Re: x86: PCI multi domain/segment config access

From: Matthew Wilcox
Date: Fri Jul 11 2008 - 17:21:29 EST


On Fri, Jul 11, 2008 at 04:13:47PM -0500, John Keller wrote:
> On x86 PCI Config space access to domains/segments > 0 appears to be broken.
> The noted patch related to PCI ext config space has all config accesses
> to offsets < 256 using conf1 if available, which is most likely the case.
>
> This would force usage of conf1 for non-extended config access (< 256) on
> PCI domains > 0.
>
> Am I missing something, or how would a conf1 access reference a domain
> other than zero?

You're correct. Sorry about that, I wasn't thinking about domains at
the time I wrote the patch. Try this:

[X86] Fix PCI config space for domains > 0

John Keller reports that PCI config space access is broken on machines
with more than one domain. conf1 accesses only work for domain 0.

Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>

diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 6e64aaf..fe33533 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -31,7 +31,7 @@ struct pci_raw_ops *raw_pci_ext_ops;
int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
int reg, int len, u32 *val)
{
- if (reg < 256 && raw_pci_ops)
+ if (domain == 0 && reg < 256 && raw_pci_ops)
return raw_pci_ops->read(domain, bus, devfn, reg, len, val);
if (raw_pci_ext_ops)
return raw_pci_ext_ops->read(domain, bus, devfn, reg, len, val);
@@ -41,7 +41,7 @@ int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
int reg, int len, u32 val)
{
- if (reg < 256 && raw_pci_ops)
+ if (domain == 0 && reg < 256 && raw_pci_ops)
return raw_pci_ops->write(domain, bus, devfn, reg, len, val);
if (raw_pci_ext_ops)
return raw_pci_ext_ops->write(domain, bus, devfn, reg, len, val);

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