Re: [PATCH v2 00/18] add PCI bus-to-resource offset support in core

[Yinghai Lu <yinghai@kernel.org>]

On Fri, Feb 10, 2012 at 8:55 AM, Bjorn Helgaas <bhelgaas@google.com> wrote:
...
>>
>> I mean, we can unify sysdata usuage, make them all most the same.
>>
>> and for some sysdata, already acting like host_bridge struct with
>> domain, numa_node, and resources.
>>
>>> If you can show an example of what you mean, maybe it will help me understand.
>>
>> just looked the sys_data of different arch,
>>
>> looks like pci_sys_data for arm already include the io offset
>>
>> arch/arm/include/asm/mach/pci.h::
>>
>> struct pci_sys_data {
>> #ifdef CONFIG_PCI_DOMAINS
>>        int             domain;
>> #endif
>>        struct list_head node;
>>        int             busnr;          /* primary bus number
>>         */
>>        u64             mem_offset;     /* bus->cpu memory mapping
>> offset       */
>>        unsigned long   io_offset;      /* bus->cpu IO mapping offset
>>         */
>>        struct pci_bus  *bus;           /* PCI bus
>>         */
>>        struct list_head resources;     /* root bus resources (apertures)
>
> Let me try again.  Maybe your idea is that we should create something
> like "struct pcibios_sysdata" and require every arch to define a
> struct with that name.  Every arch's struct would contain some members
> such as "domain," "mem_offset," "io_offset," and "resources."  These
> would have standard names & types across all arches and would be
> referenced by the PCI core.  In addition, the struct could include
> arch-specific data such as "acpi_handle," "iommu," etc.
>
> That way, the core could implement things like pci_domain_nr() and
> pci_bus_to_resource() by using the data in struct pcibios_sysdata.
> The current "void *sysdata" parameters to pci_scan_bus() and friends
> would become "struct pcibios_sysdata *sysdata".
>
> I like the idea of unifying the sysdata struct name and changing from
> a "void *" to something like "struct pcibios_sysdata *".  That might
> be worth doing.

what i am mean:
1. make every arch to use same name for the struct, but could have
different contents.
   struct pci_sys_data.
2. unify member field name, by changing name
    pci_first_busno ==> first_busno
    pci_last_busno ==> last_busno
    or adding
    first_busno
    last_busno
3. changing more filed like domain, node
    and io_offset, mem_offset
...

Yinghai