x86: sparse_irq needs spin_lock in allocations
Suresh Siddha noticed that we should have a spinlock around it.
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 24c83a3..d638a91 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -107,6 +107,11 @@
}
}
+/*
+ * Protect the sparse_irqs_free freelist:
+ */
+static DEFINE_SPINLOCK(sparse_irq_lock);
+
#ifdef CONFIG_HAVE_SPARSE_IRQ
static struct irq_desc *sparse_irqs_free;
struct irq_desc *sparse_irqs;
@@ -166,11 +171,13 @@
}
return NULL;
}
+
struct irq_desc *irq_to_desc_alloc(unsigned int irq)
{
struct irq_desc *desc, *desc_pri;
- int i;
+ unsigned long flags;
int count = 0;
+ int i;
desc_pri = desc = sparse_irqs;
while (desc) {
@@ -182,6 +189,7 @@
count++;
}
+ spin_lock_irqsave(&sparse_irq_lock, flags);
/*
* we run out of pre-allocate ones, allocate more
*/
@@ -223,6 +231,9 @@
else
sparse_irqs = desc;
desc->irq = irq;
+
+ spin_unlock_irqrestore(&sparse_irq_lock, flags);
+
printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq);
#ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG
{