forked from mirrors/linux
dd2cb34861
Continue consolidating Hyper-V clock and timer code into an ISA independent Hyper-V clocksource driver. Move the existing clocksource code under drivers/hv and arch/x86 to the new clocksource driver while separating out the ISA dependencies. Update Hyper-V initialization to call initialization and cleanup routines since the Hyper-V synthetic clock is not independently enumerated in ACPI. Update Hyper-V clocksource users in KVM and VDSO to get definitions from the new include file. 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/1561955054-1838-3-git-send-email-mikelley@microsoft.com
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
/* 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
|
|
|
|
#include <linux/clocksource.h>
|
|
#include <linux/math64.h>
|
|
#include <asm/mshyperv.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);
|
|
|
|
#if IS_ENABLED(CONFIG_HYPERV)
|
|
extern struct clocksource *hyperv_cs;
|
|
extern void hv_init_clocksource(void);
|
|
#endif /* CONFIG_HYPERV */
|
|
|
|
#ifdef CONFIG_HYPERV_TSCPAGE
|
|
extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
|
|
|
|
static inline notrace u64
|
|
hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, u64 *cur_tsc)
|
|
{
|
|
u64 scale, offset;
|
|
u32 sequence;
|
|
|
|
/*
|
|
* The protocol for reading Hyper-V TSC page is specified in Hypervisor
|
|
* Top-Level Functional Specification ver. 3.0 and above. To get the
|
|
* reference time we must do the following:
|
|
* - READ ReferenceTscSequence
|
|
* A special '0' value indicates the time source is unreliable and we
|
|
* need to use something else. The currently published specification
|
|
* versions (up to 4.0b) contain a mistake and wrongly claim '-1'
|
|
* instead of '0' as the special value, see commit c35b82ef0294.
|
|
* - ReferenceTime =
|
|
* ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset
|
|
* - READ ReferenceTscSequence again. In case its value has changed
|
|
* since our first reading we need to discard ReferenceTime and repeat
|
|
* the whole sequence as the hypervisor was updating the page in
|
|
* between.
|
|
*/
|
|
do {
|
|
sequence = READ_ONCE(tsc_pg->tsc_sequence);
|
|
if (!sequence)
|
|
return U64_MAX;
|
|
/*
|
|
* Make sure we read sequence before we read other values from
|
|
* TSC page.
|
|
*/
|
|
smp_rmb();
|
|
|
|
scale = READ_ONCE(tsc_pg->tsc_scale);
|
|
offset = READ_ONCE(tsc_pg->tsc_offset);
|
|
*cur_tsc = hv_get_raw_timer();
|
|
|
|
/*
|
|
* Make sure we read sequence after we read all other values
|
|
* from TSC page.
|
|
*/
|
|
smp_rmb();
|
|
|
|
} while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);
|
|
|
|
return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset;
|
|
}
|
|
|
|
static inline notrace u64
|
|
hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
|
|
{
|
|
u64 cur_tsc;
|
|
|
|
return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
|
|
}
|
|
|
|
#else /* CONFIG_HYPERV_TSC_PAGE */
|
|
static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
|
|
u64 *cur_tsc)
|
|
{
|
|
return U64_MAX;
|
|
}
|
|
#endif /* CONFIG_HYPERV_TSCPAGE */
|
|
|
|
#endif
|