irq: add irq_desc_without_new
add an irq_desc accessor that will not allocate any sparse entry
but returns failure if there's no entry present.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/irq.h b/include/linux/irq.h
index cbf471a..c9ffef7 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -191,10 +191,23 @@
} ____cacheline_internodealigned_in_smp;
extern struct irq_desc *irq_to_desc(unsigned int irq);
+extern struct irq_desc *__irq_to_desc(unsigned int irq);
+
+#ifndef CONFIG_HAVE_SPARSE_IRQ
+
#ifndef CONFIG_HAVE_DYN_ARRAY
/* could be removed if we get rid of all irq_desc reference */
extern struct irq_desc irq_desc[NR_IRQS];
+#else
+extern struct irq_desc *irq_desc;
#endif
+
+#else
+
+extern struct irq_desc *sparse_irqs;
+
+#endif
+
#define kstat_irqs_this_cpu(DESC) \
((DESC)->kstat_irqs[smp_processor_id()])
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 1f34699..8e55dbe 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -112,7 +112,6 @@
}
}
-
static void __init init_work(void *data)
{
struct dyn_array *da = data;
@@ -149,9 +148,27 @@
early_param("nr_irq_desc", parse_nr_irq_desc);
-static struct irq_desc *sparse_irqs;
+struct irq_desc *sparse_irqs;
DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work);
+struct irq_desc *__irq_to_desc(unsigned int irq)
+{
+ struct irq_desc *desc;
+
+ BUG_ON(irq == -1U);
+
+ desc = &sparse_irqs[0];
+ while (desc) {
+ if (desc->irq == irq)
+ return desc;
+
+ if (desc->irq == -1U)
+ return NULL;
+
+ desc = desc->next;
+ }
+ return NULL;
+}
struct irq_desc *irq_to_desc(unsigned int irq)
{
struct irq_desc *desc, *desc_pri;
@@ -208,8 +225,7 @@
return desc;
}
#else
-
-static struct irq_desc *irq_desc;
+struct irq_desc *irq_desc;
DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work);
#endif
@@ -239,6 +255,10 @@
return NULL;
}
+struct irq_desc *__irq_to_desc(unsigned int irq)
+{
+ return irq_to_desc(irq);
+}
#endif
/*