clocksource/drivers: Make Hyper-V clocksource ISA agnostic

Hyper-V clock/timer code and data structures are currently mixed
in with other code in the ISA independent drivers/hv directory as
well as the ISA dependent Hyper-V code under arch/x86.

Consolidate this code and data structures into a Hyper-V clocksource driver
to better follow the Linux model. In doing so, separate out the ISA
dependent portions so the new clocksource driver works for x86 and for the
in-process Hyper-V on ARM64 code.

To start, move the existing clockevents code to create the new clocksource
driver. Update the VMbus driver to call initialization and cleanup routines
since the Hyper-V synthetic timers are not independently enumerated in
ACPI.

No behavior is changed and no new functionality is added.

Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: "bp@alien8.de" <bp@alien8.de>
Cc: "will.deacon@arm.com" <will.deacon@arm.com>
Cc: "catalin.marinas@arm.com" <catalin.marinas@arm.com>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>
Cc: "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>
Cc: "olaf@aepfle.de" <olaf@aepfle.de>
Cc: "apw@canonical.com" <apw@canonical.com>
Cc: "jasowang@redhat.com" <jasowang@redhat.com>
Cc: "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com>
Cc: Sunil Muthuswamy <sunilmut@microsoft.com>
Cc: KY Srinivasan <kys@microsoft.com>
Cc: "sashal@kernel.org" <sashal@kernel.org>
Cc: "vincenzo.frascino@arm.com" <vincenzo.frascino@arm.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>
Cc: "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>
Cc: "arnd@arndb.de" <arnd@arndb.de>
Cc: "linux@armlinux.org.uk" <linux@armlinux.org.uk>
Cc: "ralf@linux-mips.org" <ralf@linux-mips.org>
Cc: "paul.burton@mips.com" <paul.burton@mips.com>
Cc: "daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>
Cc: "salyzyn@android.com" <salyzyn@android.com>
Cc: "pcc@google.com" <pcc@google.com>
Cc: "shuah@kernel.org" <shuah@kernel.org>
Cc: "0x7f454c46@gmail.com" <0x7f454c46@gmail.com>
Cc: "linux@rasmusvillemoes.dk" <linux@rasmusvillemoes.dk>
Cc: "huw@codeweavers.com" <huw@codeweavers.com>
Cc: "sfr@canb.auug.org.au" <sfr@canb.auug.org.au>
Cc: "pbonzini@redhat.com" <pbonzini@redhat.com>
Cc: "rkrcmar@redhat.com" <rkrcmar@redhat.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Link: https://lkml.kernel.org/r/1561955054-1838-2-git-send-email-mikelley@microsoft.com
This commit is contained in:
Michael Kelley 2019-07-01 04:25:56 +00:00 committed by Thomas Gleixner
parent 3419240495
commit fd1fea6834
10 changed files with 268 additions and 176 deletions

View File

@ -7313,6 +7313,7 @@ F: arch/x86/include/asm/trace/hyperv.h
F: arch/x86/include/asm/hyperv-tlfs.h
F: arch/x86/kernel/cpu/mshyperv.c
F: arch/x86/hyperv
F: drivers/clocksource/hyperv_timer.c
F: drivers/hid/hid-hyperv.c
F: drivers/hv/
F: drivers/input/serio/hyperv-keyboard.c
@ -7323,6 +7324,7 @@ F: drivers/uio/uio_hv_generic.c
F: drivers/video/fbdev/hyperv_fb.c
F: drivers/iommu/hyperv_iommu.c
F: net/vmw_vsock/hyperv_transport.c
F: include/clocksource/hyperv_timer.h
F: include/linux/hyperv.h
F: include/uapi/linux/hyperv.h
F: tools/hv/

View File

@ -401,6 +401,12 @@ enum HV_GENERIC_SET_FORMAT {
#define HV_STATUS_INVALID_CONNECTION_ID 18
#define HV_STATUS_INSUFFICIENT_BUFFERS 19
/*
* The Hyper-V TimeRefCount register and the TSC
* page provide a guest VM clock with 100ns tick rate
*/
#define HV_CLOCK_HZ (NSEC_PER_SEC/100)
typedef struct _HV_REFERENCE_TSC_PAGE {
__u32 tsc_sequence;
__u32 res1;

View File

@ -17,6 +17,7 @@
#include <linux/irq.h>
#include <linux/kexec.h>
#include <linux/i8253.h>
#include <linux/random.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
#include <asm/hyperv-tlfs.h>
@ -80,6 +81,7 @@ __visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
inc_irq_stat(hyperv_stimer0_count);
if (hv_stimer0_handler)
hv_stimer0_handler();
add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
ack_APIC_irq();
exiting_irq();
@ -89,7 +91,7 @@ __visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void))
{
*vector = HYPERV_STIMER0_VECTOR;
*irq = 0; /* Unused on x86/x64 */
*irq = -1; /* Unused on x86/x64 */
hv_stimer0_handler = handler;
return 0;
}

View File

@ -86,3 +86,4 @@ obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o
obj-$(CONFIG_RISCV_TIMER) += timer-riscv.o
obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o
obj-$(CONFIG_HYPERV_TIMER) += hyperv_timer.o

View File

@ -0,0 +1,200 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Clocksource driver for the synthetic counter and timers
* provided by the Hyper-V hypervisor to guest VMs, as described
* in the Hyper-V Top Level Functional Spec (TLFS). This driver
* is instruction set architecture independent.
*
* Copyright (C) 2019, Microsoft, Inc.
*
* Author: Michael Kelley <mikelley@microsoft.com>
*/
#include <linux/percpu.h>
#include <linux/cpumask.h>
#include <linux/clockchips.h>
#include <linux/mm.h>
#include <clocksource/hyperv_timer.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
static struct clock_event_device __percpu *hv_clock_event;
/*
* If false, we're using the old mechanism for stimer0 interrupts
* where it sends a VMbus message when it expires. The old
* mechanism is used when running on older versions of Hyper-V
* that don't support Direct Mode. While Hyper-V provides
* four stimer's per CPU, Linux uses only stimer0.
*/
static bool direct_mode_enabled;
static int stimer0_irq;
static int stimer0_vector;
static int stimer0_message_sint;
/*
* ISR for when stimer0 is operating in Direct Mode. Direct Mode
* does not use VMbus or any VMbus messages, so process here and not
* in the VMbus driver code.
*/
void hv_stimer0_isr(void)
{
struct clock_event_device *ce;
ce = this_cpu_ptr(hv_clock_event);
ce->event_handler(ce);
}
EXPORT_SYMBOL_GPL(hv_stimer0_isr);
static int hv_ce_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
u64 current_tick;
current_tick = hyperv_cs->read(NULL);
current_tick += delta;
hv_init_timer(0, current_tick);
return 0;
}
static int hv_ce_shutdown(struct clock_event_device *evt)
{
hv_init_timer(0, 0);
hv_init_timer_config(0, 0);
if (direct_mode_enabled)
hv_disable_stimer0_percpu_irq(stimer0_irq);
return 0;
}
static int hv_ce_set_oneshot(struct clock_event_device *evt)
{
union hv_stimer_config timer_cfg;
timer_cfg.as_uint64 = 0;
timer_cfg.enable = 1;
timer_cfg.auto_enable = 1;
if (direct_mode_enabled) {
/*
* When it expires, the timer will directly interrupt
* on the specified hardware vector/IRQ.
*/
timer_cfg.direct_mode = 1;
timer_cfg.apic_vector = stimer0_vector;
hv_enable_stimer0_percpu_irq(stimer0_irq);
} else {
/*
* When it expires, the timer will generate a VMbus message,
* to be handled by the normal VMbus interrupt handler.
*/
timer_cfg.direct_mode = 0;
timer_cfg.sintx = stimer0_message_sint;
}
hv_init_timer_config(0, timer_cfg.as_uint64);
return 0;
}
/*
* hv_stimer_init - Per-cpu initialization of the clockevent
*/
void hv_stimer_init(unsigned int cpu)
{
struct clock_event_device *ce;
/*
* Synthetic timers are always available except on old versions of
* Hyper-V on x86. In that case, just return as Linux will use a
* clocksource based on emulated PIT or LAPIC timer hardware.
*/
if (!(ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE))
return;
ce = per_cpu_ptr(hv_clock_event, cpu);
ce->name = "Hyper-V clockevent";
ce->features = CLOCK_EVT_FEAT_ONESHOT;
ce->cpumask = cpumask_of(cpu);
ce->rating = 1000;
ce->set_state_shutdown = hv_ce_shutdown;
ce->set_state_oneshot = hv_ce_set_oneshot;
ce->set_next_event = hv_ce_set_next_event;
clockevents_config_and_register(ce,
HV_CLOCK_HZ,
HV_MIN_DELTA_TICKS,
HV_MAX_MAX_DELTA_TICKS);
}
EXPORT_SYMBOL_GPL(hv_stimer_init);
/*
* hv_stimer_cleanup - Per-cpu cleanup of the clockevent
*/
void hv_stimer_cleanup(unsigned int cpu)
{
struct clock_event_device *ce;
/* Turn off clockevent device */
if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
ce = per_cpu_ptr(hv_clock_event, cpu);
hv_ce_shutdown(ce);
}
}
EXPORT_SYMBOL_GPL(hv_stimer_cleanup);
/* hv_stimer_alloc - Global initialization of the clockevent and stimer0 */
int hv_stimer_alloc(int sint)
{
int ret;
hv_clock_event = alloc_percpu(struct clock_event_device);
if (!hv_clock_event)
return -ENOMEM;
direct_mode_enabled = ms_hyperv.misc_features &
HV_STIMER_DIRECT_MODE_AVAILABLE;
if (direct_mode_enabled) {
ret = hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector,
hv_stimer0_isr);
if (ret) {
free_percpu(hv_clock_event);
hv_clock_event = NULL;
return ret;
}
}
stimer0_message_sint = sint;
return 0;
}
EXPORT_SYMBOL_GPL(hv_stimer_alloc);
/* hv_stimer_free - Free global resources allocated by hv_stimer_alloc() */
void hv_stimer_free(void)
{
if (direct_mode_enabled && (stimer0_irq != 0)) {
hv_remove_stimer0_irq(stimer0_irq);
stimer0_irq = 0;
}
free_percpu(hv_clock_event);
hv_clock_event = NULL;
}
EXPORT_SYMBOL_GPL(hv_stimer_free);
/*
* Do a global cleanup of clockevents for the cases of kexec and
* vmbus exit
*/
void hv_stimer_global_cleanup(void)
{
int cpu;
struct clock_event_device *ce;
if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
for_each_present_cpu(cpu) {
ce = per_cpu_ptr(hv_clock_event, cpu);
clockevents_unbind_device(ce, cpu);
}
}
hv_stimer_free();
}
EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup);

View File

@ -10,6 +10,9 @@ config HYPERV
Select this option to run Linux as a Hyper-V client operating
system.
config HYPERV_TIMER
def_bool HYPERV
config HYPERV_TSCPAGE
def_bool HYPERV && X86_64

View File

@ -16,27 +16,13 @@
#include <linux/version.h>
#include <linux/random.h>
#include <linux/clockchips.h>
#include <clocksource/hyperv_timer.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
/* The one and only */
struct hv_context hv_context;
/*
* If false, we're using the old mechanism for stimer0 interrupts
* where it sends a VMbus message when it expires. The old
* mechanism is used when running on older versions of Hyper-V
* that don't support Direct Mode. While Hyper-V provides
* four stimer's per CPU, Linux uses only stimer0.
*/
static bool direct_mode_enabled;
static int stimer0_irq;
static int stimer0_vector;
#define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
#define HV_MIN_DELTA_TICKS 1
/*
* hv_init - Main initialization routine.
*
@ -47,9 +33,6 @@ int hv_init(void)
hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
if (!hv_context.cpu_context)
return -ENOMEM;
direct_mode_enabled = ms_hyperv.misc_features &
HV_STIMER_DIRECT_MODE_AVAILABLE;
return 0;
}
@ -88,89 +71,6 @@ int hv_post_message(union hv_connection_id connection_id,
return status & 0xFFFF;
}
/*
* ISR for when stimer0 is operating in Direct Mode. Direct Mode
* does not use VMbus or any VMbus messages, so process here and not
* in the VMbus driver code.
*/
static void hv_stimer0_isr(void)
{
struct hv_per_cpu_context *hv_cpu;
hv_cpu = this_cpu_ptr(hv_context.cpu_context);
hv_cpu->clk_evt->event_handler(hv_cpu->clk_evt);
add_interrupt_randomness(stimer0_vector, 0);
}
static int hv_ce_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
u64 current_tick;
WARN_ON(!clockevent_state_oneshot(evt));
current_tick = hyperv_cs->read(NULL);
current_tick += delta;
hv_init_timer(0, current_tick);
return 0;
}
static int hv_ce_shutdown(struct clock_event_device *evt)
{
hv_init_timer(0, 0);
hv_init_timer_config(0, 0);
if (direct_mode_enabled)
hv_disable_stimer0_percpu_irq(stimer0_irq);
return 0;
}
static int hv_ce_set_oneshot(struct clock_event_device *evt)
{
union hv_stimer_config timer_cfg;
timer_cfg.as_uint64 = 0;
timer_cfg.enable = 1;
timer_cfg.auto_enable = 1;
if (direct_mode_enabled) {
/*
* When it expires, the timer will directly interrupt
* on the specified hardware vector/IRQ.
*/
timer_cfg.direct_mode = 1;
timer_cfg.apic_vector = stimer0_vector;
hv_enable_stimer0_percpu_irq(stimer0_irq);
} else {
/*
* When it expires, the timer will generate a VMbus message,
* to be handled by the normal VMbus interrupt handler.
*/
timer_cfg.direct_mode = 0;
timer_cfg.sintx = VMBUS_MESSAGE_SINT;
}
hv_init_timer_config(0, timer_cfg.as_uint64);
return 0;
}
static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
{
dev->name = "Hyper-V clockevent";
dev->features = CLOCK_EVT_FEAT_ONESHOT;
dev->cpumask = cpumask_of(cpu);
dev->rating = 1000;
/*
* Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
* result in clockevents_config_and_register() taking additional
* references to the hv_vmbus module making it impossible to unload.
*/
dev->set_state_shutdown = hv_ce_shutdown;
dev->set_state_oneshot = hv_ce_set_oneshot;
dev->set_next_event = hv_ce_set_next_event;
}
int hv_synic_alloc(void)
{
int cpu;
@ -199,14 +99,6 @@ int hv_synic_alloc(void)
tasklet_init(&hv_cpu->msg_dpc,
vmbus_on_msg_dpc, (unsigned long) hv_cpu);
hv_cpu->clk_evt = kzalloc(sizeof(struct clock_event_device),
GFP_KERNEL);
if (hv_cpu->clk_evt == NULL) {
pr_err("Unable to allocate clock event device\n");
goto err;
}
hv_init_clockevent_device(hv_cpu->clk_evt, cpu);
hv_cpu->synic_message_page =
(void *)get_zeroed_page(GFP_ATOMIC);
if (hv_cpu->synic_message_page == NULL) {
@ -229,11 +121,6 @@ int hv_synic_alloc(void)
INIT_LIST_HEAD(&hv_cpu->chan_list);
}
if (direct_mode_enabled &&
hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector,
hv_stimer0_isr))
goto err;
return 0;
err:
/*
@ -252,7 +139,6 @@ void hv_synic_free(void)
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
kfree(hv_cpu->clk_evt);
free_page((unsigned long)hv_cpu->synic_event_page);
free_page((unsigned long)hv_cpu->synic_message_page);
free_page((unsigned long)hv_cpu->post_msg_page);
@ -311,38 +197,11 @@ int hv_synic_init(unsigned int cpu)
hv_set_synic_state(sctrl.as_uint64);
/*
* Register the per-cpu clockevent source.
*/
if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE)
clockevents_config_and_register(hv_cpu->clk_evt,
HV_TIMER_FREQUENCY,
HV_MIN_DELTA_TICKS,
HV_MAX_MAX_DELTA_TICKS);
hv_stimer_init(cpu);
return 0;
}
/*
* hv_synic_clockevents_cleanup - Cleanup clockevent devices
*/
void hv_synic_clockevents_cleanup(void)
{
int cpu;
if (!(ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE))
return;
if (direct_mode_enabled)
hv_remove_stimer0_irq(stimer0_irq);
for_each_present_cpu(cpu) {
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
clockevents_unbind_device(hv_cpu->clk_evt, cpu);
}
}
/*
* hv_synic_cleanup - Cleanup routine for hv_synic_init().
*/
@ -388,14 +247,7 @@ int hv_synic_cleanup(unsigned int cpu)
if (channel_found && vmbus_connection.conn_state == CONNECTED)
return -EBUSY;
/* Turn off clockevent device */
if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
struct hv_per_cpu_context *hv_cpu
= this_cpu_ptr(hv_context.cpu_context);
clockevents_unbind_device(hv_cpu->clk_evt, cpu);
hv_ce_shutdown(hv_cpu->clk_evt);
}
hv_stimer_cleanup(cpu);
hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);

View File

@ -138,7 +138,6 @@ struct hv_per_cpu_context {
* per-cpu list of the channels based on their CPU affinity.
*/
struct list_head chan_list;
struct clock_event_device *clk_evt;
};
struct hv_context {
@ -176,8 +175,6 @@ extern int hv_synic_init(unsigned int cpu);
extern int hv_synic_cleanup(unsigned int cpu);
extern void hv_synic_clockevents_cleanup(void);
/* Interface */
void hv_ringbuffer_pre_init(struct vmbus_channel *channel);

View File

@ -30,6 +30,7 @@
#include <linux/kdebug.h>
#include <linux/efi.h>
#include <linux/random.h>
#include <clocksource/hyperv_timer.h>
#include "hyperv_vmbus.h"
struct vmbus_dynid {
@ -955,17 +956,6 @@ static void vmbus_onmessage_work(struct work_struct *work)
kfree(ctx);
}
static void hv_process_timer_expiration(struct hv_message *msg,
struct hv_per_cpu_context *hv_cpu)
{
struct clock_event_device *dev = hv_cpu->clk_evt;
if (dev->event_handler)
dev->event_handler(dev);
vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
}
void vmbus_on_msg_dpc(unsigned long data)
{
struct hv_per_cpu_context *hv_cpu = (void *)data;
@ -1159,9 +1149,10 @@ static void vmbus_isr(void)
/* Check if there are actual msgs to be processed */
if (msg->header.message_type != HVMSG_NONE) {
if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
hv_process_timer_expiration(msg, hv_cpu);
else
if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
hv_stimer0_isr();
vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
} else
tasklet_schedule(&hv_cpu->msg_dpc);
}
@ -1263,14 +1254,19 @@ static int vmbus_bus_init(void)
ret = hv_synic_alloc();
if (ret)
goto err_alloc;
ret = hv_stimer_alloc(VMBUS_MESSAGE_SINT);
if (ret < 0)
goto err_alloc;
/*
* Initialize the per-cpu interrupt state and
* connect to the host.
* Initialize the per-cpu interrupt state and stimer state.
* Then connect to the host.
*/
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
hv_synic_init, hv_synic_cleanup);
if (ret < 0)
goto err_alloc;
goto err_cpuhp;
hyperv_cpuhp_online = ret;
ret = vmbus_connect();
@ -1318,6 +1314,8 @@ static int vmbus_bus_init(void)
err_connect:
cpuhp_remove_state(hyperv_cpuhp_online);
err_cpuhp:
hv_stimer_free();
err_alloc:
hv_synic_free();
hv_remove_vmbus_irq();
@ -2064,7 +2062,7 @@ static struct acpi_driver vmbus_acpi_driver = {
static void hv_kexec_handler(void)
{
hv_synic_clockevents_cleanup();
hv_stimer_global_cleanup();
vmbus_initiate_unload(false);
vmbus_connection.conn_state = DISCONNECTED;
/* Make sure conn_state is set as hv_synic_cleanup checks for it */
@ -2075,6 +2073,8 @@ static void hv_kexec_handler(void)
static void hv_crash_handler(struct pt_regs *regs)
{
int cpu;
vmbus_initiate_unload(true);
/*
* In crash handler we can't schedule synic cleanup for all CPUs,
@ -2082,7 +2082,9 @@ static void hv_crash_handler(struct pt_regs *regs)
* for kdump.
*/
vmbus_connection.conn_state = DISCONNECTED;
hv_synic_cleanup(smp_processor_id());
cpu = smp_processor_id();
hv_stimer_cleanup(cpu);
hv_synic_cleanup(cpu);
hyperv_cleanup();
};
@ -2131,7 +2133,7 @@ static void __exit vmbus_exit(void)
hv_remove_kexec_handler();
hv_remove_crash_handler();
vmbus_connection.conn_state = DISCONNECTED;
hv_synic_clockevents_cleanup();
hv_stimer_global_cleanup();
vmbus_disconnect();
hv_remove_vmbus_irq();
for_each_online_cpu(cpu) {

View File

@ -0,0 +1,27 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Definitions for the clocksource provided by the Hyper-V
* hypervisor to guest VMs, as described in the Hyper-V Top
* Level Functional Spec (TLFS).
*
* Copyright (C) 2019, Microsoft, Inc.
*
* Author: Michael Kelley <mikelley@microsoft.com>
*/
#ifndef __CLKSOURCE_HYPERV_TIMER_H
#define __CLKSOURCE_HYPERV_TIMER_H
#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
#define HV_MIN_DELTA_TICKS 1
/* Routines called by the VMbus driver */
extern int hv_stimer_alloc(int sint);
extern void hv_stimer_free(void);
extern void hv_stimer_init(unsigned int cpu);
extern void hv_stimer_cleanup(unsigned int cpu);
extern void hv_stimer_global_cleanup(void);
extern void hv_stimer0_isr(void);
#endif