Re: [PATCH] pci: Add support for creating a generic host_bridge from device tree

[Jingoo Han <jg1.han@samsung.com>]

On 

> -----Original Message-----
> From: Jingoo Han [mailto:jg1.han@samsung.com]
> Sent: Thursday, February 13, 2014 5:10 PM
> To: 'Liviu Dudau'; 'Tanmay Inamdar'
> Cc: 'Arnd Bergmann'; devicetree@vger.kernel.org; 'linaro-kernel'; 'linux-pci'; 'Will Deacon'; 'LKML';
> 'Catalin Marinas'; 'Bjorn Helgaas'; 'LAKML'; 'Jingoo Han'
> Subject: Re: [PATCH] pci: Add support for creating a generic host_bridge from device tree
> 
> On Thursday, February 06, 2014 7:18 PM, Liviu Dudau wrote:
> > On Wed, Feb 05, 2014 at 10:26:27PM +0000, Tanmay Inamdar wrote:
> > > Hello Liviu,
> > >
> > > I did not get the first email of this particular patch on any of
> > > subscribed mailing lists (don't know why), hence replying here.
> >
> > Strange, it shows in the MARC and GMANE archive for linux-pci, probably
> > a hickup on your receiving side?
> >
> > >
> > > +struct pci_host_bridge *
> > > +pci_host_bridge_of_init(struct device *parent, int busno, struct pci_ops *ops,
> > > + void *host_data, struct list_head *resources)
> > > +{
> > > + struct pci_bus *root_bus;
> > > + struct pci_host_bridge *bridge;
> > > +
> > > + /* first parse the host bridge bus ranges */
> > > + if (pci_host_bridge_of_get_ranges(parent->of_node, resources))
> > > + return NULL;
> > > +
> > > + /* then create the root bus */
> > > + root_bus = pci_create_root_bus(parent, busno, ops, host_data, resources);
> > > + if (!root_bus)
> > > + return NULL;
> > > +
> > > + bridge = to_pci_host_bridge(root_bus->bridge);
> > > +
> > > + return bridge;
> > > +}
> > >
> > > You are keeping the domain_nr inside pci_host_bridge structure. In
> > > above API, domain_nr is required in 'pci_find_bus' function called
> > > from 'pci_create_root_bus'. Since the bridge is allocated after
> > > creating root bus, 'pci_find_bus' always gets domain_nr as 0. This
> > > will cause problem for scanning multiple domains.
> >
> > Good catch. I was switching between creating a pci_controller in arch/arm64 and
> > adding the needed bits in pci_host_bridge. After internal review I've decided to
> > add the domain_nr to pci_host_bridge, but forgot to update the code everywhere.
> 
> Hi Liviu Dudau,
> 
> One more thing,
> I am reviewing and compiling your patch.
> Would you consider adding 'struct pci_sys_data' and 'struct hw_pci'?
> 
> Currently, 4 PCIe Host drivers (pci-mvebu.c, pci-tegra.c,
> pci-rcar-gen2.c, pcie-designware.c) are using 'struct pci_sys_data'
> and 'struct hw_pci' in their drivers. Without this, it makes build
> errors.
> 
> In arm32, 'struct pci_sys_data' and 'struct hw_pci' is defined
> in "arch/arm/include/asm/mach/pci.h".
> 
> Tanmay Inamdar,
> Your 'APM X-Gene PCIe' patch also needs 'struct pci_sys_data' and
> 'struct hw_pci'. With Liviu Dudau's patch, it will make build
> errors. Would you check this?

I mean the patch '[PATCH] arm64: Add architecture support for PCI'.
With this patch, it makes build errors in PCIe Host drivers such as
pcie-designware.c.

Best regards,
Jingoo Han