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

From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Tomasz Nowicki <tomasz.nowicki@linaro.org>,
	Tomasz Nowicki <tn@semihalf.com>,
	bhelgaas@google.com, arnd@arndb.de, will.deacon@arm.com,
	catalin.marinas@arm.com, rjw@rjwysocki.net,
	hanjun.guo@linaro.org, Lorenzo.Pieralisi@arm.com
Cc: 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,
	Stefano.Stabellini@eu.citrix.com
Subject: Re: [Linaro-acpi] [PATCH V1 07/11] XEN / PCI: Remove the dependence on arch x86 when PCI_MMCONFIG=y
Date: Tue, 27 Oct 2015 13:25:57 -0400	[thread overview]
Message-ID: <562FB3A5.3050500@oracle.com> (raw)
In-Reply-To: <562FAA88.3020609@linaro.org>

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>

>>
>>   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;
>>
>>