[PATCH 4.19 015/114] powerpc/mce: Schedule work from irq_work

[Greg Kroah-Hartman]

From: Santosh Sivaraj <santosh@xxxxxxxxxx>

commit b5bda6263cad9a927e1a4edb7493d542da0c1410 upstream.

schedule_work() cannot be called from MCE exception context as MCE can
interrupt even in interrupt disabled context.

Fixes: 733e4a4c4467 ("powerpc/mce: hookup memory_failure for UE errors")
Cc: stable@xxxxxxxxxxxxxxx # v4.15+
Reviewed-by: Mahesh Salgaonkar <mahesh@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Acked-by: Balbir Singh <bsingharora@xxxxxxxxx>
Signed-off-by: Santosh Sivaraj <santosh@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20190820081352.8641-2-santosh@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/powerpc/kernel/mce.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -45,6 +45,7 @@ static DEFINE_PER_CPU(struct machine_che
 					mce_ue_event_queue);
 
 static void machine_check_process_queued_event(struct irq_work *work);
+static void machine_check_ue_irq_work(struct irq_work *work);
 void machine_check_ue_event(struct machine_check_event *evt);
 static void machine_process_ue_event(struct work_struct *work);
 
@@ -52,6 +53,10 @@ static struct irq_work mce_event_process
         .func = machine_check_process_queued_event,
 };
 
+static struct irq_work mce_ue_event_irq_work = {
+	.func = machine_check_ue_irq_work,
+};
+
 DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
 
 static void mce_set_error_info(struct machine_check_event *mce,
@@ -208,6 +213,10 @@ void release_mce_event(void)
 	get_mce_event(NULL, true);
 }
 
+static void machine_check_ue_irq_work(struct irq_work *work)
+{
+	schedule_work(&mce_ue_event_work);
+}
 
 /*
  * Queue up the MCE event which then can be handled later.
@@ -225,7 +234,7 @@ void machine_check_ue_event(struct machi
 	memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
 
 	/* Queue work to process this event later. */
-	schedule_work(&mce_ue_event_work);
+	irq_work_queue(&mce_ue_event_irq_work);
 }
 
 /*