[PATCH] i386: cleanups to help using per-cpu variables from asm

This patch does a few small cleanups:
 - use PER_CPU_NAME to generate the names of per-cpu variables
 - use lea to add the per_cpu offset in PER_CPU(), because it doesn't
   affect condition flags
 - add PER_CPU_VAR which allows direct access to pre-cpu variables
   with the %fs: prefix on SMP.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>

include/asm-i386/percpu.h

@@ -16,12 +16,14 @@
  *    PER_CPU(cpu_gdt_descr, %ebx)
  */
 #ifdef CONFIG_SMP
-#define PER_CPU(var, reg)			\
-	movl %fs:per_cpu__this_cpu_off, reg;		\
-	addl $per_cpu__##var, reg
+#define PER_CPU(var, reg)				\
+	movl %fs:per_cpu__##this_cpu_off, reg;		\
+	lea per_cpu__##var(reg), reg
+#define PER_CPU_VAR(var)	%fs:per_cpu__##var
 #else /* ! SMP */
-#define PER_CPU(var, reg) \
-	movl $per_cpu__##var, reg;
+#define PER_CPU(var, reg)			\
+	movl $per_cpu__##var, reg
+#define PER_CPU_VAR(var)	per_cpu__##var
 #endif	/* SMP */
 
 #else /* ...!ASSEMBLY */