Re: [RFC Part2 v1 00/21] Enable hierarchy irqdomian on x86 platforms

[Jiang Liu <jiang.liu@linux.intel.com>]

On 2014/9/24 15:59, Yasuaki Ishimatsu wrote:
> (2014/09/11 23:03), Jiang Liu wrote:
>> We plan to restructure x86 interrupt code based on hierarchy irqdomain,
>> that is to build irqdomains for CPU vector, interrupt remapping unit,
>> IOAPIC, MSI and HPET etc and organize those irqdomains in hierarchy mode.
>> Each irqdomain manages corresponding interrupt controller and talks to
>> parent interrupt controller through public irqdomain interfaces. We also
>> support stacked irq_chip based on hierarchy irqdomain. It will make the
>> x86 interrupt architecture much more clear and more easy to maintain
>> with hierarchy irqdomain and stacked irq_chip. It may also help ARM
>> interrupt management architecture too.
> 
> Do you have a documentation which more detailed information is written?
> I'm interested in this feature. And I want to know more detailed information.
> 
> I cannot imagine why the feature makes x86 irq architecture much more clear
> and more easy to maintain in this description. Of course, I have read the
> following threads:
> 
> https://lkml.org/lkml/2014/9/11/101
Hi Yasuaki,

Do these help?
http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg729924.html
https://lkml.org/lkml/2014/8/1/67

Regards!
Gerry

> 
> Thanks,
> Yasuaki Ishimatsu
> 
>>
>> This is the second patch set to enable support of hierarchy irqdomain
>> on x86 platforms. It depends on the first part at:
>> https://lkml.org/lkml/2014/9/11/101
>> And you may access it at:
>> https://github.com/jiangliu/linux.git irqdomain/p2v1
>>
>> And there will be a third patch set to convert IOAPIC driver to support
>> hierarchy irqdomain and clean up code.
>>
>> The first patch extends irqdomain interfaces to support hierarchy
>> irqdomain. Hope this interface could be used by other architectures too,
>> such as ARM/ARM64.
>> The second patch introduces two helper functions to support stacked
>> irq_chip.
>> Patch 3-9 implements an irqdomain to manange CPU interrupt vectors, and
>> it's the root irqdomain for x86 platforms.
>> Patch 10-13 converts Intel and AMD interrupt remapping drivers to
>> support hierarchy irqdomain.
>> Patch 14-17 converts HPET, MSI and HT_IRQ drivers to support hierarchy
>> irqdomain.
>> Patch 18-21 cleans up unsued code in x86 arch and interrupt remapping
>> drivers.
>>
>> We have tested this patchset on Intel 32-bit and 64-bit systems. But we
>> have only done compilation tests for HT_IRQ and AMD interrupt remapping
>> drivers due to hardware resource limitation. Tests on AMD platforms are
>> warmly welcomed!
>>
>> Jiang Liu (21):
>>    irqdomain: Introduce new interfaces to support hierarchy irqdomains
>>    genirq: Introduce helper functions to support stacked irq_chip
>>    x86, irq: Save destination CPU ID in irq_cfg
>>    x86, irq: Use hierarchy irqdomain to manage CPU interrupt vectors
>>    x86, hpet: Use new irqdomain interfaces to allocate/free IRQ
>>    x86, MSI: Use new irqdomain interfaces to allocate/free IRQ
>>    x86, uv: Use new irqdomain interfaces to allocate/free IRQ
>>    x86, htirq: Use new irqdomain interfaces to allocate/free IRQ
>>    x86, dmar: Use new irqdomain interfaces to allocate/free IRQ
>>    x86: irq_remapping: Introduce new interfaces to support hierarchy
>>      irqdomain
>>    iommu/vt-d: Change prototypes to prepare for enabling hierarchy
>>      irqdomain
>>    iommu/vt-d: Enhance Intel IR driver to suppport hierarchy irqdomain
>>    iommu/amd: Enhance AMD IR driver to suppport hierarchy irqdomain
>>    x86, hpet: Enhance HPET IRQ to support hierarchy irqdomain
>>    x86, MSI: Use hierarchy irqdomain to manage MSI interrupts
>>    x86, irq: Directly call native_compose_msi_msg() for DMAR IRQ
>>    x86, htirq: Use hierarchy irqdomain to manage Hypertransport
>>      interrupts
>>    iommu/vt-d: Clean up unused MSI related code
>>    iommu/amd: Clean up unused MSI related code
>>    x86: irq_remapping: Clean up unused MSI related code
>>    x86, irq: Clean up unused MSI related code and interfaces
>>
>>   arch/x86/Kconfig                     |    3 +-
>>   arch/x86/include/asm/hpet.h          |   16 +-
>>   arch/x86/include/asm/hw_irq.h        |   64 +++++
>>   arch/x86/include/asm/irq_remapping.h |   66 +++--
>>   arch/x86/include/asm/pci.h           |    5 -
>>   arch/x86/include/asm/x86_init.h      |    4 -
>>   arch/x86/kernel/apic/htirq.c         |  179 +++++++++----
>>   arch/x86/kernel/apic/io_apic.c       |    3 -
>>   arch/x86/kernel/apic/msi.c           |  430 +++++++++++++++++++++++--------
>>   arch/x86/kernel/apic/vector.c        |  158 +++++++++++-
>>   arch/x86/kernel/hpet.c               |   57 ++---
>>   arch/x86/kernel/x86_init.c           |    2 -
>>   arch/x86/platform/uv/uv_irq.c        |   27 +-
>>   drivers/iommu/amd_iommu.c            |  385 ++++++++++++++++++++++------
>>   drivers/iommu/amd_iommu_init.c       |    4 +
>>   drivers/iommu/amd_iommu_proto.h      |    9 +
>>   drivers/iommu/amd_iommu_types.h      |    5 +
>>   drivers/iommu/intel_irq_remapping.c  |  468 +++++++++++++++++++++++-----------
>>   drivers/iommu/irq_remapping.c        |  221 ++++++----------
>>   drivers/iommu/irq_remapping.h        |   22 +-
>>   drivers/pci/htirq.c                  |   48 +---
>>   include/linux/htirq.h                |   22 +-
>>   include/linux/intel-iommu.h          |    4 +
>>   include/linux/irq.h                  |    8 +
>>   include/linux/irqdomain.h            |   60 +++++
>>   kernel/irq/Kconfig                   |    3 +
>>   kernel/irq/chip.c                    |   21 ++
>>   kernel/irq/irqdomain.c               |  349 ++++++++++++++++++++++++-
>>   28 files changed, 1934 insertions(+), 709 deletions(-)
>>
> 
>