diff options
| author | Michael Kelley <mikelley@microsoft.com> | 2021-07-13 17:01:46 -0700 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2021-07-19 09:24:28 +0000 |
| commit | 31e5e64694cf9879e63b2802007fa934f4131126 (patch) | |
| tree | d2efd0afb5e7073fd3c47f1d663126a9c57705a3 /drivers/hv/hv_common.c | |
| parent | 5f92b45c3b67e3d222caf10e2eb898af31756b67 (diff) | |
drivers: hv: Decouple Hyper-V clock/timer code from VMbus drivers
Hyper-V clock/timer code in hyperv_timer.c is mostly independent from
other VMbus drivers, but building for ARM64 without hyperv_timer.c
shows some remaining entanglements. A default implementation of
hv_read_reference_counter can just read a Hyper-V synthetic register
and be independent of hyperv_timer.c, so move this code out and into
hv_common.c. Then it can be used by the timesync driver even if
hyperv_timer.c isn't built on a particular architecture. If
hyperv_timer.c *is* built, it can override with a faster implementation.
Also provide stubs for stimer functions called by the VMbus driver when
hyperv_timer.c isn't built.
No functional changes.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1626220906-22629-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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 |