1#ifndef _ASM_X86_FUTEX_H
2#define _ASM_X86_FUTEX_H
3
4#ifdef __KERNEL__
5
6#include <linux/futex.h>
7#include <linux/uaccess.h>
8
9#include <asm/asm.h>
10#include <asm/errno.h>
11#include <asm/processor.h>
12#include <asm/system.h>
13
14#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
15 asm volatile("1:\t" insn "\n" \
16 "2:\t.section .fixup,\"ax\"\n" \
17 "3:\tmov\t%3, %1\n" \
18 "\tjmp\t2b\n" \
19 "\t.previous\n" \
20 _ASM_EXTABLE(1b, 3b) \
21 : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \
22 : "i" (-EFAULT), "0" (oparg), "1" (0))
23
24#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
25 asm volatile("1:\tmovl %2, %0\n" \
26 "\tmovl\t%0, %3\n" \
27 "\t" insn "\n" \
28 "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \
29 "\tjnz\t1b\n" \
30 "3:\t.section .fixup,\"ax\"\n" \
31 "4:\tmov\t%5, %1\n" \
32 "\tjmp\t3b\n" \
33 "\t.previous\n" \
34 _ASM_EXTABLE(1b, 4b) \
35 _ASM_EXTABLE(2b, 4b) \
36 : "=&a" (oldval), "=&r" (ret), \
37 "+m" (*uaddr), "=&r" (tem) \
38 : "r" (oparg), "i" (-EFAULT), "1" (0))
39
40static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
41{
42 int op = (encoded_op >> 28) & 7;
43 int cmp = (encoded_op >> 24) & 15;
44 int oparg = (encoded_op << 8) >> 20;
45 int cmparg = (encoded_op << 20) >> 20;
46 int oldval = 0, ret, tem;
47
48 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
49 oparg = 1 << oparg;
50
51 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
52 return -EFAULT;
53
54#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
55
56 if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3)
57 return -ENOSYS;
58#endif
59
60 pagefault_disable();
61
62 switch (op) {
63 case FUTEX_OP_SET:
64 __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
65 break;
66 case FUTEX_OP_ADD:
67 __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
68 uaddr, oparg);
69 break;
70 case FUTEX_OP_OR:
71 __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
72 break;
73 case FUTEX_OP_ANDN:
74 __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
75 break;
76 case FUTEX_OP_XOR:
77 __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg);
78 break;
79 default:
80 ret = -ENOSYS;
81 }
82
83 pagefault_enable();
84
85 if (!ret) {
86 switch (cmp) {
87 case FUTEX_OP_CMP_EQ:
88 ret = (oldval == cmparg);
89 break;
90 case FUTEX_OP_CMP_NE:
91 ret = (oldval != cmparg);
92 break;
93 case FUTEX_OP_CMP_LT:
94 ret = (oldval < cmparg);
95 break;
96 case FUTEX_OP_CMP_GE:
97 ret = (oldval >= cmparg);
98 break;
99 case FUTEX_OP_CMP_LE:
100 ret = (oldval <= cmparg);
101 break;
102 case FUTEX_OP_CMP_GT:
103 ret = (oldval > cmparg);
104 break;
105 default:
106 ret = -ENOSYS;
107 }
108 }
109 return ret;
110}
111
112static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval,
113 int newval)
114{
115
116#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
117
118 if (boot_cpu_data.x86 == 3)
119 return -ENOSYS;
120#endif
121
122 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
123 return -EFAULT;
124
125 asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %3, %1\n"
126 "2:\t.section .fixup, \"ax\"\n"
127 "3:\tmov %2, %0\n"
128 "\tjmp 2b\n"
129 "\t.previous\n"
130 _ASM_EXTABLE(1b, 3b)
131 : "=a" (oldval), "+m" (*uaddr)
132 : "i" (-EFAULT), "r" (newval), "0" (oldval)
133 : "memory"
134 );
135
136 return oldval;
137}
138
139#endif
140#endif
141
