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From:   Atish Patra <atishp@atishpatra.org>
Date:   Wed, 7 Sep 2022 16:20:53 -0700
Message-ID: <CAOnJCUJU_2vfiWO7PXSpDmkBuQhw_R9iUURhSCwjU=3OW7c+eg@mail.gmail.com>
Subject: Re: [PATCH v9 2/7] irqchip/riscv-intc: Allow drivers to directly
 discover INTC hwnode
To:     Anup Patel <apatel@ventanamicro.com>
Cc:     Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Alistair Francis <Alistair.Francis@wdc.com>,
        Anup Patel <anup@brainfault.org>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
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On Sat, Sep 3, 2022 at 9:13 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> Various RISC-V drivers (such as SBI IPI, SBI Timer, SBI PMU, and
> KVM RISC-V) don't have associated DT node but these drivers need
> standard per-CPU (local) interrupts defined by the RISC-V privileged
> specification.
>
> We add riscv_get_intc_hwnode() in arch/riscv which allows RISC-V
> drivers not having DT node to discover INTC hwnode which in-turn
> helps these drivers to map per-CPU (local) interrupts provided
> by the INTC driver.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/include/asm/irq.h     |  4 ++++
>  arch/riscv/kernel/irq.c          | 18 ++++++++++++++++++
>  drivers/irqchip/irq-riscv-intc.c |  7 +++++++
>  3 files changed, 29 insertions(+)
>
> diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h
> index e4c435509983..43b9ebfbd943 100644
> --- a/arch/riscv/include/asm/irq.h
> +++ b/arch/riscv/include/asm/irq.h
> @@ -12,6 +12,10 @@
>
>  #include <asm-generic/irq.h>
>
> +void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void));
> +
> +struct fwnode_handle *riscv_get_intc_hwnode(void);
> +
>  extern void __init init_IRQ(void);
>
>  #endif /* _ASM_RISCV_IRQ_H */
> diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
> index 7207fa08d78f..96d3171f0ca1 100644
> --- a/arch/riscv/kernel/irq.c
> +++ b/arch/riscv/kernel/irq.c
> @@ -7,9 +7,27 @@
>
>  #include <linux/interrupt.h>
>  #include <linux/irqchip.h>
> +#include <linux/irqdomain.h>
> +#include <linux/module.h>
>  #include <linux/seq_file.h>
>  #include <asm/smp.h>
>
> +static struct fwnode_handle *(*__get_intc_node)(void);
> +
> +void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void))
> +{
> +       __get_intc_node = fn;
> +}
> +
> +struct fwnode_handle *riscv_get_intc_hwnode(void)
> +{
> +       if (__get_intc_node)
> +               return __get_intc_node();
> +
> +       return NULL;
> +}
> +EXPORT_SYMBOL_GPL(riscv_get_intc_hwnode);
> +
>  int arch_show_interrupts(struct seq_file *p, int prec)
>  {
>         show_ipi_stats(p, prec);
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> index 499e5f81b3fe..9066467e99e4 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -92,6 +92,11 @@ static const struct irq_domain_ops riscv_intc_domain_ops = {
>         .xlate  = irq_domain_xlate_onecell,
>  };
>
> +static struct fwnode_handle *riscv_intc_hwnode(void)
> +{
> +       return intc_domain->fwnode;
> +}
> +
>  static int __init riscv_intc_init(struct device_node *node,
>                                   struct device_node *parent)
>  {
> @@ -126,6 +131,8 @@ static int __init riscv_intc_init(struct device_node *node,
>                 return rc;
>         }
>
> +       riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
> +
>         cpuhp_setup_state(CPUHP_AP_IRQ_RISCV_STARTING,
>                           "irqchip/riscv/intc:starting",
>                           riscv_intc_cpu_starting,
> --
> 2.34.1
>


Reviewed-by: Atish Patra <atishp@rivosinc.com>
-- 
Regards,
Atish