[PATCH 6/14] kexec: ioapic-virtwire-on-shutdown.x86_64

From: Eric W. Biederman
Date: Fri Aug 20 2004 - 13:15:10 EST



Restore an ioapic to virtual wire mode on reboot if it has an ExtInt
input.

diff -uNr linux-2.6.8.1-mm2-ioapic-virtwire-on-shutdown.i386/arch/x86_64/kernel/io_apic.c linux-2.6.8.1-mm2-ioapic-virtwire-on-shutdown.x86_64/arch/x86_64/kernel/io_apic.c
--- linux-2.6.8.1-mm2-ioapic-virtwire-on-shutdown.i386/arch/x86_64/kernel/io_apic.c Sat Aug 14 11:55:02 2004
+++ linux-2.6.8.1-mm2-ioapic-virtwire-on-shutdown.x86_64/arch/x86_64/kernel/io_apic.c Fri Aug 20 10:13:41 2004
@@ -1123,10 +1123,42 @@
*/
void disable_IO_APIC(void)
{
+ int pin;
/*
* Clear the IO-APIC before rebooting:
*/
clear_IO_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();
}

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