Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH 1/2] genirq: Allow an interrupt to be marked as 'naked' | Date | Sun, 1 Nov 2020 14:33:05 +0000 |
| |
From: Marc Zyngier > Sent: 01 November 2020 13:14 > > 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. > > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > include/linux/irq.h | 4 +++- > kernel/irq/debugfs.c | 1 + > kernel/irq/irqdesc.c | 17 ++++++++++++----- > kernel/irq/settings.h | 7 +++++++ > 4 files changed, 23 insertions(+), 6 deletions(-) > ... > diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c > index 1a7723604399..c08a1c19d061 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)) { > + desc = irq_to_desc(irq); > + if (unlikely(!desc || irq >= nr_irqs)) {
Should those tests be in the other order? Probably as: if (unlikely(irq >= nr_irqs || !(desc = irq_to_desc(irq))) { ...
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
| |