Re: [PATCH v2 0/6] Add support for the ICU unit in Marvell Armada 7K/8K

From: Gregory CLEMENT
Date: Tue Jun 06 2017 - 12:28:53 EST


Hi Thomas,

On ven., juin 02 2017, Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> wrote:

> Hello,
>
> The Marvell Armada 7K/8K SoCs are composed of two parts: the AP (which
> contains the CPU cores) and the CP (which contains most
> peripherals). The 7K SoCs have one CP, while the 8K SoCs have two CPs,
> doubling the number of available peripherals.
>
> In terms of interrupt handling, all devices in the CPs are connected
> through wired interrupt to a unit called ICU located in each CP. This
> unit converts the wired interrupts from the devices into memory
> transactions.
>
> Inside the AP, there is a GIC extension called GICP, which allows a
> memory write transaction to trigger a GIC SPI interrupt. The ICUs in
> each CP are therefore configured to trigger a memory write into the
> appropriate GICP register so that a wired interrupt from a CP device
> is converted into a memory write, itself converted into a regular GIC
> SPI interrupt.
>
> Until now, the configuration of the ICU was done statically by the
> firmware, and therefore the Device Tree files in Linux were specifying
> directly GIC interrupts for the interrupts of CP devices. However,
> with the growing number of devices in the CP, a static allocation
> scheme doesn't work for the long term.
>
> This patch series therefore makes Linux aware of the ICU: GIC SPI
> interrupts are dynamically allocated, and the ICU is configured
> accordingly to route a CP wired interrupt to the allocated GIC SPI
> interrupt.
>
> In detail:
>
> - The first two patches are the Device Tree binding patches
>
> - The third patch is a minimal driver for the GICP unit, which simply
> allows to allocate GICP interrupts.
>
> - The fourth patch is the most important done, which adds the driver
> for the ICU itself.
>
> - The fifth patch adjust Kconfig.platforms to select the GICP and ICU
> drivers.
>
> - The last patch adjusts the Device Tree files of the Armada 7K/8K to
> use the ICU.
>
> Changes since v1:
>
> - Fix the #interrupt-cells value in the ICU DT binding
> example. Pointed by Marc Zyngier.
>
> - Add details about the possible group types in the ICU DT binding
> documentation, as requested by Marc Zyngier. This allowed to
> discover that the list of types listed was not matching the macros
> provided in <dt-bindings/interrupt-controller/mvebu-icu.h>, so this
> was fixed as well.
>
> - Changed the "gicp" property of the ICU to "marvell,gicp", as
> suggested by Marc Zyngier.
>
> - Add a marvell,spi-ranges property to the gicp node, which defines
> which ranges of GIC SPI interrupts are available for us by the
> GICP.
>
> - Move more GICP logic into the gicp driver. Indeed, it was confusing
> to have in the ICU driver some global logic mixed with per-ICU
> logic: there is only one GICP per system, but one ICU per CP (so in
> an Armada 8K we have one GICP but two ICUs). So it makes more sense
> to handle the GICP aspects in one driver (which has only one
> device) and the ICU aspects in another driver (which has one device
> per ICU).
>
> - Use writel_relaxed() as suggested by Marc Zyngier.
>
> - Use irq_set_irqchip_state() in the ICU driver to clear any pending
> interrupt when allocating an interrupt. This ensures we don't get
> bothered by an interrupt left pending by the firmware. This
> replaces a more manual pending interrupt clearing done in the GICP
> driver, which wasn't suitable for edge triggered
> interrupts. Suggested by Marc Zyngier.
>
> - Use devm_kstrdup() instead of kstrdup() to fix a potential memory
> leak in the error path of ICU's ->probe() function. Noticed by Marc
> Zyngier.
>
> - Change compatible strings from "marvell,gicp" to
> "marvell,ap806-gicp" and "marvell,icu" to "marvell,cp110-icu", as
> future versions of those IP blocks may be different. Suggested by
> Yehuda Yitschak.
>
> - Use a shorter name for the irqchip domain, suggested by GrÃgory
> Clement.
>
> - Rename ICU_{SATA0,SATA1}_IRQ_INT to ICU_{SATA0,SATA1}_ICU_ID to
> clarify we're talking about ICU identifiers and not interrupt
> numbers. Suggested by Yehuda Yitschak.
>
> - Fix bogus message when checking the ICU group type, make sure the
> message says "wrong ICU group type" and not "wrong ICU
> type". Suggested by Yehuda Yitschak.
>
> - Add a check that the ICU identifier used in the DT is not higher
> than ICU_MAX_IRQS. Suggested by Yehuda Yitschak.
>
> Best regards,
>
> Thomas
>
>
> Thomas Petazzoni (6):
> dt-bindings: interrupt-controller: add DT binding for the Marvell GICP
> dt-bindings: interrupt-controller: add DT binding for the Marvell ICU
> irqchip: irq-mvebu-gicp: new driver for Marvell GICP
> irqchip: irq-mvebu-icu: new driver for Marvell ICU
> arm64: marvell: enable ICU and GICP drivers
> arm64: dts: marvell: enable GICP and ICU on Armada 7K/8K

The series looks very good now, for all the patches:
Reviewed-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>

Once the binding and the drivers will be approved I will applu patch 5
and 6 to the mvebu trees.

Thanks,

Gregory


>
> .../bindings/interrupt-controller/marvell,gicp.txt | 24 ++
> .../bindings/interrupt-controller/marvell,icu.txt | 54 ++++
> arch/arm64/Kconfig.platforms | 2 +
> arch/arm64/boot/dts/marvell/armada-ap806.dtsi | 6 +
> .../boot/dts/marvell/armada-cp110-master.dtsi | 60 ++--
> .../arm64/boot/dts/marvell/armada-cp110-slave.dtsi | 54 ++--
> drivers/irqchip/Kconfig | 6 +
> drivers/irqchip/Makefile | 2 +
> drivers/irqchip/irq-mvebu-gicp.c | 170 ++++++++++
> drivers/irqchip/irq-mvebu-gicp.h | 15 +
> drivers/irqchip/irq-mvebu-icu.c | 346 +++++++++++++++++++++
> .../dt-bindings/interrupt-controller/mvebu-icu.h | 15 +
> 12 files changed, 706 insertions(+), 48 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/interrupt-controller/marvell,gicp.txt
> create mode 100644 Documentation/devicetree/bindings/interrupt-controller/marvell,icu.txt
> create mode 100644 drivers/irqchip/irq-mvebu-gicp.c
> create mode 100644 drivers/irqchip/irq-mvebu-gicp.h
> create mode 100644 drivers/irqchip/irq-mvebu-icu.c
> create mode 100644 include/dt-bindings/interrupt-controller/mvebu-icu.h
>
> --
> 2.7.4
>

--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com