[PATCH v3 00/13] arm64: PCI/MSI: GICv3 ITS support (stacked domain edition)

Marc Zyngier marc.zyngier at arm.com
Mon Nov 24 06:35:07 PST 2014

The GICv3 architecture provides a way to implement support for
MSI/MSI-X using a specific block called the ITS (Interrupt Translation

The ITS can be accurately described as "page tables for
interrupts". If you think this sounds scary, you're spot on. It uses a
set of opaque memory tables that are manipulated through commands
(software almost never touches the tables directly). In order to make
it slightly easier to digest, the code has been split into (mostly)
logical units.

To make things more fun, this relies on Jiang Liu's stacked domain
patch series as now merged in tip/irq/irqdomain:

- patch 1 imports the new asm-generic/msi.h file into arch/arm64
- patches 2 to 13 are the bulk of the ITS driver.

This has been tested on arm64 with an FVP model, and is based on
tip/irq/irqdomain. The whole thing is available at:

git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git irq/gicv3-its

Unless someone screams murder, I consider this to be ready for merge.


>From v2 [2]:
- rebased on top of the stable version of tip/irq/irqdomain
- use irq_domain_reset_irq_data instead of
  irq_domain_set_hwirq_and_chip on the free path
- use pci_msi_mask_irq instead of mask_msi_irq
- use host_data to pass the ITS structure around
- top-level MSI domain is now indentified by the ITS of_node

>From v1 [1]:
- rebased on top of tip/irq/irqdomain
- dropped the arm64-specific implementation of arch_setup_msi_irqs and co.
- reworked the whole ITS/MSI setup to use the new MSI/PCI split

[1]: http://lwn.net/Articles/619788/
[2]: https://lkml.org/lkml/2014/11/18/825

Marc Zyngier (13):
  arm64: PCI/MSI: Use asm-generic/msi.h
  irqchip: GICv3: Convert to domain hierarchy
  irqchip: GICv3: rework redistributor structure
  irqchip: GICv3: ITS command queue
  irqchip: GICv3: ITS: irqchip implementation
  irqchip: GICv3: ITS: LPI allocator
  irqchip: GICv3: ITS: tables allocators
  irqchip: GICv3: ITS: device allocation and configuration
  irqchip: GICv3: ITS: MSI support
  irqchip: GICv3: ITS: DT probing and initialization
  irqchip: GICv3: ITS: plug ITS init into main GICv3 code
  irqchip: GICv3: ITS: enable compilation of the ITS driver
  irqchip: GICv3: Binding updates for ITS

 Documentation/devicetree/bindings/arm/gic-v3.txt |   39 +
 arch/arm64/Kconfig                               |    1 +
 arch/arm64/include/asm/Kbuild                    |    1 +
 drivers/irqchip/Kconfig                          |    5 +
 drivers/irqchip/Makefile                         |    1 +
 drivers/irqchip/irq-gic-v3-its.c                 | 1402 ++++++++++++++++++++++
 drivers/irqchip/irq-gic-v3.c                     |  156 ++-
 include/linux/irqchip/arm-gic-v3.h               |  128 ++
 8 files changed, 1693 insertions(+), 40 deletions(-)
 create mode 100644 drivers/irqchip/irq-gic-v3-its.c


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