Date:   Sun, 16 Sep 2018 20:07:55 +0100
From:   Marc Zyngier <marc.zyngier@....com>
To:     Guo Ren <ren_guo@...ky.com>
Cc:     <tglx@...utronix.de>, <jason@...edaemon.net>, <robh+dt@...nel.org>,
        <mark.rutland@....com>, <linux-kernel@...r.kernel.org>,
        <devicetree@...r.kernel.org>
Subject: Re: [PATCH V5 1/3] irqchip: add C-SKY irqchip drivers

On Sun, 16 Sep 2018 09:50:02 +0100,
Guo Ren <ren_guo@...ky.com> wrote:
> 
> This patch add C-SKY two interrupt conrollers.
> 
>  - irq-csky-apb-intc is a simple SOC interrupt controller which is
>    used in a lot of C-SKY SOC products.
> 
>  - irq-csky-mpintc is C-SKY smp system interrupt controller and it
>    could support 16 soft irqs, 16 private irqs, and 992 max common
>    irqs.
> 
> Changelog:
>  - add support-pulse-signal in irq-csky-apb-intc.c
>  - change name with upstream feed-back
>  - remove CSKY_VECIRQ_LEGENCY
>  - change irq map, reserve soft_irq & private_irq space
>  - add License and Copyright
>  - change to generic irq chip framework
>  - support set_affinity for irq balance in SMP
>  - add INTC_IFR to clear irq-pending
>  - use irq_domain_add_linear instead of leagcy
> 
> Signed-off-by: Guo Ren <ren_guo@...ky.com>
> ---
>  drivers/irqchip/Kconfig           |  16 +++
>  drivers/irqchip/Makefile          |   2 +
>  drivers/irqchip/irq-csky-mpintc.c | 191 ++++++++++++++++++++++++++++
>  irq-csky-apb-intc.c               | 260 ++++++++++++++++++++++++++++++++++++++
>  4 files changed, 469 insertions(+)
>  create mode 100644 drivers/irqchip/irq-csky-mpintc.c
>  create mode 100644 irq-csky-apb-intc.c
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 383e7b7..bf12549 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -371,6 +371,22 @@ config QCOM_PDC
>  	  Power Domain Controller driver to manage and configure wakeup
>  	  IRQs for Qualcomm Technologies Inc (QTI) mobile chips.
>  
> +config CSKY_MPINTC
> +	bool "C-SKY Multi Processor Interrupt Controller"
> +	depends on CSKY
> +	help
> +	  Say yes here to enable C-SKY SMP interrupt controller driver used
> +	  for C-SKY SMP system. In fact it's not mmio map and it use ld/st
> +	  to visit the controller's register inside CPU.
> +
> +config CSKY_APB_INTC
> +	bool "C-SKY APB Interrupt Controller"
> +	depends on CSKY
> +	help
> +	  Say yes here to enable C-SKY APB interrupt controller driver used
> +	  by C-SKY single core SOC system. It use mmio map apb-bus to visit
> +	  the controller's register.
> +
>  endmenu
>  
>  config SIFIVE_PLIC
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index fbd1ec8..72eaf53 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -87,4 +87,6 @@ obj-$(CONFIG_MESON_IRQ_GPIO)		+= irq-meson-gpio.o
>  obj-$(CONFIG_GOLDFISH_PIC) 		+= irq-goldfish-pic.o
>  obj-$(CONFIG_NDS32)			+= irq-ativic32.o
>  obj-$(CONFIG_QCOM_PDC)			+= qcom-pdc.o
> +obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
> +obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
> diff --git a/drivers/irqchip/irq-csky-mpintc.c b/drivers/irqchip/irq-csky-mpintc.c
> new file mode 100644
> index 0000000..2b2f75c
> --- /dev/null
> +++ b/drivers/irqchip/irq-csky-mpintc.c
> @@ -0,0 +1,191 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
> +
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/module.h>
> +#include <linux/irqdomain.h>
> +#include <linux/irqchip.h>
> +#include <linux/irq.h>
> +#include <linux/interrupt.h>
> +#include <asm/irq.h>
> +#include <asm/io.h>
> +#include <asm/traps.h>
> +#include <asm/reg_ops.h>
> +#include <asm/smp.h>
> +
> +static void __iomem *INTCG_base;
> +static void __iomem *INTCL_base;
> +
> +#define COMM_IRQ_BASE	32
> +
> +#define INTCG_SIZE	0x8000
> +#define INTCL_SIZE	0x1000
> +#define INTC_SIZE	INTCL_SIZE*nr_cpu_ids + INTCG_SIZE
> +
> +#define INTCG_ICTLR	0x0
> +#define INTCG_CICFGR	0x100
> +#define INTCG_CIDSTR	0x1000
> +
> +#define INTCL_PICTLR	0x0
> +#define INTCL_SIGR	0x60
> +#define INTCL_HPPIR	0x68
> +#define INTCL_RDYIR	0x6c
> +#define INTCL_SENR	0xa0
> +#define INTCL_CENR	0xa4
> +#define INTCL_CACR	0xb4
> +
> +#define INTC_IRQS	256
> +
> +static DEFINE_PER_CPU(void __iomem *, intcl_reg);
> +
> +static void csky_mpintc_handler(struct pt_regs *regs)
> +{
> +	void __iomem *reg_base = this_cpu_read(intcl_reg);
> +
> +	do {
> +		handle_domain_irq(NULL,

It is definitely odd to call into handle_domain_irq without a
domain. A new architecture (which C-SKY apparently is) shouldn't
depend on this, and should always provide a domain.

> +				  readl_relaxed(reg_base + INTCL_RDYIR),
> +				  regs);
> +	} while (readl_relaxed(reg_base + INTCL_HPPIR) & BIT(31));
> +}
> +
> +static void csky_mpintc_enable(struct irq_data *d)
> +{
> +	void __iomem *reg_base = this_cpu_read(intcl_reg);
> +
> +	writel_relaxed(d->hwirq, reg_base + INTCL_SENR);
> +}
> +
> +static void csky_mpintc_disable(struct irq_data *d)
> +{
> +	void __iomem *reg_base = this_cpu_read(intcl_reg);
> +
> +	writel_relaxed(d->hwirq, reg_base + INTCL_CENR);
> +}
> +
> +static void csky_mpintc_eoi(struct irq_data *d)
> +{
> +	void __iomem *reg_base = this_cpu_read(intcl_reg);
> +
> +	writel_relaxed(d->hwirq, reg_base + INTCL_CACR);
> +}
> +
> +#ifdef CONFIG_SMP
> +static int csky_irq_set_affinity(struct irq_data *d,
> +				 const struct cpumask *mask_val,
> +				 bool force)
> +{
> +	unsigned int cpu;
> +	unsigned int offset = 4 * (d->hwirq - COMM_IRQ_BASE);
> +
> +	if (!force)
> +		cpu = cpumask_any_and(mask_val, cpu_online_mask);
> +	else
> +		cpu = cpumask_first(mask_val);
> +
> +	if (cpu >= nr_cpu_ids)
> +		return -EINVAL;
> +
> +	/* Enable interrupt destination */
> +	cpu |= BIT(31);
> +
> +	writel_relaxed(cpu, INTCG_base + INTCG_CIDSTR + offset);
> +
> +	irq_data_update_effective_affinity(d, cpumask_of(cpu));
> +
> +	return IRQ_SET_MASK_OK_DONE;
> +}
> +#endif
> +
> +static struct irq_chip csky_irq_chip = {
> +	.name           = "C-SKY SMP Intc V2",
> +	.irq_eoi	= csky_mpintc_eoi,
> +	.irq_enable	= csky_mpintc_enable,
> +	.irq_disable	= csky_mpintc_disable,
> +#ifdef CONFIG_SMP
> +	.irq_set_affinity = csky_irq_set_affinity,
> +#endif
> +};
> +
> +static int csky_irqdomain_map(struct irq_domain *d, unsigned int irq,
> +			      irq_hw_number_t hwirq)
> +{
> +	if(hwirq < COMM_IRQ_BASE) {
> +		irq_set_percpu_devid(irq);
> +		irq_set_chip_and_handler(irq, &csky_irq_chip, handle_percpu_irq);
> +	} else {
> +		irq_set_chip_and_handler(irq, &csky_irq_chip, handle_fasteoi_irq);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct irq_domain_ops csky_irqdomain_ops = {
> +	.map	= csky_irqdomain_map,
> +	.xlate	= irq_domain_xlate_onecell,
> +};
> +
> +#ifdef CONFIG_SMP
> +static void csky_mpintc_send_ipi(const unsigned long *mask, unsigned long irq)
> +{
> +	void __iomem *reg_base = this_cpu_read(intcl_reg);
> +
> +	/*
> +	 * INTCL_SIGR[3:0] INTID
> +	 * INTCL_SIGR[8:15] CPUMASK
> +	 */
> +	writel_relaxed((*mask) << 8 | irq, reg_base + INTCL_SIGR);
> +}
> +#endif
> +
> +/* C-SKY multi processor interrupt controller */
> +static int __init
> +csky_mpintc_init(struct device_node *node, struct device_node *parent)
> +{
> +	struct irq_domain *root_domain;
> +	unsigned int cpu, nr_irq;
> +	int ret;
> +
> +	if (parent)
> +		return 0;
> +
> +	ret = of_property_read_u32(node, "csky,num-irqs", &nr_irq);
> +	if (ret < 0) {
> +		nr_irq = INTC_IRQS;
> +	}

Drop the extra braces.

> +
> +	if (INTCG_base == NULL) {
> +		INTCG_base = ioremap(mfcr("cr<31, 14>"), INTC_SIZE);
> +		if (INTCG_base == NULL)
> +			return -EIO;
> +
> +		INTCL_base = INTCG_base + INTCG_SIZE;
> +
> +		writel_relaxed(BIT(0), INTCG_base + INTCG_ICTLR);
> +	}
> +
> +	root_domain = irq_domain_add_linear(node, nr_irq, &csky_irqdomain_ops,
> +					    NULL);
> +	if (!root_domain)
> +		return -ENXIO;
> +
> +	irq_set_default_host(root_domain);

Please drop this. There is no reason to use this on any modern, DT
based architecture.

> +
> +	/* for every cpu */
> +	for_each_present_cpu(cpu) {
> +		per_cpu(intcl_reg, cpu) = INTCL_base + (INTCL_SIZE * cpu);
> +		writel_relaxed(BIT(0), per_cpu(intcl_reg, cpu) + INTCL_PICTLR);
> +	}
> +
> +	set_handle_irq(&csky_mpintc_handler);
> +
> +#ifdef CONFIG_SMP
> +	set_send_ipi(&csky_mpintc_send_ipi);
> +#endif
> +
> +	return 0;
> +}
> +IRQCHIP_DECLARE(csky_mpintc, "csky,mpintc", csky_mpintc_init);
> diff --git a/irq-csky-apb-intc.c b/irq-csky-apb-intc.c
> new file mode 100644
> index 0000000..d56e6b5
> --- /dev/null
> +++ b/irq-csky-apb-intc.c

This is a separate driver, right? Please make it a separate patch.

> @@ -0,0 +1,260 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
> +
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/module.h>
> +#include <linux/irqdomain.h>
> +#include <linux/irqchip.h>
> +#include <linux/irq.h>
> +#include <linux/interrupt.h>
> +#include <asm/irq.h>
> +#include <asm/io.h>
> +
> +#define INTC_IRQS		64
> +
> +#define CK_INTC_ICR		0x00
> +#define CK_INTC_PEN31_00	0x14
> +#define CK_INTC_PEN63_32	0x2c
> +#define CK_INTC_NEN31_00	0x10
> +#define CK_INTC_NEN63_32	0x28
> +#define CK_INTC_SOURCE		0x40
> +#define CK_INTC_DUAL_BASE	0x100
> +
> +#define GX_INTC_PEN31_00	0x00
> +#define GX_INTC_PEN63_32	0x04
> +#define GX_INTC_NEN31_00	0x40
> +#define GX_INTC_NEN63_32	0x44
> +#define GX_INTC_NMASK31_00	0x50
> +#define GX_INTC_NMASK63_32	0x54
> +#define GX_INTC_SOURCE		0x60
> +
> +static void __iomem *reg_base;
> +static struct irq_domain *root_domain;
> +
> +static int nr_irq = INTC_IRQS;
> +
> +/*
> + * When controller support pulse signal, the PEN_reg will hold on signal
> + * without software trigger.
> + *
> + * So, to support pulse signal we need to clear IFR_reg and the address of
> + * IFR_offset is NEN_offset - 8.
> + */
> +static void irq_ck_mask_set_bit(struct irq_data *d)
> +{
> +	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +	struct irq_chip_type *ct = irq_data_get_chip_type(d);
> +	unsigned long ifr = ct->regs.mask - 8;
> +	u32 mask = d->mask;
> +
> +	irq_gc_lock(gc);
> +	*ct->mask_cache |= mask;
> +	irq_reg_writel(gc, *ct->mask_cache, ct->regs.mask);
> +	irq_reg_writel(gc, irq_reg_readl(gc, ifr) & ~mask, ifr);
> +	irq_gc_unlock(gc);
> +}
> +
> +static void __init ck_set_gc(struct device_node *node, void __iomem *reg_base,
> +			     u32 mask_reg, u32 irq_base)
> +{
> +	struct irq_chip_generic *gc;
> +
> +	gc = irq_get_domain_generic_chip(root_domain, irq_base);
> +	gc->reg_base = reg_base;
> +	gc->chip_types[0].regs.mask = mask_reg;
> +	gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
> +	gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
> +
> +	if (of_find_property(node, "support-pulse-signal", NULL))
> +		gc->chip_types[0].chip.irq_unmask = irq_ck_mask_set_bit;
> +}
> +
> +static inline u32 build_channel_val(u32 idx, u32 magic)
> +{
> +	u32 res;
> +
> +	/*
> +	 * Set the same index for each channel
> +	 */
> +	res = idx | (idx << 8) | (idx << 16) | (idx << 24);
> +
> +	/*
> +	 * Set the channel magic number in descending order.
> +	 * The magic is 0x00010203 for ck-intc
> +	 * The magic is 0x03020100 for gx6605s-intc
> +	 */
> +	return res | magic;
> +}
> +
> +static inline void setup_irq_channel(u32 magic, void __iomem *reg_addr)
> +{
> +	u32 i;
> +
> +	/* Setup 64 channel slots */
> +	for (i = 0; i < INTC_IRQS; i += 4) {
> +		writel_relaxed(build_channel_val(i, magic), reg_addr + i);
> +	}
> +}
> +
> +static int __init
> +ck_intc_init_comm(struct device_node *node, struct device_node *parent)
> +{
> +	int ret;
> +
> +	if (parent) {
> +		pr_err("C-SKY Intc not a root irq controller\n");
> +		return -EINVAL;
> +	}
> +
> +	reg_base = of_iomap(node, 0);
> +	if (!reg_base) {
> +		pr_err("C-SKY Intc unable to map: %p.\n", node);
> +		return -EINVAL;
> +	}
> +
> +	root_domain = irq_domain_add_linear(node, nr_irq, &irq_generic_chip_ops, NULL);
> +	if (!root_domain) {
> +		pr_err("C-SKY Intc irq_domain_add failed.\n");
> +		return -ENOMEM;
> +	}
> +
> +	ret = irq_alloc_domain_generic_chips(root_domain, 32, 1,
> +					     "csky_intc", handle_level_irq,
> +					     IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN,
> +					     0, 0);
> +	if (ret) {
> +		pr_err("C-SKY Intc irq_alloc_gc failed.\n");
> +		return -ENOMEM;
> +	}
> +
> +	return 0;
> +}
> +
> +static inline int handle_irq_perbit(struct pt_regs *regs, u32 hwirq, u32 irq_base)

Consider using bool as the return type, and use true/false as return
values.

> +{
> +	u32 irq;
> +
> +	if (hwirq == 0) return 0;
> +
> +	while (hwirq) {
> +		irq = __ffs(hwirq);
> +		hwirq &= ~BIT(irq);
> +		handle_domain_irq(root_domain, irq_base + irq, regs);
> +	}
> +
> +	return 1;
> +}
> +
> +/* gx6605s 64 irqs interrupt controller */
> +static void gx_irq_handler(struct pt_regs *regs)
> +{
> +	int ret;

bool.

> +
> +	do {
> +		ret  = handle_irq_perbit(regs ,readl_relaxed(reg_base + GX_INTC_PEN31_00), 0);
> +		ret |= handle_irq_perbit(regs ,readl_relaxed(reg_base + GX_INTC_PEN63_32), 32);
> +	} while(ret);
> +}
> +
> +static int __init
> +gx_intc_init(struct device_node *node, struct device_node *parent)
> +{
> +	int ret;
> +
> +	ret = ck_intc_init_comm(node, parent);
> +	if (ret)
> +		return ret;
> +
> +	/* Initial enable reg to disable all interrupts */
> +	writel_relaxed(0x0, reg_base + GX_INTC_NEN31_00);
> +	writel_relaxed(0x0, reg_base + GX_INTC_NEN63_32);
> +
> +	/* Initial mask reg with all unmasked, becasue we only use enalbe reg */
> +	writel_relaxed(0x0, reg_base + GX_INTC_NMASK31_00);
> +	writel_relaxed(0x0, reg_base + GX_INTC_NMASK63_32);
> +
> +	setup_irq_channel(0x03020100, reg_base + GX_INTC_SOURCE);
> +
> +	ck_set_gc(node, reg_base, GX_INTC_NEN31_00, 0);
> +	ck_set_gc(node, reg_base, GX_INTC_NEN63_32, 32);
> +
> +	set_handle_irq(gx_irq_handler);
> +
> +	return 0;
> +}
> +IRQCHIP_DECLARE(csky_gx6605s_intc, "csky,gx6605s-intc", gx_intc_init);
> +
> +/* C-SKY simple 64 irqs interrupt controller, dual-together could support 128 irqs */
> +static void ck_irq_handler(struct pt_regs *regs)
> +{
> +	int ret;

bool.

> +
> +	do {
> +		/* handle 0 - 31 irqs */
> +		ret  = handle_irq_perbit(regs, readl_relaxed(reg_base + CK_INTC_PEN31_00), 0);
> +		ret |= handle_irq_perbit(regs, readl_relaxed(reg_base + CK_INTC_PEN63_32), 32);
> +
> +		if (nr_irq == INTC_IRQS) continue;
> +
> +		/* handle 64 - 127 irqs */
> +		ret |= handle_irq_perbit(regs,
> +			   readl_relaxed(reg_base + CK_INTC_PEN31_00 + CK_INTC_DUAL_BASE), 64);
> +		ret |= handle_irq_perbit(regs,
> +			   readl_relaxed(reg_base + CK_INTC_PEN63_32 + CK_INTC_DUAL_BASE), 96);
> +	} while(ret);
> +}
> +
> +static int __init
> +ck_intc_init(struct device_node *node, struct device_node *parent)
> +{
> +	int ret;
> +
> +	ret = ck_intc_init_comm(node, parent);
> +	if (ret)
> +		return ret;
> +
> +	/* Initial enable reg to disable all interrupts */
> +	writel_relaxed(0, reg_base + CK_INTC_NEN31_00);
> +	writel_relaxed(0, reg_base + CK_INTC_NEN63_32);
> +
> +	/* Enable irq intc */
> +	writel_relaxed(BIT(31), reg_base + CK_INTC_ICR);
> +
> +	ck_set_gc(node, reg_base, CK_INTC_NEN31_00, 0);
> +	ck_set_gc(node, reg_base, CK_INTC_NEN63_32, 32);
> +
> +	setup_irq_channel(0x00010203, reg_base + CK_INTC_SOURCE);
> +
> +	set_handle_irq(ck_irq_handler);
> +
> +	return 0;
> +}
> +IRQCHIP_DECLARE(ck_intc, "csky,apb-intc", ck_intc_init);
> +
> +static int __init
> +ck_dual_intc_init(struct device_node *node, struct device_node *parent)
> +{
> +	int ret;
> +
> +	/* dual-apb-intc up to 128 irq sources*/
> +	nr_irq = INTC_IRQS * 2;
> +
> +	ret = ck_intc_init(node, parent);
> +	if (ret)
> +		return ret;
> +
> +	/* Initial enable reg to disable all interrupts */
> +	writel_relaxed(0, reg_base + CK_INTC_NEN31_00 + CK_INTC_DUAL_BASE);
> +	writel_relaxed(0, reg_base + CK_INTC_NEN63_32 + CK_INTC_DUAL_BASE);
> +
> +	ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN31_00, 64);
> +	ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN63_32, 96);
> +
> +	setup_irq_channel(0x00010203, reg_base + CK_INTC_SOURCE + CK_INTC_DUAL_BASE);
> +
> +	return 0;
> +}
> +IRQCHIP_DECLARE(ck_dual_intc, "csky,dual-apb-intc", ck_dual_intc_init);
> -- 
> 2.7.4
> 

Thanks,

	M.

-- 
Jazz is not dead, it just smell funny.

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