07 Jun, 2013

1 commit

  • Switching between reading the virtual or physical counters is
    problematic, as some core code wants a view of time before we're fully
    set up. Using a function pointer and switching the source after the
    first read can make time appear to go backwards, and having a check in
    the read function is an unfortunate block on what we want to be a fast
    path.

    Instead, this patch makes us always use the virtual counters. If we're a
    guest, or don't have hyp mode, we'll use the virtual timers, and as such
    don't care about CNTVOFF as long as it doesn't change in such a way as
    to make time appear to travel backwards. As the guest will use the
    virtual timers, a (potential) KVM host must use the physical timers
    (which can wake up the host even if they fire while a guest is
    executing), and hence a host must have CNTVOFF set to zero so as to have
    a consistent view of time between the physical timers and virtual
    counters.

    Signed-off-by: Mark Rutland
    Acked-by: Catalin Marinas
    Acked-by: Marc Zyngier
    Acked-by: Santosh Shilimkar
    Cc: Rob Herring

    Mark Rutland
     

12 Apr, 2013

1 commit

  • This converts arm and arm64 to use CLKSRC_OF DT based initialization for
    the arch timer. A new function arch_timer_arch_init is added to allow for
    arch specific setup.

    This has a side effect of enabling sched_clock on omap5 and exynos5. There
    should not be any reason not to use the arch timers for sched_clock.

    Signed-off-by: Rob Herring
    Cc: Russell King
    Cc: Kukjin Kim
    Cc: Tony Lindgren
    Cc: Simon Horman
    Cc: Magnus Damm
    Cc: Catalin Marinas
    Cc: Will Deacon
    Cc: John Stultz
    Cc: Thomas Gleixner
    Cc: linux-samsung-soc@vger.kernel.org
    Cc: linux-omap@vger.kernel.org
    Cc: linux-sh@vger.kernel.org
    Acked-by: Santosh Shilimkar

    Rob Herring
     

12 Feb, 2013

1 commit


31 Jan, 2013

1 commit

  • The core functionality of the arch_timer driver is not directly tied to
    anything under arch/arm, and can be split out.

    This patch factors out the core of the arch_timer driver, so it can be
    shared with other architectures. A couple of functions are added so
    that architecture-specific code can interact with the driver without
    needing to touch its internals.

    The ARM_ARCH_TIMER config variable is moved out to
    drivers/clocksource/Kconfig, existing uses in arch/arm are replaced with
    HAVE_ARM_ARCH_TIMER, which selects it.

    Signed-off-by: Mark Rutland
    Acked-by: Catalin Marinas
    Acked-by: Marc Zyngier

    Mark Rutland