From: Andrea Parri <parri.andrea@xxxxxxxxx> 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@xxxxxxxxxxxxx> Signed-off-by: Andrea Parri <parri.andrea@xxxxxxxxx> Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200109160650.16150-2-parri.andrea@xxxxxxxxx --- drivers/clocksource/hyperv_timer.c | 36 +++++++++++++++++++----------- drivers/hv/hv_util.c | 8 +++---- include/clocksource/hyperv_timer.h | 2 +- 3 files changed, 28 insertions(+), 18 deletions(-) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 12d75b50a317..42748adccc98 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -66,7 +66,7 @@ static int hv_ce_set_next_event(unsigned long delta, { u64 current_tick; - current_tick = hyperv_cs->read(NULL); + current_tick = hv_read_reference_counter(); current_tick += delta; hv_init_timer(0, current_tick); return 0; @@ -304,8 +304,8 @@ EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup); * Hyper-V and 32-bit x86. The TSC reference page version is preferred. */ -struct clocksource *hyperv_cs; -EXPORT_SYMBOL_GPL(hyperv_cs); +u64 (*hv_read_reference_counter)(void); +EXPORT_SYMBOL_GPL(hv_read_reference_counter); static union { struct ms_hyperv_tsc_page page; @@ -318,7 +318,7 @@ struct ms_hyperv_tsc_page *hv_get_tsc_page(void) } EXPORT_SYMBOL_GPL(hv_get_tsc_page); -static u64 notrace read_hv_clock_tsc(struct clocksource *arg) +static u64 notrace read_hv_clock_tsc(void) { u64 current_tick = hv_read_tsc_page(hv_get_tsc_page()); @@ -328,9 +328,14 @@ static u64 notrace read_hv_clock_tsc(struct clocksource *arg) return current_tick; } +static u64 notrace read_hv_clock_tsc_cs(struct clocksource *arg) +{ + return read_hv_clock_tsc(); +} + static u64 read_hv_sched_clock_tsc(void) { - return read_hv_clock_tsc(NULL) - hv_sched_clock_offset; + return read_hv_clock_tsc() - hv_sched_clock_offset; } static void suspend_hv_clock_tsc(struct clocksource *arg) @@ -359,14 +364,14 @@ static void resume_hv_clock_tsc(struct clocksource *arg) static struct clocksource hyperv_cs_tsc = { .name = "hyperv_clocksource_tsc_page", .rating = 400, - .read = read_hv_clock_tsc, + .read = read_hv_clock_tsc_cs, .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS, .suspend= suspend_hv_clock_tsc, .resume = resume_hv_clock_tsc, }; -static u64 notrace read_hv_clock_msr(struct clocksource *arg) +static u64 notrace read_hv_clock_msr(void) { u64 current_tick; /* @@ -378,15 +383,20 @@ static u64 notrace read_hv_clock_msr(struct clocksource *arg) return current_tick; } +static u64 notrace read_hv_clock_msr_cs(struct clocksource *arg) +{ + return read_hv_clock_msr(); +} + static u64 read_hv_sched_clock_msr(void) { - return read_hv_clock_msr(NULL) - hv_sched_clock_offset; + return read_hv_clock_msr() - hv_sched_clock_offset; } static struct clocksource hyperv_cs_msr = { .name = "hyperv_clocksource_msr", .rating = 400, - .read = read_hv_clock_msr, + .read = read_hv_clock_msr_cs, .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; @@ -399,7 +409,7 @@ static bool __init hv_init_tsc_clocksource(void) if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) return false; - hyperv_cs = &hyperv_cs_tsc; + hv_read_reference_counter = read_hv_clock_tsc; phys_addr = virt_to_phys(hv_get_tsc_page()); /* @@ -417,7 +427,7 @@ static bool __init hv_init_tsc_clocksource(void) hv_set_clocksource_vdso(hyperv_cs_tsc); clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100); - hv_sched_clock_offset = hyperv_cs->read(hyperv_cs); + hv_sched_clock_offset = hv_read_reference_counter(); hv_setup_sched_clock(read_hv_sched_clock_tsc); return true; @@ -439,10 +449,10 @@ void __init hv_init_clocksource(void) if (!(ms_hyperv.features & HV_MSR_TIME_REF_COUNT_AVAILABLE)) return; - hyperv_cs = &hyperv_cs_msr; + hv_read_reference_counter = read_hv_clock_msr; clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100); - hv_sched_clock_offset = hyperv_cs->read(hyperv_cs); + hv_sched_clock_offset = hv_read_reference_counter(); hv_setup_sched_clock(read_hv_sched_clock_msr); } EXPORT_SYMBOL_GPL(hv_init_clocksource); diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c index 766bd8457346..296f9098c9e4 100644 --- a/drivers/hv/hv_util.c +++ b/drivers/hv/hv_util.c @@ -211,7 +211,7 @@ static struct timespec64 hv_get_adj_host_time(void) unsigned long flags; spin_lock_irqsave(&host_ts.lock, flags); - reftime = hyperv_cs->read(hyperv_cs); + reftime = hv_read_reference_counter(); newtime = host_ts.host_time + (reftime - host_ts.ref_time); ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100); spin_unlock_irqrestore(&host_ts.lock, flags); @@ -250,7 +250,7 @@ static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags) */ spin_lock_irqsave(&host_ts.lock, flags); - cur_reftime = hyperv_cs->read(hyperv_cs); + cur_reftime = hv_read_reference_counter(); host_ts.host_time = hosttime; host_ts.ref_time = cur_reftime; @@ -315,7 +315,7 @@ static void timesync_onchannelcallback(void *context) sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr)]; adj_guesttime(timedatap->parenttime, - hyperv_cs->read(hyperv_cs), + hv_read_reference_counter(), timedatap->flags); } } @@ -524,7 +524,7 @@ static struct ptp_clock *hv_ptp_clock; static int hv_timesync_init(struct hv_util_service *srv) { /* TimeSync requires Hyper-V clocksource. */ - if (!hyperv_cs) + if (!hv_read_reference_counter) return -ENODEV; spin_lock_init(&host_ts.lock); diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h index 553e539469f0..34eef083c988 100644 --- a/include/clocksource/hyperv_timer.h +++ b/include/clocksource/hyperv_timer.h @@ -30,7 +30,7 @@ extern void hv_stimer_global_cleanup(void); extern void hv_stimer0_isr(void); #ifdef CONFIG_HYPERV_TIMER -extern struct clocksource *hyperv_cs; +extern u64 (*hv_read_reference_counter)(void); extern void hv_init_clocksource(void); extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void); -- 2.17.1
