From 6ffc4b85358f6b7d252420cfa5862312cf5f83d8 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Sat, 3 Dec 2016 12:34:35 -0800 Subject: [PATCH] hv: change clockevents unbind tactics To get prepared to CPU offlining support we need co change the way how we unbind clockevent devices. As one CPU may go online/offline multiple times we need to bind it in hv_synic_init() and unbind it in hv_synic_cleanup(). There is an additional corner case: when we unload the module completely we need to switch to some other clockevent mechanism before stopping VMBus or we will hang. We can't call hv_synic_cleanup() before unloading VMBus as we won't be able to send UNLOAD request and get a response so hv_synic_clockevents_cleanup() has to live. Luckily, we can always call clockevents_unbind_device(), even if it wasn't bound before and there is no issue if we call it twice. Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index 60dbd6cb4640..446802ae8f1b 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -575,7 +575,7 @@ void hv_synic_clockevents_cleanup(void) if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)) return; - for_each_online_cpu(cpu) + for_each_present_cpu(cpu) clockevents_unbind_device(hv_context.clk_evt[cpu], cpu); } @@ -594,8 +594,10 @@ void hv_synic_cleanup(void *arg) return; /* Turn off clockevent device */ - if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE) + if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE) { + clockevents_unbind_device(hv_context.clk_evt[cpu], cpu); hv_ce_shutdown(hv_context.clk_evt[cpu]); + } rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);