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authorPaul Mundt <lethal@linux-sh.org>2011-04-07 06:01:44 +0900
committerThomas Gleixner <tglx@linutronix.de>2011-04-23 15:56:24 +0200
commit7f1b1244e159a8490d7fb13667c6cb7e1e75046b (patch)
tree1d5f5ff0ec14e3ac84d4ec17b0de4d43dacf8118
parent770767787c23040dc152e7ae230597ff55b39470 (diff)
downloadop-kernel-dev-7f1b1244e159a8490d7fb13667c6cb7e1e75046b.zip
op-kernel-dev-7f1b1244e159a8490d7fb13667c6cb7e1e75046b.tar.gz
genirq: Support per-IRQ thread disabling.
This adds support for disabling threading on a per-IRQ basis via the IRQ status instead of the IRQ flow, which is necessary for interrupts that don't follow the natural IRQ flow channels, such as those that are virtually created. The new APIs added are simply: irq_set_thread() irq_set_nothread() which follow the rest of the IRQ status routines. Chained handlers also have IRQ_NOTHREAD set on them automatically, making the lack of threading explicit rather than implicit. Subsequently, the nothread flag can be viewed through the standard genirq debugging facilities. [ tglx: Fixed cleanup fallout ] Signed-off-by: Paul Mundt <lethal@linux-sh.org> Link: http://lkml.kernel.org/r/%3C20110406210135.GF18426%40linux-sh.org%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--include/linux/irq.h14
-rw-r--r--kernel/irq/chip.c1
-rw-r--r--kernel/irq/debug.h1
-rw-r--r--kernel/irq/manage.c3
-rw-r--r--kernel/irq/settings.h17
5 files changed, 34 insertions, 2 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index a71dd18..39c2378 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -59,6 +59,7 @@ typedef void (*irq_preflow_handler_t)(struct irq_data *data);
* IRQ_NOPROBE - Interrupt cannot be probed by autoprobing
* IRQ_NOREQUEST - Interrupt cannot be requested via
* request_irq()
+ * IRQ_NOTHREAD - Interrupt cannot be threaded
* IRQ_NOAUTOEN - Interrupt is not automatically enabled in
* request/setup_irq()
* IRQ_NO_BALANCING - Interrupt cannot be balanced (affinity set)
@@ -85,6 +86,7 @@ enum {
IRQ_NO_BALANCING = (1 << 13),
IRQ_MOVE_PCNTXT = (1 << 14),
IRQ_NESTED_THREAD = (1 << 15),
+ IRQ_NOTHREAD = (1 << 16),
};
#define IRQF_MODIFY_MASK \
@@ -422,7 +424,7 @@ irq_set_handler(unsigned int irq, irq_flow_handler_t handle)
/*
* Set a highlevel chained flow handler for a given IRQ.
* (a chained handler is automatically enabled and set to
- * IRQ_NOREQUEST and IRQ_NOPROBE)
+ * IRQ_NOREQUEST, IRQ_NOPROBE, and IRQ_NOTHREAD)
*/
static inline void
irq_set_chained_handler(unsigned int irq, irq_flow_handler_t handle)
@@ -452,6 +454,16 @@ static inline void irq_set_probe(unsigned int irq)
irq_modify_status(irq, IRQ_NOPROBE, 0);
}
+static inline void irq_set_nothread(unsigned int irq)
+{
+ irq_modify_status(irq, 0, IRQ_NOTHREAD);
+}
+
+static inline void irq_set_thread(unsigned int irq)
+{
+ irq_modify_status(irq, IRQ_NOTHREAD, 0);
+}
+
static inline void irq_set_nested_thread(unsigned int irq, bool nest)
{
if (nest)
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 4af1e2b..52d856d 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -573,6 +573,7 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
if (handle != handle_bad_irq && is_chained) {
irq_settings_set_noprobe(desc);
irq_settings_set_norequest(desc);
+ irq_settings_set_nothread(desc);
irq_startup(desc);
}
out:
diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h
index 306cba3..97a8bfa 100644
--- a/kernel/irq/debug.h
+++ b/kernel/irq/debug.h
@@ -27,6 +27,7 @@ static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
P(IRQ_PER_CPU);
P(IRQ_NOPROBE);
P(IRQ_NOREQUEST);
+ P(IRQ_NOTHREAD);
P(IRQ_NOAUTOEN);
PS(IRQS_AUTODETECT);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 07c1611..f7ce002 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -900,7 +900,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
*/
new->handler = irq_nested_primary_handler;
} else {
- irq_setup_forced_threading(new);
+ if (irq_settings_can_thread(desc))
+ irq_setup_forced_threading(new);
}
/*
diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h
index 0d91730..f166783 100644
--- a/kernel/irq/settings.h
+++ b/kernel/irq/settings.h
@@ -8,6 +8,7 @@ enum {
_IRQ_LEVEL = IRQ_LEVEL,
_IRQ_NOPROBE = IRQ_NOPROBE,
_IRQ_NOREQUEST = IRQ_NOREQUEST,
+ _IRQ_NOTHREAD = IRQ_NOTHREAD,
_IRQ_NOAUTOEN = IRQ_NOAUTOEN,
_IRQ_MOVE_PCNTXT = IRQ_MOVE_PCNTXT,
_IRQ_NO_BALANCING = IRQ_NO_BALANCING,
@@ -20,6 +21,7 @@ enum {
#define IRQ_LEVEL GOT_YOU_MORON
#define IRQ_NOPROBE GOT_YOU_MORON
#define IRQ_NOREQUEST GOT_YOU_MORON
+#define IRQ_NOTHREAD GOT_YOU_MORON
#define IRQ_NOAUTOEN GOT_YOU_MORON
#define IRQ_NESTED_THREAD GOT_YOU_MORON
#undef IRQF_MODIFY_MASK
@@ -94,6 +96,21 @@ static inline void irq_settings_set_norequest(struct irq_desc *desc)
desc->status_use_accessors |= _IRQ_NOREQUEST;
}
+static inline bool irq_settings_can_thread(struct irq_desc *desc)
+{
+ return !(desc->status_use_accessors & _IRQ_NOTHREAD);
+}
+
+static inline void irq_settings_clr_nothread(struct irq_desc *desc)
+{
+ desc->status_use_accessors &= ~_IRQ_NOTHREAD;
+}
+
+static inline void irq_settings_set_nothread(struct irq_desc *desc)
+{
+ desc->status_use_accessors |= _IRQ_NOTHREAD;
+}
+
static inline bool irq_settings_can_probe(struct irq_desc *desc)
{
return !(desc->status_use_accessors & _IRQ_NOPROBE);
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