[PATCH] x86: sparse_irq need spin_lock in alloc

[Yinghai Lu <yhlu.kernel@gmail.com>]

acording to Suresh Siddha, we should have spin_lock around it

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>

---
 arch/x86/kernel/io_apic.c |    6 ++++++
 kernel/irq/handle.c       |    7 +++++++
 2 files changed, 13 insertions(+)

Index: linux-2.6/kernel/irq/handle.c
===================================================================
--- linux-2.6.orig/kernel/irq/handle.c
+++ linux-2.6/kernel/irq/handle.c
@@ -166,6 +166,9 @@ struct irq_desc *irq_to_desc(unsigned in
 	}
 	return NULL;
 }
+
+static DEFINE_SPINLOCK(sparse_irq_lock);
+
 struct irq_desc *irq_to_desc_alloc(unsigned int irq)
 {
 	struct irq_desc *desc, *desc_pri;
@@ -182,6 +185,7 @@ struct irq_desc *irq_to_desc_alloc(unsig
 		count++;
 	}
 
+	spin_lock(&sparse_irq_lock);
 	/*
 	 *  we run out of pre-allocate ones, allocate more
 	 */
@@ -223,6 +227,9 @@ struct irq_desc *irq_to_desc_alloc(unsig
 	else
 		sparse_irqs = desc;
 	desc->irq = irq;
+
+	spin_unlock(&sparse_irq_lock);
+
 	printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq);
 #ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG
 	{
Index: linux-2.6/arch/x86/kernel/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/io_apic.c
+++ linux-2.6/arch/x86/kernel/io_apic.c
@@ -210,6 +210,8 @@ static struct irq_cfg *irq_cfg(unsigned
 	return NULL;
 }
 
+static DEFINE_SPINLOCK(irq_cfg_lock);
+
 static struct irq_cfg *irq_cfg_alloc(unsigned int irq)
 {
 	struct irq_cfg *cfg, *cfg_pri;
@@ -226,6 +228,7 @@ static struct irq_cfg *irq_cfg_alloc(uns
 		count++;
 	}
 
+	spin_lock(&irq_cfg_lock);
 	if (!irq_cfgx_free) {
 		unsigned long phys;
 		unsigned long total_bytes;
@@ -263,6 +266,9 @@ static struct irq_cfg *irq_cfg_alloc(uns
 	else
 		irq_cfgx = cfg;
 	cfg->irq = irq;
+
+	spin_unlock(&irq_cfg_lock);
+
 	printk(KERN_DEBUG "found new irq_cfg for irq %d\n", cfg->irq);
 #ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG
 	{