[PATCH] xen: x86_64: Add macro for debugreg

Add 2 macros to set and get debugreg on x86_64.  This is useful for Xen
because it will need only to redefine each macro to a hypervisor call.

Signed-off-by: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index 8b55f139968..106f666517b 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -280,6 +280,14 @@ struct thread_struct {
         set_fs(USER_DS);                                                         \
 } while(0) 
 
+#define get_debugreg(var, register)                             \
+                __asm__("movq %%db" #register ", %0"            \
+                        :"=r" (var))
+#define set_debugreg(value, register)                   \
+                __asm__("movq %0,%%db" #register                \
+                        : /* no output */                       \
+                        :"r" (value))
+
 struct task_struct;
 struct mm_struct;