genirq: Query arch for number of early descriptors

sparse irq sets up NR_IRQS_LEGACY irq descriptors and archs then go
ahead and allocate more.

Use the unused return value of arch_probe_nr_irqs() to let the
architecture return the number of early allocations. Fix up all users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 8 insertions, 6 deletions

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 7cbe4f93e2fb..a1fbd1d347af 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -226,16 +226,16 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
 
 int __init early_irq_init(void)
 {
-        int i, node = first_online_node;
+        int i, initcnt, node = first_online_node;
         struct irq_desc *desc;
 
         init_irq_default_affinity();
 
-         /* initialize nr_irqs based on nr_cpu_ids */
-        arch_probe_nr_irqs();
-        printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d\n", NR_IRQS, nr_irqs);
+        /* Let arch update nr_irqs and return the nr of preallocated irqs */
+        initcnt = arch_probe_nr_irqs();
+        printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
 
-        for (i = 0; i < NR_IRQS_LEGACY; i++) {
+        for (i = 0; i < initcnt; i++) {
                 desc = alloc_desc(i, node);
                 set_bit(i, allocated_irqs);
                 irq_insert_desc(i, desc);
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 07b4f1b1a73a..14a7b80b2cce 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -886,9 +886,10 @@ int __init __weak early_irq_init(void)
         return 0;
 }
 
+#ifdef CONFIG_GENERIC_HARDIRQS
 int __init __weak arch_probe_nr_irqs(void)
 {
-        return 0;
+        return NR_IRQS_LEGACY;
 }
 
 int __init __weak arch_early_irq_init(void)
@@ -900,3 +901,4 @@ int __weak arch_init_chip_data(struct irq_desc *desc, int node)
 {
         return 0;
 }
+#endif