linker script: define __per_cpu_load on all SMP capable archs

Impact: __per_cpu_load available on all SMP capable archs

Percpu now requires three symbols to be defined - __per_cpu_load,
__per_cpu_start and __per_cpu_end.  There were three archs which
didn't have it.  Update them as follows.

* powerpc: can use generic PERCPU() macro.  Compile tested for
  powerpc32, compile/boot tested for powerpc64.

* ia64: can use generic PERCPU_VADDR() macro.  __phys_per_cpu_start is
  identical to __per_cpu_load.  Compile tested and symbol table looks
  identical after the change except for the additional __per_cpu_load.

* arm: added explicit __per_cpu_load definition.  Currently uses
  unified .init output section so can't use the generic macro.  Dunno
  whether the unified .init ouput section is required by arch
  peculiarity so I left it alone.  Please break it up and use PERCPU()
  if possible.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Pat Gefre <pfg@sgi.com>
Cc: Russell King <rmk@arm.linux.org.uk>

1 files changed, 1 insertions, 8 deletions

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 295ccc5e86b1..67f07f453385 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -181,14 +181,7 @@ SECTIONS
                 __initramfs_end = .;
         }
 #endif
-        . = ALIGN(PAGE_SIZE);
-        .data.percpu  : AT(ADDR(.data.percpu) - LOAD_OFFSET) {
-                __per_cpu_start = .;
-                *(.data.percpu.page_aligned)
-                *(.data.percpu)
-                *(.data.percpu.shared_aligned)
-                __per_cpu_end = .;
-        }
+        PERCPU(PAGE_SIZE)
 
         . = ALIGN(8);
         .machine.desc : AT(ADDR(.machine.desc) - LOAD_OFFSET) {