Re: one more apic merging preliminary series

From: Ingo Molnar
Date: Mon Aug 18 2008 - 20:22:19 EST



* Suresh Siddha <suresh.b.siddha@xxxxxxxxx> wrote:

> On Sun, Aug 17, 2008 at 05:45:40AM -0700, Ingo Molnar wrote:
> >
> > * Cyrill Gorcunov <gorcunov@xxxxxxxxx> wrote:
> >
> > > Please review - any comments are welcome!
> > >
> > > For now it's like code bloating - but it's just preliminary series to
> > > make apic_*.c code more or less similar. And it's still a bit far from
> > > being ready to be merged down.
> >
> > applied to tip/x86/apic - thanks Cyrill.
> >
> > Maciej's point about cleaning up the x2apic impact is very much true -
> > i've Cc:-ed Suresh and Venki. Even if we wont truly use x2apic in 32-bit
> > kernels, it's a piece of glue hardware that does not depend on which
> > mode the CPU is in, so support for it should be bitsize agnostic. It
> > will also obviously be good for test coverage, once x2apic capable hw
> > will be more widespread.
>
> Interrupt-remapping(part of chipset) must be enabled before
> enabling/using x2apic mode.
>
> So, there is little bit more work (adding the intr-remapping pieces to
> 32bit kernel etc) to be done, before enabling x2apic for 32-bit kernel
> aswell.
>
> I am planning to do some work (introduce some kind of
> interrupt-remapping ops and cleanup some of the code in the existing
> io_apic_64.c), that will eventually make it easy to add
> interrupt-remapping and x2apic to 32bit aswell.

Yinghai unified io_apic.c in latest tip/master, and that means that the
CONFIG_INTR_REMAP bit are now all in 32-bit code as well. It's not yet
enabled in the Kconfig:

config INTR_REMAP
bool "Support for Interrupt Remapping (EXPERIMENTAL)"
depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL

but it should be a lot less work now i suspect.

Ingo
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