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authorThomas Gleixner <tglx@linutronix.de>2014-03-13 19:03:51 +0100
committerThomas Gleixner <tglx@linutronix.de>2014-03-14 13:43:33 +0100
commit328a4978df833249b099c9875738d7b72042ffe1 (patch)
tree8d35f45b166d16d5bdcbf40d12331118453384d6
parent4f6e4f71c9d39cf49e0cb1be5b7721db5fbe92ac (diff)
downloadlinux-328a4978df833249b099c9875738d7b72042ffe1.tar.bz2
genirq: Add a new IRQCHIP_EOI_THREADED flag
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>
-rw-r--r--include/linux/irq.h2
-rw-r--r--kernel/irq/chip.c48
-rw-r--r--kernel/irq/internals.h1
-rw-r--r--kernel/irq/manage.c2
4 files changed, 44 insertions, 9 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 67ace7aa7947..d278838908cb 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -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 */
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index dc04c166c54d..6397df2d6945 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -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);
}
/**
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 17b671713d5f..ddf1ffeb79f1 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -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);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index de1a8ed29b40..2486a4c1a710 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -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);