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authorVitaly Kuznetsov <vkuznets@redhat.com>2015-02-27 22:25:57 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-02 06:30:07 +0300
commite086748c655ab99bac91b87d1bb59d9cc45867b9 (patch)
tree004fda805ee1c6124bcd275357ccafed6c786ad5 /drivers/hv/hv.c
parent32a158325acf12842764b1681f53903673f2f22e (diff)
downloadlinux-e086748c655ab99bac91b87d1bb59d9cc45867b9.tar.xz
Drivers: hv: vmbus: Teardown clockevent devices on module unload
Newly introduced clockevent devices made it impossible to unload hv_vmbus module as clockevents_config_and_register() takes additional reverence to the module. To make it possible again we do the following: - avoid setting dev->owner for clockevent devices; - implement hv_synic_clockevents_cleanup() doing clockevents_unbind_device(); - call it from vmbus_exit(). In theory hv_synic_clockevents_cleanup() can be merged with hv_synic_cleanup(), however, we call hv_synic_cleanup() from smp_call_function_single() and this doesn't work for clockevents_unbind_device() as it does such call on its own. I opted for a separate function. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/hv.c')
-rw-r--r--drivers/hv/hv.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 39531dcf582f..d3943bceecc3 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -312,7 +312,11 @@ static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
dev->features = CLOCK_EVT_FEAT_ONESHOT;
dev->cpumask = cpumask_of(cpu);
dev->rating = 1000;
- dev->owner = THIS_MODULE;
+ /*
+ * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
+ * result in clockevents_config_and_register() taking additional
+ * references to the hv_vmbus module making it impossible to unload.
+ */
dev->set_mode = hv_ce_setmode;
dev->set_next_event = hv_ce_set_next_event;
@@ -470,6 +474,20 @@ void hv_synic_init(void *arg)
}
/*
+ * hv_synic_clockevents_cleanup - Cleanup clockevent devices
+ */
+void hv_synic_clockevents_cleanup(void)
+{
+ int cpu;
+
+ if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE))
+ return;
+
+ for_each_online_cpu(cpu)
+ clockevents_unbind_device(hv_context.clk_evt[cpu], cpu);
+}
+
+/*
* hv_synic_cleanup - Cleanup routine for hv_synic_init().
*/
void hv_synic_cleanup(void *arg)
@@ -483,6 +501,11 @@ void hv_synic_cleanup(void *arg)
if (!hv_context.synic_initialized)
return;
+ /* Turn off clockevent device */
+ if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
+ hv_ce_setmode(CLOCK_EVT_MODE_SHUTDOWN,
+ hv_context.clk_evt[cpu]);
+
rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
shared_sint.masked = 1;