Re: [RFC] Build with arm64 configuration

[Jaehoon Chung <jh80.chung@samsung.com>]

Dear, Bjorn.

On 03/10/2015 11:17 AM, Bjorn Helgaas wrote:
> [+cc Jingoo, Mohit]
> 
> On Mon, Mar 9, 2015 at 8:36 PM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> Dear, Bjorn.
>>
>> Thanks for reply.
>>
>> On 03/10/2015 08:35 AM, Bjorn Helgaas wrote:
>>> On Mon, Mar 9, 2015 at 7:18 AM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>> Hi,
>>>>
>>>> I have a question for building arm64.
>>>> (Actually, i didn't have many knowledges for PCIe.)
>>>> When i built with arm64 configuration, then i always found the compiler errors.
>>>
>>> The kernel does build for arm64, so you'll have to be more specific
>>> about the problem you're seeing.
>>
>> I built the pcie-designware.c and pci-exynos.c.
>>
>> When pcie-designware.c is built, i found the below error message.
>> drivers/pci/host/pcie-designware.c:74:52: warning: Ëœstruct pci_sys_dataâ„¢ declared inside parameter list
>>  static inline struct pcie_port *sys_to_pcie(struct pci_sys_data *sys)
>>                                                     ^
>> drivers/pci/host/pcie-designware.c:74:52: warning: its scope is only this definition or declaration, which is probably not what you want
>> In file included from include/uapi/linux/stddef.h:1:0,
>>                  from include/linux/stddef.h:4,
>>                  from ./include/uapi/linux/posix_types.h:4,
>>                  from include/uapi/linux/types.h:13,
>>                  from include/linux/types.h:5,
>>                  from include/linux/smp.h:10,
>>                  from include/linux/irq.h:12,
>>                  from drivers/pci/host/pcie-designware.c:14:
>> drivers/pci/host/pcie-designware.c: In function Ëœsys_to_pcie":
>> drivers/pci/host/pcie-designware.c:76:13: error: dereferencing pointer to incomplete type
>>   BUG_ON(!sys->private_data);
>>
>> I found it's located at arch/arm/include/asm/mach/pci.h.
>> It can't refer when do build for arm64.
>> So I think that i missed something..I have also searched the patches relevant to this at patchwork.
>> Some patch have copied header files relevant to "pci" to "arch/arm64/include/".
>> (This is not solution.)
>>
>> And i don't want to add #ifdef CONFIG_ARM64 into pcie-designware.c
>> I think mailing should know the graceful solution.
>>
>> If i can solve this problem, i will contribute for pci-exynos.c.
> 
> Oh, I think pcie-designware.c and pci-exynos.c currently only work on
> arm, not on arm64.  I don't know enough about them to know whether
> they could be made to work on arm64.  But Jingoo and Mohit probably
> do.

I'm checking the code..
If my understanding is right, pci_sys_data is just used to take data relevant to pice_port.
So I think it can get from device-tree or other.
I don't exactly know why needs "pci_sys_data".

It seems to discuss about pcie (struct pci_sys_data and hw_pci) on arm64 at mailing..right?
([RFC 2/4] PCI: generic: Add support for ARM64 and MSI(x))

If need to work, i have interesting for contributing pcie on arm64.(pcie-designware.c and pci-exynos.c)
But i need to gain the knowledge of pcie..

Best Regards,
Jaehoon Chung

> 
> Bjorn
>