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authorEric W. Biederman <ebiederm@xmission.com>2005-06-25 14:57:45 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-25 16:24:47 -0700
commit208fb93162d51faa69b9774fa7809858d84fd9dc (patch)
tree895115891463d3318677df4c3d76f6eca751eccd /arch/x86_64/kernel/io_apic.c
parent650927ef8ab1e9b05b77a3f32ca7adcedaae9306 (diff)
[PATCH] kexec: x86_64: restore 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>
Diffstat (limited to 'arch/x86_64/kernel/io_apic.c')
-rw-r--r--arch/x86_64/kernel/io_apic.c36
1 files changed, 34 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index afd87e64d0a..157190d986b 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);
}
/*