x86/Kconfig: where to place a new chipset

x86/Kconfig: where to place a new chipset

[Alessandro Rubini]

Hello.

I'm currently working on a PCIe chipset (or IO-Hub), called STA2X11.
The device hosts a number of peripherals (sata, ether, spi, uart, ...)
and a DMA controller.  The individual PCI functions can't be enabled
by themselves, as chip support must be activated first.  This is both
because some internal mappings must be setup and because internal
device functions rely on the internal DMA engine. Actually, an
instance of swiotlb is being used.

While I'm sure core code should be in arch/x86/platform (and there is
where I placed the initialization code), I'm wondering where should
the device fall in the Kconfig tree. I tend to put it in the
X86_32_NON_STANDARD stanza, even if the resulting kernel will also
work on standard computers (the "SGI Visual Workstation" config option
does the same).

On the other hand, the device can either be the core chipset (main use
case) or it can be plugged on a PCIe board.

Any suggestion is welcome about Kconfig placement.  Being a "vi
.config" and "make oldconfig" kind of guy, I can't really understand
the manu layout, so I'm finding a hard time in making a sensible
choice.

thanks
/alessandro

Re: x86/Kconfig: where to place a new chipset

[H. Peter Anvin]

On 10/27/2011 03:17 AM, Alessandro Rubini wrote:
> Hello.
> 
> I'm currently working on a PCIe chipset (or IO-Hub), called STA2X11.
> The device hosts a number of peripherals (sata, ether, spi, uart, ...)
> and a DMA controller.  The individual PCI functions can't be enabled
> by themselves, as chip support must be activated first.  This is both
> because some internal mappings must be setup and because internal
> device functions rely on the internal DMA engine. Actually, an
> instance of swiotlb is being used.
> 
> While I'm sure core code should be in arch/x86/platform (and there is
> where I placed the initialization code), I'm wondering where should
> the device fall in the Kconfig tree. I tend to put it in the
> X86_32_NON_STANDARD stanza, even if the resulting kernel will also
> work on standard computers (the "SGI Visual Workstation" config option
> does the same).
> 
> On the other hand, the device can either be the core chipset (main use
> case) or it can be plugged on a PCIe board.
> 

The nonstandard platform location seems fine to me.

	-hpa