ARM: mach-shmobile: SMP base support

Add SMP base support for R-Mobile / SH-Mobile processors.

This patch contains all base code to support CONFIG_SMP
regardless of ARCH_SHMOBILE processor type. Both local timer
and CPU hotplug are supported, but no processor specific
code is included.

At this point only the default behavior is in place, so
a single core will always be used even though CONFIG_SMP
is enabled on multicore systems.

The SMP Kconfig entry for arch/arm/Kconfig is excluded from
this patch to simplify merging.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/arch/arm/mach-shmobile/hotplug.c b/arch/arm/mach-shmobile/hotplug.c
new file mode 100644
index 000000000000..238a0d97d2d5
--- /dev/null
+++ b/arch/arm/mach-shmobile/hotplug.c
@@ -0,0 +1,41 @@
+/*
+ * SMP support for R-Mobile / SH-Mobile
+ *
+ * Copyright (C) 2010  Magnus Damm
+ *
+ * Based on realview, Copyright (C) 2002 ARM Ltd, All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+
+int platform_cpu_kill(unsigned int cpu)
+{
+        return 1;
+}
+
+void platform_cpu_die(unsigned int cpu)
+{
+        while (1) {
+                /*
+                 * here's the WFI
+                 */
+                asm(".word      0xe320f003\n"
+                    :
+                    :
+                    : "memory", "cc");
+        }
+}
+
+int platform_cpu_disable(unsigned int cpu)
+{
+        /*
+         * we don't allow CPU 0 to be shutdown (it is still too special
+         * e.g. clock tick interrupts)
+         */
+        return cpu == 0 ? -EPERM : 0;
+}