On Thu, May 16, 2024 at 8:23 PM maobibo <maobibo@xxxxxxxxxxx> wrote:
>
>
>
> On 2024/5/14 下午3:32, Huacai Chen wrote:
> > Add irq_work support for LoongArch via self IPIs. This make it possible
> > to run works in hardware interrupt context, which is a prerequisite for
> > NOHZ_FULL.
> >
> > Implement:
> > - arch_irq_work_raise()
> > - arch_irq_work_has_interrupt()
> >
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
> > arch/loongarch/include/asm/hardirq.h | 3 ++-
> > arch/loongarch/include/asm/irq_work.h | 10 ++++++++++
> > arch/loongarch/include/asm/smp.h | 2 ++
> > arch/loongarch/kernel/paravirt.c | 6 ++++++
> > arch/loongarch/kernel/smp.c | 14 ++++++++++++++
> > 5 files changed, 34 insertions(+), 1 deletion(-)
> > create mode 100644 arch/loongarch/include/asm/irq_work.h
> >
> > diff --git a/arch/loongarch/include/asm/hardirq.h b/arch/loongarch/include/asm/hardirq.h
> > index d41138abcf26..1d7feb719515 100644
> > --- a/arch/loongarch/include/asm/hardirq.h
> > +++ b/arch/loongarch/include/asm/hardirq.h
> > @@ -12,11 +12,12 @@
> > extern void ack_bad_irq(unsigned int irq);
> > #define ack_bad_irq ack_bad_irq
> >
> > -#define NR_IPI 2
> > +#define NR_IPI 3
> >
> > enum ipi_msg_type {
> > IPI_RESCHEDULE,
> > IPI_CALL_FUNCTION,
> > + IPI_IRQ_WORK,
> > };
> >
> > typedef struct {
> > diff --git a/arch/loongarch/include/asm/irq_work.h b/arch/loongarch/include/asm/irq_work.h
> > new file mode 100644
> > index 000000000000..d63076e9160d
> > --- /dev/null
> > +++ b/arch/loongarch/include/asm/irq_work.h
> > @@ -0,0 +1,10 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _ASM_LOONGARCH_IRQ_WORK_H
> > +#define _ASM_LOONGARCH_IRQ_WORK_H
> > +
> > +static inline bool arch_irq_work_has_interrupt(void)
> > +{
> > + return IS_ENABLED(CONFIG_SMP);
> > +}
> > +
> > +#endif /* _ASM_LOONGARCH_IRQ_WORK_H */
> > diff --git a/arch/loongarch/include/asm/smp.h b/arch/loongarch/include/asm/smp.h
> > index 278700cfee88..50db503f44e3 100644
> > --- a/arch/loongarch/include/asm/smp.h
> > +++ b/arch/loongarch/include/asm/smp.h
> > @@ -69,9 +69,11 @@ extern int __cpu_logical_map[NR_CPUS];
> > #define ACTION_BOOT_CPU 0
> > #define ACTION_RESCHEDULE 1
> > #define ACTION_CALL_FUNCTION 2
> > +#define ACTION_IRQ_WORK 3
> > #define SMP_BOOT_CPU BIT(ACTION_BOOT_CPU)
> > #define SMP_RESCHEDULE BIT(ACTION_RESCHEDULE)
> > #define SMP_CALL_FUNCTION BIT(ACTION_CALL_FUNCTION)
> > +#define SMP_IRQ_WORK BIT(ACTION_IRQ_WORK)
> >
> > struct secondary_data {
> > unsigned long stack;
> > diff --git a/arch/loongarch/kernel/paravirt.c b/arch/loongarch/kernel/paravirt.c
> > index 1633ed4f692f..4272d2447445 100644
> > --- a/arch/loongarch/kernel/paravirt.c
> > +++ b/arch/loongarch/kernel/paravirt.c
> > @@ -2,6 +2,7 @@
> > #include <linux/export.h>
> > #include <linux/types.h>
> > #include <linux/interrupt.h>
> > +#include <linux/irq_work.h>
> > #include <linux/jump_label.h>
> > #include <linux/kvm_para.h>
> > #include <linux/static_call.h>
> > @@ -97,6 +98,11 @@ static irqreturn_t pv_ipi_interrupt(int irq, void *dev)
> > info->ipi_irqs[IPI_CALL_FUNCTION]++;
> > }
> >
> > + if (action & SMP_IRQ_WORK) {
> > + irq_work_run();
> > + info->ipi_irqs[IPI_IRQ_WORK]++;
> > + }
> > +
> Would you mind adding common api so that pv ipi handler and hw ipi
> handler can call it both? The coming avec MSI interrupt driver has the
> same requirement for ipi.
We can refactor it after AVEC upstream, if needed.
Huacai
>
> void do_ipi_demux(unsigned int action)
> {
> irq_cpustat_t *info;
>
> info = this_cpu_ptr(&irq_stat);
> if (action & SMP_RESCHEDULE) {
> scheduler_ipi();
> info->ipi_irqs[IPI_RESCHEDULE]++;
> }
>
> if (action & SMP_CALL_FUNCTION) {
> generic_smp_call_function_interrupt();
> info->ipi_irqs[IPI_CALL_FUNCTION]++;
> }
>
> if (action & SMP_IRQ_WORK) {
> irq_work_run();
> info->ipi_irqs[IPI_IRQ_WORK]++;
> }
>
> Regards
> Bibo Mao
> > return IRQ_HANDLED;
> > }
> >
> > diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
> > index 0dfe2388ef41..7366de776f6e 100644
> > --- a/arch/loongarch/kernel/smp.c
> > +++ b/arch/loongarch/kernel/smp.c
> > @@ -13,6 +13,7 @@
> > #include <linux/cpumask.h>
> > #include <linux/init.h>
> > #include <linux/interrupt.h>
> > +#include <linux/irq_work.h>
> > #include <linux/profile.h>
> > #include <linux/seq_file.h>
> > #include <linux/smp.h>
> > @@ -70,6 +71,7 @@ static DEFINE_PER_CPU(int, cpu_state);
> > static const char *ipi_types[NR_IPI] __tracepoint_string = {
> > [IPI_RESCHEDULE] = "Rescheduling interrupts",
> > [IPI_CALL_FUNCTION] = "Function call interrupts",
> > + [IPI_IRQ_WORK] = "IRQ work interrupts",
> > };
> >
> > void show_ipi_list(struct seq_file *p, int prec)
> > @@ -217,6 +219,13 @@ void arch_smp_send_reschedule(int cpu)
> > }
> > EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);
> >
> > +#ifdef CONFIG_IRQ_WORK
> > +void arch_irq_work_raise(void)
> > +{
> > + mp_ops.send_ipi_single(smp_processor_id(), ACTION_IRQ_WORK);
> > +}
> > +#endif
> > +
> > static irqreturn_t loongson_ipi_interrupt(int irq, void *dev)
> > {
> > unsigned int action;
> > @@ -234,6 +243,11 @@ static irqreturn_t loongson_ipi_interrupt(int irq, void *dev)
> > per_cpu(irq_stat, cpu).ipi_irqs[IPI_CALL_FUNCTION]++;
> > }
> >
> > + if (action & SMP_IRQ_WORK) {
> > + irq_work_run();
> > + per_cpu(irq_stat, cpu).ipi_irqs[IPI_IRQ_WORK]++;
> > + }
> > +
> > return IRQ_HANDLED;
> > }
> >
> >
>
>
