x86: use __page_aligned_data/bss

Update arch/x86's use of page-aligned variables.  The change to
arch/x86/xen/mmu.c fixes an actual bug, but the rest are cleanups
and to set a precedent.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/common_64.c

@@ -16,6 +16,7 @@
 #include <asm/i387.h>
 #include <asm/msr.h>
 #include <asm/io.h>
+#include <asm/linkage.h>
 #include <asm/mmu_context.h>
 #include <asm/mtrr.h>
 #include <asm/mce.h>
@@ -517,8 +518,7 @@ void pda_init(int cpu)
 }
 
 char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
-			   DEBUG_STKSZ]
-__attribute__((section(".bss.page_aligned")));
+			   DEBUG_STKSZ] __page_aligned_bss;
 
 extern asmlinkage void ignore_sysret(void);
 

arch/x86/kernel/irq_32.c

@@ -83,11 +83,8 @@ union irq_ctx {
 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
 
-static char softirq_stack[NR_CPUS * THREAD_SIZE]
-		__attribute__((__section__(".bss.page_aligned")));
-
-static char hardirq_stack[NR_CPUS * THREAD_SIZE]
-		__attribute__((__section__(".bss.page_aligned")));
+static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
+static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
 
 static void call_on_stack(void *func, void *stack)
 {

arch/x86/xen/mmu.c

@@ -46,6 +46,7 @@
 #include <asm/tlbflush.h>
 #include <asm/mmu_context.h>
 #include <asm/paravirt.h>
+#include <asm/linkage.h>
 
 #include <asm/xen/hypercall.h>
 #include <asm/xen/hypervisor.h>
@@ -60,22 +61,18 @@
 #define TOP_ENTRIES		(MAX_DOMAIN_PAGES / P2M_ENTRIES_PER_PAGE)
 
 /* Placeholder for holes in the address space */
-static unsigned long p2m_missing[P2M_ENTRIES_PER_PAGE]
-	__attribute__((section(".data.page_aligned"))) =
+static unsigned long p2m_missing[P2M_ENTRIES_PER_PAGE] __page_aligned_data =
 		{ [ 0 ... P2M_ENTRIES_PER_PAGE-1 ] = ~0UL };
 
  /* Array of pointers to pages containing p2m entries */
-static unsigned long *p2m_top[TOP_ENTRIES]
-	__attribute__((section(".data.page_aligned"))) =
+static unsigned long *p2m_top[TOP_ENTRIES] __page_aligned_data =
 		{ [ 0 ... TOP_ENTRIES - 1] = &p2m_missing[0] };
 
 /* Arrays of p2m arrays expressed in mfns used for save/restore */
-static unsigned long p2m_top_mfn[TOP_ENTRIES]
-	__attribute__((section(".bss.page_aligned")));
+static unsigned long p2m_top_mfn[TOP_ENTRIES] __page_aligned_bss;
 
-static unsigned long p2m_top_mfn_list[
-			PAGE_ALIGN(TOP_ENTRIES / P2M_ENTRIES_PER_PAGE)]
-	__attribute__((section(".bss.page_aligned")));
+static unsigned long p2m_top_mfn_list[TOP_ENTRIES / P2M_ENTRIES_PER_PAGE]
+	__page_aligned_bss;
 
 static inline unsigned p2m_top_index(unsigned long pfn)
 {