diff options
| author | Yubo Xie <yuboxie@microsoft.com> | 2020-03-26 19:11:59 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-01 11:02:12 +0200 |
| commit | f23f37fe702fec4d6e250354432f1921ec9fe5b4 (patch) | |
| tree | 4ef9c6b12fddcbcf752f8b63a2f9349b1a2406cf /drivers/clocksource | |
| parent | 791c420f42289fe9afed9e325c6b21eb6a5a329e (diff) | |
clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources
[ Upstream commit 0af3e137c144377fbaf5025ba784ff5ba7ad40c9 ]
hyperv_timer.c exports hyperv_cs, which is used by stimers and the
timesync mechanism. However, the clocksource dependency is not
needed: these mechanisms only depend on the partition reference
counter (which can be read via a MSR or via the TSC Reference Page).
Introduce the (function) pointer hv_read_reference_counter, as an
embodiment of the partition reference counter read, and export it
in place of the hyperv_cs pointer. The latter can be removed.
This should clarify that there's no relationship between Hyper-V
stimers & timesync and the Linux clocksource abstractions. No
functional or semantic change.
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200109160650.16150-2-parri.andrea@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/hyperv_timer.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 2317d4e3daaf..36933e2b3b0d 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -233,7 +233,8 @@ static u64 notrace read_hv_clock_tsc(struct clocksource *arg) static u64 read_hv_sched_clock_tsc(void) { - return read_hv_clock_tsc(NULL) - hv_sched_clock_offset; + return (read_hv_clock_tsc(NULL) - hv_sched_clock_offset) * + (NSEC_PER_SEC / HV_CLOCK_HZ); } static struct clocksource hyperv_cs_tsc = { @@ -258,7 +259,8 @@ static u64 notrace read_hv_clock_msr(struct clocksource *arg) static u64 read_hv_sched_clock_msr(void) { - return read_hv_clock_msr(NULL) - hv_sched_clock_offset; + return (read_hv_clock_msr(NULL) - hv_sched_clock_offset) * + (NSEC_PER_SEC / HV_CLOCK_HZ); } static struct clocksource hyperv_cs_msr = { |