1 files changed, 67 insertions, 0 deletions

diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h
index b903d5ea3941..2d91580bf228 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 */