[PATCH] kexec: x86: resture apic virtual wire mode on shutdown

When coming out of apic mode attempt to set the appropriate
apic back into virtual wire mode.  This improves on previous versions
of this patch by by never setting bot the local apic and the ioapic
into veritual wire mode.

This code looks at data from the mptable to see if an ioapic has
an ExtInt input to make this decision.  A future improvement
is to figure out which apic or ioapic was in virtual wire mode
at boot time and to remember it.  That is potentially a more accurate
method, of selecting which apic to place in virutal wire mode.

Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index cf45bed96d08dddf3a039bb266376e9ff787194a..93df90bbb87e00e4f438d10d449f91b8faa4b801 100644 (file)
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -211,7 +211,7 @@ void __init connect_bsp_APIC(void)
        enable_apic_mode();
 }
 
-void disconnect_bsp_APIC(void)
+void disconnect_bsp_APIC(int virt_wire_setup)
 {
        if (pic_mode) {
                /*
@@ -225,6 +225,42 @@ 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/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 3c2b3bdfc807c1dca19eb33115c8d991c0d6af38..fc81c8cddd22e9118013d2b6fb4c84e4b5b00fba 100644 (file)
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -1636,12 +1636,43 @@ 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-i386/apic.h b/include/asm-i386/apic.h
index 53268cd9306e10957a0c49cf9caf275abb42657c..6a1b1882285c004a1c5f80b109c046fe483c8bee 100644 (file)
--- a/include/asm-i386/apic.h
+++ b/include/asm-i386/apic.h
@@ -100,7 +100,7 @@ extern void (*wait_timer_tick)(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 void lapic_shutdown (void);
 extern int verify_local_APIC (void);

diff --git a/include/asm-i386/apicdef.h b/include/asm-i386/apicdef.h
index 41e8d2d918e06e03e545620b0707073c98a8710e..0fed5e3c699c738009d3113edcc2c7436433f6c0 100644 (file)
--- a/include/asm-i386/apicdef.h
+++ b/include/asm-i386/apicdef.h
@@ -86,6 +86,7 @@
 #define                        APIC_LVT_REMOTE_IRR             (1<<14)
 #define                        APIC_INPUT_POLARITY             (1<<13)
 #define                        APIC_SEND_PENDING               (1<<12)
+#define                        APIC_MODE_MASK                  0x700
 #define                        GET_APIC_DELIVERY_MODE(x)       (((x)>>8)&0x7)
 #define                        SET_APIC_DELIVERY_MODE(x,y)     (((x)&~0x700)|((y)<<8))
 #define                                APIC_MODE_FIXED         0x0