Re: PCI DMA to small buffers on cache-incoherent arch

From: Benjamin Herrenschmidt (benh@kernel.crashing.org)
Date: Wed Jun 12 2002 - 10:00:20 EST


> Those would be designed so they could be shared between
> devices, invisibly to code talking to a struct device.
>
> Example: all USB devices connected to a given bus would
> normally delegate to the PCI device underlying that bus.
> (Except for non-PCI host controllers, of course!)
>
> And the PCI versions of those methods have rather obvious
> implementations ... :)

Yup. The simplest way I see here is to have a device automatically
inherit, by default, his parent device ones. The arch will provide
default "root" allocators, so a fully coherent or fully non-coherent
arch may not have to do anything but these.

Now, if a given bus in the arch need specific quirks, it's up to
the bus device node to put it's own versions to be used by it's
childs.

Ben.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Jun 15 2002 - 22:00:25 EST