x86/dmar: Use new irqdomain interfaces to allocate/free IRQ

Use new irqdomain interfaces to allocate/free IRQ for DMAR and interrupt
remapping, so we can remove GENERIC_IRQ_LEGACY_ALLOC_HWIRQ later.

The private definitions of irq_alloc_hwirqs()/irq_free_hwirqs() are a
temporary solution, they will be removed once we have converted the
interrupt remapping driver to use irqdomain framework.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Cohen <david.a.cohen@linux.intel.com>
Cc: Sander Eikelenboom <linux@eikelenboom.it>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: iommu@lists.linux-foundation.org
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Joerg Roedel <joro@8bytes.org>
Link: http://lkml.kernel.org/r/1428905519-23704-8-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic/msi.c

@@ -223,6 +223,16 @@ int arch_setup_dmar_msi(unsigned int irq)
 				      "edge");
 	return 0;
 }
+
+int dmar_alloc_hwirq(void)
+{
+	return irq_domain_alloc_irqs(NULL, 1, NUMA_NO_NODE, NULL);
+}
+
+void dmar_free_hwirq(int irq)
+{
+	irq_domain_free_irqs(irq, 1);
+}
 #endif
 
 /*