3 files changed, 72 insertions, 4 deletions

diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 2a6c893ccf60..375d369570ca 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -133,7 +133,7 @@ void __init connect_bsp_APIC(void)
         }
 }
 
-void disconnect_bsp_APIC(void)
+void disconnect_bsp_APIC(int virt_wire_setup)
 {
         if (pic_mode) {
                 /*
@@ -146,6 +146,42 @@ void disconnect_bsp_APIC(void)
                 outb(0x70, 0x22);
                 outb(0x00, 0x23);
         }
+        else {
+                /* Go back to Virtual Wire compatibility mode */
+                unsigned long value;
+
+                /* For the spurious interrupt use vector F, and enable it */
+                value = apic_read(APIC_SPIV);
+                value &= ~APIC_VECTOR_MASK;
+                value |= APIC_SPIV_APIC_ENABLED;
+                value |= 0xf;
+                apic_write_around(APIC_SPIV, value);
+
+                if (!virt_wire_setup) {
+                        /* For LVT0 make it edge triggered, active high, external and enabled */
+                        value = apic_read(APIC_LVT0);
+                        value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
+                                APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
+                                APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
+                        value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
+                        value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
+                        apic_write_around(APIC_LVT0, value);
+                }
+                else {
+                        /* Disable LVT0 */
+                        apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
+                }
+
+                /* For LVT1 make it edge triggered, active high, nmi and enabled */
+                value = apic_read(APIC_LVT1);
+                value &= ~(
+                        APIC_MODE_MASK | APIC_SEND_PENDING |
+                        APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
+                        APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
+                value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
+                value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
+                apic_write_around(APIC_LVT1, value);
+        }
 }
 
 void disable_local_APIC(void)
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index afd87e64d0a8..157190d986bb 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -330,7 +330,7 @@ static int find_irq_entry(int apic, int pin, int type)
 /*
  * Find the pin to which IRQ[irq] (ISA) is connected
  */
-static int __init find_isa_irq_pin(int irq, int type)
+static int find_isa_irq_pin(int irq, int type)
 {
         int i;
 
@@ -1132,12 +1132,44 @@ static void __init enable_IO_APIC(void)
  */
 void disable_IO_APIC(void)
 {
+        int pin;
         /*
          * Clear the IO-APIC before rebooting:
          */
         clear_IO_APIC();
 
-        disconnect_bsp_APIC();
+        /*
+         * If the i82559 is routed through an IOAPIC
+         * Put that IOAPIC in virtual wire mode
+         * so legacy interrups can be delivered.
+         */
+        pin = find_isa_irq_pin(0, mp_ExtINT);
+        if (pin != -1) {
+                struct IO_APIC_route_entry entry;
+                unsigned long flags;
+
+                memset(&entry, 0, sizeof(entry));
+                entry.mask            = 0; /* Enabled */
+                entry.trigger         = 0; /* Edge */
+                entry.irr             = 0;
+                entry.polarity        = 0; /* High */
+                entry.delivery_status = 0;
+                entry.dest_mode       = 0; /* Physical */
+                entry.delivery_mode   = 7; /* ExtInt */
+                entry.vector          = 0;
+                entry.dest.physical.physical_dest = 0;
+
+
+                /*
+                 * Add it to the IO-APIC irq-routing table:
+                 */
+                spin_lock_irqsave(&ioapic_lock, flags);
+                io_apic_write(0, 0x11+2*pin, *(((int *)&entry)+1));
+                io_apic_write(0, 0x10+2*pin, *(((int *)&entry)+0));
+                spin_unlock_irqrestore(&ioapic_lock, flags);
+        }
+
+        disconnect_bsp_APIC(pin != -1);
 }
 
 /*
diff --git a/include/asm-x86_64/apic.h b/include/asm-x86_64/apic.h
index e4b1017b8b2b..16ec82e16b21 100644
--- a/include/asm-x86_64/apic.h
+++ b/include/asm-x86_64/apic.h
@@ -77,7 +77,7 @@ static inline void ack_APIC_irq(void)
 extern int get_maxlvt (void);
 extern void clear_local_APIC (void);
 extern void connect_bsp_APIC (void);
-extern void disconnect_bsp_APIC (void);
+extern void disconnect_bsp_APIC (int virt_wire_setup);
 extern void disable_local_APIC (void);
 extern int verify_local_APIC (void);
 extern void cache_APIC_registers (void);