From: Juergen Gross <jgross@xxxxxxxx>
commit 7beb290caa2adb0a399e735a1e175db9aae0523a upstream.
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@xxxxxxxxxxxxxxx
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Wei Liu <wl@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/xen/events/events_base.c | 47 +++++++++++++++++++++++++++
drivers/xen/events/events_fifo.c | 59 ++++++++++++++---------------------
drivers/xen/events/events_internal.h | 3 +
3 files changed, 74 insertions(+), 35 deletions(-)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -33,6 +33,7 @@
#include <linux/irqnr.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
+#include <linux/cpu.h>
#ifdef CONFIG_X86
#include <asm/desc.h>
@@ -1832,6 +1833,50 @@ void xen_callback_vector(void) {}
static bool fifo_events = true;
module_param(fifo_events, bool, 0);
+static int xen_evtchn_cpu_prepare(unsigned int cpu)
+{
+ int ret = 0;
+
+ if (evtchn_ops->percpu_init)
+ ret = evtchn_ops->percpu_init(cpu);
+
+ return ret;
+}
+
+static int xen_evtchn_cpu_dead(unsigned int cpu)
+{
+ int ret = 0;
+
+ if (evtchn_ops->percpu_deinit)
+ ret = evtchn_ops->percpu_deinit(cpu);
+
+ return ret;
+}
+
+static int evtchn_cpu_notification(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (long)hcpu;
+ int ret = 0;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ ret = xen_evtchn_cpu_prepare(cpu);
+ break;
+ case CPU_DEAD:
+ ret = xen_evtchn_cpu_dead(cpu);
+ break;
+ default:
+ break;
+ }
+
+ return ret < 0 ? NOTIFY_BAD : NOTIFY_OK;
+}
+
+static struct notifier_block evtchn_cpu_notifier = {
+ .notifier_call = evtchn_cpu_notification,
+};
+
void __init xen_init_IRQ(void)
{
int ret = -EINVAL;
@@ -1841,6 +1886,8 @@ void __init xen_init_IRQ(void)
if (ret < 0)
xen_evtchn_2l_init();
+ register_cpu_notifier(&evtchn_cpu_notifier);
+
evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
sizeof(*evtchn_to_irq), GFP_KERNEL);
BUG_ON(!evtchn_to_irq);
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -386,21 +386,6 @@ 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;
@@ -423,29 +408,34 @@ static int evtchn_fifo_alloc_control_blo
return ret;
}
-static int evtchn_fifo_cpu_notification(struct notifier_block *self,
- unsigned long action,
- void *hcpu)
+static int evtchn_fifo_percpu_init(unsigned int cpu)
{
- int cpu = (long)hcpu;
- int ret = 0;
+ if (!per_cpu(cpu_control_block, cpu))
+ return evtchn_fifo_alloc_control_block(cpu);
+ return 0;
+}
- switch (action) {
- case CPU_UP_PREPARE:
- if (!per_cpu(cpu_control_block, cpu))
- ret = evtchn_fifo_alloc_control_block(cpu);
- break;
- case CPU_DEAD:
- __evtchn_fifo_handle_events(cpu, true);
- break;
- default:
- break;
- }
- return ret < 0 ? NOTIFY_BAD : NOTIFY_OK;
+static int evtchn_fifo_percpu_deinit(unsigned int cpu)
+{
+ __evtchn_fifo_handle_events(cpu, true);
+ return 0;
}
-static struct notifier_block evtchn_fifo_cpu_notifier = {
- .notifier_call = evtchn_fifo_cpu_notification,
+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)
@@ -461,7 +451,6 @@ int __init xen_evtchn_fifo_init(void)
evtchn_ops = &evtchn_ops_fifo;
- register_cpu_notifier(&evtchn_fifo_cpu_notifier);
out:
put_cpu();
return ret;
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -71,6 +71,9 @@ struct evtchn_ops {
void (*handle_events)(unsigned cpu);
void (*resume)(void);
+
+ int (*percpu_init)(unsigned int cpu);
+ int (*percpu_deinit)(unsigned int cpu);
};
extern const struct evtchn_ops *evtchn_ops;
