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
13#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
14 asm volatile("1:\t" insn "\n" \
15 "2:\t.section .fixup,\"ax\"\n" \
16 "3:\tmov\t%3, %1\n" \
17 "\tjmp\t2b\n" \
18 "\t.previous\n" \
19 _ASM_EXTABLE(1b, 3b) \
20 : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \
21 : "i" (-EFAULT), "0" (oparg), "1" (0))
22
23#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
24 asm volatile("1:\tmovl %2, %0\n" \
25 "\tmovl\t%0, %3\n" \
26 "\t" insn "\n" \
27 "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \
28 "\tjnz\t1b\n" \
29 "3:\t.section .fixup,\"ax\"\n" \
30 "4:\tmov\t%5, %1\n" \
31 "\tjmp\t3b\n" \
32 "\t.previous\n" \
33 _ASM_EXTABLE(1b, 4b) \
34 _ASM_EXTABLE(2b, 4b) \
35 : "=&a" (oldval), "=&r" (ret), \
36 "+m" (*uaddr), "=&r" (tem) \
37 : "r" (oparg), "i" (-EFAULT), "1" (0))
38
39static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
40{
41 int op = (encoded_op >> 28) & 7;
42 int cmp = (encoded_op >> 24) & 15;
43 int oparg = (encoded_op << 8) >> 20;
44 int cmparg = (encoded_op << 20) >> 20;
45 int oldval = 0, ret, tem;
46
47 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
48 oparg = 1 << oparg;
49
50 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
51 return -EFAULT;
52
53#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
54
55 if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3)
56 return -ENOSYS;
57#endif
58
59 pagefault_disable();
60
61 switch (op) {
62 case FUTEX_OP_SET:
63 __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
64 break;
65 case FUTEX_OP_ADD:
66 __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
67 uaddr, oparg);
68 break;
69 case FUTEX_OP_OR:
70 __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
71 break;
72 case FUTEX_OP_ANDN:
73 __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
74 break;
75 case FUTEX_OP_XOR:
76 __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg);
77 break;
78 default:
79 ret = -ENOSYS;
80 }
81
82 pagefault_enable();
83
84 if (!ret) {
85 switch (cmp) {
86 case FUTEX_OP_CMP_EQ:
87 ret = (oldval == cmparg);
88 break;
89 case FUTEX_OP_CMP_NE:
90 ret = (oldval != cmparg);
91 break;
92 case FUTEX_OP_CMP_LT:
93 ret = (oldval < cmparg);
94 break;
95 case FUTEX_OP_CMP_GE:
96 ret = (oldval >= cmparg);
97 break;
98 case FUTEX_OP_CMP_LE:
99 ret = (oldval <= cmparg);
100 break;
101 case FUTEX_OP_CMP_GT:
102 ret = (oldval > cmparg);
103 break;
104 default:
105 ret = -ENOSYS;
106 }
107 }
108 return ret;
109}
110
111static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
112 u32 oldval, u32 newval)
113{
114 int ret = 0;
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(u32)))
123 return -EFAULT;
124
125 asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
126 "2:\t.section .fixup, \"ax\"\n"
127 "3:\tmov %3, %0\n"
128 "\tjmp 2b\n"
129 "\t.previous\n"
130 _ASM_EXTABLE(1b, 3b)
131 : "+r" (ret), "=a" (oldval), "+m" (*uaddr)
132 : "i" (-EFAULT), "r" (newval), "1" (oldval)
133 : "memory"
134 );
135
136 *uval = oldval;
137 return ret;
138}
139
140#endif
141#endif
142
