From dee863b571b0a76e9c549ee99e8782bb4bc6502b Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Sat, 4 Feb 2017 09:57:13 -0700 Subject: hv: export current Hyper-V clocksource As a preparation to implementing Hyper-V PTP device supporting .getcrosststamp we need to export a reference to the current Hyper-V clocksource in use (MSR or TSC page). Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- arch/x86/hyperv/hv_init.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'arch/x86/hyperv/hv_init.c') diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index b371d0e984a9..c224b7df4d21 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -99,6 +99,9 @@ static struct clocksource hyperv_cs_msr = { }; static void *hypercall_pg; +struct clocksource *hyperv_cs; +EXPORT_SYMBOL_GPL(hyperv_cs); + /* * This function is to be invoked early in the boot sequence after the * hypervisor has been detected. @@ -141,10 +144,10 @@ void hyperv_init(void) union hv_x64_msr_hypercall_contents tsc_msr; tsc_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL); - if (!tsc_pg) { - clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100); - return; - } + if (!tsc_pg) + goto register_msr_cs; + + hyperv_cs = &hyperv_cs_tsc; rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64); @@ -161,6 +164,8 @@ void hyperv_init(void) * the partition counter. */ +register_msr_cs: + hyperv_cs = &hyperv_cs_msr; if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE) clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100); } -- cgit v1.2.3