Re: [PATCH] irqchip/gic-v3: Support MSIs via aliases and distributor

From: Rob Herring
Date: Tue Nov 28 2017 - 09:05:03 EST


On Mon, Nov 27, 2017 at 02:24:08AM -0800, Stephen Boyd wrote:
> Some GIC configurations don't have an accessible ITS, but they
> want to support MSIs through the distributor's SETSPI registers
> or through the IMPLEMENTATION DEFINED message-based interrupt
> request register region. This mode of operation is similar to the
> v2m support on gic-400, but we don't necessarily know what
> particular SPIs are supported as MSIs so we need some help from
> firmware to know what to do.
>
> Introduce an "arm,spi-ranges" property for this, similar to the
> "marvell,spi-ranges" property, that indicates the base and size
> of each MSI range. This property applies equally to the
> distributor and alias registers. In either case, we detect this
> mode of operation by looking for a node with the "msi-controller"
> property and then probe the v2m frame code on top of it. Assume
> these nodes will have the "arm,spi-ranges" property in them so
> that the v2m code works mostly unmodified.
>
> Cc: <devicetree@xxxxxxxxxxxxxxx>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> ---
> .../bindings/interrupt-controller/arm,gic-v3.txt | 48 +++++++++-

Acked-by: Rob Herring <robh@xxxxxxxxxx>

> drivers/irqchip/irq-gic-v2m.c | 102 ++++++++++++++++-----
> drivers/irqchip/irq-gic-v3.c | 4 +
> include/linux/irqchip/arm-gic-common.h | 3 +
> 4 files changed, 129 insertions(+), 28 deletions(-)