1 files changed, 105 insertions, 0 deletions
diff --git a/arch/x86/include/asm/control_regs.h b/arch/x86/include/asm/control_regs.h
new file mode 100644
index 0000000000..aa8be30bac
--- /dev/null
+++ b/arch/x86/include/asm/control_regs.h
@@ -0,0 +1,105 @@
+/*
+ * 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
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#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