iommu/vt-d: Make intr-remapping initialization generic

This patch introduces irq_remap_ops to hold implementation
specific function pointer to handle interrupt remapping. As
the first part the initialization functions for VT-d are
converted to these ops.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/intr_remapping.h b/drivers/iommu/intr_remapping.h
new file mode 100644
index 0000000..d6df732
--- /dev/null
+++ b/drivers/iommu/intr_remapping.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2012 Advanced Micro Devices, Inc.
+ * Author: Joerg Roedel <joerg.roedel@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ * This header file contains stuff that is shared between different interrupt
+ * remapping drivers but with no need to be visible outside of the IOMMU layer.
+ */
+
+#ifndef __INTR_REMAPPING_H
+#define __INTR_REMAPPING_H
+
+#ifdef CONFIG_IRQ_REMAP
+
+extern int disable_intremap;
+extern int disable_sourceid_checking;
+extern int no_x2apic_optout;
+
+struct irq_remap_ops {
+	/* Check whether Interrupt Remapping is supported */
+	int (*supported)(void);
+
+	/* Initializes hardware and makes it ready for remapping interrupts */
+	int  (*hardware_init)(void);
+
+	/* Enables the remapping hardware */
+	int  (*hardware_enable)(void);
+};
+
+extern struct irq_remap_ops intel_irq_remap_ops;
+
+#endif /* CONFIG_IRQ_REMAP */
+
+#endif /* __INTR_REMAPPING_H */