1#ifndef _ASM_FUTEX_H
2#define _ASM_FUTEX_H
3
4#ifdef __KERNEL__
5
6#include <linux/futex.h>
7#include <asm/errno.h>
8#include <asm/system.h>
9#include <asm/uaccess.h>
10
11#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
12  __asm__ __volatile (						\
13"1:	" insn "\n"						\
14"2:	.section .fixup,\"ax\"\n\
153:	mov	%3, %1\n\
16	jmp	2b\n\
17	.previous\n\
18	.section __ex_table,\"a\"\n\
19	.align	8\n\
20	.quad	1b,3b\n\
21	.previous"						\
22	: "=r" (oldval), "=r" (ret), "=m" (*uaddr)		\
23	: "i" (-EFAULT), "m" (*uaddr), "0" (oparg), "1" (0))
24
25#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
26  __asm__ __volatile (						\
27"1:	movl	%2, %0\n\
28	movl	%0, %3\n"					\
29	insn "\n"						\
30"2:	" LOCK_PREFIX "cmpxchgl %3, %2\n\
31	jnz	1b\n\
323:	.section .fixup,\"ax\"\n\
334:	mov	%5, %1\n\
34	jmp	3b\n\
35	.previous\n\
36	.section __ex_table,\"a\"\n\
37	.align	8\n\
38	.quad	1b,4b,2b,4b\n\
39	.previous"						\
40	: "=&a" (oldval), "=&r" (ret), "=m" (*uaddr),		\
41	  "=&r" (tem)						\
42	: "r" (oparg), "i" (-EFAULT), "m" (*uaddr), "1" (0))
43
44static inline int
45futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
46{
47	int op = (encoded_op >> 28) & 7;
48	int cmp = (encoded_op >> 24) & 15;
49	int oparg = (encoded_op << 8) >> 20;
50	int cmparg = (encoded_op << 20) >> 20;
51	int oldval = 0, ret, tem;
52	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
53		oparg = 1 << oparg;
54
55	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
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: ret = (oldval == cmparg); break;
86		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
87		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
88		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
89		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
90		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
91		default: ret = -ENOSYS;
92		}
93	}
94	return ret;
95}
96
97static inline int
98futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
99{
100	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
101		return -EFAULT;
102
103	__asm__ __volatile__(
104		"1:	" LOCK_PREFIX "cmpxchgl %3, %1		\n"
105
106		"2:	.section .fixup, \"ax\"			\n"
107		"3:	mov     %2, %0				\n"
108		"	jmp     2b				\n"
109		"	.previous				\n"
110
111		"	.section __ex_table, \"a\"		\n"
112		"	.align  8				\n"
113		"	.quad   1b,3b				\n"
114		"	.previous				\n"
115
116		: "=a" (oldval), "=m" (*uaddr)
117		: "i" (-EFAULT), "r" (newval), "0" (oldval)
118		: "memory"
119	);
120
121	return oldval;
122}
123
124#endif
125#endif
126