On 01/03/17 01:48, David Daney wrote:
> Follow-on patch for gpio-thunderx uses a irqdomain hierarchy which
> requires slightly different flow handlers, add them to chip.c which
> contains most of the other flow handlers.
>
> Signed-off-by: David Daney <[email protected]>
> ---
> include/linux/irq.h | 2 ++
> kernel/irq/chip.c | 102
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 104 insertions(+)
>
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index f887351..3db0eb8 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -518,6 +518,8 @@ static inline int irq_set_parent(int irq, int parent_irq)
> extern int irq_chip_pm_get(struct irq_data *data);
> extern int irq_chip_pm_put(struct irq_data *data);
> #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> +extern void handle_fasteoi_edge_irq(struct irq_desc *desc);
> +extern void handle_fasteoi_level_irq(struct irq_desc *desc);
> extern void irq_chip_enable_parent(struct irq_data *data);
> extern void irq_chip_disable_parent(struct irq_data *data);
> extern void irq_chip_ack_parent(struct irq_data *data);
> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> index 73ea90b..213105d 100644
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -981,6 +981,108 @@ void irq_cpu_offline(void)
>
> #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> /**
> + * handle_fasteoi_edge_irq - irq handler for edge hierarchy
> + * stacked on transparent controllers
> + *
> + * @desc: the interrupt description structure for this irq
> + *
> + * Like handle_fasteoi_irq(), but for use with hierarchy where
> + * the irq_chip also needs to have its ->irq_ack() function
> + * called.
> + */
> +void handle_fasteoi_edge_irq(struct irq_desc *desc)
> +{
> + struct irq_chip *chip = desc->irq_data.chip;
> +
> + raw_spin_lock(&desc->lock);
> +
> + if (!irq_may_run(desc))
> + goto out;
> +
> + desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
> +
> + /*
> + * If its disabled or no action available
> + * then mask it and get out of here:
> + */
> + if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
> + desc->istate |= IRQS_PENDING;
> + mask_irq(desc);
> + goto out;
> + }
> +
> + kstat_incr_irqs_this_cpu(desc);
> + if (desc->istate & IRQS_ONESHOT)
> + mask_irq(desc);
> +
> + /* Start handling the irq */
> + desc->irq_data.chip->irq_ack(&desc->irq_data);
> +
> + preflow_handler(desc);
> + handle_irq_event(desc);
> +
> + cond_unmask_eoi_irq(desc, chip);
> +
> + raw_spin_unlock(&desc->lock);
> + return;
> +out:
> + if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
> + chip->irq_eoi(&desc->irq_data);
> + raw_spin_unlock(&desc->lock);
> +}
> +EXPORT_SYMBOL_GPL(handle_fasteoi_edge_irq);
So this is handle_fasteoi_irq with an irq_ack() added in the middle. In
the spirit of making this a bit more maintainable, how about making the
handle_fasteoi_irq code reusable (if necessary by forcing the compiler
to inline stuff)?
But the one thing that makes me uncomfortable here is that we're seem to
have this irq_ack() propagated all along the irqdata chain, which is not
what's happening. Only the EOI gets propagated.
Why can't you just put the irq_ack call in your top level irq_eoi
callback? That'd make it similar to what is happening on the mbigen side
(not exactly surprising, since they are doing very similar things).
Same remark about handle_fasteoi_level_irq.
Thoughts?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
