movl    %0, %3\n"                                       \
32         insn "\n"                                               \
33 "2:     lock; cmpxchgl %3, %2\n                                 \
34         jnz     1b\n                                            \
35 3:      .section .fixup,\"ax\"\n                                \
36 4:      mov     %5, %1\n                                        \
37         jmp     3b\n                                            \
38         .previous\n                                             \
39         .section __ex_table,\"a\"\n                             \
40         .align  8\n"                                            \
41         _ASM_PTR "1b,4b,2b,4b\n                                 \
42         .previous"                                              \
43         : "=&a" (oldval), "=&r" (ret), "+m" (*uaddr),           \
44           "=&r" (tem)                                           \
45         : "r" (oparg), "i" (-EFAULT), "1" (0))
46
47 static inline int
48 futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
49 {
50         int op = (encoded_op >> 28) & 7;
51         int cmp = (encoded_op >> 24) & 15;
52         int oparg = (encoded_op << 8) >> 20;
53         int cmparg = (encoded_op << 20) >> 20;
54         int oldval = 0, ret, tem;
55
56         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
57                 oparg = 1 << oparg;
58
59         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
60                 return -EFAULT;
61
62 #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
63         /* Real i386 machines can only support FUTEX_OP_SET */
64         if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3)
65                 return -ENOSYS;
66 #endif
67
68         pagefault_disable();
69
70         switch (op) {
71         case FUTEX_OP_SET:
72                 __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
73                 break;
74         case FUTEX_OP_ADD:
75                 __futex_atomic_op1("lock; xaddl %0, %2", ret, oldval,
76                                    uaddr, oparg);
77                 break;
78         case FUTEX_OP_OR:
79                 __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
80                 break;
81         case FUTEX_OP_ANDN:
82                 __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
83                 break;
84         case FUTEX_OP_XOR:
85                 __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg);
86                 break;
87         default:
88                 ret = -ENOSYS;
89         }
90
91         pagefault_enable();
92
93         if (!ret) {
94                 switch (cmp) {
95                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
96                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
97                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
98                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
99                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
100                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
101                 default: ret = -ENOSYS;
102                 }
103         }
104         return ret;
105 }
106
107 static inline int
108 futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
109 {
110         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
111                 return -EFAULT;
112
113         __asm__ __volatile__(
114
115                 "1:     lock; cmpxchgl %3, %1                   \n"
116                 "2:     .section .fixup, \"ax\"                 \n"
117                 "3:     mov     %2, %0                          \n"
118                 "       jmp     2b                              \n"
119                 "       .previous                               \n"
120
121                 "       .section __ex_table, \"a\"              \n"
122                 "       .align  8                               \n"
123                         _ASM_PTR " 1b,3b                        \n"
124                 "       .previous                               \n"
125
126                 : "=a" (oldval), "+m" (*uaddr)
127                 : "i" (-EFAULT), "r" (newval), "0" (oldval)
128                 : "memory"
129         );
130
131         return oldval;
132 }
133
134 #endif
135 #endif