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 <apatel@ventanamicro.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230328035223.1480939-8-apatel@ventanamicro.com
This commit is contained in:
Anup Patel 2023-03-28 09:22:23 +05:30 committed by Marc Zyngier
parent 6279228432
commit f8415f2def
1 changed files with 17 additions and 0 deletions

View File

@ -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,