Re: [PATCH V4 15/23] irqchip/riscv-intc: Add ACPI support

Andrew Jones
2023-04-05T15:49:31Z

On Tue, Apr 04, 2023 at 11:50:29PM +0530, Sunil V L wrote:
> Add support for initializing the RISC-V INTC driver on ACPI
> platforms.
>
> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> ---
> drivers/irqchip/irq-riscv-intc.c | 74 ++++++++++++++++++++++++++------
> 1 file changed, 61 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> index f229e3e66387..6b476fa356c0 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -6,6 +6,7 @@
> */
>
> #define pr_fmt(fmt) "riscv-intc: " fmt
> +#include <linux/acpi.h>
> #include <linux/atomic.h>
> #include <linux/bits.h>
> #include <linux/cpu.h>
> @@ -112,6 +113,30 @@ static struct fwnode_handle *riscv_intc_hwnode(void)
> return intc_domain->fwnode;
> }
>
> +static int __init riscv_intc_init_common(struct fwnode_handle *fn)
> +{
> + int rc;
> +
> + intc_domain = irq_domain_create_linear(fn, BITS_PER_LONG,
> + &riscv_intc_domain_ops, NULL);
> + if (!intc_domain) {
> + pr_err("unable to add IRQ domain\n");
> + return -ENXIO;
> + }
> +
> + rc = set_handle_irq(&riscv_intc_irq);
> + if (rc) {
> + pr_err("failed to set irq handler\n");
> + return rc;
> + }
> +
> + riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
> +
> + pr_info("%d local interrupts mapped\n", BITS_PER_LONG);
> +
> + return 0;
> +}
> +
> static int __init riscv_intc_init(struct device_node *node,
> struct device_node *parent)
> {
> @@ -133,24 +158,47 @@ static int __init riscv_intc_init(struct device_node *node,
> if (riscv_hartid_to_cpuid(hartid) != smp_processor_id())
> return 0;
>
> - intc_domain = irq_domain_add_linear(node, BITS_PER_LONG,
> - &riscv_intc_domain_ops, NULL);
> - if (!intc_domain) {
> - pr_err("unable to add IRQ domain\n");
> - return -ENXIO;
> - }
> -
> - rc = set_handle_irq(&riscv_intc_irq);
> + rc = riscv_intc_init_common(of_node_to_fwnode(node));
> if (rc) {
> - pr_err("failed to set irq handler\n");
> + pr_err("failed to initialize INTC\n");

The ACPI version doesn't output this error when riscv_intc_init_common()
fails. It should probably be consistent. Either removing it here, if the
errors output within riscv_intc_init_common() are sufficient, or adding
it to the ACPI version.

> return rc;
> }
>
> - riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
> -
> - pr_info("%d local interrupts mapped\n", BITS_PER_LONG);
> -
> return 0;
> }
>
> IRQCHIP_DECLARE(riscv, "riscv,cpu-intc", riscv_intc_init);
> +
> +#ifdef CONFIG_ACPI
> +
> +static int __init riscv_intc_acpi_init(union acpi_subtable_headers *header,
> + const unsigned long end)
> +{
> + int rc;
> + struct fwnode_handle *fn;
> + struct acpi_madt_rintc *rintc;
> +
> + rintc = (struct acpi_madt_rintc *)header;
> +
> + /*
> + * The ACPI MADT will have one INTC for each CPU (or HART)
> + * so riscv_intc_acpi_init() function will be called once
> + * for each INTC. We only do INTC initialization
> + * for the INTC belonging to the boot CPU (or boot HART).
> + */
> + if (riscv_hartid_to_cpuid(rintc->hart_id) != smp_processor_id())
> + return 0;
> +
> + fn = irq_domain_alloc_named_fwnode("RISCV-INTC");
> + if (!fn) {
> + pr_err("unable to allocate INTC FW node\n");
> + return -ENOMEM;
> + }
> +
> + rc = riscv_intc_init_common(fn);
> + return rc;

nit: If we don't add the error message here, then rc can be removed and we
can just do

return riscv_intc_init_common(fn);

And, if we remove the error above, then we reduce the return there too.

> +}
> +
> +IRQCHIP_ACPI_DECLARE(riscv_intc, ACPI_MADT_TYPE_RINTC, NULL,
> + ACPI_MADT_RINTC_VERSION_V1, riscv_intc_acpi_init);
> +#endif
> --
> 2.34.1
>

Thanks,
drew