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

From: Hanjun Guo <hanjun.guo@linaro.org>
To: Tomasz Nowicki <tomasz.nowicki@linaro.org>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tomasz Nowicki <tn@semihalf.com>,
	bhelgaas@google.com, arnd@arndb.de, will.deacon@arm.com,
	catalin.marinas@arm.com, rjw@rjwysocki.net,
	Lorenzo.Pieralisi@arm.com, linux-kernel@vger.kernel.org,
	linaro-acpi@lists.linaro.org, linux-pci@vger.kernel.org,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Liviu.Dudau@arm.com, ddaney@caviumnetworks.com,
	Narinder.Dhillon@caviumnetworks.com, linux-acpi@vger.kernel.org,
	robert.richter@caviumnetworks.com, wangyijing@huawei.com,
	tglx@linutronix.de, jiang.liu@linux.intel.com,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [Linaro-acpi] [PATCH V1 07/11] XEN / PCI: Remove the dependence on arch x86 when PCI_MMCONFIG=y
Date: Wed, 28 Oct 2015 21:45:29 +0800	[thread overview]
Message-ID: <5630D179.9050403@linaro.org> (raw)
In-Reply-To: <5630A9D3.1030607@linaro.org>

On 10/28/2015 06:56 PM, Tomasz Nowicki wrote:
> 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 <hanjun.guo@linaro.org>
>>>>>
>>>>> 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 <hanjun.guo@linaro.org>
>>>>> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
>>>>> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>>>>> ---
>>>>>    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 <boris.ostrovsky@oracle.com>
>>
>> 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!

Hmm, I think we just missed the head file, but the logic
of this patch is still right.

Thanks
Hanjun