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Commit e086748c authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Greg Kroah-Hartman
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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: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 32a15832

drivers/hv/hv.c

+24 −1
Original line number Diff line number Diff line
@@ -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;
@@ -469,6 +473,20 @@ void hv_synic_init(void *arg) 
	return;

}



/*

 * 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().

 */
@@ -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;

drivers/hv/hyperv_vmbus.h

+2 −0
Original line number Diff line number Diff line
@@ -572,6 +572,8 @@ extern void hv_synic_init(void *irqarg); 


extern void hv_synic_cleanup(void *arg);



extern void hv_synic_clockevents_cleanup(void);



/*

 * Host version information.

 */

drivers/hv/vmbus_drv.c

+1 −0
Original line number Diff line number Diff line
@@ -1032,6 +1032,7 @@ static void __exit vmbus_exit(void) 
	int cpu;



	vmbus_connection.conn_state = DISCONNECTED;

	hv_synic_clockevents_cleanup();

	hv_remove_vmbus_irq();

	vmbus_free_channels();

	bus_unregister(&hv_bus);