[PATCH v2 0/8] Introducing per-device MSI domain

From: Marc Zyngier
Date: Thu Jan 08 2015 - 12:06:24 EST


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 MSI
domain patches recognise that fact, and start 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 (yet
another) way for PCI to propagate the domain pointer through the PCI
device hierarchy, provides a method for OF to kick-start the
propagation process, and finally allows the PCI/MSI layer to use that
information. Hopefully this can serve as a model to implement support
for different but types.

Additionally, the last three patches use all the above to remove any
trace of the msi_controller structure from the two GIC interrupt
controllers we use on arm64, so that they solely rely on the above
infrastructure. 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 3.19-rc3 and available at:

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

As always, comments most welcome.

M.

>From v1:

- Allow arch code to set the MSI domain before we try to do so in core
code (which is used as a fallback).
- Allow the MSI domain to be looked-up by using the PHB node.
- Remove domain field from msi_controller

[1] https://lkml.org/lkml/2014/12/8/581

Marc Zyngier (8):
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 PHB node
PCI/MSI: Let pci_msi_get_domain use struct device's msi_domain
irqchip: GICv2m: Get rid of struct msi_controller
irqchip: gicv3-its: Get rid of struct msi_controller
PCI/MSI: Drop domain field from msi_controller

drivers/irqchip/irq-gic-v2m.c | 26 +++++++++-----------------
drivers/irqchip/irq-gic-v3-its.c | 33 ++++++++++++++-------------------
drivers/pci/msi.c | 3 +--
drivers/pci/of.c | 20 ++++++++++++++++++++
drivers/pci/probe.c | 31 +++++++++++++++++++++++++++++++
include/linux/device.h | 20 ++++++++++++++++++++
include/linux/msi.h | 3 ---
include/linux/pci.h | 3 +++
8 files changed, 98 insertions(+), 41 deletions(-)

--
2.1.4

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