powerpc/kexec: Restore ppc_md.machine_kexec

Kyle Moffett points out that mpc85xx has started using the
ppc_md.machine_kexec hook. As such, revert patch c94868788cf2
(powerpc/kexec: Remove ppc_md.machine_kexec).

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 10 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 991d5998d6be..fe56a23e1ff0 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -240,6 +240,12 @@ struct machdep_calls {
          * claims to support kexec.
          */
         int (*machine_kexec_prepare)(struct kimage *image);
+
+        /* Called to perform the _real_ kexec.
+         * Do NOT allocate memory or fail here. We are past the point of
+         * no return.
+         */
+        void (*machine_kexec)(struct kimage *image);
 #endif /* CONFIG_KEXEC */
 
 #ifdef CONFIG_SUSPEND
diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index 49a170af8145..a5f8672eeff3 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -87,7 +87,10 @@ void machine_kexec(struct kimage *image)
 
         save_ftrace_enabled = __ftrace_enabled_save();
 
-        default_machine_kexec(image);
+        if (ppc_md.machine_kexec)
+                ppc_md.machine_kexec(image);
+        else
+                default_machine_kexec(image);
 
         __ftrace_enabled_restore(save_ftrace_enabled);