13 files changed, 84 insertions, 109 deletions

diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index f6ea94b74da..74917658b00 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -170,7 +170,7 @@ static struct irq_cfg irq_cfgx[NR_IRQS] = {
         [15] = { .domain = CPU_MASK_ALL, .vector = IRQ15_VECTOR, },
 };
 
-void __init arch_early_irq_init(void)
+int __init arch_early_irq_init(void)
 {
         struct irq_cfg *cfg;
         struct irq_desc *desc;
@@ -184,6 +184,8 @@ void __init arch_early_irq_init(void)
                 desc = irq_to_desc(i);
                 desc->chip_data = &cfg[i];
         }
+
+        return 0;
 }
 
 #ifdef CONFIG_SPARSE_IRQ
@@ -212,7 +214,7 @@ static struct irq_cfg *get_one_free_irq_cfg(int cpu)
         return cfg;
 }
 
-void arch_init_chip_data(struct irq_desc *desc, int cpu)
+int arch_init_chip_data(struct irq_desc *desc, int cpu)
 {
         struct irq_cfg *cfg;
 
@@ -224,6 +226,8 @@ void arch_init_chip_data(struct irq_desc *desc, int cpu)
                         BUG_ON(1);
                 }
         }
+
+        return 0;
 }
 
 #ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
@@ -1345,8 +1349,6 @@ void __setup_vector_irq(int cpu)
 
         /* Mark the inuse vectors */
         for_each_irq_desc(irq, desc) {
-                if (!desc)
-                        continue;
                 cfg = desc->chip_data;
                 if (!cpu_isset(cpu, cfg->domain))
                         continue;
@@ -1730,8 +1732,6 @@ __apicdebuginit(void) print_IO_APIC(void)
         for_each_irq_desc(irq, desc) {
                 struct irq_pin_list *entry;
 
-                if (!desc)
-                        continue;
                 cfg = desc->chip_data;
                 entry = cfg->irq_2_pin;
                 if (!entry)
@@ -2378,9 +2378,6 @@ static void ir_irq_migration(struct work_struct *work)
         struct irq_desc *desc;
 
         for_each_irq_desc(irq, desc) {
-                if (!desc)
-                        continue;
-
                 if (desc->status & IRQ_MOVE_PENDING) {
                         unsigned long flags;
 
@@ -2670,9 +2667,6 @@ static inline void init_IO_APIC_traps(void)
          * 0x80, because int 0x80 is hm, kind of importantish. ;)
          */
         for_each_irq_desc(irq, desc) {
-                if (!desc)
-                        continue;
-
                 cfg = desc->chip_data;
                 if (IO_APIC_IRQ(irq) && cfg && !cfg->vector) {
                         /*
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 46625cd3874..e26733a9df2 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -142,9 +142,6 @@ static void init_evtchn_cpu_bindings(void)
 
         /* By default all event channels notify CPU#0. */
         for_each_irq_desc(i, desc) {
-                if (!desc)
-                        continue;
-
                 desc->affinity = cpumask_of_cpu(0);
         }
 #endif
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 3bb1cf1e742..f75efa22df5 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -9,6 +9,7 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/time.h>
+#include <linux/irqnr.h>
 #include <asm/cputime.h>
 
 #ifndef arch_irq_stat_cpu
@@ -45,10 +46,6 @@ static int show_stat(struct seq_file *p, void *v)
                 steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal);
                 guest = cputime64_add(guest, kstat_cpu(i).cpustat.guest);
                 for_each_irq_nr(j) {
-#ifdef CONFIG_SPARSE_IRQ
-                        if (!irq_to_desc(j))
-                                continue;
-#endif
                         sum += kstat_irqs_cpu(j, i);
                 }
                 sum += arch_irq_stat_cpu(i);
@@ -95,12 +92,6 @@ static int show_stat(struct seq_file *p, void *v)
         /* sum again ? it could be updated? */
         for_each_irq_nr(j) {
                 per_irq_sum = 0;
-#ifdef CONFIG_SPARSE_IRQ
-                if (!irq_to_desc(j)) {
-                        seq_printf(p, " %u", per_irq_sum);
-                        continue;
-                }
-#endif
                 for_each_possible_cpu(i)
                         per_irq_sum += kstat_irqs_cpu(j, i);
 
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index be3c484b524..8cc8ef47f5b 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -464,4 +464,10 @@ static inline void init_irq_proc(void)
 
 int show_interrupts(struct seq_file *p, void *v);
 
+struct irq_desc;
+
+extern int early_irq_init(void);
+extern int arch_early_irq_init(void);
+extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
+
 #endif
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 98564dc6447..d64a6d49bde 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -193,42 +193,23 @@ struct irq_desc {
         const char              *name;
 } ____cacheline_internodealigned_in_smp;
 
-extern void early_irq_init(void);
-extern void arch_early_irq_init(void);
-extern void arch_init_chip_data(struct irq_desc *desc, int cpu);
 extern void arch_init_copy_chip_data(struct irq_desc *old_desc,
                                         struct irq_desc *desc, int cpu);
 extern void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc);
 
 #ifndef CONFIG_SPARSE_IRQ
 extern struct irq_desc irq_desc[NR_IRQS];
-
-static inline struct irq_desc *irq_to_desc(unsigned int irq)
-{
-        return (irq < NR_IRQS) ? irq_desc + irq : NULL;
-}
-static inline struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
-{
-        return irq_to_desc(irq);
-}
-
-#else
-
-extern struct irq_desc *irq_to_desc(unsigned int irq);
+#else /* CONFIG_SPARSE_IRQ */