irq: replace loop with nr_irqs with for_each_irq_desc
There are a handful of loops that go from 0 to nr_irqs and use
get_irq_desc() on them. These would allocate all the irq_desc
entries, regardless of the need for them.
Use the smarter for_each_irq_desc() iterator that will only iterate
over the present ones.
v2: make sure arch without GENERIC_HARDIRQS work too
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index 51ef7eb..708be97 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -1871,10 +1871,10 @@
static void ir_irq_migration(struct work_struct *work)
{
- int irq;
+ unsigned int irq;
+ struct irq_desc *desc;
- for (irq = 0; irq < nr_irqs; irq++) {
- struct irq_desc *desc = irq_to_desc(irq);
+ for_each_irq_desc(irq, desc) {
if (desc->status & IRQ_MOVE_PENDING) {
unsigned long flags;
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 4a0a4eb..b3cf55e 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -224,17 +224,16 @@
{
unsigned int irq;
static int warned;
+ struct irq_desc *desc;
- for (irq = 0; irq < nr_irqs; irq++) {
+ for_each_irq_desc(irq, desc) {
cpumask_t mask;
int break_affinity = 0;
int set_affinity = 1;
- struct irq_desc *desc;
if (irq == 2)
continue;
- desc = irq_to_desc(irq);
/* interrupt's are disabled at this point */
spin_lock(&desc->lock);
diff --git a/arch/x86/kernel/irqinit_64.c b/arch/x86/kernel/irqinit_64.c
index 0744b49..cd9f42d 100644
--- a/arch/x86/kernel/irqinit_64.c
+++ b/arch/x86/kernel/irqinit_64.c
@@ -142,25 +142,18 @@
init_bsp_APIC();
init_8259A(0);
- for (i = 0; i < nr_irqs; i++) {
+ for (i = 0; i < 16; i++) {
struct irq_desc *desc = irq_to_desc(i);
desc->status = IRQ_DISABLED;
desc->action = NULL;
desc->depth = 1;
- if (i < 16) {
- /*
- * 16 old-style INTA-cycle interrupts:
- */
- set_irq_chip_and_handler_name(i, &i8259A_chip,
+ /*
+ * 16 old-style INTA-cycle interrupts:
+ */
+ set_irq_chip_and_handler_name(i, &i8259A_chip,
handle_level_irq, "XT");
- } else {
- /*
- * 'high' PCI IRQs filled in on demand
- */
- desc->chip = &no_irq_chip;
- }
}
}
diff --git a/include/linux/irq.h b/include/linux/irq.h
index c9ffef7..9de16ca 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -202,9 +202,16 @@
extern struct irq_desc *irq_desc;
#endif
+#ifdef CONFIG_GENERIC_HARDIRQS
+#define for_each_irq_desc(irq, desc) \
+ for (irq = 0, desc = irq_desc; irq < nr_irqs; irq++, desc = &irq_desc[irq])
+#endif
+
#else
extern struct irq_desc *sparse_irqs;
+#define for_each_irq_desc(irqX, desc) \
+ for (desc = sparse_irqs, irqX = desc->irq; desc && irqX != -1U; desc = desc->next, irqX = desc ? desc->irq : -1U)
#endif
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 422dd00..c9767e6 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -14,11 +14,11 @@
unsigned long flags);
#ifdef CONFIG_PROC_FS
-extern void register_irq_proc(unsigned int irq);
+extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
extern void register_handler_proc(unsigned int irq, struct irqaction *action);
extern void unregister_handler_proc(unsigned int irq, struct irqaction *action);
#else
-static inline void register_irq_proc(unsigned int irq) { }
+static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { }
static inline void register_handler_proc(unsigned int irq,
struct irqaction *action) { }
static inline void unregister_handler_proc(unsigned int irq,
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index b5943e9..5070f55 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -478,7 +478,7 @@
spin_unlock_irqrestore(&desc->lock, flags);
new->irq = irq;
- register_irq_proc(irq);
+ register_irq_proc(irq, desc);
new->dir = NULL;
register_handler_proc(irq, new);
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index c2f356c..bc0993d 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -182,11 +182,10 @@
#define MAX_NAMELEN 10
-void register_irq_proc(unsigned int irq)
+void register_irq_proc(unsigned int irq, struct irq_desc *desc)
{
char name [MAX_NAMELEN];
struct proc_dir_entry *entry;
- struct irq_desc *desc = irq_to_desc(irq);
if (!root_irq_dir || (desc->chip == &no_irq_chip) || desc->dir)
return;
@@ -230,7 +229,8 @@
void init_irq_proc(void)
{
- int i;
+ unsigned int irq;
+ struct irq_desc *desc;
/* create /proc/irq */
root_irq_dir = proc_mkdir("irq", NULL);
@@ -242,7 +242,7 @@
/*
* Create entries for all existing IRQs.
*/
- for (i = 0; i < nr_irqs; i++)
- register_irq_proc(i);
+ for_each_irq_desc(irq, desc)
+ register_irq_proc(irq, desc);
}
