Re: [PATCH v2 0/2] Drivers: hv: Move Hyper-V clock/timer code to separate clocksource driver

[Vitaly Kuznetsov <vkuznets@redhat.com>]

Michael Kelley <mikelley@microsoft.com> writes:

> This patch series moves Hyper-V clock/timer code to a separate Hyper-V
> clocksource driver. Previously, Hyper-V clock/timer code and data
> structures were mixed in with other Hyper-V code in the ISA independent
> drivers/hv code as well as in arch dependent code. The new Hyper-V
> clocksource driver is ISA independent, with a just few dependencies on
> arch specific functions. The patch series does not change any behavior
> or functionality -- it only reorganizes the existing code and fixes up
> the linkages. A few places outside of Hyper-V code are fixed up to use
> the new #include file structure.
>
> This restructuring is in response to Marc Zyngier's review comments
> on supporting Hyper-V running on ARM64, and is a good idea in general.
> It increases the amount of code shared between the x86 and ARM64
> architectures, and reduces the size of the new code for supporting
> Hyper-V on ARM64. A new version of the Hyper-V on ARM64 patches will
> follow once this clocksource restructuring is accepted.
>
> The code is currently diff'ed against Linux 5.0.  I'll rebase
> to linux-next once 5.1-rc1 is available.
>
> Changes in v2:
> * Revised commit short descriptions so the distinction between
> the two patches is clearer [GregKH]
> * Renamed new clocksource driver files and functions to use
> existing "timer" and "stimer" names instead of introducing
> "syntimer". [Vitaly Kuznetsov]
> * Introduced CONFIG_HYPER_TIMER to fix build problem when
> CONFIG_HYPERV=m [Vitaly Kuznetsov]

Actually, it is "CONFIG_HYPERV_TIMER" but the typo appears only in this
blurb :-)

> * Added "Suggested-by: Marc Zyngier"
>
> Michael Kelley (2):
>   Drivers: hv: Create Hyper-V clocksource driver from existing
>     clockevents code
>   Drivers: hv: Move Hyper-V clocksource code to new clocksource driver

Thanks for fixing v1 issues!

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

>
>  MAINTAINERS                          |   2 +
>  arch/x86/entry/vdso/vclock_gettime.c |   1 +
>  arch/x86/entry/vdso/vma.c            |   2 +-
>  arch/x86/hyperv/hv_init.c            |  91 +---------
>  arch/x86/include/asm/hyperv-tlfs.h   |   6 +
>  arch/x86/include/asm/mshyperv.h      |  80 ++-------
>  arch/x86/kernel/cpu/mshyperv.c       |   2 +
>  arch/x86/kvm/x86.c                   |   1 +
>  drivers/clocksource/Makefile         |   1 +
>  drivers/clocksource/hyperv_timer.c   | 328 +++++++++++++++++++++++++++++++++++
>  drivers/hv/Kconfig                   |   3 +
>  drivers/hv/hv.c                      | 154 ----------------
>  drivers/hv/hyperv_vmbus.h            |   3 -
>  drivers/hv/vmbus_drv.c               |  39 +++--
>  include/clocksource/hyperv_timer.h   | 104 +++++++++++
>  15 files changed, 485 insertions(+), 332 deletions(-)
>  create mode 100644 drivers/clocksource/hyperv_timer.c
>  create mode 100644 include/clocksource/hyperv_timer.h

-- 
Vitaly