Commit f8415f2d authored by Anup Patel's avatar Anup Patel Committed by Marc Zyngier
Browse files

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: default avatarAnup Patel <apatel@ventanamicro.com>
Acked-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230328035223.1480939-8-apatel@ventanamicro.com
parent 62792284

drivers/irqchip/irq-riscv-intc.c

+17 −0
Original line number Diff line number Diff line
@@ -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,