powerpc/kexec: Adds correct calling convention for kexec purgatory

Call kexec purgatory code correctly. We were getting lucky before.
If you examine the powerpc 32bit kexec "purgatory" code you will
see it expects the following:

>From kexec-tools: purgatory/arch/ppc/v2wrap_32.S
-> calling convention:
->   r3 = physical number of this cpu (all cpus)
->   r4 = address of this chunk (master only)

As such, we need to set r3 to the current core, r4 happens to be
unused by purgatory at the moment but we go ahead and set it
here as well

Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 6bbd7a604d243c9f8f9f906d683a9a20df2f9a43..a7a570dcdd571c8fb861562e549dbf094147fb32 100644 (file)
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -810,6 +810,9 @@ relocate_new_kernel:
        isync
        sync
 
+       mfspr   r3, SPRN_PIR /* current core we are running on */
+       mr      r4, r5 /* load physical address of chunk called */
+
        /* jump to the entry point, usually the setup routine */
        mtlr    r5
        blrl