Re: [PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

Anup Patel
2023-09-28T04:39:29Z

On Mon, Sep 25, 2023 at 1:26 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> Hi Anup,
>
> On Tue, Sep 12, 2023 at 11:19:25PM +0530, Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification defines
> > advanced platform-level interrupt controller (APLIC) which has two modes
> > of operation: 1) Direct mode and 2) MSI mode.
> > (For more details, refer https://github.com/riscv/riscv-aia)
> >
> > In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
> > as a local external interrupt.
> >
> > We add a platform irqchip driver for the RISC-V APLIC direct-mode to
> > support RISC-V platforms having only wired interrupts.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> > drivers/irqchip/Kconfig | 5 +
> > drivers/irqchip/Makefile | 1 +
> > drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
> > drivers/irqchip/irq-riscv-aplic-main.c | 240 +++++++++++++++++
> > drivers/irqchip/irq-riscv-aplic-main.h | 45 ++++
> > include/linux/irqchip/riscv-aplic.h | 119 +++++++++
> > 6 files changed, 736 insertions(+)
> > create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
> > create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
> > create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
> > create mode 100644 include/linux/irqchip/riscv-aplic.h
> >
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index a6aad78076a0..44c455084d09 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -545,6 +545,11 @@ config SIFIVE_PLIC
> > select IRQ_DOMAIN_HIERARCHY
> > select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >
> > +config RISCV_APLIC
> > + bool
> > + depends on RISCV
> > + select IRQ_DOMAIN_HIERARCHY
> > +
> > config RISCV_IMSIC
> > bool
> > depends on RISCV
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index abca445a3229..7f8289790ed8 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM) += irq-qcom-mpm.o
> > obj-$(CONFIG_CSKY_MPINTC) += irq-csky-mpintc.o
> > obj-$(CONFIG_CSKY_APB_INTC) += irq-csky-apb-intc.o
> > obj-$(CONFIG_RISCV_INTC) += irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_APLIC) += irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
> > obj-$(CONFIG_RISCV_IMSIC) += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
> > obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o
> > obj-$(CONFIG_IMX_IRQSTEER) += irq-imx-irqsteer.o
> > diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
> > new file mode 100644
> > index 000000000000..e36d655a1490
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-direct.c
> > @@ -0,0 +1,326 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/printk.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +#define APLIC_DISABLE_IDELIVERY 0
> > +#define APLIC_ENABLE_IDELIVERY 1
> > +#define APLIC_DISABLE_ITHRESHOLD 1
> > +#define APLIC_ENABLE_ITHRESHOLD 0
> > +
> > +struct aplic_direct {
> > + struct aplic_priv priv;
> > + struct irq_domain *irqdomain;
> > + struct cpumask lmask;
> > +};
> > +
> > +struct aplic_idc {
> > + unsigned int hart_index;
> > + void __iomem *regs;
> > + struct aplic_direct *direct;
> > +};
> > +
> > +static unsigned int aplic_direct_parent_irq;
> > +static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
> > +
> > +static void aplic_direct_irq_eoi(struct irq_data *d)
> > +{
> > + /*
> > + * The fasteoi_handler requires irq_eoi() callback hence
> > + * provide a dummy handler.
> > + */
> > +}
> > +
> > +#ifdef CONFIG_SMP
> > +static int aplic_direct_set_affinity(struct irq_data *d,
> > + const struct cpumask *mask_val, bool force)
> > +{
> > + struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > + struct aplic_direct *direct =
> > + container_of(priv, struct aplic_direct, priv);
> > + struct aplic_idc *idc;
> > + unsigned int cpu, val;
> > + struct cpumask amask;
> > + void __iomem *target;
> > +
> > + cpumask_and(&amask, &direct->lmask, mask_val);
> > +
> > + if (force)
> > + cpu = cpumask_first(&amask);
> > + else
> > + cpu = cpumask_any_and(&amask, cpu_online_mask);
> > +
> > + if (cpu >= nr_cpu_ids)
> > + return -EINVAL;
> > +
> > + idc = per_cpu_ptr(&aplic_idcs, cpu);
> > + target = priv->regs + APLIC_TARGET_BASE;
> > + target += (d->hwirq - 1) * sizeof(u32);
> > + val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > + val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > + val |= APLIC_DEFAULT_PRIORITY;
> > + writel(val, target);
> > +
> > + irq_data_update_effective_affinity(d, cpumask_of(cpu));
> > +
> > + return IRQ_SET_MASK_OK_DONE;
> > +}
> > +#endif
> > +
> > +static struct irq_chip aplic_direct_chip = {
> > + .name = "APLIC-DIRECT",
> > + .irq_mask = aplic_irq_mask,
> > + .irq_unmask = aplic_irq_unmask,
> > + .irq_set_type = aplic_irq_set_type,
> > + .irq_eoi = aplic_direct_irq_eoi,
> > +#ifdef CONFIG_SMP
> > + .irq_set_affinity = aplic_direct_set_affinity,
> > +#endif
> > + .flags = IRQCHIP_SET_TYPE_MASKED |
> > + IRQCHIP_SKIP_SET_WAKE |
> > + IRQCHIP_MASK_ON_SUSPEND,
> > +};
> > +
> > +static int aplic_direct_irqdomain_translate(struct irq_domain *d,
> > + struct irq_fwspec *fwspec,
> > + unsigned long *hwirq,
> > + unsigned int *type)
> > +{
> > + struct aplic_priv *priv = d->host_data;
> > +
> > + return aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > + hwirq, type);
> > +}
> > +
> > +static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
> > + unsigned int virq, unsigned int nr_irqs,
> > + void *arg)
> > +{
> > + int i, ret;
> > + unsigned int type;
> > + irq_hw_number_t hwirq;
> > + struct irq_fwspec *fwspec = arg;
> > + struct aplic_priv *priv = domain->host_data;
> > + struct aplic_direct *direct =
> > + container_of(priv, struct aplic_direct, priv);
> > +
> > + ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > + &hwirq, &type);
> > + if (ret)
> > + return ret;
> > +
> > + for (i = 0; i < nr_irqs; i++) {
> > + irq_domain_set_info(domain, virq + i, hwirq + i,
> > + &aplic_direct_chip, priv,
> > + handle_fasteoi_irq, NULL, NULL);
> > + irq_set_affinity(virq + i, &direct->lmask);
> > + /* See the reason described in aplic_msi_irqdomain_alloc() */
> > + irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
> > + .translate = aplic_direct_irqdomain_translate,
> > + .alloc = aplic_direct_irqdomain_alloc,
> > + .free = irq_domain_free_irqs_top,
> > +};
> > +
> > +/*
> > + * To handle an APLIC direct interrupts, we just read the CLAIMI register
> > + * which will return highest priority pending interrupt and clear the
> > + * pending bit of the interrupt. This process is repeated until CLAIMI
> > + * register return zero value.
> > + */
> > +static void aplic_direct_handle_irq(struct irq_desc *desc)
> > +{
> > + struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
> > + struct irq_chip *chip = irq_desc_get_chip(desc);
> > + struct irq_domain *irqdomain = idc->direct->irqdomain;
> > + irq_hw_number_t hw_irq;
> > + int irq;
> > +
> > + chained_irq_enter(chip, desc);
> > +
> > + while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
> > + hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
> > + irq = irq_find_mapping(irqdomain, hw_irq);
> > +
> > + if (unlikely(irq <= 0))
> > + dev_warn_ratelimited(idc->direct->priv.dev,
> > + "hw_irq %lu mapping not found\n",
> > + hw_irq);
> > + else
> > + generic_handle_irq(irq);
> > + }
> > +
> > + chained_irq_exit(chip, desc);
> > +}
> > +
> > +static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
> > +{
> > + u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
> > + u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
> > +
> > + /* Priority must be less than threshold for interrupt triggering */
> > + writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
> > +
> > + /* Delivery must be set to 1 for interrupt triggering */
> > + writel(de, idc->regs + APLIC_IDC_IDELIVERY);
> > +}
> > +
> > +static int aplic_direct_dying_cpu(unsigned int cpu)
> > +{
> > + if (aplic_direct_parent_irq)
> > + disable_percpu_irq(aplic_direct_parent_irq);
> > +
> > + return 0;
> > +}
> > +
> > +static int aplic_direct_starting_cpu(unsigned int cpu)
> > +{
> > + if (aplic_direct_parent_irq)
> > + enable_percpu_irq(aplic_direct_parent_irq,
> > + irq_get_trigger_type(aplic_direct_parent_irq));
> > +
> > + return 0;
> > +}
> > +
> > +int aplic_direct_setup(struct device *dev, void __iomem *regs)
> > +{
> > + int i, j, rc, cpu, setup_count = 0;
> > + struct fwnode_reference_args parent;
> > + struct aplic_direct *direct;
> > + struct aplic_priv *priv;
> > + struct irq_domain *domain;
> > + unsigned long hartid;
> > + struct aplic_idc *idc;
> > + u32 val;
> > +
> > + direct = kzalloc(sizeof(*direct), GFP_KERNEL);
> > + if (!direct)
> > + return -ENOMEM;
> > + priv = &direct->priv;
> > +
> > + rc = aplic_setup_priv(priv, dev, regs);
> > + if (rc) {
> > + dev_err(dev, "failed to create APLIC context\n");
> > + kfree(direct);
> > + return rc;
> > + }
> > +
> > + /* Setup per-CPU IDC and target CPU mask */
> > + for (i = 0; i < priv->nr_idcs; i++) {
> > + rc = fwnode_property_get_reference_args(dev->fwnode,
> > + "interrupts-extended", "#interrupt-cells",
> > + 0, i, &parent);
> > + if (rc) {
> > + dev_warn(dev, "parent irq for IDC%d not found\n", i);
> > + continue;
> > + }
> > +
> > + /*
> > + * Skip interrupts other than external interrupts for
> > + * current privilege level.
> > + */
> > + if (parent.args[0] != RV_IRQ_EXT)
> > + continue;
> > +
> > + rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
> > + if (rc) {
> > + dev_warn(dev, "invalid hartid for IDC%d\n", i);
> > + continue;
> > + }
> > +
> > + cpu = riscv_hartid_to_cpuid(hartid);
> > + if (cpu < 0) {
> > + dev_warn(dev, "invalid cpuid for IDC%d\n", i);
> > + continue;
> > + }
> > +
> > + cpumask_set_cpu(cpu, &direct->lmask);
> > +
> > + idc = per_cpu_ptr(&aplic_idcs, cpu);
> > + idc->hart_index = i;
> > + idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
> > + idc->direct = direct;
> > +
> > + aplic_idc_set_delivery(idc, true);
> > +
> > + /*
> > + * Boot cpu might not have APLIC hart_index = 0 so check
> > + * and update target registers of all interrupts.
> > + */
> > + if (cpu == smp_processor_id() && idc->hart_index) {
> > + val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > + val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > + val |= APLIC_DEFAULT_PRIORITY;
> > + for (j = 1; j <= priv->nr_irqs; j++)
> > + writel(val, priv->regs + APLIC_TARGET_BASE +
> > + (j - 1) * sizeof(u32));
> > + }
> > +
> > + setup_count++;
> > + }
> > +
> > + /* Find parent domain and register chained handler */
> > + domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > + DOMAIN_BUS_ANY);
> > + if (!aplic_direct_parent_irq && domain) {
> > + aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > + if (aplic_direct_parent_irq) {
> > + irq_set_chained_handler(aplic_direct_parent_irq,
> > + aplic_direct_handle_irq);
> > +
> > + /*
> > + * Setup CPUHP notifier to enable parent
> > + * interrupt on all CPUs
> > + */
> > + cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > + "irqchip/riscv/aplic:starting",
> > + aplic_direct_starting_cpu,
> > + aplic_direct_dying_cpu);
> > + }
> > + }
> > +
> > + /* Fail if we were not able to setup IDC for any CPU */
> > + if (!setup_count) {
> > + kfree(direct);
> > + return -ENODEV;
> > + }
> > +
> > + /* Setup global config and interrupt delivery */
> > + aplic_init_hw_global(priv, false);
> > +
> > + /* Create irq domain instance for the APLIC */
> > + direct->irqdomain = irq_domain_create_linear(dev->fwnode,
> > + priv->nr_irqs + 1,
> > + &aplic_direct_irqdomain_ops,
> > + priv);
> > + if (!direct->irqdomain) {
> > + dev_err(dev, "failed to create direct irq domain\n");
> > + kfree(direct);
> > + return -ENOMEM;
> > + }
> > +
> > + /* Advertise the interrupt controller */
> > + dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
> > + priv->nr_irqs, priv->nr_idcs);
> > +
> > + return 0;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> > new file mode 100644
> > index 000000000000..d62a096774c4
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.c
> > @@ -0,0 +1,240 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/printk.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +void aplic_irq_unmask(struct irq_data *d)
> > +{
> > + struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > + writel(d->hwirq, priv->regs + APLIC_SETIENUM);
> > +}
> > +
> > +void aplic_irq_mask(struct irq_data *d)
> > +{
> > + struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > + writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
> > +}
> > +
> > +int aplic_irq_set_type(struct irq_data *d, unsigned int type)
> > +{
> > + u32 val = 0;
> > + void __iomem *sourcecfg;
> > + struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > + switch (type) {
> > + case IRQ_TYPE_NONE:
> > + val = APLIC_SOURCECFG_SM_INACTIVE;
> > + break;
> > + case IRQ_TYPE_LEVEL_LOW:
> > + val = APLIC_SOURCECFG_SM_LEVEL_LOW;
> > + break;
> > + case IRQ_TYPE_LEVEL_HIGH:
> > + val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
> > + break;
> > + case IRQ_TYPE_EDGE_FALLING:
> > + val = APLIC_SOURCECFG_SM_EDGE_FALL;
> > + break;
> > + case IRQ_TYPE_EDGE_RISING:
> > + val = APLIC_SOURCECFG_SM_EDGE_RISE;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
> > + sourcecfg += (d->hwirq - 1) * sizeof(u32);
> > + writel(val, sourcecfg);
> > +
> > + return 0;
> > +}
> > +
> > +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > + unsigned long *hwirq, unsigned int *type)
> > +{
> > + if (WARN_ON(fwspec->param_count < 2))
> > + return -EINVAL;
> > + if (WARN_ON(!fwspec->param[0]))
> > + return -EINVAL;
> > +
> > + /* For DT, gsi_base is always zero. */
> > + *hwirq = fwspec->param[0] - gsi_base;
> > + *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> > +
> > + WARN_ON(*type == IRQ_TYPE_NONE);
> > +
> > + return 0;
> > +}
> > +
> > +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> > +{
> > + u32 val;
> > +#ifdef CONFIG_RISCV_M_MODE
> > + u32 valH;
> > +
> > + if (msi_mode) {
> > + val = priv->msicfg.base_ppn;
> > + valH = ((u64)priv->msicfg.base_ppn >> 32) &
> > + APLIC_xMSICFGADDRH_BAPPN_MASK;
> > + valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
> > + << APLIC_xMSICFGADDRH_LHXW_SHIFT;
> > + valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
> > + << APLIC_xMSICFGADDRH_HHXW_SHIFT;
> > + valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
> > + << APLIC_xMSICFGADDRH_LHXS_SHIFT;
> > + valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
> > + << APLIC_xMSICFGADDRH_HHXS_SHIFT;
> > + writel(val, priv->regs + APLIC_xMSICFGADDR);
> > + writel(valH, priv->regs + APLIC_xMSICFGADDRH);
> > + }
> > +#endif
> > +
> > + /* Setup APLIC domaincfg register */
> > + val = readl(priv->regs + APLIC_DOMAINCFG);
> > + val |= APLIC_DOMAINCFG_IE;
> > + if (msi_mode)
> > + val |= APLIC_DOMAINCFG_DM;
> > + writel(val, priv->regs + APLIC_DOMAINCFG);
> > + if (readl(priv->regs + APLIC_DOMAINCFG) != val)
> > + dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
> > + val);
> > +}
> > +
> > +static void aplic_init_hw_irqs(struct aplic_priv *priv)
> > +{
> > + int i;
> > +
> > + /* Disable all interrupts */
> > + for (i = 0; i <= priv->nr_irqs; i += 32)
> > + writel(-1U, priv->regs + APLIC_CLRIE_BASE +
> > + (i / 32) * sizeof(u32));
> > +
> > + /* Set interrupt type and default priority for all interrupts */
> > + for (i = 1; i <= priv->nr_irqs; i++) {
> > + writel(0, priv->regs + APLIC_SOURCECFG_BASE +
> > + (i - 1) * sizeof(u32));
> > + writel(APLIC_DEFAULT_PRIORITY,
> > + priv->regs + APLIC_TARGET_BASE +
> > + (i - 1) * sizeof(u32));
> > + }
> > +
> > + /* Clear APLIC domaincfg */
> > + writel(0, priv->regs + APLIC_DOMAINCFG);
> > +}
> > +
> > +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> > + void __iomem *regs)
> > +{
> > + struct fwnode_reference_args parent;
> > + int rc;
> > +
> > + /* Save device pointer and register base */
> > + priv->dev = dev;
> > + priv->regs = regs;
> > +
> > + /*
> > + * Find out GSI base number
> > + *
> > + * Note: DT does not define "riscv,gsi-base" property so GSI
> > + * base is always zero for DT.
> > + */
> > + rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
> > + &priv->gsi_base, 1);
> For DT, you can just initialize this to 0 without reading the property.

Okay, I will update.

>
> > + if (rc)
> > + priv->gsi_base = 0;
> > +
> > + /* Find out number of interrupt sources */
> > + rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
> > + &priv->nr_irqs, 1);
> > + if (rc) {
> > + dev_err(dev, "failed to get number of interrupt sources\n");
> > + return rc;
> > + }
> > +
> > + /* Setup initial state APLIC interrupts */
> > + aplic_init_hw_irqs(priv);
> > +
> > + /*
> > + * Find out number of IDCs based on parent interrupts
> > + *
> > + * If "msi-parent" property is present then we ignore the
> > + * APLIC IDCs which forces the APLIC driver to use MSI mode.
> > + */
> > + if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
> > + while (!fwnode_property_get_reference_args(dev->fwnode,
> > + "interrupts-extended", "#interrupt-cells",
> > + 0, priv->nr_idcs, &parent))
> > + priv->nr_idcs++;
> > + }
> > +
> Can this finding nr_idcs be done after aplic_init_hw_irqs() above?

Okay, I will update.

>
> > + return 0;
> > +}
> > +
> > +static int aplic_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct resource *res;
> > + void __iomem *regs;
> > + int rc;
> > +
> > + /* Map the MMIO registers */
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + if (!res) {
> > + dev_err(dev, "failed to get MMIO resource\n");
> > + return -EINVAL;
> > + }
> > + regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> > + if (!regs) {
> > + dev_err(dev, "failed map MMIO registers\n");
> > + return -ENOMEM;
> > + }
> > +
> > + /*
> > + * If msi-parent property is present then setup APLIC MSI mode
> > + * otherwise setup APLIC direct mode.
> > + */
> > + if (fwnode_property_present(dev->fwnode, "msi-parent"))
> Can this check be based on nr_idcs instead of checking for msi-parent
> again?

nr_idcs are not available at this point. I will think of something else
and maybe you can comment on v9 if it does not work for you.

>
> Thanks!
> Sunil
> > + rc = -ENODEV;
> > + else
> > + rc = aplic_direct_setup(dev, regs);
> > + if (rc) {
> > + dev_err(dev, "failed setup APLIC in %s mode\n",
> > + fwnode_property_present(dev->fwnode, "msi-parent") ?
> > + "MSI" : "direct");
> > + return rc;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id aplic_match[] = {
> > + { .compatible = "riscv,aplic" },
> > + {}
> > +};
> > +
> > +static struct platform_driver aplic_driver = {
> > + .driver = {
> > + .name = "riscv-aplic",
> > + .of_match_table = aplic_match,
> > + },
> > + .probe = aplic_probe,
> > +};
> > +
> > +static int __init aplic_init(void)
> > +{
> > + /*
> > + * Register APLIC driver as early as possible so that APLIC
> > + * platform device is probed as soon as it is created.
> > + */
> > + return platform_driver_register(&aplic_driver);
> > +}
> > +core_initcall(aplic_init);
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
> > new file mode 100644
> > index 000000000000..474a04229334
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.h
> > @@ -0,0 +1,45 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#ifndef _IRQ_RISCV_APLIC_MAIN_H
> > +#define _IRQ_RISCV_APLIC_MAIN_H
> > +
> > +#include <linux/device.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/fwnode.h>
> > +
> > +#define APLIC_DEFAULT_PRIORITY 1
> > +
> > +struct aplic_msicfg {
> > + phys_addr_t base_ppn;
> > + u32 hhxs;
> > + u32 hhxw;
> > + u32 lhxs;
> > + u32 lhxw;
> > +};
> > +
> > +struct aplic_priv {
> > + struct device *dev;
> > + u32 gsi_base;
> > + u32 nr_irqs;
> > + u32 nr_idcs;
> > + void __iomem *regs;
> > + struct aplic_msicfg msicfg;
> > +};
> > +
> > +void aplic_irq_unmask(struct irq_data *d);
> > +void aplic_irq_mask(struct irq_data *d);
> > +int aplic_irq_set_type(struct irq_data *d, unsigned int type);
> > +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > + unsigned long *hwirq, unsigned int *type);
> > +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
> > +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> > + void __iomem *regs);
> > +int aplic_direct_setup(struct device *dev, void __iomem *regs);
> > +
> > +#endif
> > diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
> > new file mode 100644
> > index 000000000000..97e198ea0109
> > --- /dev/null
> > +++ b/include/linux/irqchip/riscv-aplic.h
> > @@ -0,0 +1,119 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
> > +#define __LINUX_IRQCHIP_RISCV_APLIC_H
> > +
> > +#include <linux/bitops.h>
> > +
> > +#define APLIC_MAX_IDC BIT(14)
> > +#define APLIC_MAX_SOURCE 1024
> > +
> > +#define APLIC_DOMAINCFG 0x0000
> > +#define APLIC_DOMAINCFG_RDONLY 0x80000000
> > +#define APLIC_DOMAINCFG_IE BIT(8)
> > +#define APLIC_DOMAINCFG_DM BIT(2)
> > +#define APLIC_DOMAINCFG_BE BIT(0)
> > +
> > +#define APLIC_SOURCECFG_BASE 0x0004
> > +#define APLIC_SOURCECFG_D BIT(10)
> > +#define APLIC_SOURCECFG_CHILDIDX_MASK 0x000003ff
> > +#define APLIC_SOURCECFG_SM_MASK 0x00000007
> > +#define APLIC_SOURCECFG_SM_INACTIVE 0x0
> > +#define APLIC_SOURCECFG_SM_DETACH 0x1
> > +#define APLIC_SOURCECFG_SM_EDGE_RISE 0x4
> > +#define APLIC_SOURCECFG_SM_EDGE_FALL 0x5
> > +#define APLIC_SOURCECFG_SM_LEVEL_HIGH 0x6
> > +#define APLIC_SOURCECFG_SM_LEVEL_LOW 0x7
> > +
> > +#define APLIC_MMSICFGADDR 0x1bc0
> > +#define APLIC_MMSICFGADDRH 0x1bc4
> > +#define APLIC_SMSICFGADDR 0x1bc8
> > +#define APLIC_SMSICFGADDRH 0x1bcc
> > +
> > +#ifdef CONFIG_RISCV_M_MODE
> > +#define APLIC_xMSICFGADDR APLIC_MMSICFGADDR
> > +#define APLIC_xMSICFGADDRH APLIC_MMSICFGADDRH
> > +#else
> > +#define APLIC_xMSICFGADDR APLIC_SMSICFGADDR
> > +#define APLIC_xMSICFGADDRH APLIC_SMSICFGADDRH
> > +#endif
> > +
> > +#define APLIC_xMSICFGADDRH_L BIT(31)
> > +#define APLIC_xMSICFGADDRH_HHXS_MASK 0x1f
> > +#define APLIC_xMSICFGADDRH_HHXS_SHIFT 24
> > +#define APLIC_xMSICFGADDRH_LHXS_MASK 0x7
> > +#define APLIC_xMSICFGADDRH_LHXS_SHIFT 20
> > +#define APLIC_xMSICFGADDRH_HHXW_MASK 0x7
> > +#define APLIC_xMSICFGADDRH_HHXW_SHIFT 16
> > +#define APLIC_xMSICFGADDRH_LHXW_MASK 0xf
> > +#define APLIC_xMSICFGADDRH_LHXW_SHIFT 12
> > +#define APLIC_xMSICFGADDRH_BAPPN_MASK 0xfff
> > +
> > +#define APLIC_xMSICFGADDR_PPN_SHIFT 12
> > +
> > +#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
> > + (BIT(__lhxs) - 1)
> > +
> > +#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
> > + (BIT(__lhxw) - 1)
> > +#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
> > + ((__lhxs))
> > +#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
> > + (APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
> > + APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
> > +
> > +#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
> > + (BIT(__hhxw) - 1)
> > +#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
> > + ((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
> > +#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
> > + (APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
> > + APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
> > +
> > +#define APLIC_IRQBITS_PER_REG 32
> > +
> > +#define APLIC_SETIP_BASE 0x1c00
> > +#define APLIC_SETIPNUM 0x1cdc
> > +
> > +#define APLIC_CLRIP_BASE 0x1d00
> > +#define APLIC_CLRIPNUM 0x1ddc
> > +
> > +#define APLIC_SETIE_BASE 0x1e00
> > +#define APLIC_SETIENUM 0x1edc
> > +
> > +#define APLIC_CLRIE_BASE 0x1f00
> > +#define APLIC_CLRIENUM 0x1fdc
> > +
> > +#define APLIC_SETIPNUM_LE 0x2000
> > +#define APLIC_SETIPNUM_BE 0x2004
> > +
> > +#define APLIC_GENMSI 0x3000
> > +
> > +#define APLIC_TARGET_BASE 0x3004
> > +#define APLIC_TARGET_HART_IDX_SHIFT 18
> > +#define APLIC_TARGET_HART_IDX_MASK 0x3fff
> > +#define APLIC_TARGET_GUEST_IDX_SHIFT 12
> > +#define APLIC_TARGET_GUEST_IDX_MASK 0x3f
> > +#define APLIC_TARGET_IPRIO_MASK 0xff
> > +#define APLIC_TARGET_EIID_MASK 0x7ff
> > +
> > +#define APLIC_IDC_BASE 0x4000
> > +#define APLIC_IDC_SIZE 32
> > +
> > +#define APLIC_IDC_IDELIVERY 0x00
> > +
> > +#define APLIC_IDC_IFORCE 0x04
> > +
> > +#define APLIC_IDC_ITHRESHOLD 0x08
> > +
> > +#define APLIC_IDC_TOPI 0x18
> > +#define APLIC_IDC_TOPI_ID_SHIFT 16
> > +#define APLIC_IDC_TOPI_ID_MASK 0x3ff
> > +#define APLIC_IDC_TOPI_PRIO_MASK 0xff
> > +
> > +#define APLIC_IDC_CLAIMI 0x1c
> > +
> > +#endif
> > --
> > 2.34.1
> >

Regards,
Anup