[Linux-ia64] RE: [Pcihpd-discuss] PCI hotplug broken on IA64

[Linux-ia64] RE: [Pcihpd-discuss] PCI hotplug broken on IA64

[Lee, Jung-Ik]

> I don't think the current way of accessing PCI configuration space
> with temporary pci_dev and pci_bus is definitive answer but we
> are depending on it now.
> Could someone enlighten me?
> Any ideas?

All pci config space access before pci_dev/pci_bus are built
should be able to make direct call to
pci_config_{read|write}(seg, bus, dev, func, offset, size, value).

Thanks,
J.I.

[Linux-ia64] Re: [Pcihpd-discuss] PCI hotplug broken on IA64

[Greg KH]

On Wed, Oct 30, 2002 at 08:49:24PM -0800, Lee, Jung-Ik wrote:
> 
> > I don't think the current way of accessing PCI configuration space
> > with temporary pci_dev and pci_bus is definitive answer but we
> > are depending on it now.
> > Could someone enlighten me?
> > Any ideas?
> 
> All pci config space access before pci_dev/pci_bus are built
> should be able to make direct call to
> pci_config_{read|write}(seg, bus, dev, func, offset, size, value).

Um, where are these functions exported?  I don't see them in the 2.4
tree :)

thanks,

greg k-h

[Linux-ia64] Re: [Pcihpd-discuss] PCI hotplug broken on IA64

[Greg KH]

On Wed, Oct 30, 2002 at 06:00:40PM -0800, KOCHI, Takayoshi wrote:
> Hi,
> 
> The PCI segment support which was introduced at 2.4.19-020821 ia64 patch
> broke PCI hotplug core driver.  The way ia64 port does is using
> ia64 specific 'pci_controller' structure, embedding a segment
> number in it and making pci_bus->sysdata point to the structure.

Yes, Chris McDermott just sent me a patch much like this one a few days
ago.

> All config space access functions refer to the structure so if
> pci_controller structures are not setup correctly, all pci
> configuration space acesss will fail.
> 
> I don't think the current way of accessing PCI configuration space
> with temporary pci_dev and pci_bus is definitive answer but we
> are depending on it now.
> 
> Could someone enlighten me?
> Any ideas?

The correct thing to do is do what we did in 2.5.  There is no more
*_nodev functions, as we changed the pci_ops structure.  Even when
segment support goes into 2.5, the pci hotplug code should not care at
all.

That being said, I don't think the huge pci_ops change would be a good
thing to do right now in 2.4.  I also do not want to be forced to add
the segment value to the *_nodev functions, as that is just getting too
messy.

Maybe a backport of the pci_ops changes is the best thing to do...

Any other ideas?

thanks,

greg k-h

[Linux-ia64] Re: [Pcihpd-discuss] PCI hotplug broken on IA64

[Greg KH]

On Wed, Oct 30, 2002 at 09:52:44PM -0800, Greg KH wrote:
> On Wed, Oct 30, 2002 at 08:49:24PM -0800, Lee, Jung-Ik wrote:
> > 
> > > I don't think the current way of accessing PCI configuration space
> > > with temporary pci_dev and pci_bus is definitive answer but we
> > > are depending on it now.
> > > Could someone enlighten me?
> > > Any ideas?
> > 
> > All pci config space access before pci_dev/pci_bus are built
> > should be able to make direct call to
> > pci_config_{read|write}(seg, bus, dev, func, offset, size, value).
> 
> Um, where are these functions exported?  I don't see them in the 2.4
> tree :)

Ok, just to make myself clear, yes I know the functions are there, but
no, they are not explicitly exported, or supported on all archs.

thanks,

greg k-h

[Linux-ia64] RE: [Pcihpd-discuss] PCI hotplug broken on IA64

[Lee, Jung-Ik]

> On Wed, Oct 30, 2002 at 09:52:44PM -0800, Greg KH wrote:
> > On Wed, Oct 30, 2002 at 08:49:24PM -0800, Lee, Jung-Ik wrote:
> > > 
> > > > I don't think the current way of accessing PCI 
> configuration space
> > > > with temporary pci_dev and pci_bus is definitive answer but we
> > > > are depending on it now.
> > > > Could someone enlighten me?
> > > > Any ideas?
> > > 
> > > All pci config space access before pci_dev/pci_bus are built
> > > should be able to make direct call to
> > > pci_config_{read|write}(seg, bus, dev, func, offset, size, value).
> > 
> > Um, where are these functions exported?  I don't see them in the 2.4
> > tree :)
> 
> Ok, just to make myself clear, yes I know the functions are there, but
> no, they are not explicitly exported, or supported on all archs.
> 

Hotplug drivers in drivers/hotplug are for Intel architecture,
and the above APIs are available as global for both i386 and ia64.
Actually, acpi driver uses them for ACPI/PCI population before 
pci_dev is built for the hierarchy.

thanks,
J.I.

[Linux-ia64] Re: [Pcihpd-discuss] PCI hotplug broken on IA64

[Greg KH]

On Wed, Oct 30, 2002 at 10:55:12PM -0800, Lee, Jung-Ik wrote:
> 
> Hotplug drivers in drivers/hotplug are for Intel architecture,
> and the above APIs are available as global for both i386 and ia64.

Right now they are, but I have seen drivers for other architectures, and
can not change the pci hotplug core to rely on a ia64 and i386 only
solution, sorry.  Hopefully those other drivers will be in the main tree
soon.

> Actually, acpi driver uses them for ACPI/PCI population before 
> pci_dev is built for the hierarchy.

Yes, but acpi is only on ia64 and i386 platforms right now.  And for 2.5
I got rid of that usage :)

thanks,

greg k-h

[Linux-ia64] Re: [Pcihpd-discuss] PCI hotplug broken on IA64

[Scott Murray]

On Wed, 30 Oct 2002, Greg KH wrote:

> On Wed, Oct 30, 2002 at 10:55:12PM -0800, Lee, Jung-Ik wrote:
> >
> > Hotplug drivers in drivers/hotplug are for Intel architecture,
> > and the above APIs are available as global for both i386 and ia64.
>
> Right now they are, but I have seen drivers for other architectures, and
> can not change the pci hotplug core to rely on a ia64 and i386 only
> solution, sorry.  Hopefully those other drivers will be in the main tree
> soon.

I'm hopeful we'll see a bunch of drivers for various non-x86 CompactPCI
CPU boards appear if my CompactPCI driver goes in.  If I get the time,
I'll probably take the required bits for the Motorola PowerPC boards from
the code MontaVista released a while back and build something for them
myself.

By the way, Greg, are you interested in patches against 2.5.45, even with
the device unregistration stuff still up in the air?  Barring that and
waiting to see what Russell and Alan are cooking up for PCI resource
reservation, I'm kind of doneish my port to 2.5.

Scott


-- 
Scott Murray
SOMA Networks, Inc.
Toronto, Ontario
e-mail: scottm@somanetworks.com

[Linux-ia64] Re: [Pcihpd-discuss] PCI hotplug broken on IA64

[Greg KH]

On Thu, Oct 31, 2002 at 03:03:09AM -0500, Scott Murray wrote:
> 
> I'm hopeful we'll see a bunch of drivers for various non-x86 CompactPCI
> CPU boards appear if my CompactPCI driver goes in.  If I get the time,
> I'll probably take the required bits for the Motorola PowerPC boards from
> the code MontaVista released a while back and build something for them
> myself.

Sounds good, further reinforcement of the "no i386 and ia64 only"
restrictions on the pci hotplug core :)

> By the way, Greg, are you interested in patches against 2.5.45, even with
> the device unregistration stuff still up in the air?  Barring that and
> waiting to see what Russell and Alan are cooking up for PCI resource
> reservation, I'm kind of doneish my port to 2.5.

Yes I am, please send them on.

thanks,

greg k-h

[Linux-ia64] Re: [Pcihpd-discuss] PCI hotplug broken on IA64

[Scott Murray]

On Thu, 31 Oct 2002, Greg KH wrote:

> On Thu, Oct 31, 2002 at 03:03:09AM -0500, Scott Murray wrote:
> >
> > I'm hopeful we'll see a bunch of drivers for various non-x86 CompactPCI
> > CPU boards appear if my CompactPCI driver goes in.  If I get the time,
> > I'll probably take the required bits for the Motorola PowerPC boards from
> > the code MontaVista released a while back and build something for them
> > myself.
>
> Sounds good, further reinforcement of the "no i386 and ia64 only"
> restrictions on the pci hotplug core :)

Considering the wide variety of cPCI CPU boards that are floating around,
and the non-zero chance that someone here at SOMA will decide out of the
blue they want us to use a non-x86 one, I'm keen to hedge my bets. :)

> > By the way, Greg, are you interested in patches against 2.5.45, even with
> > the device unregistration stuff still up in the air?  Barring that and
> > waiting to see what Russell and Alan are cooking up for PCI resource
> > reservation, I'm kind of doneish my port to 2.5.
>
> Yes I am, please send them on.

There are a couple of things I want to test at the office tomorrow, I'll
send something on after I'm sure they work.

Scott


-- 
Scott Murray
SOMA Networks, Inc.
Toronto, Ontario
e-mail: scottm@somanetworks.com

Re: [Linux-ia64] Re: [Pcihpd-discuss] PCI hotplug broken on IA64

[Matthew Wilcox]

On Wed, Oct 30, 2002 at 11:40:21PM -0800, Greg KH wrote:
> Right now they are, but I have seen drivers for other architectures, and
> can not change the pci hotplug core to rely on a ia64 and i386 only
> solution, sorry.  Hopefully those other drivers will be in the main tree
> soon.

yep, at some point i hope to find docs on Elroy's hotplug controller for
PA-RISC.

-- 
Revolutions do not require corporate support.