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x86: Hyper-V: Integrate the clocksource with Hyper-V detection code

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The Hyper-V clocksource driver is best integrated with Hyper-V
detection code since: 

  (a) Linux guests running on Hyper-V require it

  (b) Integration into that code significanly reduces code size

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Cc: gregkh@suse.de
Cc: devel@linuxdriverproject.org
Cc: virtualization@lists.osdl.org
Link: http://lkml.kernel.org/r/1315434310-4827-1-git-send-email-kys@microsoft.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
K. Y. Srinivasan 2011-09-07 15:25:10 -07:00 committed by Thomas Gleixner
parent ddf28352b8
commit 6f4151c89b
3 changed files with 24 additions and 102 deletions
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23
arch/x86/kernel/cpu/mshyperv.c
View File

@ -11,6 +11,8 @@
*/
#include <linux/types.h>
#include <linux/time.h>
#include <linux/clocksource.h>
#include <linux/module.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
@ -36,6 +38,25 @@ static bool __init ms_hyperv_platform(void)
!memcmp("Microsoft Hv", hyp_signature, 12);
}
static cycle_t read_hv_clock(struct clocksource *arg)
{
cycle_t current_tick;
/*
* Read the partition counter to get the current tick count. This count
* is set to 0 when the partition is created and is incremented in
* 100 nanosecond units.
*/
rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
return current_tick;
}
static struct clocksource hyperv_cs = {
.name = "hyperv_clocksource",
.rating = 400, /* use this when running on Hyperv*/
.read = read_hv_clock,
.mask = CLOCKSOURCE_MASK(64),
};
static void __init ms_hyperv_init_platform(void)
{
/*
@ -46,6 +67,8 @@ static void __init ms_hyperv_init_platform(void)
printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
ms_hyperv.features, ms_hyperv.hints);
clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
}
const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {

2
drivers/staging/hv/Makefile
View File

@ -1,4 +1,4 @@
obj-$(CONFIG_HYPERV) += hv_vmbus.o hv_timesource.o
obj-$(CONFIG_HYPERV) += hv_vmbus.o
obj-$(CONFIG_HYPERV_STORAGE) += hv_storvsc.o
obj-$(CONFIG_HYPERV_BLOCK) += hv_blkvsc.o
obj-$(CONFIG_HYPERV_NET) += hv_netvsc.o

101
drivers/staging/hv/hv_timesource.c
View File

@ -1,101 +0,0 @@
/*
* A clocksource for Linux running on HyperV.
*
*
* Copyright (C) 2010, Novell, Inc.
* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clocksource.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/dmi.h>
#include <asm/hyperv.h>
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
#define HV_CLOCK_SHIFT 22
static cycle_t read_hv_clock(struct clocksource *arg)
{
cycle_t current_tick;
/*
* Read the partition counter to get the current tick count. This count
* is set to 0 when the partition is created and is incremented in
* 100 nanosecond units.
*/
rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
return current_tick;
}
static struct clocksource hyperv_cs = {
.name = "hyperv_clocksource",
.rating = 400, /* use this when running on Hyperv*/
.read = read_hv_clock,
.mask = CLOCKSOURCE_MASK(64),
/*
* The time ref counter in HyperV is in 100ns units.
* The definition of mult is:
* mult/2^shift = ns/cyc = 100
* mult = (100 << shift)
*/
.mult = (100 << HV_CLOCK_SHIFT),
.shift = HV_CLOCK_SHIFT,
};
static const struct dmi_system_id __initconst
hv_timesource_dmi_table[] __maybe_unused = {
{
.ident = "Hyper-V",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
DMI_MATCH(DMI_PRODUCT_NAME, "Virtual Machine"),
DMI_MATCH(DMI_BOARD_NAME, "Virtual Machine"),
},
},
{ },
};
MODULE_DEVICE_TABLE(dmi, hv_timesource_dmi_table);
static const struct pci_device_id __initconst
hv_timesource_pci_table[] __maybe_unused = {
{ PCI_DEVICE(0x1414, 0x5353) }, /* VGA compatible controller */
{ 0 }
};
MODULE_DEVICE_TABLE(pci, hv_timesource_pci_table);
static int __init init_hv_clocksource(void)
{
if ((x86_hyper != &x86_hyper_ms_hyperv) ||
!(ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE))
return -ENODEV;
if (!dmi_check_system(hv_timesource_dmi_table))
return -ENODEV;
pr_info("Registering HyperV clock source\n");
return clocksource_register(&hyperv_cs);
}
module_init(init_hv_clocksource);
MODULE_DESCRIPTION("HyperV based clocksource");
MODULE_AUTHOR("K. Y. Srinivasan <ksrinivasan@novell.com>");
MODULE_LICENSE("GPL");