[PATCH 03/19] x86, io_apic: Introduce x86_io_apic_ops.disable()

[Joerg Roedel <joerg.roedel@amd.com>]

This function pointer is used to call a system-specific
function for disabling the IO-APIC. Currently this is used
for IRQ remapping which has its own disable routine.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/x86/include/asm/io_apic.h  |    1 +
 arch/x86/include/asm/x86_init.h |    9 +++++----
 arch/x86/kernel/apic/io_apic.c  |   41 ++++++++++++++++++---------------------
 arch/x86/kernel/x86_init.c      |    9 +++++----
 drivers/iommu/irq_remapping.c   |   31 ++++++++++++++++++++++++++++-
 5 files changed, 60 insertions(+), 31 deletions(-)

diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 73d8c53..57e5917 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -179,6 +179,7 @@ extern void __init native_io_apic_init_mappings(void);
 extern unsigned int native_io_apic_read(unsigned int apic, unsigned int reg);
 extern void native_io_apic_write(unsigned int apic, unsigned int reg, unsigned int val);
 extern void native_io_apic_modify(unsigned int apic, unsigned int reg, unsigned int val);
+extern void native_disable_io_apic(void);
 
 static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg)
 {
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 38155f6..8e1b44c 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -189,10 +189,11 @@ struct x86_msi_ops {
 };
 
 struct x86_io_apic_ops {
-	void		(*init)  (void);
-	unsigned int	(*read)  (unsigned int apic, unsigned int reg);
-	void		(*write) (unsigned int apic, unsigned int reg, unsigned int value);
-	void		(*modify)(unsigned int apic, unsigned int reg, unsigned int value);
+	void		(*init)   (void);
+	unsigned int	(*read)   (unsigned int apic, unsigned int reg);
+	void		(*write)  (unsigned int apic, unsigned int reg, unsigned int value);
+	void		(*modify) (unsigned int apic, unsigned int reg, unsigned int value);
+	void		(*disable)(void);
 };
 
 extern struct x86_init_ops x86_init;
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 406eee7..3b77b60 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1925,30 +1925,14 @@ void __init enable_IO_APIC(void)
 	clear_IO_APIC();
 }
 
-/*
- * Not an __init, needed by the reboot code
- */
-void disable_IO_APIC(void)
+void native_disable_io_apic(void)
 {
 	/*
-	 * Clear the IO-APIC before rebooting:
-	 */
-	clear_IO_APIC();
-
-	if (!legacy_pic->nr_legacy_irqs)
-		return;
-
-	/*
 	 * If the i8259 is routed through an IOAPIC
 	 * Put that IOAPIC in virtual wire mode
 	 * so legacy interrupts can be delivered.
-	 *
-	 * With interrupt-remapping, for now we will use virtual wire A mode,
-	 * as virtual wire B is little complex (need to configure both
-	 * IOAPIC RTE as well as interrupt-remapping table entry).
-	 * As this gets called during crash dump, keep this simple for now.
 	 */
-	if (ioapic_i8259.pin != -1 && !irq_remapping_enabled) {
+	if (ioapic_i8259.pin != -1) {
 		struct IO_APIC_route_entry entry;
 
 		memset(&entry, 0, sizeof(entry));
@@ -1968,12 +1952,25 @@ void disable_IO_APIC(void)
 		ioapic_write_entry(ioapic_i8259.apic, ioapic_i8259.pin, entry);
 	}
 
+	if (cpu_has_apic || apic_from_smp_config())
+		disconnect_bsp_APIC(ioapic_i8259.pin != -1);
+
+}
+
+/*
+ * Not an __init, needed by the reboot code
+ */
+void disable_IO_APIC(void)
+{
 	/*
-	 * Use virtual wire A mode when interrupt remapping is enabled.
+	 * Clear the IO-APIC before rebooting:
 	 */
-	if (cpu_has_apic || apic_from_smp_config())
-		disconnect_bsp_APIC(!irq_remapping_enabled &&
-				ioapic_i8259.pin != -1);
+	clear_IO_APIC();
+
+	if (!legacy_pic->nr_legacy_irqs)
+		return;
+
+	x86_io_apic_ops.disable();
 }
 
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 9f3167e..3ea56c2 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -120,8 +120,9 @@ struct x86_msi_ops x86_msi = {
 };
 
 struct x86_io_apic_ops x86_io_apic_ops = {
-	.init	= native_io_apic_init_mappings,
-	.read	= native_io_apic_read,
-	.write	= native_io_apic_write,
-	.modify	= native_io_apic_modify,
+	.init			= native_io_apic_init_mappings,
+	.read			= native_io_apic_read,
+	.write			= native_io_apic_write,
+	.modify			= native_io_apic_modify,
+	.disable		= native_disable_io_apic,
 };
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index 283a43f..f72a5e8 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -1,3 +1,4 @@
+#include <linux/cpumask.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/cpumask.h>
@@ -6,6 +7,9 @@
 
 #include <asm/hw_irq.h>
 #include <asm/irq_remapping.h>
+#include <asm/processor.h>
+#include <asm/x86_init.h>
+#include <asm/apic.h>
 
 #include "irq_remapping.h"
 
@@ -17,6 +21,24 @@ int no_x2apic_optout;
 
 static struct irq_remap_ops *remap_ops;
 
+static void irq_remapping_disable_io_apic(void)
+{
+	/*
+	 * With interrupt-remapping, for now we will use virtual wire A
+	 * mode, as virtual wire B is little complex (need to configure
+	 * both IOAPIC RTE as well as interrupt-remapping table entry).
+	 * As this gets called during crash dump, keep this simple for
+	 * now.
+	 */
+	if (cpu_has_apic || apic_from_smp_config())
+		disconnect_bsp_APIC(0);
+}
+
+static void __init irq_remapping_modify_x86_ops(void)
+{
+	x86_io_apic_ops.disable	=	irq_remapping_disable_io_apic;
+}
+
 static __init int setup_nointremap(char *str)
 {
 	disable_irq_remap = 1;
@@ -74,10 +96,17 @@ int __init irq_remapping_prepare(void)
 
 int __init irq_remapping_enable(void)
 {
+	int ret;
+
 	if (!remap_ops || !remap_ops->enable)
 		return -ENODEV;
 
-	return remap_ops->enable();
+	ret = remap_ops->enable();
+
+	if (irq_remapping_enabled)
+		irq_remapping_modify_x86_ops();
+
+	return ret;
 }
 
 void irq_remapping_disable(void)
-- 
1.7.9.5