x86: use generic percpu on 64-bit

x86_64 provides an optimized way to determine the local per cpu area
offset through the pda and determines the base by accessing a remote
pda.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/asm-x86/percpu_64.h

@@ -12,21 +12,10 @@
 #include <asm/pda.h>
 
 #define __per_cpu_offset(cpu) (cpu_pda(cpu)->data_offset)
-#define __my_cpu_offset() read_pda(data_offset)
+#define __my_cpu_offset read_pda(data_offset)
 
 #define per_cpu_offset(x) (__per_cpu_offset(x))
 
-/* var is in discarded region: offset to particular copy we want */
-#define per_cpu(var, cpu) (*({				\
-	extern int simple_identifier_##var(void);	\
-	RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu)); }))
-#define __get_cpu_var(var) (*({				\
-	extern int simple_identifier_##var(void);	\
-	RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()); }))
-#define __raw_get_cpu_var(var) (*({			\
-	extern int simple_identifier_##var(void);	\
-	RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()); }))
-
 /* A macro to avoid #include hell... */
 #define percpu_modcopy(pcpudst, src, size)			\
 do {								\
@@ -36,16 +25,8 @@ do {								\
 		       (src), (size));				\
 } while (0)
 
-extern void setup_per_cpu_areas(void);
-
-#else /* ! SMP */
-
-#define per_cpu(var, cpu)			(*((void)(cpu), &per_cpu__##var))
-#define __get_cpu_var(var)			per_cpu__##var
-#define __raw_get_cpu_var(var)			per_cpu__##var
-
 #endif	/* SMP */
 
-#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
+#include <asm-generic/percpu.h>
 
 #endif /* _ASM_X8664_PERCPU_H_ */