From e1f5c66db85fb3e0a17b803fc2e868e9c59c193a Mon Sep 17 00:00:00 2001 From: Stanislav Kinsburskiy Date: Thu, 3 Nov 2022 17:58:54 +0000 Subject: [PATCH] clocksource: hyper-v: Introduce TSC PFN getter And rework the code to use it instead of the physical address, which isn't required by itself. This is a cleanup and precursor patch for upcoming support for TSC page mapping into Microsoft Hypervisor root partition, where TSC PFN will be defined by the hypervisor and not by the kernel. Signed-off-by: Stanislav Kinsburskiy CC: "K. Y. Srinivasan" CC: Haiyang Zhang CC: Wei Liu CC: Dexuan Cui CC: Daniel Lezcano CC: Thomas Gleixner CC: linux-hyperv@vger.kernel.org CC: linux-kernel@vger.kernel.org Reviewed-by: Michael Kelley Reviewed-by: Anirudh Rayabharam Link: https://lore.kernel.org/r/166749833420.218190.2102763345349472395.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net Signed-off-by: Wei Liu --- drivers/clocksource/hyperv_timer.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index b0b5df576e17..b7af19d06b51 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -368,6 +368,12 @@ static union { } tsc_pg __aligned(PAGE_SIZE); static struct ms_hyperv_tsc_page *tsc_page = &tsc_pg.page; +static unsigned long tsc_pfn; + +static unsigned long hv_get_tsc_pfn(void) +{ + return tsc_pfn; +} struct ms_hyperv_tsc_page *hv_get_tsc_page(void) { @@ -409,13 +415,12 @@ static void suspend_hv_clock_tsc(struct clocksource *arg) static void resume_hv_clock_tsc(struct clocksource *arg) { - phys_addr_t phys_addr = virt_to_phys(tsc_page); union hv_reference_tsc_msr tsc_msr; /* Re-enable the TSC page */ tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC); tsc_msr.enable = 1; - tsc_msr.pfn = HVPFN_DOWN(phys_addr); + tsc_msr.pfn = tsc_pfn; hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); } @@ -499,7 +504,6 @@ static __always_inline void hv_setup_sched_clock(void *sched_clock) {} static bool __init hv_init_tsc_clocksource(void) { union hv_reference_tsc_msr tsc_msr; - phys_addr_t phys_addr; if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) return false; @@ -524,7 +528,7 @@ static bool __init hv_init_tsc_clocksource(void) } hv_read_reference_counter = read_hv_clock_tsc; - phys_addr = virt_to_phys(hv_get_tsc_page()); + tsc_pfn = HVPFN_DOWN(virt_to_phys(tsc_page)); /* * The Hyper-V TLFS specifies to preserve the value of reserved @@ -535,7 +539,7 @@ static bool __init hv_init_tsc_clocksource(void) */ tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC); tsc_msr.enable = 1; - tsc_msr.pfn = HVPFN_DOWN(phys_addr); + tsc_msr.pfn = tsc_pfn; hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100); -- 2.20.1