Re: [RFC] Build with arm64 configuration

[Liviu Dudau <Liviu.Dudau@arm.com>]

On Thu, Mar 19, 2015 at 07:14:29AM +0000, Jaehoon Chung wrote:
> Dear, Liviu.
> 
> On 03/19/2015 12:16 AM, Liviu Dudau wrote:
> > On Wed, Mar 11, 2015 at 08:00:11AM +0000, Jaehoon Chung wrote:
> >> 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.
> > 
> > Jaehoon,
> > 
> > pci-exynos and pcie-designware need to be converted to the generic PCIe framework and then
> > they will work on both arm and arm64. For an example of a driver that successfully works
> > in both worlds look at pci-versatile.c.
> 
> Thanks a lot! I'm looking at pci-versatile.c and comparing with pcie-designware and pci-exynos.
> 
> One question..
> At pci-versatile.c, i found the resource_list_for_each_entry() into versatile_pci_parse_request_of_pci_ranges().
> resource_list_for_each_entry needs two arguments, but it's passed three arguments.
> It seems to want using "resource_list_for_each_entry_safe()", doesn't it? (+CC'd Rob Herring)

Yes, there is a patch already in the mailing lists from Yijing I belive.

Best regards,
Liviu

> 
> diff --git a/drivers/pci/host/pci-versatile.c b/drivers/pci/host/pci-versatile.c
> index 1ec694a..8eb3b80 100644
> --- a/drivers/pci/host/pci-versatile.c
> +++ b/drivers/pci/host/pci-versatile.c
> @@ -80,7 +80,7 @@ static int versatile_pci_parse_request_of_pci_ranges(struct device *dev,
>         if (err)
>                 return err;
>  
> -       resource_list_for_each_entry(win, res, list) {
> +       resource_list_for_each_entry_safe(win, res, list) {
>                 struct resource *parent, *res = win->res;
>  
>                 switch (resource_type(res)) {
> 
> 
> Best Regards,
> Jaehoon Chung
> 
> > 
> > Currently, PCI host bridges that work on arch/arm depend on pci_sys_data, like you have
> > discovered. There is no reason to do that nowadays, and Lorenzo Pieralisi, Yijing Wang
> > and others are trying to get rid of that structure from arch/arm.
> > 
> > Best regards,
> > Liviu
> > 
> >>
> >> 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
> >>>
> >>
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> >> the body of a message to majordomo@vger.kernel.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>
> > 
> 
> 
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯