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/*
* Copyright (c) 2012 The Chromium OS Authors.
*
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* Portions of this file are derived from the Linux kernel source
* Copyright (C) 1991, 1992 Linus Torvalds
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef __X86_CONTROL_REGS_H
#define __X86_CONTROL_REGS_H
/*
* The memory clobber prevents the GCC from reordering the read/write order
* of CR0
*/
static inline unsigned long read_cr0(void)
{
unsigned long val;
asm volatile ("movl %%cr0, %0" : "=r" (val) : : "memory");
return val;
}
static inline void write_cr0(unsigned long val)
{
asm volatile ("movl %0, %%cr0" : : "r" (val) : "memory");
}
static inline unsigned long read_cr2(void)
{
unsigned long val;
asm volatile("mov %%cr2,%0\n\t" : "=r" (val) : : "memory");
return val;
}
static inline unsigned long read_cr3(void)
{
unsigned long val;
asm volatile("mov %%cr3,%0\n\t" : "=r" (val) : : "memory");
return val;
}
static inline unsigned long read_cr4(void)
{
unsigned long val;
asm volatile("mov %%cr4,%0\n\t" : "=r" (val) : : "memory");
return val;
}
static inline unsigned long get_debugreg(int regno)
{
unsigned long val = 0; /* Damn you, gcc! */
switch (regno) {
case 0:
asm("mov %%db0, %0" : "=r" (val));
break;
case 1:
asm("mov %%db1, %0" : "=r" (val));
break;
case 2:
asm("mov %%db2, %0" : "=r" (val));
break;
case 3:
asm("mov %%db3, %0" : "=r" (val));
break;
case 6:
asm("mov %%db6, %0" : "=r" (val));
break;
case 7:
asm("mov %%db7, %0" : "=r" (val));
break;
default:
val = 0;
}
return val;
}
#endif