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 /* _ASM_X86_FUTEX_H */
118