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clocksource/drivers/hyper-v: Handle vDSO differences inline

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While the driver for the Hyper-V Reference TSC and STIMERs is architecture
neutral, vDSO is implemented for x86/x64, but not for ARM64.  Current code
calls into utility functions under arch/x86 (and coming, under arch/arm64)
to handle the difference.

Change this approach to handle the difference inline based on whether
VDSO_CLOCK_MODE_HVCLOCK is present.  The new approach removes code under
arch/* since the difference is tied more to the specifics of the Linux
implementation than to the architecture.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1614721102-2241-8-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Michael Kelley 2021-03-02 13:38:19 -08:00 committed by Wei Liu
parent d608715d47
commit e4ab4658f1
2 changed files with 8 additions and 6 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
arch/x86/include/asm/mshyperv.h
View file

@ -27,10 +27,6 @@ static inline u64 hv_get_register(unsigned int reg)
return value;
}
#define hv_set_clocksource_vdso(val) \
((val).vdso_clock_mode = VDSO_CLOCKMODE_HVCLOCK)
#define hv_enable_vdso_clocksource() \
vclocks_set_used(VDSO_CLOCKMODE_HVCLOCK);
#define hv_get_raw_timer() rdtsc_ordered()
/*

10
drivers/clocksource/hyperv_timer.c
View file

@ -370,11 +370,13 @@ static void resume_hv_clock_tsc(struct clocksource *arg)
hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
}
#ifdef VDSO_CLOCKMODE_HVCLOCK
static int hv_cs_enable(struct clocksource *cs)
{
hv_enable_vdso_clocksource();
vclocks_set_used(VDSO_CLOCKMODE_HVCLOCK);
return 0;
}
#endif
static struct clocksource hyperv_cs_tsc = {
.name = "hyperv_clocksource_tsc_page",
@ -384,7 +386,12 @@ static struct clocksource hyperv_cs_tsc = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.suspend= suspend_hv_clock_tsc,
.resume = resume_hv_clock_tsc,
#ifdef VDSO_CLOCKMODE_HVCLOCK
.enable = hv_cs_enable,
.vdso_clock_mode = VDSO_CLOCKMODE_HVCLOCK,
#else
.vdso_clock_mode = VDSO_CLOCKMODE_NONE,
#endif
};
static u64 notrace read_hv_clock_msr(void)
@ -442,7 +449,6 @@ static bool __init hv_init_tsc_clocksource(void)
tsc_msr = tsc_msr | 0x1 | (u64)phys_addr;
hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
hv_set_clocksource_vdso(hyperv_cs_tsc);
clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
hv_sched_clock_offset = hv_read_reference_counter();