[PATCH v3 00/15] Introducing per-device MSI domain

[Marc Zyngier]

[Picking up this series again after sleeping on it for too long,
 hopefully still relevant]

MSI-like interrupts are starting to creep out of the PCI world, and
can now be seen into a number of "platform"-type busses. The
introduction of the MSI domains feature in v3.19 recognised that fact,
and started providing a way to implement this.

Another problem we have to solve is to identify which MSI domain a
device is "connected" to. Currently, PCI gets away with a mixture of
arch-specific callbacks, and a msi_controller structure that can
optionally carry a pointer to an MSI domain. As we add new bus types
and start dealing with topologies that do not map to what PCI does,
this doesn't scale anymore.

This patch series tries to address some of it by providing a basic
link between 'struct device' and an MSI domain. It also adds :

- a way to "tag" domains according to the "type" of interrupt it
  provides (PCI/MSI, platform MSI...), allowing a driver for a piece
  of HW identified by its device_node to provide several IRQ domains

- (yet another) way for PCI to propagate the domain pointer through
  the PCI device hierarchy, providing a method for OF to kick-start
  the propagation process, and finally allowing the PCI/MSI layer to
  use that information

- a similar way to hook an MSI domain to a platform device.

Hopefully this can serve as a model to implement support for different
but types.

Additionally, the last few patches use all the above to remove any
trace of the msi_controller structure from the three MSI controllers
we use on arm64, so that they solely rely on the above infrastructure,
leading to some interesting improvements. We take this opportunity to
also kill the domain pointer from the msi_controller structure.

My hope is to eventually kill msi_controller entirely, and only rely
on the msi_domain contained in the device structure (any help
welcomed).

This has been tested on arm64 with GICv2m (AMD Seattle) and GICv3 ITS
(FVP model).

Patches are on top of 4.2-rc1 and available at:

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

As always, comments most welcome.

Marc Zyngier (15):
  genirq: irqdomain: Allow irq domain aliasing
  PCI: MSI: Register irq domain with specific token
  device core: Introduce per-device MSI domain pointer
  PCI/MSI: Add hooks to populate the msi_domain field
  PCI/MSI: of: Add support for OF-provided msi_domain
  PCI/MSI: of: Allow msi_domain lookup using the host bridge node
  PCI/MSI: Let pci_msi_get_domain use struct device's msi_domain
  platform: of: Assign MSI domain to platform device
  irqchip: gicv3-its: Split PCI/MSI code from the core ITS driver
  irqchip: gicv3-its: Register irq domain with platform MSI token
  irqchip: GICv2m: Get rid of struct msi_controller
  irqchip: gicv3-its: Get rid of struct msi_controller
  irqchip: gicv3-its: Make the PCI/MSI code standalone
  PCI/MSI: pci-xgene-msi: Get rid of struct msi_controller
  PCI/MSI: Drop domain field from msi_controller

 arch/powerpc/platforms/512x/mpc5121_ads_cpld.c   |   3 +-
 arch/powerpc/platforms/cell/interrupt.c          |   3 +-
 arch/powerpc/platforms/embedded6xx/flipper-pic.c |   3 +-
 arch/powerpc/platforms/powermac/pic.c            |   3 +-
 arch/powerpc/platforms/powernv/opal-irqchip.c    |   3 +-
 arch/powerpc/platforms/ps3/interrupt.c           |   3 +-
 arch/powerpc/sysdev/ehv_pic.c                    |   3 +-
 arch/powerpc/sysdev/i8259.c                      |   3 +-
 arch/powerpc/sysdev/ipic.c                       |   3 +-
 arch/powerpc/sysdev/mpic.c                       |   3 +-
 arch/powerpc/sysdev/qe_lib/qe_ic.c               |   3 +-
 arch/powerpc/sysdev/xics/xics-common.c           |   3 +-
 drivers/irqchip/Makefile                         |   2 +-
 drivers/irqchip/irq-gic-v2m.c                    |  27 ++---
 drivers/irqchip/irq-gic-v3-its-pci-msi.c         | 135 +++++++++++++++++++++++
 drivers/irqchip/irq-gic-v3-its.c                 | 130 ++++------------------
 drivers/of/irq.c                                 |  16 +++
 drivers/of/platform.c                            |   1 +
 drivers/pci/host/pci-xgene-msi.c                 |  41 +++----
 drivers/pci/msi.c                                |  11 +-
 drivers/pci/of.c                                 |  24 ++++
 drivers/pci/probe.c                              |  31 ++++++
 include/linux/device.h                           |  20 ++++
 include/linux/irqchip/arm-gic-v3.h               |   3 +
 include/linux/irqdomain.h                        |  25 ++++-
 include/linux/msi.h                              |   3 -
 include/linux/of_irq.h                           |   1 +
 include/linux/pci.h                              |   3 +
 kernel/irq/irqdomain.c                           |  18 ++-
 29 files changed, 350 insertions(+), 177 deletions(-)
 create mode 100644 drivers/irqchip/irq-gic-v3-its-pci-msi.c

-- 
2.1.4

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