diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c01580d8..3aa79f8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -56,6 +56,16 @@
 	bool
 	default y
 
+config NR_IRQS
+	int "Number of virtual interrupt numbers"
+	range 32 512
+	default "512"
+	help
+	  This defines the number of virtual interrupt numbers the kernel
+	  can manage. Virtual interrupt numbers are what you see in
+	  /proc/interrupts. If you configure your system to have too few,
+	  drivers will fail to load or worse - handle with care.
+
 config STACKTRACE_SUPPORT
 	bool
 	default y
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index bbcd1aa..b83fcc8 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -34,8 +34,8 @@
  */
 #define NO_IRQ_IGNORE		((unsigned int)-1)
 
-/* Total number of virq in the platform (make it a CONFIG_* option ? */
-#define NR_IRQS		512
+/* Total number of virq in the platform */
+#define NR_IRQS		CONFIG_NR_IRQS
 
 /* Number of irqs reserved for the legacy controller */
 #define NUM_ISA_INTERRUPTS	16