From adb87ff4f96c9700718e09c97a804124d5cd61ff Mon Sep 17 00:00:00 2001 From: Tianyu Lan Date: Wed, 14 Aug 2019 20:32:15 +0800 Subject: [PATCH] clocksource/drivers/hyperv: Allocate Hyper-V TSC page statically Prepare to add Hyper-V sched clock callback and move Hyper-V Reference TSC initialization much earlier in the boot process. Earlier initialization is needed so that it happens while the timestamp value is still 0 and no discontinuity in the timestamp will occur when pv_ops.time.sched_clock calculates its offset. The earlier initialization requires that the Hyper-V TSC page be allocated statically instead of with vmalloc(), so fixup the references to the TSC page and the method of getting its physical address. Signed-off-by: Tianyu Lan Signed-off-by: Thomas Gleixner Acked-by: Daniel Lezcano Link: https://lkml.kernel.org/r/20190814123216.32245-2-Tianyu.Lan@microsoft.com --- arch/x86/entry/vdso/vma.c | 2 +- drivers/clocksource/hyperv_timer.c | 12 ++++-------- 2 files changed, 5 insertions(+), 9 deletions(-) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 349a61d..f593774 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -122,7 +122,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK)) return vmf_insert_pfn(vma, vmf->address, - vmalloc_to_pfn(tsc_pg)); + virt_to_phys(tsc_pg) >> PAGE_SHIFT); } return VM_FAULT_SIGBUS; diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index ba2c79e..432aa33 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -214,17 +214,17 @@ EXPORT_SYMBOL_GPL(hyperv_cs); #ifdef CONFIG_HYPERV_TSCPAGE -static struct ms_hyperv_tsc_page *tsc_pg; +static struct ms_hyperv_tsc_page tsc_pg __aligned(PAGE_SIZE); struct ms_hyperv_tsc_page *hv_get_tsc_page(void) { - return tsc_pg; + return &tsc_pg; } EXPORT_SYMBOL_GPL(hv_get_tsc_page); static u64 notrace read_hv_sched_clock_tsc(void) { - u64 current_tick = hv_read_tsc_page(tsc_pg); + u64 current_tick = hv_read_tsc_page(&tsc_pg); if (current_tick == U64_MAX) hv_get_time_ref_count(current_tick); @@ -280,12 +280,8 @@ static bool __init hv_init_tsc_clocksource(void) if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) return false; - tsc_pg = vmalloc(PAGE_SIZE); - if (!tsc_pg) - return false; - hyperv_cs = &hyperv_cs_tsc; - phys_addr = page_to_phys(vmalloc_to_page(tsc_pg)); + phys_addr = virt_to_phys(&tsc_pg); /* * The Hyper-V TLFS specifies to preserve the value of reserved -- 2.7.4