From dee863b571b0a76e9c549ee99e8782bb4bc6502b Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Sat, 4 Feb 2017 09:57:13 -0700 Subject: [PATCH] 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 +++++++++---- arch/x86/include/asm/mshyperv.h | 3 +++ 2 files changed, 12 insertions(+), 4 deletions(-) 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); } diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 56407c6d2397..7c9c895432a9 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -3,6 +3,7 @@ #include #include +#include #include /* @@ -168,6 +169,8 @@ void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); void hv_remove_crash_handler(void); #if IS_ENABLED(CONFIG_HYPERV) +extern struct clocksource *hyperv_cs; + void hyperv_init(void); void hyperv_report_panic(struct pt_regs *regs); bool hv_is_hypercall_page_setup(void);