[PATCH] sparseirq: Enable early irq_desc allocation.

[Paul Mundt <lethal@linux-sh.org>]

Presently non-legacy IRQs have their irq_desc allocated with
kzalloc_node(). This assumes that all callers of irq_to_desc_cpu_alloc()
will be sufficiently late in the boot process that kmalloc is available.

While porting sparseirq support to sh this blew up immediately, as at the
time that we register the CPU's interrupt vector map only bootmem is
available.

This adds in a simple after_bootmem check to see where the allocation
needs to come from, which is likewise provided by all of the platforms
that support sparse irq today. :-)

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

---

 kernel/irq/handle.c |   17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index d82142b..5fb3a5c 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -19,7 +19,7 @@
 #include <linux/hash.h>
 #include <trace/irq.h>
 #include <linux/bootmem.h>
-
+#include <linux/mm.h>
 #include "internals.h"
 
 /*
@@ -81,13 +81,17 @@ static struct irq_desc irq_desc_init = {
 	.lock       = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
 };
 
-void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
+void __ref init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
 {
 	int node;
 	void *ptr;
 
 	node = cpu_to_node(cpu);
-	ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs), GFP_ATOMIC, node);
+	if (after_bootmem)
+		ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs), GFP_ATOMIC, node);
+	else
+		ptr = alloc_bootmem_node(NODE_DATA(node),
+				nr * sizeof(*desc->kstat_irqs));
 
 	/*
 	 * don't overwite if can not get new one
@@ -187,7 +191,7 @@ struct irq_desc *irq_to_desc(unsigned int irq)
 	return NULL;
 }
 
-struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+struct irq_desc * __ref irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
 {
 	struct irq_desc *desc;
 	unsigned long flags;
@@ -211,7 +215,10 @@ struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
 		goto out_unlock;
 
 	node = cpu_to_node(cpu);
-	desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
+	if (after_bootmem)
+		desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
+	else
+		desc = alloc_bootmem_node(NODE_DATA(node), sizeof(*desc));
 	printk(KERN_DEBUG "  alloc irq_desc for %d on cpu %d node %d\n",
 		 irq, cpu, node);
 	if (!desc) {