Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 into rmobile-latest

Conflicts:
	arch/arm/mach-shmobile/Kconfig

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 23 insertions, 1 deletions

diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 8063a322c790..0797cb528b46 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -10,9 +10,12 @@
  */
 #include <linux/module.h>
 #include <linux/types.h>
+#include <linux/cpu.h>
 #include <linux/kernel.h>
+#include <linux/notifier.h>
 #include <linux/signal.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/init.h>
 
 #include <asm/cputype.h>
@@ -484,7 +487,24 @@ void vfp_flush_hwstate(struct thread_info *thread)
 	put_cpu();
 }
 
-#include <linux/smp.h>
+/*
+ * VFP hardware can lose all context when a CPU goes offline.
+ * Safely clear our held state when a CPU has been killed, and
+ * re-enable access to VFP when the CPU comes back online.
+ *
+ * Both CPU_DYING and CPU_STARTING are called on the CPU which
+ * is being offlined/onlined.
+ */
+static int vfp_hotplug(struct notifier_block *b, unsigned long action,
+	void *hcpu)
+{
+	if (action == CPU_DYING || action == CPU_DYING_FROZEN) {
+		unsigned int cpu = (long)hcpu;
+		last_VFP_context[cpu] = NULL;
+	} else if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
+		vfp_enable(NULL);
+	return NOTIFY_OK;
+}
 
 /*
  * VFP support code initialisation.
@@ -514,6 +534,8 @@ static int __init vfp_init(void)
 	else if (vfpsid & FPSID_NODOUBLE) {
 		printk("no double precision support\n");
 	} else {
+		hotcpu_notifier(vfp_hotplug, 0);
+
 		smp_call_function(vfp_enable, NULL, 1);
 
 		VFP_arch = (vfpsid & FPSID_ARCH_MASK) >> FPSID_ARCH_BIT;  /* Extract the architecture version */