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/smap.h>
13
14#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
15 asm volatile("\t" ASM_STAC "\n" \
16 "1:\t" insn "\n" \
17 "2:\t" ASM_CLAC "\n" \
18 "\t.section .fixup,\"ax\"\n" \
19 "3:\tmov\t%3, %1\n" \
20 "\tjmp\t2b\n" \
21 "\t.previous\n" \
22 _ASM_EXTABLE(1b, 3b) \
23 : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \
24 : "i" (-EFAULT), "0" (oparg), "1" (0))
25
26#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
27 asm volatile("\t" ASM_STAC "\n" \
28 "1:\tmovl %2, %0\n" \
29 "\tmovl\t%0, %3\n" \
30 "\t" insn "\n" \
31 "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \
32 "\tjnz\t1b\n" \
33 "3:\t" ASM_CLAC "\n" \
34 "\t.section .fixup,\"ax\"\n" \
35 "4:\tmov\t%5, %1\n" \
36 "\tjmp\t3b\n" \
37 "\t.previous\n" \
38 _ASM_EXTABLE(1b, 4b) \
39 _ASM_EXTABLE(2b, 4b) \
40 : "=&a" (oldval), "=&r" (ret), \
41 "+m" (*uaddr), "=&r" (tem) \
42 : "r" (oparg), "i" (-EFAULT), "1" (0))
43
44static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
45{
46 int op = (encoded_op >> 28) & 7;
47 int cmp = (encoded_op >> 24) & 15;
48 int oparg = (encoded_op << 8) >> 20;
49 int cmparg = (encoded_op << 20) >> 20;
50 int oldval = 0, ret, tem;
51
52 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
53 oparg = 1 << oparg;
54
55 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
56 return -EFAULT;
57
58 pagefault_disable();
59
60 switch (op) {
61 case FUTEX_OP_SET:
62 __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
63 break;
64 case FUTEX_OP_ADD:
65 __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
66 uaddr, oparg);
67 break;
68 case FUTEX_OP_OR:
69 __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
70 break;
71 case FUTEX_OP_ANDN:
72 __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
73 break;
74 case FUTEX_OP_XOR:
75 __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg);
76 break;
77 default:
78 ret = -ENOSYS;
79 }
80
81 pagefault_enable();
82
83 if (!ret) {
84 switch (cmp) {
85 case FUTEX_OP_CMP_EQ:
86 ret = (oldval == cmparg);
87 break;
88 case FUTEX_OP_CMP_NE:
89 ret = (oldval != cmparg);
90 break;
91 case FUTEX_OP_CMP_LT:
92 ret = (oldval < cmparg);
93 break;
94 case FUTEX_OP_CMP_GE:
95 ret = (oldval >= cmparg);
96 break;
97 case FUTEX_OP_CMP_LE:
98 ret = (oldval <= cmparg);
99 break;
100 case FUTEX_OP_CMP_GT:
101 ret = (oldval > cmparg);
102 break;
103 default:
104 ret = -ENOSYS;
105 }
106 }
107 return ret;
108}
109
110static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
111 u32 oldval, u32 newval)
112{
113 return user_atomic_cmpxchg_inatomic(uval, uaddr, oldval, newval);
114}
115
116#endif
117#endif
118
