Re: [Patch v7 4/7] PCI/ACPI: Add interface acpi_pci_root_create()
From: Jiang Liu
Date: Fri Nov 06 2015 - 08:22:58 EST
This is a multi-part message in MIME format.On 2015/11/6 20:40, Tomasz Nowicki wrote:
> On 06.11.2015 12:46, Jiang Liu wrote:
>> On 2015/11/6 18:37, Tomasz Nowicki wrote:
>>> On 06.11.2015 09:52, Jiang Liu wrote:
>>> Sure, ARM64 (0-16M IO space) QEMU example:
>>> DWordIO (ResourceProducer, MinFixed, MaxFixed, PosDecode, EntireRange,
>>> 0x00000000, // Granularity
>>> 0x00000000, // Range Minimum
>>> 0x0000FFFF, // Range Maximum
>>> 0x3EFF0000, // Translation Offset
>>> 0x00010000, // Length
>>> ,, , TypeStatic)
>> The above DWordIO resource descriptor doesn't confirm to the ACPI spec.
>> According to my understanding, ARM/ARM64 has no concept of IO port
>> address space, so the PCI host bridge will map IO port on PCI side
>> onto MMIO on host side. In other words, PCI host bridge on ARM64
>> implement a IO Port->MMIO translation instead of a IO Port->IO Port
>> translation. If that's true, it should use 'TypeTranslation' instead
>> of 'TypeStatic'. And kernel ACPI resource parsing interface doesn't
>> support 'TypeTranslation' yet, so we need to find a solution for it.
>
> I think you are right, we need TypeTranslation flag for ARM64 DWordIO
> descriptors and an extra kernel patch to support it.
How about the attached to patch to support TypeTranslation?
It only passes compilation:)
>
> Thanks,
> Tomasz