xen/events: use a common cpu hotplug hook for event channels

Today only fifo event channels have a cpu hotplug callback. In order
to prepare for more percpu (de)init work move that callback into
events_base.c and add percpu_init() and percpu_deinit() hooks to
struct evtchn_ops.

This is part of XSA-332.

Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wl@xen.org>

1 files changed, 19 insertions, 21 deletions

diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c
index 7fd39c64d4b5..40e4ca1685aa 100644
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -385,21 +385,6 @@ static void evtchn_fifo_resume(void)
 	event_array_pages = 0;
 }
 
-static const struct evtchn_ops evtchn_ops_fifo = {
-	.max_channels      = evtchn_fifo_max_channels,
-	.nr_channels       = evtchn_fifo_nr_channels,
-	.setup             = evtchn_fifo_setup,
-	.bind_to_cpu       = evtchn_fifo_bind_to_cpu,
-	.clear_pending     = evtchn_fifo_clear_pending,
-	.set_pending       = evtchn_fifo_set_pending,
-	.is_pending        = evtchn_fifo_is_pending,
-	.test_and_set_mask = evtchn_fifo_test_and_set_mask,
-	.mask              = evtchn_fifo_mask,
-	.unmask            = evtchn_fifo_unmask,
-	.handle_events     = evtchn_fifo_handle_events,
-	.resume            = evtchn_fifo_resume,
-};
-
 static int evtchn_fifo_alloc_control_block(unsigned cpu)
 {
 	void *control_block = NULL;
@@ -422,19 +407,36 @@ static int evtchn_fifo_alloc_control_block(unsigned cpu)
 	return ret;
 }
 
-static int xen_evtchn_cpu_prepare(unsigned int cpu)
+static int evtchn_fifo_percpu_init(unsigned int cpu)
 {
 	if (!per_cpu(cpu_control_block, cpu))
 		return evtchn_fifo_alloc_control_block(cpu);
 	return 0;
 }
 
-static int xen_evtchn_cpu_dead(unsigned int cpu)
+static int evtchn_fifo_percpu_deinit(unsigned int cpu)
 {
 	__evtchn_fifo_handle_events(cpu, true);
 	return 0;
 }
 
+static const struct evtchn_ops evtchn_ops_fifo = {
+	.max_channels      = evtchn_fifo_max_channels,
+	.nr_channels       = evtchn_fifo_nr_channels,
+	.setup             = evtchn_fifo_setup,
+	.bind_to_cpu       = evtchn_fifo_bind_to_cpu,
+	.clear_pending     = evtchn_fifo_clear_pending,
+	.set_pending       = evtchn_fifo_set_pending,
+	.is_pending        = evtchn_fifo_is_pending,
+	.test_and_set_mask = evtchn_fifo_test_and_set_mask,
+	.mask              = evtchn_fifo_mask,
+	.unmask            = evtchn_fifo_unmask,
+	.handle_events     = evtchn_fifo_handle_events,
+	.resume            = evtchn_fifo_resume,
+	.percpu_init       = evtchn_fifo_percpu_init,
+	.percpu_deinit     = evtchn_fifo_percpu_deinit,
+};
+
 int __init xen_evtchn_fifo_init(void)
 {
 	int cpu = smp_processor_id();
@@ -448,9 +450,5 @@ int __init xen_evtchn_fifo_init(void)
 
 	evtchn_ops = &evtchn_ops_fifo;
 
-	cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
-				  "xen/evtchn:prepare",
-				  xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
-
 	return ret;
 }