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>

4 files changed, 59 insertions, 5 deletions

diff --git a/arch/ia64/include/asm/intr_remapping.h b/arch/ia64/include/asm/intr_remapping.h
new file mode 100644
index 0000000..095aa0d
--- /dev/null
+++ b/arch/ia64/include/asm/intr_remapping.h
@@ -0,0 +1,4 @@
+#ifndef __IA64_INTR_REMAPPING_H
+#define __IA64_INTR_REMAPPING_H
+#define intr_remapping_enabled 0
+#endif
diff --git a/arch/x86/include/asm/intr_remapping.h b/arch/x86/include/asm/intr_remapping.h
new file mode 100644
index 0000000..207c605
--- /dev/null
+++ b/arch/x86/include/asm/intr_remapping.h
@@ -0,0 +1,45 @@
+/*
+ * 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 the interface of the interrupt remapping code to
+ * the x86 interrupt management code.
+ */
+
+#ifndef __X86_INTR_REMAPPING_H
+#define __X86_INTR_REMAPPING_H
+
+#ifdef CONFIG_IRQ_REMAP
+
+extern int intr_remapping_enabled;
+
+extern void setup_intr_remapping(void);
+extern int intr_remapping_supported(void);
+extern int intr_hardware_init(void);
+extern int intr_hardware_enable(void);
+
+#else  /* CONFIG_IRQ_REMAP */
+
+#define intr_remapping_enabled	0
+
+static inline void setup_intr_remapping(void) { }
+static inline int intr_remapping_supported(void) { return 0; }
+static inline int intr_hardware_init(void) { return -ENODEV; }
+static inline int intr_hardware_enable(void) { return -ENODEV; }
+
+#endif /* CONFIG_IRQ_REMAP */
+
+#endif /* __X86_INTR_REMAPPING_H */
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index edc2448..1db6f63 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -35,6 +35,7 @@
 #include <linux/smp.h>
 #include <linux/mm.h>
 
+#include <asm/intr_remapping.h>
 #include <asm/perf_event.h>
 #include <asm/x86_init.h>
 #include <asm/pgalloc.h>
@@ -1528,7 +1529,7 @@ int __init enable_IR(void)
 		return -1;
 	}
 
-	return enable_intr_remapping();
+	return intr_hardware_enable();
 #endif
 	return -1;
 }
@@ -1537,10 +1538,13 @@ void __init enable_IR_x2apic(void)
 {
 	unsigned long flags;
 	int ret, x2apic_enabled = 0;
-	int dmar_table_init_ret;
+	int hardware_init_ret;
 
-	dmar_table_init_ret = dmar_table_init();
-	if (dmar_table_init_ret && !x2apic_supported())
+	/* Make sure irq_remap_ops are initialized */
+	setup_intr_remapping();
+
+	hardware_init_ret = intr_hardware_init();
+	if (hardware_init_ret && !x2apic_supported())
 		return;
 
 	ret = save_ioapic_entries();
@@ -1556,7 +1560,7 @@ void __init enable_IR_x2apic(void)
 	if (x2apic_preenabled && nox2apic)
 		disable_x2apic();
 
-	if (dmar_table_init_ret)
+	if (hardware_init_ret)
 		ret = -1;
 	else
 		ret = enable_IR();
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e88300d..1151fdc 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -57,6 +57,7 @@
 #include <asm/msidef.h>
 #include <asm/hypertransport.h>
 #include <asm/setup.h>
+#include <asm/intr_remapping.h>
 #include <asm/irq_remapping.h>
 #include <asm/hpet.h>
 #include <asm/hw_irq.h>