Subject: [PATCH 10/11] XEN / PCI: Remove the dependence on arch x86 when PCI_MMCONFIG=y

From: [email-masked] (Boris Ostrovsky)
Date: Tue, 26 May 2015 10:00:52 -0400

On 05/26/2015 09:54 AM, Boris Ostrovsky wrote:
> On 05/26/2015 08:49 AM, Hanjun Guo wrote:
>> In drivers/xen/pci.c, there are arch x86 dependent codes when
>> CONFIG_PCI_MMCONFIG is enabled, since CONFIG_PCI_MMCONFIG
>> depends on ACPI, so this will prevent XEN PCI running on other
>> architectures using ACPI with PCI_MMCONFIG enabled (such as ARM64).
>>
>> Fortunatly, it can be sloved in a simple way. In drivers/xen/pci.c,
>> the only x86 dependent code is if ((pci_probe & PCI_PROBE_MMCONF) == 0),
>> and it's defined in asm/pci_x86.h, the code means that
>> if the PCI resource is not probed in PCI_PROBE_MMCONF way, just
>> ingnore the xen mcfg init. Actually this is duplicate, because
>> if PCI resource is not probed in PCI_PROBE_MMCONF way, the
>> pci_mmconfig_list will be empty, and the if (list_empty())
>> after it will do the same job.
>>
>> So just remove the arch related code and the head file, this
>> will be no functional change for x86, and also makes xen/pci.c
>> usable for other architectures.
>>
>> Signed-off-by: Hanjun Guo <[email-masked]>
>> CC: Konrad Rzeszutek Wilk <[email-masked]>
>> CC: Boris Ostrovsky <[email-masked]>
>> ---
>>   drivers/xen/pci.c | 6 ------
>>   1 file changed, 6 deletions(-)
>>
>> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
>> index 6785ebb..9a8dbe3 100644
>> --- a/drivers/xen/pci.c
>> +++ b/drivers/xen/pci.c
>> @@ -28,9 +28,6 @@
>>   #include <asm/xen/hypervisor.h>
>>   #include <asm/xen/hypercall.h>
>>   #include "../pci/pci.h"
>> -#ifdef CONFIG_PCI_MMCONFIG
>> -#include <asm/pci_x86.h>
>> -#endif
>>
>>   static bool __read_mostly pci_seg_supported = true;
>>
>> @@ -222,9 +219,6 @@ static int __init xen_mcfg_late(void)
>>       if (!xen_initial_domain())
>>           return 0;
>>
>> -    if ((pci_probe & PCI_PROBE_MMCONF) == 0)
>> -        return 0;
>> -
>>       if (list_empty(&pci_mmcfg_list))
>>           return 0;
>>
>
> (+Stefano who is Xen ARM maintainer)
>
> This will not build on x86 since pci_mmcfg_list since, for example, 
> pci_mmcfg_list is declared in pci_x86.h.

And now really with Stefano and with parsable first sentence, sorry:

This will not build on x86 since pci_mmcfg_list, for example, is 
declared in pci_x86.h.

>
> And I am not sure I understand why you are trying to do this since 
> AFAIK CONFIG_PCI_MMCONFIG is only defined on x86 so neither pci_x86.h 
> will be included nor xen_mcfg_late() will be defined on ARM.
>
>
> -boris
>
>
>