Subject: [PATCH] ARM: pl2x0/pl310: Refactor Kconfig to be more maintainable

From: [email-masked] (Dave Martin)
Date: Tue, 6 Dec 2011 16:26:46 +0000

On Tue, Nov 29, 2011 at 01:25:55PM -0600, Rob Herring wrote:
> On 11/29/2011 10:32 AM, Dave Martin wrote:
> > Making CACHE_L2X0 depends on (huge list of MACH_ and ARCH_ configs)
> > is bothersome to maintain and likely to lead to merge conflicts.
> > 
> > This patch moves the knowledge of which platforms have a L2x0 or
> > PL310 cache controller to the individual machines.  To enable this,
> > a new HAVE_L2X0_L2CC config option is introduced to allow machines
> > to indicate that they have such a cache controller independently of
> > each other.
> > 
> > Signed-off-by: Dave Martin <[email-masked]>
> > ---
> >  arch/arm/Kconfig               |    8 ++++++++
> >  arch/arm/mach-exynos/Kconfig   |    1 +
> >  arch/arm/mach-omap2/Kconfig    |    1 +
> >  arch/arm/mach-realview/Kconfig |    5 +++++
> >  arch/arm/mach-vexpress/Kconfig |    1 +
> >  arch/arm/mm/Kconfig            |   13 ++++++++-----
> >  arch/arm/plat-mxc/Kconfig      |    1 +
> >  7 files changed, 25 insertions(+), 5 deletions(-)
> > 
> > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > index 44789ef..4068fe5 100644
> > --- a/arch/arm/Kconfig
> > +++ b/arch/arm/Kconfig
> > @@ -339,6 +339,7 @@ config ARCH_HIGHBANK
> >  	select ARCH_WANT_OPTIONAL_GPIOLIB
> >  	select ARM_AMBA
> >  	select ARM_GIC
> > +	select HAVE_L2X0_L2CC
> >  	select ARM_TIMER_SP804
> >  	select CLKDEV_LOOKUP
> >  	select CPU_V7
> 
> These entries are sorted per rmk's review, so please keep it that way.

Can you explain what order they should be in?  Alphabetical?

> 
> > @@ -359,6 +360,7 @@ config ARCH_CLPS711X
> >  config ARCH_CNS3XXX
> >  	bool "Cavium Networks CNS3XXX family"
> >  	select CPU_V6K
> > +	select HAVE_L2X0_L2CC
> >  	select GENERIC_CLOCKEVENTS
> >  	select ARM_GIC
> >  	select MIGHT_HAVE_PCI
> 
> But as you can see, that's rarely the case...

Do you mean "things are not always in alphabetical order?"

Apologies if I'm being obtuse -- your comments are rather terse for me.

[...]

> > +config HAVE_L2X0_L2CC
> > +	bool
> > +	default n
> 
> n is the default already.

Good point -- I'll kill that.

> > +	help
> > +	  This option should be selected by machines which have a L2x0
> > +	  or PL310 cache controller.
> > +
> >  config CACHE_L2X0
> >  	bool "Enable the L2x0 outer cache controller"
> > -	depends on REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || MACH_REALVIEW_PB1176 || \
> > -		   REALVIEW_EB_A9MP || ARCH_IMX_V6_V7 || MACH_REALVIEW_PBX || \
> > -		   ARCH_NOMADIK || ARCH_OMAP4 || ARCH_EXYNOS4 || ARCH_TEGRA || \
> > -		   ARCH_U8500 || ARCH_VEXPRESS_CA9X4 || ARCH_SHMOBILE || \
> > -		   ARCH_PRIMA2 || ARCH_ZYNQ || ARCH_CNS3XXX || ARCH_HIGHBANK
> > +	depends on HAVE_L2X0_L2CC
> 
> For platforms that run in non-secure mode, this shouldn't really be a
> user selectable option. Perhaps those should just select CACHE_L2X0
> directly. I'm not sure which one's those are other than Highbank and OMAP4.

The idea here is to make the option user-selectable on platforms where it
makes sense (and only those platforms).

So yes, I think that platforms which require this option _should_ select
it directly, rather than it being reverse-selected from arch/arm/mm/Kconfig.
This puts the knowledge in the logical place.  Does this apply to OMAP3?
I think we're always running in the Normal World there too.

Cheers
---Dave