Re: [PATCH] drm: Fix support for PCI domains

From: Jesse Barnes
Date: Thu Aug 12 2010 - 19:46:07 EST


On Fri, 13 Aug 2010 09:33:35 +1000
Dave Airlie <airlied@xxxxxxxxx> wrote:

> On Fri, Aug 13, 2010 at 7:30 AM, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> wrote:
> > On Fri, Aug 6, 2010 at 05:55, Benjamin Herrenschmidt
> > <benh@xxxxxxxxxxxxxxxxxxx> wrote:
> >> (For some reason I thought that went in ages ago ...)
> >>
> >> This fixes support for PCI domains in what should hopefully be a backward
> >> compatible way along with a change to libdrm.
> >>
> >> When the interface version is set to 1.4, we assume userspace understands
> >> domains and the world is at peace. We thus pass proper domain numbers
> >> instead of 0 to userspace.
> >>
> >> The newer libdrm will then try 1.4 first, and fallback to 1.1, along with
> >> ignoring domains in the later case (well, except on alpha of course)
> >>
> >> Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> >> ---
> >> Âdrivers/gpu/drm/drm_ioctl.c | Â Â1 +
> >> Âinclude/drm/drmP.h     Â|  18 +++++++++++++-----
> >> Âinclude/drm/drm_core.h   Â|  Â2 +-
> >> Â3 files changed, 15 insertions(+), 6 deletions(-)
> >
> >> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> >> index c1b9871..6d4bad5 100644
> >> --- a/include/drm/drmP.h
> >> +++ b/include/drm/drmP.h
> >> @@ -1071,11 +1071,19 @@ static __inline__ int drm_core_check_feature(struct drm_device *dev,
> >> Â Â Â Âreturn ((dev->driver->driver_features & feature) ? 1 : 0);
> >> Â}
> >>
> >> -#ifdef __alpha__
> >> -#define drm_get_pci_domain(dev) dev->hose->index
> >> -#else
> >> -#define drm_get_pci_domain(dev) 0
> >> -#endif
> >> +static inline int drm_get_pci_domain(struct drm_device *dev)
> >> +{
> >> +#ifndef __alpha__
> >> + Â Â Â /* For historical reasons, drm_get_pci_domain() is busticated
> >> + Â Â Â Â* on most archs and has to remain so for userspace interface
> >> + Â Â Â Â* < 1.4, except on alpha which was right from the beginning
> >> + Â Â Â Â*/
> >> + Â Â Â if (dev->if_version < 0x10004)
> >> + Â Â Â Â Â Â Â return 0;
> >> +#endif /* __alpha__ */
> >> +
> >> + Â Â Â return pci_domain_nr(dev->pdev->bus);
> >
> > error: implicit declaration of function âpci_domain_nrâ
> > on m68k without PCI.
>
> I don't think I want to add an ifdef CONFIG_PCI into the drm layer for
> this, since we seem to be okay everywhere else,
>
> lets ask jbarnes, not sure if its safe to just add this to the
> !CONFIG_PCI section of the linux/pci.h

Hm, so pci_domain_nr should just return 0 on platforms where
CONFIG_PCI_DOMAINS isn't set. I'd expect that to be the case when
CONFIG_PCI=n... Maybe we just need to shuffle the definition around?

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