Messages in this thread | | | Subject | Re: [PATCH v3 1/3] irqchip/loongson-eiointc: Skip handling if there is no pending irq | From | maobibo <> | Date | Wed, 24 Jan 2024 18:02:10 +0800 |
| |
On 2024/1/24 下午5:51, Huacai Chen wrote: > Hi, Bibo, > > On Thu, Jan 18, 2024 at 8:15 PM Bibo Mao <maobibo@loongson.cn> wrote: >> >> There is one simple optimization in the interrupt dispatch function >> eiointc_irq_dispatch. There are 256 IRQs supported for eiointc, eiointc >> irq handler reads the bitmap and find pending irqs when irq happens. >> So there are four times of consecutive iocsr_read64 operations for the >> total 256 bits to find all pending irqs. If the pending bitmap is zero, >> it means that there is no pending irq for the this irq bitmap range, >> we can skip handling to avoid some useless operations such as clearing >> hw ISR. >> >> Signed-off-by: Bibo Mao <maobibo@loongson.cn> >> --- >> drivers/irqchip/irq-loongson-eiointc.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/drivers/irqchip/irq-loongson-eiointc.c b/drivers/irqchip/irq-loongson-eiointc.c >> index 1623cd779175..6143adb1b73b 100644 >> --- a/drivers/irqchip/irq-loongson-eiointc.c >> +++ b/drivers/irqchip/irq-loongson-eiointc.c >> @@ -198,6 +198,17 @@ static void eiointc_irq_dispatch(struct irq_desc *desc) >> >> for (i = 0; i < eiointc_priv[0]->vec_count / VEC_COUNT_PER_REG; i++) { >> pending = iocsr_read64(EIOINTC_REG_ISR + (i << 3)); >> + >> + /* >> + * Get pending eiointc irq from bitmap status, there are 4 times >> + * consecutive iocsr_read64 operations for 256 IRQs. >> + * >> + * Skip handling if pending bitmap is zero > This driver is shared by Loongson-2 and Loongson-3 series, for > Loongson-2K0500 there is only 128 IRQs, so I suggest only keep the > last line "Skip handling if current pending bitmap is zero" is enough. Sure, will refine the patch in this way.
Regards Bibo Mao > > Huacai > >> + */ >> + if (!pending) >> + continue; >> + >> + /* Clear the IRQs */ >> iocsr_write64(pending, EIOINTC_REG_ISR + (i << 3)); >> while (pending) { >> int bit = __ffs(pending); >> -- >> 2.39.3 >>
| |