[Patch v4 5/8] ARM64/PCI/ACPI: Introduce struct pci_controller for ACPI
Jiang Liu
jiang.liu at linux.intel.com
Wed Jun 3 02:36:19 PDT 2015
On 2015/6/3 16:44, Hanjun Guo wrote:
> On 2015年06月02日 17:35, Lorenzo Pieralisi wrote:
>> On Tue, Jun 02, 2015 at 07:12:53AM +0100, Jiang Liu wrote:
>>> From: Hanjun Guo <hanjun.guo at linaro.org>
>>>
>>> ARM64 ACPI based PCI host bridge init needs a arch dependent
>>> struct pci_controller to accommodate common PCI host bridge
>>> code which is introduced later, or it will lead to compile
>>> errors on ARM64.
>>>
>>> Signed-off-by: Hanjun Guo <hanjun.guo at linaro.org>
>>> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit at amd.com>
>>> CC: Arnd Bergmann <arnd at arndb.de>
>>> CC: Catalin Marinas <catalin.marinas at arm.com>
>>> CC: Liviu Dudau <Liviu.Dudau at arm.com>
>>> CC: Lorenzo Pieralisi <Lorenzo.Pieralisi at arm.com>
>>> CC: Will Deacon <will.deacon at arm.com>
>>> Signed-off-by: Jiang Liu <jiang.liu at linux.intel.com>
>>> ---
>>> arch/arm64/include/asm/pci.h | 10 ++++++++++
>>> 1 file changed, 10 insertions(+)
>>>
>>> diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h
>>> index b008a72f8bc0..70884957f253 100644
>>> --- a/arch/arm64/include/asm/pci.h
>>> +++ b/arch/arm64/include/asm/pci.h
>>> @@ -10,6 +10,16 @@
>>> #include <asm-generic/pci-bridge.h>
>>> #include <asm-generic/pci-dma-compat.h>
>>>
>>> +struct acpi_device;
>>> +
>>> +struct pci_controller {
>>> +#ifdef CONFIG_ACPI
>>> + struct acpi_device *companion; /* ACPI companion device */
>>> +#endif
>>> + int segment; /* PCI domain */
>>> + int node; /* NUMA node */
>>> +};
>>
>> There is nothing ARM64 specific in this structure. The only
>> reason I see you want to keep it arch specific is the iommu
>> pointer on x86,
>
> And also plarform_data for IA64 too.
>
>> but I think we should find a way to make
>> the common bits shared across archs (ie the struct above) and
>> add (maybe a void*) to the generic struct to cater for arch
>> specific data.
>>
>> Thoughts ?
>
> We discussed this already, it has limitations to make it
> common to all archs, I think the limitation are:
>
> - struct pci_controller are also used for other archs
> such as PowerPC and Tile, they will not use it for
> ACPI purpose, so we can not used for all archs.
>
> - if we let struct pci_controller defined only for archs
> using ACPI, such as introduce it in linux/acpi.h, we still
> can not satisfy that the struct pci_controller is not
> only used for ACPI case on x86, it will be used for
> non-ACPI too.
>
> So it's pretty difficult to share it with across archs to me,
> any more ideas?
Hi Hanjun and Lorenzo,
As mentioned by Hanjun, I have no idea yet about how to
consolidating "struct pci_controller" further. One possible
way is to move "struct pci_controller" related code into
arch, but apparently that will reduce code reusing.
Thanks!
Gerry
>
> Thanks
> Hanjun
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