Re: [PATCH][2.6] PCI Scan all functions

[Greg KH <greg@kroah.com>]

On Tue, Jan 27, 2004 at 01:33:14PM -0800, Andrew Morton wrote:
> Greg KH <greg@kroah.com> wrote:
> >
> > On Tue, Jan 27, 2004 at 10:55:01AM -0600, Jake Moilanen wrote:
> > > There are some arch, like PPC64, that need to be able to scan all the
> > > PCI functions.  The problem comes in on a logically partitioned system
> > > where function 0 on a PCI-PCI bridge is assigned to one partition and
> > > say function 2 is assiged to another partition.  On the second
> > > partition, it would appear that function 0 does not exist, but function
> > > 2 does.  If all the functions are not scanned, everything under function
> > > 2 would not be detected.
> > 
> > Heh, I think the PPC64 people need to get together and all talk about
> > this, as I just got a different patch, that solves much the same problem
> > from John Rose (it's on the linuxppc64 mailing list.)
> > 
> > Can you two get together and not patch the same section of code to do
> > the same thing in different ways?
> 
> While we're on the topic, what's with the below patch?  I've had it in -mm
> for ages but apparently there's some disagreement over it.

It looks ok to me, but Linus and Ivan were the ones disagreeing over how
to implement this correctly, as they understand the resource management
logic a lot better than I.

They should be the ones to say if this is ok or not.

thanks,

greg k-h

> From: Anton Blanchard <anton@samba.org>
> 
> We have IO BARs on ppc64 machines that begin at address 0. The current
> pci probe code will ignore anything that starts at 0. Remove these checks.
> 
> 
> 
> ---
> 
>  drivers/pci/probe.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff -puN drivers/pci/probe.c~ppc64-bar-0-fix drivers/pci/probe.c
> --- 25/drivers/pci/probe.c~ppc64-bar-0-fix	2004-01-13 23:23:18.000000000 -0800
> +++ 25-akpm/drivers/pci/probe.c	2004-01-13 23:23:18.000000000 -0800
> @@ -176,7 +176,7 @@ void __devinit pci_read_bridge_bases(str
>  		limit |= (io_limit_hi << 16);
>  	}
>  
> -	if (base && base <= limit) {
> +	if (base <= limit) {
>  		res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
>  		res->start = base;
>  		res->end = limit + 0xfff;
> @@ -187,7 +187,7 @@ void __devinit pci_read_bridge_bases(str
>  	pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo);
>  	base = (mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16;
>  	limit = (mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16;
> -	if (base && base <= limit) {
> +	if (base <= limit) {
>  		res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
>  		res->start = base;
>  		res->end = limit + 0xfffff;
> @@ -213,7 +213,7 @@ void __devinit pci_read_bridge_bases(str
>  		}
>  #endif
>  	}
> -	if (base && base <= limit) {
> +	if (base <= limit) {
>  		res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM | IORESOURCE_PREFETCH;
>  		res->start = base;
>  		res->end = limit + 0xfffff;
> 
> _