[PATCH v6 4/4] arm/arm64: arch_timer: Use archdata to indicate vdso suitability
Russell King - ARM Linux
linux at armlinux.org.uk
Fri Sep 23 07:32:03 PDT 2016
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On Thu, Sep 22, 2016 at 03:35:18AM -0500, Scott Wood wrote:
> Instead of comparing the name to a magic string, use archdata to
> explicitly communicate whether the arch timer is suitable for
> direct vdso access.
>
> Signed-off-by: Scott Wood <oss at buserror.net>
> Acked-by: Will Deacon <will.deacon at arm.com>
> ---
> arch/arm/Kconfig | 1 +
> arch/arm/include/asm/clocksource.h | 8 ++++++++
> arch/arm/kernel/vdso.c | 2 +-
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/clocksource.h | 8 ++++++++
> arch/arm64/kernel/vdso.c | 2 +-
> drivers/clocksource/arm_arch_timer.c | 11 +++--------
> 7 files changed, 23 insertions(+), 10 deletions(-)
> create mode 100644 arch/arm/include/asm/clocksource.h
> create mode 100644 arch/arm64/include/asm/clocksource.h
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index a9c4e48..b2113c2 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1,6 +1,7 @@
> config ARM
> bool
> default y
> + select ARCH_CLOCKSOURCE_DATA
> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
> select ARCH_HAS_DEVMEM_IS_ALLOWED
> select ARCH_HAS_ELF_RANDOMIZE
> diff --git a/arch/arm/include/asm/clocksource.h b/arch/arm/include/asm/clocksource.h
> new file mode 100644
> index 0000000..0b350a7
> --- /dev/null
> +++ b/arch/arm/include/asm/clocksource.h
> @@ -0,0 +1,8 @@
> +#ifndef _ASM_CLOCKSOURCE_H
> +#define _ASM_CLOCKSOURCE_H
> +
> +struct arch_clocksource_data {
> + bool vdso_direct; /* Usable for direct VDSO access? */
> +};
> +
> +#endif
> diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
> index 994e971..a0affd1 100644
> --- a/arch/arm/kernel/vdso.c
> +++ b/arch/arm/kernel/vdso.c
> @@ -270,7 +270,7 @@ static bool tk_is_cntvct(const struct timekeeper *tk)
> if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
> return false;
>
> - if (strcmp(tk->tkr_mono.clock->name, "arch_sys_counter") != 0)
> + if (!tk->tkr_mono.clock->archdata.vdso_direct)
> return false;
>
> return true;
For the ARM bits:
Acked-by: Russell King <rmk+kernel at armlinux.org.uk>
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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