[PATCH] Add a function to handle interrupt affinity setting
Provide funtions to:
- check, whether an interrupt can set the affinity
- pin the interrupt to a given cpu
Necessary for the ability to setup clocksources more flexible (e.g. use the
different HPET channels per CPU)
[akpm@osdl.org: alpha build fix]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 8930fb0..29f715e 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -238,11 +238,21 @@
#endif /* CONFIG_GENERIC_PENDING_IRQ */
+extern int irq_set_affinity(unsigned int irq, cpumask_t cpumask);
+extern int irq_can_set_affinity(unsigned int irq);
+
#else /* CONFIG_SMP */
#define move_native_irq(x)
#define move_masked_irq(x)
+static inline int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
+{
+ return -EINVAL;
+}
+
+static inline int irq_can_set_affinity(unsigned int irq) { return 0; }
+
#endif /* CONFIG_SMP */
#ifdef CONFIG_IRQBALANCE
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index cd790ad..5597c15 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -38,6 +38,46 @@
}
EXPORT_SYMBOL(synchronize_irq);
+/**
+ * irq_can_set_affinity - Check if the affinity of a given irq can be set
+ * @irq: Interrupt to check
+ *
+ */
+int irq_can_set_affinity(unsigned int irq)
+{
+ struct irq_desc *desc = irq_desc + irq;
+
+ if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip ||
+ !desc->chip->set_affinity)
+ return 0;
+
+ return 1;
+}
+
+/**
+ * irq_set_affinity - Set the irq affinity of a given irq
+ * @irq: Interrupt to set affinity
+ * @cpumask: cpumask
+ *
+ */
+int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
+{
+ struct irq_desc *desc = irq_desc + irq;
+
+ if (!desc->chip->set_affinity)
+ return -EINVAL;
+
+ set_balance_irq_affinity(irq, cpumask);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+ set_pending_irq(irq, cpumask);
+#else
+ desc->affinity = cpumask;
+ desc->chip->set_affinity(irq, cpumask);
+#endif
+ return 0;
+}
+
#endif
/**
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index bb44bc9..2db91eb 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -16,26 +16,6 @@
#ifdef CONFIG_SMP
-#ifdef CONFIG_GENERIC_PENDING_IRQ
-void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
-{
- set_balance_irq_affinity(irq, mask_val);
-
- /*
- * Save these away for later use. Re-progam when the
- * interrupt is pending
- */
- set_pending_irq(irq, mask_val);
-}
-#else
-void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
-{
- set_balance_irq_affinity(irq, mask_val);
- irq_desc[irq].affinity = mask_val;
- irq_desc[irq].chip->set_affinity(irq, mask_val);
-}
-#endif
-
static int irq_affinity_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
@@ -73,7 +53,7 @@
code to set default SMP affinity. */
return select_smp_affinity(irq) ? -EINVAL : full_count;
- proc_set_irq_affinity(irq, new_value);
+ irq_set_affinity(irq, new_value);
return full_count;
}