From: lantianyu1986@gmail.com
To: luto@kernel.org, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, hpa@zytor.com, x86@kernel.org, kys@microsoft.com,
haiyangz@microsoft.com, sthemmin@microsoft.com,
sashal@kernel.org, daniel.lezcano@linaro.org, arnd@arndb.de,
michael.h.kelley@microsoft.com
Cc: Tianyu Lan <Tianyu.Lan@microsoft.com>,
linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
linux-arch@vger.kernel.org
Subject: [PATCH V2 1/2] clocksource/Hyper-v: Allocate Hyper-V tsc page statically
Date: Wed, 14 Aug 2019 20:32:15 +0800 [thread overview]
Message-ID: <20190814123216.32245-2-Tianyu.Lan@microsoft.com> (raw)
In-Reply-To: <20190814123216.32245-1-Tianyu.Lan@microsoft.com>
From: Tianyu Lan <Tianyu.Lan@microsoft.com>
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 <Tianyu.Lan@microsoft.com>
---
Change since v1:
- Update commit log
- Remove and operation of tsc page's va with PAGE_MASK
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 349a61d8bf34..f5937742b290 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 ba2c79e6a0ee..432aa331df04 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
--
2.14.5
next prev parent reply other threads:[~2019-08-14 12:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-14 12:32 [PATCH V2 0/2] clocksource/Hyper-V: Add Hyper-V specific sched clock lantianyu1986
2019-08-14 12:32 ` lantianyu1986 [this message]
2019-08-16 15:00 ` [PATCH V2 1/2] clocksource/Hyper-v: Allocate Hyper-V tsc page statically Daniel Lezcano
2019-08-14 12:32 ` [PATCH V2 2/2] clocksource/Hyper-V: Add Hyper-V specific sched clock function lantianyu1986
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