[PATCH] x86: Allow percpu variables to be page-aligned

Let's allow page-alignment in general for per-cpu data (wanted by Xen, and
Ingo suggested KVM as well).

Because larger alignments can use more room, we increase the max per-cpu
memory to 64k rather than 32k: it's getting a little tight.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 3 insertions, 7 deletions

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 22083ce3cc30..6018178708a5 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -582,14 +582,14 @@ void __init setup_per_cpu_areas(void)
         char *ptr;
 
         /* Copy section for each CPU (we discard the original) */
-        size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
+        size = ALIGN(__per_cpu_end - __per_cpu_start, PAGE_SIZE);
 #ifdef CONFIG_MODULES
         if (size < PERCPU_ENOUGH_ROOM)
                 size = PERCPU_ENOUGH_ROOM;
 #endif
 
         for_each_possible_cpu(i) {
-                ptr = alloc_bootmem_node(NODE_DATA(cpu_to_node(i)), size);
+                ptr = alloc_bootmem_pages_node(NODE_DATA(cpu_to_node(i)), size);
                 if (!ptr)
                         panic("Cannot allocate cpu data for CPU %d\n", i);
 
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 7eefeb4a30e7..132067313147 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -139,11 +139,7 @@ SECTIONS
                 __initramfs_end = .;
         }
 #endif
-#ifdef CONFIG_PPC32
-        . = ALIGN(32);
-#else
-        . = ALIGN(128);
-#endif
+        . = ALIGN(PAGE_SIZE);
         .data.percpu : {
                 __per_cpu_start = .;
                 *(.data.percpu)