x86: use static _cpu_pda array

_cpu_pda array first uses statically allocated storage in data.init
and then switches to allocated bootmem to conserve space.  However,
after folding pda area into percpu area, _cpu_pda array will be
removed completely.  Drop the reallocation part to simplify the code
for soon-to-follow changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h
index cbd3f48..2d5b49c 100644
--- a/arch/x86/include/asm/pda.h
+++ b/arch/x86/include/asm/pda.h
@@ -5,6 +5,7 @@
 #include <linux/stddef.h>
 #include <linux/types.h>
 #include <linux/cache.h>
+#include <linux/threads.h>
 #include <asm/page.h>
 
 /* Per processor datastructure. %gs points to it while the kernel runs */
@@ -39,7 +40,7 @@
 	unsigned irq_spurious_count;
 } ____cacheline_aligned_in_smp;
 
-extern struct x8664_pda **_cpu_pda;
+extern struct x8664_pda *_cpu_pda[NR_CPUS];
 extern void pda_init(int);
 
 #define cpu_pda(i) (_cpu_pda[i])