Messages in this thread Patch in this message | | | Date | Thu, 10 Dec 2020 15:07:57 +0000 | From | Will Deacon <> | Subject | Re: [PATCH v2 2/6] genirq: Allow an interrupt to be marked as 'raw' |
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Hi Marc,
On Tue, Nov 24, 2020 at 02:14:45PM +0000, Marc Zyngier wrote: > Some interrupts (such as the rescheduling IPI) rely on not going through > the irq_enter()/irq_exit() calls. To distinguish such interrupts, add > a new IRQ flag that allows the low-level handling code to sidestep the > enter()/exit() calls. > > Only the architecture code is expected to use this. It will do the wrong > thing on normal interrupts. Note that this is a band-aid until we can > move to some more correct infrastructure (such as kernel/entry/common.c). > > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > include/linux/irq.h | 2 ++ > kernel/irq/Kconfig | 3 +++ > kernel/irq/debugfs.c | 1 + > kernel/irq/irqdesc.c | 17 ++++++++++++----- > kernel/irq/settings.h | 15 +++++++++++++++ > 5 files changed, 33 insertions(+), 5 deletions(-)
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> diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c > index 1a7723604399..f5beee546a6f 100644 > --- a/kernel/irq/irqdesc.c > +++ b/kernel/irq/irqdesc.c > @@ -667,10 +667,9 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq, > { > struct pt_regs *old_regs = set_irq_regs(regs); > unsigned int irq = hwirq; > + struct irq_desc *desc; > int ret = 0; > > - irq_enter(); > - > #ifdef CONFIG_IRQ_DOMAIN > if (lookup) > irq = irq_find_mapping(domain, hwirq); > @@ -680,14 +679,22 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq, > * Some hardware gives randomly wrong interrupts. Rather > * than crashing, do something sensible. > */ > - if (unlikely(!irq || irq >= nr_irqs)) { > + if (unlikely(!irq || irq >= nr_irqs || !(desc = irq_to_desc(irq)))) { > ack_bad_irq(irq); > ret = -EINVAL; > + goto out; > + } > + > + if (IS_ENABLED(CONFIG_ARCH_WANTS_IRQ_RAW) && > + unlikely(irq_settings_is_raw(desc))) { > + generic_handle_irq_desc(desc);
Based on tglx's previous comments, I was expecting to see calls to __irq_{enter,exit}_raw() around this. Are they hiding somewhere else or are they not needed?
Will
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