[PATCH 4/8] arm64: Add smp_spin_table_set_die

[Geoff Levand]

Remove the const attribute from the smp_spin_table_ops instance in
smp_spin_table.c and add the new routine smp_spin_table_set_die() which allows a
custom cpu die method to be set in the smp_spin_table_ops instance.

The ability to set a custom cpu die routine is needed by kexec to allow it to
manage any secondary CPUs that need to be shut down as described in booting.txt.

Signed-off-by: Geoff Levand <geoff at infradead.org>
---
 arch/arm64/include/asm/cpu_ops.h   | 2 ++
 arch/arm64/kernel/smp_spin_table.c | 8 +++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
index 872f61a..42bcd24 100644
--- a/arch/arm64/include/asm/cpu_ops.h
+++ b/arch/arm64/include/asm/cpu_ops.h
@@ -63,4 +63,6 @@ extern int cpu_read_ops(struct device_node *dn, int cpu,
 	const struct cpu_operations **cpu_ops);
 extern void __init cpu_read_bootcpu_ops(void);
 
+void smp_spin_table_set_die(void (*fn)(unsigned int));
+
 #endif /* ifndef __ASM_CPU_OPS_H */
diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c
index 26c780b..ce7d0a3 100644
--- a/arch/arm64/kernel/smp_spin_table.c
+++ b/arch/arm64/kernel/smp_spin_table.c
@@ -153,7 +153,7 @@ static void smp_spin_table_cpu_die(unsigned int cpu)
 		cpu_relax();
 }
 
-const struct cpu_operations smp_spin_table_ops = {
+struct cpu_operations smp_spin_table_ops = {
 	.name		= "spin-table",
 	.cpu_init	= smp_spin_table_cpu_init,
 	.cpu_prepare	= smp_spin_table_cpu_prepare,
@@ -162,3 +162,9 @@ const struct cpu_operations smp_spin_table_ops = {
 	.cpu_disable	= smp_spin_table_cpu_disable,
 	.cpu_die	= smp_spin_table_cpu_die,
 };
+
+void smp_spin_table_set_die(void (*fn)(unsigned int))
+{
+	BUG_ON(!fn);
+	smp_spin_table_ops.cpu_die = fn;
+}
-- 
1.9.1