[patch 02/46] Add a functions to handle interrupt affinity setting

Thomas Gleixner
2007-01-23T22:11:50Z

[-- Attachment #1: genirq-add-set-affinity-function.patch --]
[-- Type: text/plain, Size: 4312 bytes --]

From: Thomas Gleixner <tglx@linutronix.de>

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)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
include/linux/irq.h | 20 +++++++++++++++-----
kernel/irq/manage.c | 40 ++++++++++++++++++++++++++++++++++++++++
kernel/irq/proc.c | 22 +---------------------
3 files changed, 56 insertions(+), 26 deletions(-)

Index: linux-2.6.20-rc4-mm1-bo/include/linux/irq.h
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/include/linux/irq.h
+++ linux-2.6.20-rc4-mm1-bo/include/linux/irq.h
@@ -70,11 +70,6 @@ typedef void fastcall (*irq_flow_handler
# define IRQ_NO_BALANCING_MASK IRQ_NO_BALANCING
#endif

-static inline int irq_balancing_disabled(unsigned int irq)
-{
- return irq_desc[irq].status & IRQ_NO_BALANCING_MASK;
-}
-
struct proc_dir_entry;

/**
@@ -241,11 +236,21 @@ static inline void set_pending_irq(unsig

#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
@@ -267,6 +272,11 @@ static inline int select_smp_affinity(un

extern int no_irq_affinity;

+static inline int irq_balancing_disabled(unsigned int irq)
+{
+ return irq_desc[irq].status & IRQ_NO_BALANCING_MASK;
+}
+
/* Handle irq action chains: */
extern int handle_IRQ_event(unsigned int irq, struct irqaction *action);

Index: linux-2.6.20-rc4-mm1-bo/kernel/irq/manage.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/irq/manage.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/irq/manage.c
@@ -38,6 +38,46 @@ void synchronize_irq(unsigned int irq)
}
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
+ irq_desc[irq]->affinity = cpumask;
+ irq_desc[irq]->chip->set_affinity(irq, cpumask);
+#endif
+ return 0;
+}
+
#endif

/**
Index: linux-2.6.20-rc4-mm1-bo/kernel/irq/proc.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/irq/proc.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/irq/proc.c
@@ -16,26 +16,6 @@ static struct proc_dir_entry *root_irq_d

#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 @@ static int irq_affinity_write_proc(struc
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;
}

--