x86: relocate get/set debugreg fcns to include/asm/debugreg.

Since we already have a debugreg.h header file, move the
assoc. get/set functions to it.  In addition to it being the
logical home for them, it has a secondary advantage.  The
functions that are moved use BUG().  So we really need to
have linux/bug.h in scope.  But asm/processor.h is used about
600 times, vs. only about 15 for debugreg.h -- so adding bug.h
to the latter reduces the amount of time we'll be processing
it during a compile.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h
index b903d5e..2d91580 100644
--- a/arch/x86/include/asm/debugreg.h
+++ b/arch/x86/include/asm/debugreg.h
@@ -78,8 +78,75 @@
  */
 #ifdef __KERNEL__
 
+#include <linux/bug.h>
+
 DECLARE_PER_CPU(unsigned long, cpu_dr7);
 
+#ifndef CONFIG_PARAVIRT
+/*
+ * These special macros can be used to get or set a debugging register
+ */
+#define get_debugreg(var, register)				\
+	(var) = native_get_debugreg(register)
+#define set_debugreg(value, register)				\
+	native_set_debugreg(register, value)
+#endif
+
+static inline unsigned long native_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:
+		BUG();
+	}
+	return val;
+}
+
+static inline void native_set_debugreg(int regno, unsigned long value)
+{
+	switch (regno) {
+	case 0:
+		asm("mov %0, %%db0"	::"r" (value));
+		break;
+	case 1:
+		asm("mov %0, %%db1"	::"r" (value));
+		break;
+	case 2:
+		asm("mov %0, %%db2"	::"r" (value));
+		break;
+	case 3:
+		asm("mov %0, %%db3"	::"r" (value));
+		break;
+	case 6:
+		asm("mov %0, %%db6"	::"r" (value));
+		break;
+	case 7:
+		asm("mov %0, %%db7"	::"r" (value));
+		break;
+	default:
+		BUG();
+	}
+}
+
 static inline void hw_breakpoint_disable(void)
 {
 	/* Zero the control register for HW Breakpoint */