From f8415f2def181c63486e93c511b82692e0914d9e Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 28 Mar 2023 09:22:23 +0530 Subject: irqchip/riscv-intc: Add empty irq_eoi() for chained irq handlers We add empty irq_eoi() in RISC-V INTC driver for child irqchip drivers (such as PLIC, SBI IPI, CLINT, APLIC, IMSIC, etc) which implement chained handlers for parent per-HART local interrupts. This hels us avoid unnecessary mask/unmask of per-HART local interrupts at the time of handling interrupts. Signed-off-by: Anup Patel Acked-by: Palmer Dabbelt Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230328035223.1480939-8-apatel@ventanamicro.com --- drivers/irqchip/irq-riscv-intc.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers/irqchip/irq-riscv-intc.c') diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c index 784d25645704..f229e3e66387 100644 --- a/drivers/irqchip/irq-riscv-intc.c +++ b/drivers/irqchip/irq-riscv-intc.c @@ -46,10 +46,27 @@ static void riscv_intc_irq_unmask(struct irq_data *d) csr_set(CSR_IE, BIT(d->hwirq)); } +static void riscv_intc_irq_eoi(struct irq_data *d) +{ + /* + * The RISC-V INTC driver uses handle_percpu_devid_irq() flow + * for the per-HART local interrupts and child irqchip drivers + * (such as PLIC, SBI IPI, CLINT, APLIC, IMSIC, etc) implement + * chained handlers for the per-HART local interrupts. + * + * In the absence of irq_eoi(), the chained_irq_enter() and + * chained_irq_exit() functions (used by child irqchip drivers) + * will do unnecessary mask/unmask of per-HART local interrupts + * at the time of handling interrupts. To avoid this, we provide + * an empty irq_eoi() callback for RISC-V INTC irqchip. + */ +} + static struct irq_chip riscv_intc_chip = { .name = "RISC-V INTC", .irq_mask = riscv_intc_irq_mask, .irq_unmask = riscv_intc_irq_unmask, + .irq_eoi = riscv_intc_irq_eoi, }; static int riscv_intc_domain_map(struct irq_domain *d, unsigned int irq, -- cgit v1.2.3