Re: [PATCH 06/10] x86/PCI: Enable scanning of all pci functions

Jeremy Fitzhardinge
2009-05-13T17:08:32Z

Jesse Barnes wrote:
> On Tue, 12 May 2009 14:48:07 -0700
> Jeremy Fitzhardinge <jeremy@goop.org> wrote:
>
>
>> From: Alex Nixon <alex.nixon@citrix.com>
>>
>> Xen may want to enable scanning of all pci functions - if for example
>> the device at function 0 is not passed through to the guest, but the
>> device at function 1 is.
>>
>> [Impact: allow passthrough of just some PCI functions.]
>> Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
>> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
>> Reviewed-by: "H. Peter Anvin" <hpa@zytor.com>
>> Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
>> ---
>> arch/x86/include/asm/pci.h | 8 +++++++-
>> arch/x86/pci/common.c | 1 +
>> 2 files changed, 8 insertions(+), 1 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
>> index b51a1e8..092706e 100644
>> --- a/arch/x86/include/asm/pci.h
>> +++ b/arch/x86/include/asm/pci.h
>> @@ -21,6 +21,7 @@ struct pci_sysdata {
>> extern int pci_routeirq;
>> extern int noioapicquirk;
>> extern int noioapicreroute;
>> +extern int pci_scan_all_fns;
>>
>> /* scan a bus after allocating a pci_sysdata for it */
>> extern struct pci_bus *pci_scan_bus_on_node(int busno, struct
>> pci_ops *ops, @@ -48,7 +49,11 @@ extern unsigned int
>> pcibios_assign_all_busses(void); #else
>> #define pcibios_assign_all_busses() 0
>> #endif
>> -#define pcibios_scan_all_fns(a, b) 0
>> +
>> +static inline int pcibios_scan_all_fns(struct pci_bus *bus, int
>> devfn) +{
>> + return pci_scan_all_fns;
>> +}
>>
>> extern unsigned long pci_mem_start;
>> #define PCIBIOS_MIN_IO 0x1000
>> @@ -130,6 +135,7 @@ extern void pci_iommu_alloc(void);
>>
>> /* generic pci stuff */
>> #include <asm-generic/pci.h>
>> +#undef pcibios_scan_all_fns
>>
>
> This is a little gross... But then I don't see any places where it's
> actually defined to something true either.

I've got some code to set it in a series I haven't posted yet.

> Maybe it should be a weak
> function or a new HAVE_FOO define instead.
>

I'd probably go the weak function path if I were to do either of those,
but do you think it would be significantly better?

J