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Commit adb87ff4 authored by Tianyu Lan's avatar Tianyu Lan Committed by Thomas Gleixner
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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: default avatarTianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lkml.kernel.org/r/20190814123216.32245-2-Tianyu.Lan@microsoft.com
parent dce3e8fd

arch/x86/entry/vdso/vma.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/clocksource/hyperv_timer.c

+4 −8
Original line number Diff line number Diff line
@@ -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