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, 0 deletions

diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 85598f7da407..1602373e539c 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -64,6 +64,7 @@ SECTIONS
                 __initramfs_end = .;
 #endif
                 . = ALIGN(4096);
+                __per_cpu_load = .;
                 __per_cpu_start = .;
                         *(.data.percpu.page_aligned)
                         *(.data.percpu)