RE: [PATCH v5 2/5] irqchip/irq-goldfish-pic: Add Goldfish PIC driver
From: Miodrag Dinic
Date: Mon Oct 23 2017 - 11:04:52 EST
Hi Marc,
> > +static irqreturn_t goldfish_pic_cascade(int irq, void *data)
> > +{
> > + struct goldfish_pic_data *gfpic = irq_get_handler_data(irq);
> > + u32 hwirq;
> > + u32 virq;
> > +
> > + hwirq = readl(gfpic->base + GFPIC_REG_IRQ_PENDING);
> > +
> > + virq = irq_linear_revmap(gfpic->irq_domain, hwirq);
> > + generic_handle_irq(virq);
> > +
> > + return IRQ_HANDLED;
> > +}
>
> This is not how we implement cascaded (chained) interrupt
> controllers. See existing examples everywhere in the irqchip directory.
It will be addressed in V6.
Thank you.
Kind regards,
Miodrag
________________________________________
From: Marc Zyngier [marc.zyngier@xxxxxxx]
Sent: Monday, October 23, 2017 10:20 AM
To: Aleksandar Markovic
Cc: linux-mips@xxxxxxxxxxxxxx; Miodrag Dinic; Goran Ferenc; Aleksandar Markovic; David S. Miller; Douglas Leung; Greg Kroah-Hartman; James Hogan; Jason Cooper; linux-kernel@xxxxxxxxxxxxxxx; Mauro Carvalho Chehab; Paul Burton; Petar Jovanovic; Raghu Gandham; Randy Dunlap; Thomas Gleixner
Subject: Re: [PATCH v5 2/5] irqchip/irq-goldfish-pic: Add Goldfish PIC driver
On Fri, Oct 20 2017 at 4:33:35 pm BST, Aleksandar Markovic <aleksandar.markovic@xxxxxxxxx> wrote:
> From: Miodrag Dinic <miodrag.dinic@xxxxxxxx>
>
> Add device driver for a virtual programmable interrupt controller
>
> The virtual PIC is designed as a device tree-based interrupt controller.
>
> The compatible string used by OS for binding the driver is
> "google,goldfish-pic".
>
> Signed-off-by: Miodrag Dinic <miodrag.dinic@xxxxxxxx>
> Signed-off-by: Goran Ferenc <goran.ferenc@xxxxxxxx>
> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@xxxxxxxx>
> ---
> MAINTAINERS | 1 +
> drivers/irqchip/Kconfig | 8 +++
> drivers/irqchip/Makefile | 1 +
> drivers/irqchip/irq-goldfish-pic.c | 131 +++++++++++++++++++++++++++++++++++++
> 4 files changed, 141 insertions(+)
> create mode 100644 drivers/irqchip/irq-goldfish-pic.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4d5108f..f1be016 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -876,6 +876,7 @@ ANDROID GOLDFISH PIC DRIVER
> M: Miodrag Dinic <miodrag.dinic@xxxxxxxx>
> S: Supported
> F: Documentation/devicetree/bindings/interrupt-controller/google,goldfish-pic.txt
> +F: drivers/irqchip/irq-goldfish-pic.c
>
> ANDROID GOLDFISH RTC DRIVER
> M: Miodrag Dinic <miodrag.dinic@xxxxxxxx>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 9d8a1dd..712b561 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -321,3 +321,11 @@ config IRQ_UNIPHIER_AIDET
> select IRQ_DOMAIN_HIERARCHY
> help
> Support for the UniPhier AIDET (ARM Interrupt Detector).
> +
> +config GOLDFISH_PIC
> + bool "Goldfish programmable interrupt controller"
> + depends on MIPS && (GOLDFISH || COMPILE_TEST)
> + select IRQ_DOMAIN
> + help
> + Say yes here to enable Goldfish interrupt controller driver used
> + for Goldfish based virtual platforms.
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 845abc1..0e7a224 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -79,3 +79,4 @@ obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o
> obj-$(CONFIG_STM32_EXTI) += irq-stm32-exti.o
> obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.o
> obj-$(CONFIG_IRQ_UNIPHIER_AIDET) += irq-uniphier-aidet.o
> +obj-$(CONFIG_GOLDFISH_PIC) += irq-goldfish-pic.o
> diff --git a/drivers/irqchip/irq-goldfish-pic.c b/drivers/irqchip/irq-goldfish-pic.c
> new file mode 100644
> index 0000000..d8b5277
> --- /dev/null
> +++ b/drivers/irqchip/irq-goldfish-pic.c
> @@ -0,0 +1,131 @@
> +/*
> + * Copyright (C) 2017 Imagination Technologies Ltd. All rights reserved
> + * Author: Miodrag Dinic <miodrag.dinic@xxxxxxxxxx>
> + *
> + * This file implements interrupt controller driver for MIPS Goldfish PIC.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2 of the License, or (at your
> + * option) any later version.
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqdomain.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +
> +#define GFPIC_NR_IRQS 32
> +
> +/* 8..39 Cascaded Goldfish PIC interrupts */
> +#define GFPIC_IRQ_BASE 8
> +
> +#define GFPIC_REG_IRQ_PENDING 0x04
> +#define GFPIC_REG_IRQ_DISABLE_ALL 0x08
> +#define GFPIC_REG_IRQ_DISABLE 0x0c
> +#define GFPIC_REG_IRQ_ENABLE 0x10
> +
> +struct goldfish_pic_data {
> + void __iomem *base;
> + struct irq_domain *irq_domain;
> +};
> +
> +static irqreturn_t goldfish_pic_cascade(int irq, void *data)
> +{
> + struct goldfish_pic_data *gfpic = irq_get_handler_data(irq);
> + u32 hwirq;
> + u32 virq;
> +
> + hwirq = readl(gfpic->base + GFPIC_REG_IRQ_PENDING);
> +
> + virq = irq_linear_revmap(gfpic->irq_domain, hwirq);
> + generic_handle_irq(virq);
> +
> + return IRQ_HANDLED;
> +}
This is not how we implement cascaded (chained) interrupt
controllers. See existing examples everywhere in the irqchip directory.
> +
> +static const struct irq_domain_ops goldfish_irq_domain_ops = {
> + .xlate = irq_domain_xlate_onecell,
> +};
> +
> +static struct irqaction cascade = {
> + .handler = goldfish_pic_cascade,
> + .name = "Goldfish PIC cascade",
> +};
> +
> +static int __init goldfish_pic_of_init(struct device_node *of_node,
> + struct device_node *parent)
> +{
> + struct goldfish_pic_data *gfpic;
> + struct irq_chip_generic *gc;
> + struct irq_chip_type *ct;
> + unsigned int parent_irq;
> + int ret = 0;
> +
> + gfpic = kzalloc(sizeof(*gfpic), GFP_KERNEL);
> + if (!gfpic) {
> + ret = -ENOMEM;
> + goto out_err;
> + }
> +
> + parent_irq = irq_of_parse_and_map(of_node, 0);
> + if (!parent_irq) {
> + pr_err("Failed to map Goldfish PIC parent IRQ\n");
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + ret = irq_set_handler_data(parent_irq, gfpic);
> + if (ret)
> + goto out_unmap_irq;
> +
> + gfpic->base = of_iomap(of_node, 0);
> + if (!gfpic->base) {
> + pr_err("Failed to map Goldfish PIC base\n");
> + ret = -ENOMEM;
> + goto out_unmap_irq;
> + }
> +
> + /* Mask interrupts. */
> + writel(1, gfpic->base + GFPIC_REG_IRQ_DISABLE_ALL);
> +
> + gc = irq_alloc_generic_chip("GFPIC", 1, GFPIC_IRQ_BASE, gfpic->base,
> + handle_level_irq);
> +
> + ct = gc->chip_types;
> + ct->regs.enable = GFPIC_REG_IRQ_ENABLE;
> + ct->regs.disable = GFPIC_REG_IRQ_DISABLE;
> + ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
> + ct->chip.irq_mask = irq_gc_mask_disable_reg;
> +
> + irq_setup_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS), 0, 0,
> + IRQ_NOPROBE | IRQ_LEVEL);
> +
> + gfpic->irq_domain = irq_domain_add_legacy(of_node, GFPIC_NR_IRQS,
> + GFPIC_IRQ_BASE, 0,
> + &goldfish_irq_domain_ops,
> + NULL);
> + if (!gfpic->irq_domain) {
> + pr_err("Failed to add irqdomain for Goldfish PIC\n");
> + ret = -EINVAL;
> + goto out_iounmap;
> + }
> +
> + setup_irq(parent_irq, &cascade);
> +
> + pr_info("Successfully registered Goldfish PIC\n");
> + return 0;
> +
> +out_iounmap:
> + iounmap(gfpic->base);
> +out_unmap_irq:
> + irq_dispose_mapping(parent_irq);
> +out_free:
> + kfree(gfpic);
> +out_err:
> + return ret;
> +}
> +
> +IRQCHIP_DECLARE(google_gf_pic, "google,goldfish-pic", goldfish_pic_of_init);
It otherwise looks much better than the previous versions.
Thanks,
M.
--
Jazz is not dead. It just smells funny.