summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2013-04-25 20:31:49 +0000
committerThomas Gleixner <tglx@linutronix.de>2013-05-16 11:09:17 +0200
commitccf33d6880f39a35158fff66db13000ae4943fac (patch)
treea39cb95e64c412b107c8640ae521bda78a7d1033
parent8c53daf63f56791ed47fc585206ef3049489612f (diff)
downloadop-kernel-dev-ccf33d6880f39a35158fff66db13000ae4943fac.zip
op-kernel-dev-ccf33d6880f39a35158fff66db13000ae4943fac.tar.gz
clockevents: Add module refcount
We want to be able to remove clockevent modules as well. Add a refcount so we don't remove a module with an active clock event device. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.307435149@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--include/linux/clockchips.h3
-rw-r--r--kernel/time/clockevents.c1
-rw-r--r--kernel/time/tick-broadcast.c3
-rw-r--r--kernel/time/tick-common.c4
4 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index 2f498f6..ae1193b 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -30,6 +30,7 @@ enum clock_event_nofitiers {
#include <linux/notifier.h>
struct clock_event_device;
+struct module;
/* Clock event mode commands */
enum clock_event_mode {
@@ -83,6 +84,7 @@ enum clock_event_mode {
* @irq: IRQ number (only for non CPU local devices)
* @cpumask: cpumask to indicate for which CPUs this device works
* @list: list head for the management code
+ * @owner: module reference
*/
struct clock_event_device {
void (*event_handler)(struct clock_event_device *);
@@ -112,6 +114,7 @@ struct clock_event_device {
int irq;
const struct cpumask *cpumask;
struct list_head list;
+ struct module *owner;
} ____cacheline_aligned;
/*
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 0e3a844..89e394c 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -357,6 +357,7 @@ void clockevents_exchange_device(struct clock_event_device *old,
* released list and do a notify add later.
*/
if (old) {
+ module_put(old->owner);
clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
list_del(&old->list);
list_add(&old->list, &clockevents_released);
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 3500caa..0e374cd 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -19,6 +19,7 @@
#include <linux/profile.h>
#include <linux/sched.h>
#include <linux/smp.h>
+#include <linux/module.h>
#include "tick-internal.h"
@@ -73,6 +74,8 @@ void tick_install_broadcast_device(struct clock_event_device *dev)
tick_broadcast_device.evtdev->rating >= dev->rating) ||
(dev->features & CLOCK_EVT_FEAT_C3STOP))
return;
+ if (!try_module_get(dev->owner))
+ return;
clockevents_exchange_device(tick_broadcast_device.evtdev, dev);
if (cur)
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 84c7cfc..433a1e1 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -18,6 +18,7 @@
#include <linux/percpu.h>
#include <linux/profile.h>
#include <linux/sched.h>
+#include <linux/module.h>
#include <asm/irq_regs.h>
@@ -257,6 +258,9 @@ void tick_check_new_device(struct clock_event_device *newdev)
goto out_bc;
}
+ if (!try_module_get(newdev->owner))
+ return;
+
/*
* Replace the eventually existing device by the new
* device. If the current device is the broadcast device, do
OpenPOWER on IntegriCloud