Date: Mon, 18 Sep 2017 15:43:39 -0500
From: Rob Herring <robh@kernel.org>
To: Stafford Horne <shorne@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Openrisc <openrisc@lists.librecores.org>,
        Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
        Thomas Gleixner <tglx@linutronix.de>,
        Jason Cooper <jason@lakedaemon.net>,
        Marc Zyngier <marc.zyngier@arm.com>,
        Mark Rutland <mark.rutland@arm.com>, Jonas Bonn <jonas@southpole.se>,
        devicetree@vger.kernel.org
Subject: Re: [PATCH v2 06/14] irqchip: add initial support for ompic
Message-ID: <20170918204339.gvfenavdi4frdnqe@rob-hp-laptop>
References: <20170910064926.5874-1-shorne@gmail.com>
 <20170910064926.5874-7-shorne@gmail.com>
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On Sun, Sep 10, 2017 at 03:49:18PM +0900, Stafford Horne wrote:
> From: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
> 
> IPI driver for the Open Multi-Processor Interrupt Controller (ompic) as
> described in the Multicore support section of the OpenRISC 1.2
> proposed architecture specification:
> 
>   https://github.com/stffrdhrn/doc/raw/arch-1.2-proposal/openrisc-arch-1.2-rev0.pdf
> 
> Each OpenRISC core contains a full interrupt controller which is used in
> the SMP architecture for interrupt balancing.  This IPI device, the
> ompic, is the only external device required for enabling SMP on
> OpenRISC.
> 
> Pending ops are stored in a memory bit mask which can allow multiple
> pending operations to be set and serviced at a time. This is mostly
> borrowed from the alpha IPI implementation.
> 
> Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
> [shorne@gmail.com: converted ops to bitmask, wrote commit message]
> Signed-off-by: Stafford Horne <shorne@gmail.com>
> ---
> 
> Changes since v1
>  - Added openrisc, prefix
>  - Clarified 8 bytes per cpu
>  - Removed #interrupt-cells as this will not be an irq parent

You should still have #interrupt-cells as that is required with 
"interrupt-controller". It could be 0 though.

>  - Changed ops to be percpu
>  - Added DTS and intialization failure validations
> 
>  .../interrupt-controller/openrisc,ompic.txt        |  19 ++
>  arch/openrisc/Kconfig                              |   1 +
>  drivers/irqchip/Kconfig                            |   3 +
>  drivers/irqchip/Makefile                           |   1 +
>  drivers/irqchip/irq-ompic.c                        | 205 +++++++++++++++++++++
>  5 files changed, 229 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/openrisc,ompic.txt
>  create mode 100644 drivers/irqchip/irq-ompic.c
> 
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/openrisc,ompic.txt b/Documentation/devicetree/bindings/interrupt-controller/openrisc,ompic.txt
> new file mode 100644
> index 000000000000..346e6042d62f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/openrisc,ompic.txt
> @@ -0,0 +1,19 @@
> +Open Multi-Processor Interrupt Controller
> +
> +Required properties:
> +
> +- compatible : This should be "openrisc,ompic"
> +- reg : Specifies base physical address and size of the register space. The
> +  size is based on the number of cores the controller has been configured
> +  to handle, this should be set to 8 bytes per cpu core.
> +- interrupt-controller : Identifies the node as an interrupt controller
> +- interrupts : Specifies the interrupt line to which the ompic is wired.
> +
> +Example:
> +
> +ompic: ompic {

interrupt-controller@98000000 {

> +	compatible = "openrisc,ompic";
> +	reg = <0x98000000 16>;
> +	interrupt-controller;
> +	interrupts = <1>;
> +};