GNU Linux-libre 4.4.288-gnu1
[releases.git] / arch / x86 / include / asm / 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 #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
44 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
45                 u32 __user *uaddr)
46 {
47         int oldval = 0, ret, tem;
48
49         pagefault_disable();
50
51         switch (op) {
52         case FUTEX_OP_SET:
53                 __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
54                 break;
55         case FUTEX_OP_ADD:
56                 __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
57                                    uaddr, oparg);
58                 break;
59         case FUTEX_OP_OR:
60                 __futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
61                 break;
62         case FUTEX_OP_ANDN:
63                 __futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
64                 break;
65         case FUTEX_OP_XOR:
66                 __futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg);
67                 break;
68         default:
69                 ret = -ENOSYS;
70         }
71
72         pagefault_enable();
73
74         if (!ret)
75                 *oval = oldval;
76
77         return ret;
78 }
79
80 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
81                                                 u32 oldval, u32 newval)
82 {
83         return user_atomic_cmpxchg_inatomic(uval, uaddr, oldval, newval);
84 }
85
86 #endif
87 #endif /* _ASM_X86_FUTEX_H */