[PATCH v2 07/10] clocksource/drivers/hyper-v: Handle vDSO differences inline
From: Michael Kelley <hidden>
Date: 2021-03-01 01:19:58
Also in:
linux-arch, lkml
Subsystem:
clocksource, clockevent drivers, hyper-v/azure core and drivers, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Daniel Lezcano, Thomas Gleixner, "K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Linus Torvalds, Ingo Molnar, Borislav Petkov, Dave Hansen
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 <redacted> Reviewed-by: Boqun Feng <redacted> --- arch/x86/include/asm/mshyperv.h | 4 ---- drivers/clocksource/hyperv_timer.c | 10 ++++++++-- 2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index c10dd1c..4f566db 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h@@ -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() /*
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index c73c127..5e5e08aa 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c@@ -372,7 +372,9 @@ static void resume_hv_clock_tsc(struct clocksource *arg) static int hv_cs_enable(struct clocksource *cs) { - hv_enable_vdso_clocksource(); +#ifdef VDSO_CLOCKMODE_HVCLOCK + vclocks_set_used(VDSO_CLOCKMODE_HVCLOCK); +#endif return 0; }
@@ -385,6 +387,11 @@ static int hv_cs_enable(struct clocksource *cs) .suspend= suspend_hv_clock_tsc, .resume = resume_hv_clock_tsc, .enable = hv_cs_enable, +#ifdef VDSO_CLOCKMODE_HVCLOCK + .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();
--
1.8.3.1