genirq: Replace dynamic_irq_init/cleanup

Create a new interface and confine it with a config switch which makes
clear that this is just legacy support and not to be used for new code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140507154340.574437049@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 2110f46..8ff71d1 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -637,6 +637,10 @@
 void arch_teardown_hwirq(unsigned int irq);
 #endif
 
+#ifdef CONFIG_GENERIC_IRQ_LEGACY
+void irq_init_desc(unsigned int irq);
+#endif
+
 #ifndef irq_reg_writel
 # define irq_reg_writel(val, addr)	writel(val, addr)
 #endif
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index a83f10e..d269cec 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -5,6 +5,10 @@
 config MAY_HAVE_SPARSE_IRQ
        bool
 
+# Legacy support, required for itanic
+config GENERIC_IRQ_LEGACY
+       bool
+
 # Enable the generic irq autoprobe mechanism
 config GENERIC_IRQ_PROBE
 	bool
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index d514ed6..7f26779 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -306,6 +306,13 @@
 	mutex_unlock(&sparse_irq_lock);
 }
 
+#ifdef CONFIG_GENERIC_IRQ_LEGACY
+void irq_init_desc(unsigned int irq)
+{
+	dynamic_irq_cleanup(irq);
+}
+#endif
+
 #endif /* !CONFIG_SPARSE_IRQ */
 
 /**