Re: [PATCH v7 03/16] irqchip/riscv-intc: Introduce Andes hart-level interrupt controller
From: Atish Patra
Date: Fri Jan 12 2024 - 18:44:20 EST
On Wed, Jan 10, 2024 at 7:13 AM Anup Patel <anup@xxxxxxxxxxxxxx> wrote:
>
> On Wed, Jan 10, 2024 at 1:10 PM Yu Chien Peter Lin
> <peterlin@xxxxxxxxxxxxx> wrote:
> >
> > Add support for the Andes hart-level interrupt controller. This
> > controller provides interrupt mask/unmask functions to access the
> > custom register (SLIE) where the non-standard S-mode local interrupt
> > enable bits are located. The base of custom interrupt number is set
> > to 256.
> >
> > To share the riscv_intc_domain_map() with the generic RISC-V INTC and
> > ACPI, add a chip parameter to riscv_intc_init_common(), so it can be
> > passed to the irq_domain_set_info() as a private data.
> >
> > Andes hart-level interrupt controller requires the "andestech,cpu-intc"
> > compatible string to be present in interrupt-controller of cpu node to
> > enable the use of custom local interrupt source.
> > e.g.,
> >
> > cpu0: cpu@0 {
> > compatible = "andestech,ax45mp", "riscv";
> > ...
> > cpu0-intc: interrupt-controller {
> > #interrupt-cells = <0x01>;
> > compatible = "andestech,cpu-intc", "riscv,cpu-intc";
> > interrupt-controller;
> > };
> > };
> >
> > Signed-off-by: Yu Chien Peter Lin <peterlin@xxxxxxxxxxxxx>
> > Reviewed-by: Randolph <randolph@xxxxxxxxxxxxx>
>
> Looks good to me.
>
> Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
>
> Regards,
> Anup
>
> > ---
> > Changes v1 -> v2:
> > - New patch
> > Changes v2 -> v3:
> > - Return -ENXIO if no valid compatible INTC found
> > - Allow falling back to generic RISC-V INTC
> > Changes v3 -> v4: (Suggested by Thomas [1])
> > - Add comment to andes irq chip function
> > - Refine code flow to share with generic RISC-V INTC and ACPI
> > - Move Andes specific definitions to include/linux/soc/andes/irq.h
> > Changes v4 -> v5: (Suggested by Thomas)
> > - Fix commit message
> > - Subtract ANDES_SLI_CAUSE_BASE from d->hwirq to calculate the value of mask
> > - Do not set chip_data to the chip itself with irq_domain_set_info()
> > - Follow reverse fir tree order variable declarations
> > Changes v5 -> v6:
> > - To follow the naming on datasheet, rename ANDES_RV_IRQ_PMU to ANDES_RV_IRQ_PMOVI
> > - Initialize the riscv_intc_* global variables for Andes INTC (Suggested by Anup)
> > - Use BITS_PER_LONG to compute the bit mask of SIE/SLIE as they are 64-bit registers (32-bit for RV32)
> > Changes v6 -> v7:
> > - No change
> >
> > [1] https://patchwork.kernel.org/project/linux-riscv/patch/20231019135723.3657156-1-peterlin@xxxxxxxxxxxxx/
> > ---
> > drivers/irqchip/irq-riscv-intc.c | 66 +++++++++++++++++++++++++++-----
> > include/linux/soc/andes/irq.h | 18 +++++++++
> > 2 files changed, 74 insertions(+), 10 deletions(-)
> > create mode 100644 include/linux/soc/andes/irq.h
> >
> > diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> > index b13a16b164c9..7064857f1f1d 100644
> > --- a/drivers/irqchip/irq-riscv-intc.c
> > +++ b/drivers/irqchip/irq-riscv-intc.c
> > @@ -17,6 +17,7 @@
> > #include <linux/module.h>
> > #include <linux/of.h>
> > #include <linux/smp.h>
> > +#include <linux/soc/andes/irq.h>
> >
> > static struct irq_domain *intc_domain;
> > static unsigned int riscv_intc_nr_irqs __ro_after_init;
> > @@ -49,6 +50,31 @@ static void riscv_intc_irq_unmask(struct irq_data *d)
> > csr_set(CSR_IE, BIT(d->hwirq));
> > }
> >
> > +static void andes_intc_irq_mask(struct irq_data *d)
> > +{
> > + /*
> > + * Andes specific S-mode local interrupt causes (hwirq)
> > + * are defined as (256 + n) and controlled by n-th bit
> > + * of SLIE.
> > + */
> > + unsigned int mask = BIT(d->hwirq % BITS_PER_LONG);
> > +
> > + if (d->hwirq < ANDES_SLI_CAUSE_BASE)
> > + csr_clear(CSR_IE, mask);
> > + else
> > + csr_clear(ANDES_CSR_SLIE, mask);
> > +}
> > +
> > +static void andes_intc_irq_unmask(struct irq_data *d)
> > +{
> > + unsigned int mask = BIT(d->hwirq % BITS_PER_LONG);
> > +
> > + if (d->hwirq < ANDES_SLI_CAUSE_BASE)
> > + csr_set(CSR_IE, mask);
> > + else
> > + csr_set(ANDES_CSR_SLIE, mask);
> > +}
> > +
> > static void riscv_intc_irq_eoi(struct irq_data *d)
> > {
> > /*
> > @@ -72,12 +98,21 @@ static struct irq_chip riscv_intc_chip = {
> > .irq_eoi = riscv_intc_irq_eoi,
> > };
> >
> > +static struct irq_chip andes_intc_chip = {
> > + .name = "RISC-V INTC",
> > + .irq_mask = andes_intc_irq_mask,
> > + .irq_unmask = andes_intc_irq_unmask,
> > + .irq_eoi = riscv_intc_irq_eoi,
> > +};
> > +
> > static int riscv_intc_domain_map(struct irq_domain *d, unsigned int irq,
> > irq_hw_number_t hwirq)
> > {
> > + struct irq_chip *chip = d->host_data;
> > +
> > irq_set_percpu_devid(irq);
> > - irq_domain_set_info(d, irq, hwirq, &riscv_intc_chip, d->host_data,
> > - handle_percpu_devid_irq, NULL, NULL);
> > + irq_domain_set_info(d, irq, hwirq, chip, NULL, handle_percpu_devid_irq,
> > + NULL, NULL);
> >
> > return 0;
> > }
> > @@ -123,11 +158,12 @@ static struct fwnode_handle *riscv_intc_hwnode(void)
> > return intc_domain->fwnode;
> > }
> >
> > -static int __init riscv_intc_init_common(struct fwnode_handle *fn)
> > +static int __init riscv_intc_init_common(struct fwnode_handle *fn,
> > + struct irq_chip *chip)
> > {
> > int rc;
> >
> > - intc_domain = irq_domain_create_tree(fn, &riscv_intc_domain_ops, NULL);
> > + intc_domain = irq_domain_create_tree(fn, &riscv_intc_domain_ops, chip);
> > if (!intc_domain) {
> > pr_err("unable to add IRQ domain\n");
> > return -ENXIO;
> > @@ -152,8 +188,9 @@ static int __init riscv_intc_init_common(struct fwnode_handle *fn)
> > static int __init riscv_intc_init(struct device_node *node,
> > struct device_node *parent)
> > {
> > - int rc;
> > + struct irq_chip *chip;
> > unsigned long hartid;
> > + int rc;
> >
> > rc = riscv_of_parent_hartid(node, &hartid);
> > if (rc < 0) {
> > @@ -178,14 +215,23 @@ static int __init riscv_intc_init(struct device_node *node,
> > return 0;
> > }
> >
> > - riscv_intc_nr_irqs = BITS_PER_LONG;
> > - riscv_intc_custom_base = riscv_intc_nr_irqs;
> > - riscv_intc_custom_nr_irqs = 0;
> > + if (of_device_is_compatible(node, "andestech,cpu-intc")) {
> > + riscv_intc_nr_irqs = BITS_PER_LONG;
> > + riscv_intc_custom_base = ANDES_SLI_CAUSE_BASE;
> > + riscv_intc_custom_nr_irqs = ANDES_RV_IRQ_LAST;
> > + chip = &andes_intc_chip;
There may be similar usage of custom interrupt space in the future as
well. I think it will be better if we define a generic structure and
vendor
specific registration mechanism based on compatible strings. This will
avoid a bunch of if else blocks here.
> > + } else {
> > + riscv_intc_nr_irqs = BITS_PER_LONG;
> > + riscv_intc_custom_base = riscv_intc_nr_irqs;
> > + riscv_intc_custom_nr_irqs = 0;
> > + chip = &riscv_intc_chip;
> > + }
> >
> > - return riscv_intc_init_common(of_node_to_fwnode(node));
> > + return riscv_intc_init_common(of_node_to_fwnode(node), chip);
> > }
> >
> > IRQCHIP_DECLARE(riscv, "riscv,cpu-intc", riscv_intc_init);
> > +IRQCHIP_DECLARE(andes, "andestech,cpu-intc", riscv_intc_init);
> >
> > #ifdef CONFIG_ACPI
> >
> > @@ -212,7 +258,7 @@ static int __init riscv_intc_acpi_init(union acpi_subtable_headers *header,
> > return -ENOMEM;
> > }
> >
> > - return riscv_intc_init_common(fn);
> > + return riscv_intc_init_common(fn, &riscv_intc_chip);
> > }
> >
> > IRQCHIP_ACPI_DECLARE(riscv_intc, ACPI_MADT_TYPE_RINTC, NULL,
> > diff --git a/include/linux/soc/andes/irq.h b/include/linux/soc/andes/irq.h
> > new file mode 100644
> > index 000000000000..edc3182d6e66
> > --- /dev/null
> > +++ b/include/linux/soc/andes/irq.h
> > @@ -0,0 +1,18 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2023 Andes Technology Corporation
> > + */
> > +#ifndef __ANDES_IRQ_H
> > +#define __ANDES_IRQ_H
> > +
> > +/* Andes PMU irq number */
> > +#define ANDES_RV_IRQ_PMOVI 18
> > +#define ANDES_RV_IRQ_LAST ANDES_RV_IRQ_PMOVI
> > +#define ANDES_SLI_CAUSE_BASE 256
> > +
> > +/* Andes PMU related registers */
> > +#define ANDES_CSR_SLIE 0x9c4
> > +#define ANDES_CSR_SLIP 0x9c5
> > +#define ANDES_CSR_SCOUNTEROF 0x9d4
> > +
> > +#endif /* __ANDES_IRQ_H */
> > --
> > 2.34.1
> >
--
Regards,
Atish