sparc64: Prevent sparc64 from invoking irq handlers on offline CPUs
Make sparc64 refrain from clearing a given to-be-offlined CPU's bit in the
cpu_online_mask until it has processed pending irqs. This change
prevents other CPUs from being blindsided by an apparently offline CPU
nevertheless changing globally visible state.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index 0712a44..2be166c 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -1303,10 +1303,6 @@
c->core_id = 0;
c->proc_id = -1;
- ipi_call_lock();
- cpu_clear(cpu, cpu_online_map);
- ipi_call_unlock();
-
smp_wmb();
/* Make sure no interrupts point to this cpu. */
@@ -1316,6 +1312,10 @@
mdelay(1);
local_irq_disable();
+ ipi_call_lock();
+ cpu_clear(cpu, cpu_online_map);
+ ipi_call_unlock();
+
return 0;
}