Re: [RFC PATCH] irqchip: add dumb demultiplexer implementation

From: Thomas Gleixner
Date: Tue Jan 13 2015 - 12:32:22 EST


On Tue, 13 Jan 2015, Boris Brezillon wrote:
> On Tue, 13 Jan 2015 11:38:14 +0100 (CET)
> Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> >
> > > +/**
> > > + * handle_dumb_demux_irq - Dumb demuxer irq handle function.
> > > + * @irq: the interrupt number
> > > + * @desc: the interrupt description structure for this irq
> > > + *
> > > + * Dumb demux interrupts are sent from a demultiplexing interrupt handler
> > > + * which is not able to decide which child interrupt interrupt handler
> > > + * should be called.
> > > + *
> > > + * Note: The caller is expected to handle the ack, clear, mask and
> > > + * unmask issues if necessary.
> > > + */
> > > +irqreturn_t
> > > +handle_dumb_demux_irq(unsigned int irq, struct irq_desc *desc)
> > > +{
> > > + irqreturn_t retval = IRQ_NONE;
> > > +
> > > + raw_spin_lock(&desc->lock);
> > > +
> > > + if (!irq_may_run(desc))
> > > + goto out_unlock;
> > > +
> > > + desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
> > > + kstat_incr_irqs_this_cpu(irq, desc);
> > > +
> > > + if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
> > > + desc->istate |= IRQS_PENDING;
> > > + goto out_unlock;
> > > + }
> > > +
> > > + retval = handle_irq_event_no_spurious_check(desc);
> > > +
> > > +out_unlock:
> > > + raw_spin_unlock(&desc->lock);
> > > +
> > > + return retval;
> > > +}
> > > +EXPORT_SYMBOL_GPL(handle_dumb_demux_irq);
> >
> > This should go into the new file as well, so it gets compiled out when
> > not enabled.
>
> Actually, I can't move that function out of kernel/irq/chip.c because
> it calls irq_may_run which is statically defined in this file.
> Should I export this function or just enclose it in a
> #ifdef DUMB_IRQ_DEMUX section ?

Missed that. Make it conditional then.
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