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genirq: Add a new IRQCHIP_EOI_THREADED flag

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The flag is necessary for interrupt chips which require an ACK/EOI
after the handler has run. In case of threaded handlers this needs to
happen after the threaded handler has completed before the unmask of
the interrupt.

The flag is only unseful in combination with the handle_fasteoi_irq
flow control handler.

It can be combined with the flag IRQCHIP_EOI_IF_HANDLED, so the EOI is
not issued when the interrupt is disabled or in progress.

Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-sunxi@googlegroups.com
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: http://lkml.kernel.org/r/1394733834-26839-2-git-send-email-hdegoede@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2014-03-13 19:03:51 +01:00
parent 4f6e4f71c9
commit 328a4978df
4 changed files with 44 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
include/linux/irq.h
View file

@ -356,6 +356,7 @@ struct irq_chip {
* when irq enabled
* IRQCHIP_SKIP_SET_WAKE: Skip chip.irq_set_wake(), for this irq chip
* IRQCHIP_ONESHOT_SAFE: One shot does not require mask/unmask
* IRQCHIP_EOI_THREADED: Chip requires eoi() on unmask in threaded mode
*/
enum {
IRQCHIP_SET_TYPE_MASKED = (1 << 0),
@ -364,6 +365,7 @@ enum {
IRQCHIP_ONOFFLINE_ENABLED = (1 << 3),
IRQCHIP_SKIP_SET_WAKE = (1 << 4),
IRQCHIP_ONESHOT_SAFE = (1 << 5),
IRQCHIP_EOI_THREADED = (1 << 6),
};
/* This include will go away once we isolated irq_desc usage to core code */

48
kernel/irq/chip.c
View file

@ -281,6 +281,19 @@ void unmask_irq(struct irq_desc *desc)
}
}
void unmask_threaded_irq(struct irq_desc *desc)
{
struct irq_chip *chip = desc->irq_data.chip;
if (chip->flags & IRQCHIP_EOI_THREADED)
chip->irq_eoi(&desc->irq_data);
if (chip->irq_unmask) {
chip->irq_unmask(&desc->irq_data);
irq_state_clr_masked(desc);
}
}
/*
* handle_nested_irq - Handle a nested irq from a irq thread
* @irq: the interrupt number
@ -435,6 +448,27 @@ static inline void preflow_handler(struct irq_desc *desc)
static inline void preflow_handler(struct irq_desc *desc) { }
#endif
static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
{
if (!(desc->istate & IRQS_ONESHOT)) {
chip->irq_eoi(&desc->irq_data);
return;
}
/*
* We need to unmask in the following cases:
* - Oneshot irq which did not wake the thread (caused by a
* spurious interrupt or a primary handler handling it
* completely).
*/
if (!irqd_irq_disabled(&desc->irq_data) &&
irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) {
chip->irq_eoi(&desc->irq_data);
unmask_irq(desc);
} else if (!(chip->flags & IRQCHIP_EOI_THREADED)) {
chip->irq_eoi(&desc->irq_data);
}
}
/**
* handle_fasteoi_irq - irq handler for transparent controllers
* @irq: the interrupt number
@ -448,6 +482,8 @@ static inline void preflow_handler(struct irq_desc *desc) { }
void
handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
{
struct irq_chip *chip = desc->irq_data.chip;
raw_spin_lock(&desc->lock);
if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
@ -473,18 +509,14 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
preflow_handler(desc);
handle_irq_event(desc);
if (desc->istate & IRQS_ONESHOT)
cond_unmask_irq(desc);
cond_unmask_eoi_irq(desc, chip);
out_eoi:
desc->irq_data.chip->irq_eoi(&desc->irq_data);
out_unlock:
raw_spin_unlock(&desc->lock);
return;
out:
if (!(desc->irq_data.chip->flags & IRQCHIP_EOI_IF_HANDLED))
goto out_eoi;
goto out_unlock;
if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
chip->irq_eoi(&desc->irq_data);
raw_spin_unlock(&desc->lock);
}
/**

1
kernel/irq/internals.h
View file

@ -74,6 +74,7 @@ extern void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu);
extern void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu);
extern void mask_irq(struct irq_desc *desc);
extern void unmask_irq(struct irq_desc *desc);
extern void unmask_threaded_irq(struct irq_desc *desc);
extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);

2
kernel/irq/manage.c
View file

@ -748,7 +748,7 @@ again:
if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
irqd_irq_masked(&desc->irq_data))
unmask_irq(desc);
unmask_threaded_irq(desc);
out_unlock:
raw_spin_unlock_irq(&desc->lock);