From 31e5e64694cf9879e63b2802007fa934f4131126 Mon Sep 17 00:00:00 2001 From: Michael Kelley Date: Tue, 13 Jul 2021 17:01:46 -0700 Subject: [PATCH] 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 Link: https://lore.kernel.org/r/1626220906-22629-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu --- drivers/clocksource/hyperv_timer.c | 3 --- drivers/hv/hv_common.c | 14 ++++++++++++++ drivers/hv/hv_util.c | 5 ----- include/asm-generic/mshyperv.h | 2 ++ include/clocksource/hyperv_timer.h | 11 +++++++++-- 5 files changed, 25 insertions(+), 10 deletions(-) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index d6ece7bbce89..ff188ab68496 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -361,9 +361,6 @@ EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup); * Hyper-V and 32-bit x86. The TSC reference page version is preferred. */ -u64 (*hv_read_reference_counter)(void); -EXPORT_SYMBOL_GPL(hv_read_reference_counter); - static union { struct ms_hyperv_tsc_page page; u8 reserved[PAGE_SIZE]; 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 diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c index 136576cba26f..835e6039c186 100644 --- a/drivers/hv/hv_util.c +++ b/drivers/hv/hv_util.c @@ -17,7 +17,6 @@ #include #include #include -#include #include #include "hyperv_vmbus.h" @@ -735,10 +734,6 @@ static struct ptp_clock *hv_ptp_clock; static int hv_timesync_init(struct hv_util_service *srv) { - /* TimeSync requires Hyper-V clocksource. */ - if (!hv_read_reference_counter) - return -ENODEV; - spin_lock_init(&host_ts.lock); INIT_WORK(&adj_time_work, hv_set_host_time); diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index 60cdff3e2252..c1ab6a6e72b5 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -167,6 +167,8 @@ extern bool hv_root_partition; extern u32 *hv_vp_index; extern u32 hv_max_vp_index; +extern u64 (*hv_read_reference_counter)(void); + /* Sentinel value for an uninitialized entry in hv_vp_index array */ #define VP_INVAL U32_MAX diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h index b6774aa5a4b8..b3f5d73ae1d6 100644 --- a/include/clocksource/hyperv_timer.h +++ b/include/clocksource/hyperv_timer.h @@ -20,6 +20,8 @@ #define HV_MAX_MAX_DELTA_TICKS 0xffffffff #define HV_MIN_DELTA_TICKS 1 +#ifdef CONFIG_HYPERV_TIMER + /* Routines called by the VMbus driver */ extern int hv_stimer_alloc(bool have_percpu_irqs); extern int hv_stimer_cleanup(unsigned int cpu); @@ -28,8 +30,6 @@ extern void hv_stimer_legacy_cleanup(unsigned int cpu); extern void hv_stimer_global_cleanup(void); extern void hv_stimer0_isr(void); -#ifdef CONFIG_HYPERV_TIMER -extern u64 (*hv_read_reference_counter)(void); extern void hv_init_clocksource(void); extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void); @@ -100,6 +100,13 @@ static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, { return U64_MAX; } + +static inline int hv_stimer_cleanup(unsigned int cpu) { return 0; } +static inline void hv_stimer_legacy_init(unsigned int cpu, int sint) {} +static inline void hv_stimer_legacy_cleanup(unsigned int cpu) {} +static inline void hv_stimer_global_cleanup(void) {} +static inline void hv_stimer0_isr(void) {} + #endif /* CONFIG_HYPERV_TIMER */ #endif