1 /*
2 * Copyright (c) 2012 The Chromium OS Authors.
3 *
4 * (C) Copyright 2008-2011
5 * Graeme Russ, <graeme.russ@gmail.com>
6 *
7 * (C) Copyright 2002
8 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
9 *
10 * Portions of this file are derived from the Linux kernel source
11 * Copyright (C) 1991, 1992 Linus Torvalds
12 *
13 * SPDX-License-Identifier: GPL-2.0+
14 */
15
16 #ifndef __X86_CONTROL_REGS_H
17 #define __X86_CONTROL_REGS_H
18
19 /*
20 * The memory clobber prevents the GCC from reordering the read/write order
21 * of CR0
22 */
read_cr0(void)23 static inline unsigned long read_cr0(void)
24 {
25 unsigned long val;
26
27 asm volatile ("movl %%cr0, %0" : "=r" (val) : : "memory");
28 return val;
29 }
30
write_cr0(unsigned long val)31 static inline void write_cr0(unsigned long val)
32 {
33 asm volatile ("movl %0, %%cr0" : : "r" (val) : "memory");
34 }
35
read_cr2(void)36 static inline unsigned long read_cr2(void)
37 {
38 unsigned long val;
39
40 asm volatile("mov %%cr2,%0\n\t" : "=r" (val) : : "memory");
41 return val;
42 }
43
read_cr3(void)44 static inline unsigned long read_cr3(void)
45 {
46 unsigned long val;
47
48 asm volatile("mov %%cr3,%0\n\t" : "=r" (val) : : "memory");
49 return val;
50 }
51
read_cr4(void)52 static inline unsigned long read_cr4(void)
53 {
54 unsigned long val;
55
56 asm volatile("mov %%cr4,%0\n\t" : "=r" (val) : : "memory");
57 return val;
58 }
59
get_debugreg(int regno)60 static inline unsigned long get_debugreg(int regno)
61 {
62 unsigned long val = 0; /* Damn you, gcc! */
63
64 switch (regno) {
65 case 0:
66 asm("mov %%db0, %0" : "=r" (val));
67 break;
68 case 1:
69 asm("mov %%db1, %0" : "=r" (val));
70 break;
71 case 2:
72 asm("mov %%db2, %0" : "=r" (val));
73 break;
74 case 3:
75 asm("mov %%db3, %0" : "=r" (val));
76 break;
77 case 6:
78 asm("mov %%db6, %0" : "=r" (val));
79 break;
80 case 7:
81 asm("mov %%db7, %0" : "=r" (val));
82 break;
83 default:
84 val = 0;
85 }
86 return val;
87 }
88
89 #endif
90