Re: [PATCH] xen/pci: Try harder to get PXM information for Xen

[David Vrabel <david.vrabel@citrix.com>]

On 08/04/15 15:01, Boris Ostrovsky wrote:
> On 04/08/2015 09:39 AM, Ross Lagerwall wrote:
>> If the device being added to Xen is not contained in the ACPI table,
>> walk the PCI device tree to find a parent that is contained in the ACPI
>> table before finding the PXM information from this device.
>>
>> Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
>> ---
>>   drivers/xen/pci.c | 15 +++++++++++++--
>>   1 file changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
>> index 95ee430..6837181 100644
>> --- a/drivers/xen/pci.c
>> +++ b/drivers/xen/pci.c
>> @@ -19,6 +19,7 @@
>>     #include <linux/pci.h>
>>   #include <linux/acpi.h>
>> +#include <linux/pci-acpi.h>
>>   #include <xen/xen.h>
>>   #include <xen/interface/physdev.h>
>>   #include <xen/interface/xen.h>
>> @@ -67,8 +68,18 @@ static int xen_add_device(struct device *dev)
>>     #ifdef CONFIG_ACPI
>>           handle = ACPI_HANDLE(&pci_dev->dev);
>> -        if (!handle && pci_dev->bus->bridge)
>> -            handle = ACPI_HANDLE(pci_dev->bus->bridge);
>> +        if (!handle) {
>> +            /*
>> +             * This device was not listed in the ACPI name space at
>> +             * all. Try to get acpi handle of parent pci bus.
>> +             */
>> +            struct pci_bus *pbus;
>> +            for (pbus = pci_dev->bus; pbus; pbus = pbus->parent) {
>> +                handle = acpi_pci_get_bridge_handle(pbus);
>> +                if (handle)
>> +                    break;
>> +            }
>> +        }
>>   #ifdef CONFIG_PCI_IOV
>>           if (!handle && pci_dev->is_virtfn)
>>               handle = ACPI_HANDLE(physfn->bus->bridge);
> 
> 
> Shouldn't we first look at physfn, before going up the tree?

That sounds sensible but should be a separate pre-requisite patch.

David