lkml.org 
[lkml]   [2011]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4/5] RFC genirq: allow dynamic switching of timestamping irqs
Date
Subsystems might want to dynamically switch irq timestamping,
if some subsystem driver requests timestamps.

This patch adds:
void irq_turn_on_timestamping(unsigned int irq, void *dev_id)
void irq_turn_off_timestamping(unsigned int irq, void *dev_id)

Signed-off-by: Torben Hohn <torbenh@gmx.de>
---
include/linux/interrupt.h | 3 ++
kernel/irq/manage.c | 66 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 69 insertions(+), 0 deletions(-)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 906b3b6..cc9ed9c 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -175,6 +175,9 @@ request_any_context_irq(unsigned int irq, irq_handler_t handler,
static inline void exit_irq_thread(void) { }
#endif

+extern void irq_turn_on_timestamping(unsigned int irq, void *dev_id);
+extern void irq_turn_off_timestamping(unsigned int irq, void *dev_id);
+
extern void free_irq(unsigned int, void *);

struct device;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index b60350f..66e9501 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -649,6 +649,72 @@ void exit_irq_thread(void)
}

/*
+ * irq_turn_on_timestamping - Turn on timestamping for irq line.
+ * @irq: Interrupt line
+ * @dev_id: Device Id for which to turn on timestamping.
+ * (must point to a struct timespec)
+ *
+ * Turning on timestamping nests.
+ */
+void irq_turn_on_timestamping(unsigned int irq, void *dev_id)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned long flags;
+ struct irqaction *act;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ desc->status |= IRQ_TIMESTAMP;
+
+ act = desc->action;
+ while (act) {
+ if (act->dev_id == dev_id) {
+ act->flags |= IRQF_TIMESTAMP;
+ break;
+ }
+ act = act->next;
+ }
+
+ BUG_ON( act==NULL );
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+ /* maybe we need to synchronise_irq() here ??? */
+}
+EXPORT_SYMBOL_GPL(irq_turn_on_timestamping);
+
+/*
+ * irq_turn_off_timestamping - Turn off timestamping for irq line.
+ * @irq: Interrupt line
+ * @dev_id: Device Id for which to turn off timestamping.
+ *
+ * Turning on timestamping nests.
+ */
+void irq_turn_off_timestamping(unsigned int irq, void *dev_id)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned long flags;
+ struct irqaction *act;
+ unsigned long irqf_accu = 0;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ act = desc->action;
+ while (act) {
+ if (act->dev_id == dev_id) {
+ act->flags &= ~(IRQF_TIMESTAMP);
+ }
+ irqf_accu |= act->flags;
+ act = act->next;
+ }
+
+ if ((irqf_accu & IRQF_TIMESTAMP) == 0)
+ desc->status &= ~(IRQ_TIMESTAMP);
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL_GPL(irq_turn_off_timestamping);
+
+/*
* Internal function to register an irqaction - typically used to
* allocate special interrupts that are part of the architecture.
*/
--
1.7.2.3


\
 
 \ /
  Last update: 2011-03-21 13:03    [W:1.812 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site