Subject: [Linaro-acpi] [PATCH V1 07/11] XEN / PCI: Remove the dependence on arch x86 when PCI_MMCONFIG=y

From: [email-masked] (Tomasz Nowicki)
Date: Wed, 28 Oct 2015 11:56:19 +0100

On 28.10.2015 11:49, Stefano Stabellini wrote:
> On Tue, 27 Oct 2015, Boris Ostrovsky wrote:
>> On 10/27/2015 12:47 PM, Tomasz Nowicki wrote:
>>> + Stefano
>>>
>>> On 27.10.2015 17:38, Tomasz Nowicki wrote:
>>>> From: Hanjun Guo <[email-masked]>
>>>>
>>>> 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
>>
>> Assuming this still compiles on x86 now that this include file is removed
>>
>> Reviewed-by: Boris Ostrovsky <[email-masked]>
>
> I think it does not:
>
> drivers/xen/pci.c: In function ?xen_mcfg_late?:
> drivers/xen/pci.c:221:18: error: ?pci_mmcfg_list? undeclared (first use in this function)
> drivers/xen/pci.c:221:18: note: each undeclared identifier is reported only once for each f

Right, we need:
+#include <linux/ecam.h>

Will fix this in next version, thanks!

Tomasz

>
>
>>>>
>>>>    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;
>>>>
>>>>