diff options
Diffstat (limited to 'drivers/hv/hv_common.c')
| -rw-r--r-- | drivers/hv/hv_common.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index 46658de78050..c0d9048a4112 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -222,6 +222,20 @@ bool hv_is_hibernation_supported(void) } EXPORT_SYMBOL_GPL(hv_is_hibernation_supported); +/* + * Default function to read the Hyper-V reference counter, independent + * of whether Hyper-V enlightened clocks/timers are being used. But on + * architectures where it is used, Hyper-V enlightenment code in + * hyperv_timer.c may override this function. + */ +static u64 __hv_read_ref_counter(void) +{ + return hv_get_register(HV_REGISTER_TIME_REF_COUNT); +} + +u64 (*hv_read_reference_counter)(void) = __hv_read_ref_counter; +EXPORT_SYMBOL_GPL(hv_read_reference_counter); + /* These __weak functions provide default "no-op" behavior and * may be overridden by architecture specific versions. Architectures * for which the default "no-op" behavior is sufficient can leave |