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-rw-r--r--arch/powerpc/kernel/machine_kexec_64.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index a0bcec3614e1..583af70c4b14 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -16,6 +16,7 @@
#include <linux/init_task.h>
#include <linux/errno.h>
#include <linux/kernel.h>
+#include <linux/cpu.h>
#include <asm/page.h>
#include <asm/current.h>
@@ -216,9 +217,32 @@ static void kexec_prepare_cpus_wait(int wait_state)
mb();
}
-static void kexec_prepare_cpus(void)
+/*
+ * We need to make sure each present CPU is online. The next kernel will scan
+ * the device tree and assume primary threads are online and query secondary
+ * threads via RTAS to online them if required. If we don't online primary
+ * threads, they will be stuck. However, we also online secondary threads as we
+ * may be using 'cede offline'. In this case RTAS doesn't see the secondary
+ * threads as offline -- and again, these CPUs will be stuck.
+ *
+ * So, we online all CPUs that should be running, including secondary threads.
+ */
+static void wake_offline_cpus(void)
{
+ int cpu = 0;
+
+ for_each_present_cpu(cpu) {
+ if (!cpu_online(cpu)) {
+ printk(KERN_INFO "kexec: Waking offline cpu %d.\n",
+ cpu);
+ cpu_up(cpu);
+ }
+ }
+}
+static void kexec_prepare_cpus(void)
+{
+ wake_offline_cpus();
smp_call_function(kexec_smp_down, NULL, /* wait */0);
local_irq_disable();
mb(); /* make sure IRQs are disabled before we say they are */
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