From 6f4151c89b7d036c755d8cf74729e09b76fa6676 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Wed, 7 Sep 2011 15:25:10 -0700 Subject: [PATCH] x86: Hyper-V: Integrate the clocksource with Hyper-V detection code 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 Signed-off-by: Haiyang Zhang 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 --- arch/x86/kernel/cpu/mshyperv.c | 23 +++++++ drivers/staging/hv/Makefile | 2 +- drivers/staging/hv/hv_timesource.c | 101 ----------------------------- 3 files changed, 24 insertions(+), 102 deletions(-) delete mode 100644 drivers/staging/hv/hv_timesource.c diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index d944bf6c50e9..0a630dd4b620 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -11,6 +11,8 @@ */ #include +#include +#include #include #include #include @@ -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 = { diff --git a/drivers/staging/hv/Makefile b/drivers/staging/hv/Makefile index 30046743a0b4..14e3c6a14ea4 100644 --- a/drivers/staging/hv/Makefile +++ b/drivers/staging/hv/Makefile @@ -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 diff --git a/drivers/staging/hv/hv_timesource.c b/drivers/staging/hv/hv_timesource.c deleted file mode 100644 index 2b0f9aaf9122..000000000000 --- a/drivers/staging/hv/hv_timesource.c +++ /dev/null @@ -1,101 +0,0 @@ -/* - * A clocksource for Linux running on HyperV. - * - * - * Copyright (C) 2010, Novell, Inc. - * Author : K. Y. Srinivasan - * - * 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 -#include -#include -#include -#include -#include -#include -#include - -#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 "); -MODULE_LICENSE("GPL"); -- 2.39.2