generic: sparse irqs: use irq_desc() together with dyn_array, instead of irq_desc[]
add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.
Preallocate 32 irq_desc, and irq_desc() will try to get more.
( No change in functionality is expected anywhere, except the odd build
failure where we missed a code site or where a crossing commit itroduces
new irq_desc[] usage. )
v2: according to Eric, change get_irq_desc() to irq_desc()
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 6ce3bcc..9fc33b3 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -18,6 +18,14 @@
#include "internals.h"
+#ifdef CONFIG_TRACE_IRQFLAGS
+
+/*
+ * lockdep: we want to handle all irq_desc locks as a single lock-class:
+ */
+static struct lock_class_key irq_desc_lock_class;
+#endif
+
/**
* handle_bad_irq - handle spurious and unhandled irqs
* @irq: the interrupt number
@@ -51,7 +59,8 @@
EXPORT_SYMBOL_GPL(nr_irqs);
#ifdef CONFIG_HAVE_DYN_ARRAY
-static struct irq_desc irq_desc_init __initdata = {
+static struct irq_desc irq_desc_init = {
+ .irq = -1U,
.status = IRQ_DISABLED,
.chip = &no_irq_chip,
.handle_irq = handle_bad_irq,
@@ -62,6 +71,27 @@
#endif
};
+
+static void init_one_irq_desc(struct irq_desc *desc)
+{
+ memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
+#ifdef CONFIG_TRACE_IRQFLAGS
+ lockdep_set_class(&desc->lock, &irq_desc_lock_class);
+#endif
+}
+
+#ifdef CONFIG_HAVE_SPARSE_IRQ
+static int nr_irq_desc = 32;
+
+static int __init parse_nr_irq_desc(char *arg)
+{
+ if (arg)
+ nr_irq_desc = simple_strtoul(arg, NULL, 0);
+ return 0;
+}
+
+early_param("nr_irq_desc", parse_nr_irq_desc);
+
static void __init init_work(void *data)
{
struct dyn_array *da = data;
@@ -71,12 +101,83 @@
desc = *da->name;
for (i = 0; i < *da->nr; i++)
- memcpy(&desc[i], &irq_desc_init, sizeof(struct irq_desc));
+ init_one_irq_desc(&desc[i]);
+
+ for (i = 1; i < *da->nr; i++)
+ desc[i-1].next = &desc[i];
}
-struct irq_desc *irq_desc;
+static struct irq_desc *sparse_irqs;
+DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work);
+
+extern int after_bootmem;
+extern void *__alloc_bootmem_nopanic(unsigned long size,
+ unsigned long align,
+ unsigned long goal);
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+ struct irq_desc *desc, *desc_pri;
+ int i;
+ int count = 0;
+
+ BUG_ON(irq == -1U);
+
+ desc_pri = desc = &sparse_irqs[0];
+ while (desc) {
+ if (desc->irq == irq)
+ return desc;
+
+ if (desc->irq == -1U) {
+ desc->irq = irq;
+ return desc;
+ }
+ desc_pri = desc;
+ desc = desc->next;
+ count++;
+ }
+
+ /*
+ * we run out of pre-allocate ones, allocate more
+ */
+ printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc);
+
+ if (after_bootmem)
+ desc = kzalloc(sizeof(struct irq_desc)*nr_irq_desc, GFP_ATOMIC);
+ else
+ desc = __alloc_bootmem_nopanic(sizeof(struct irq_desc)*nr_irq_desc, PAGE_SIZE, 0);
+
+ if (!desc)
+ panic("please boot with nr_irq_desc= %d\n", count * 2);
+
+ for (i = 0; i < nr_irq_desc; i++)
+ init_one_irq_desc(&desc[i]);
+
+ for (i = 1; i < nr_irq_desc; i++)
+ desc[i-1].next = &desc[i];
+
+ desc->irq = irq;
+ desc_pri->next = desc;
+
+ return desc;
+}
+#else
+static void __init init_work(void *data)
+{
+ struct dyn_array *da = data;
+ int i;
+ struct irq_desc *desc;
+
+ desc = *da->name;
+
+ for (i = 0; i < *da->nr; i++)
+ init_one_irq_desc(&desc[i]);
+
+}
+static struct irq_desc *irq_desc;
DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work);
+#endif
+
#else
struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
@@ -85,12 +186,23 @@
.chip = &no_irq_chip,
.handle_irq = handle_bad_irq,
.depth = 1,
- .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
+ .lock = __SPIN_LOCK_UNLOCKED(sparse_irqs->lock),
#ifdef CONFIG_SMP
.affinity = CPU_MASK_ALL
#endif
}
};
+
+#endif
+
+#ifndef CONFIG_HAVE_SPARSE_IRQ
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+ if (irq < nr_irqs)
+ return &irq_desc[irq];
+
+ return NULL;
+}
#endif
/*
@@ -99,7 +211,10 @@
*/
static void ack_bad(unsigned int irq)
{
- print_irq_desc(irq, irq_desc + irq);
+ struct irq_desc *desc;
+
+ desc = irq_to_desc(irq);
+ print_irq_desc(irq, desc);
ack_bad_irq(irq);
}
@@ -196,7 +311,7 @@
*/
unsigned int __do_IRQ(unsigned int irq)
{
- struct irq_desc *desc = irq_desc + irq;
+ struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action;
unsigned int status;
@@ -287,19 +402,16 @@
}
#endif
+
#ifdef CONFIG_TRACE_IRQFLAGS
-
-/*
- * lockdep: we want to handle all irq_desc locks as a single lock-class:
- */
-static struct lock_class_key irq_desc_lock_class;
-
void early_init_irq_lock_class(void)
{
+#ifndef CONFIG_HAVE_DYN_ARRAY
int i;
for (i = 0; i < nr_irqs; i++)
lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class);
-}
-
#endif
+}
+#endif
+