From: Vitaly Kuznetsov <[mailto:vkuznets@xxxxxxxxxx]> 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@xxxxxxxxxx> Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> --- drivers/hv/hv.c | 25 ++++++++++++++++++++++++- drivers/hv/hyperv_vmbus.h | 2 ++ drivers/hv/vmbus_drv.c | 1 + 3 files changed, 27 insertions(+), 1 deletions(-) diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index 39531dc..d3943bc 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; diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 6cf2de9..b055e53 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -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. */ diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 28d19e8..3cd44ae 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1102,6 +1102,7 @@ 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); -- 1.7.4.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
