smp: Add generic smpboot facility
Start a new file, which will hold SMP and CPU hotplug related generic
infrastructure.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124557.035417523@linutronix.de
diff --git a/kernel/Makefile b/kernel/Makefile
index cb41b95..6c07f30 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -43,6 +43,7 @@
obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_SMP) += smpboot.o
ifneq ($(CONFIG_SMP),y)
obj-y += up.o
endif
diff --git a/kernel/cpu.c b/kernel/cpu.c
index e711aef..e58b99a 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -17,6 +17,8 @@
#include <linux/gfp.h>
#include <linux/suspend.h>
+#include "smpboot.h"
+
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_mask, cpu_present_mask */
static DEFINE_MUTEX(cpu_add_remove_lock);
@@ -300,6 +302,11 @@
return -EINVAL;
cpu_hotplug_begin();
+
+ ret = smpboot_prepare(cpu);
+ if (ret)
+ goto out;
+
ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
if (ret) {
nr_calls--;
@@ -320,6 +327,7 @@
out_notify:
if (ret != 0)
__cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
+out:
cpu_hotplug_done();
return ret;
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
new file mode 100644
index 0000000..6dae6a3
--- /dev/null
+++ b/kernel/smpboot.c
@@ -0,0 +1,14 @@
+/*
+ * Common SMP CPU bringup/teardown functions
+ */
+#include <linux/init.h>
+
+#include "smpboot.h"
+
+/**
+ * smpboot_prepare - generic smpboot preparation
+ */
+int __cpuinit smpboot_prepare(unsigned int cpu)
+{
+ return 0;
+}
diff --git a/kernel/smpboot.h b/kernel/smpboot.h
new file mode 100644
index 0000000..d88e771
--- /dev/null
+++ b/kernel/smpboot.h
@@ -0,0 +1,6 @@
+#ifndef SMPBOOT_H
+#define SMPBOOT_H
+
+int smpboot_prepare(unsigned int cpu);
+
+#endif