From af5b98042452cc6f50de8afa9d079bda8556d74d Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Wed, 11 Jan 2006 22:46:21 +0100 Subject: [PATCH] [PATCH] x86_64: ioapic virtual wire mode fix o Currently, during kexec reboot, IOAPIC is re-programmed back to virtual wire mode if there was an i8259 connected to it. This enables getting timer interrupts in second kernel in legacy mode. o After putting into virtual wire mode, IOAPIC delivers the i8259 interrupts to CPU0. This works well for kexec but not for kdump as we might crash on a different CPU and second kernel will not see timer interrupts. o This patch modifies the redirection table entry to deliver the timer interrupts to the cpu we are rebooting (instead of hardcoding to zero). This ensures that second kernel receives timer interrupts even on a non-boot cpu. Signed-off-by: Vivek Goyal Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/io_apic.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c index 6c938c60fa3b..fd1e7c36dc23 100644 --- a/arch/x86_64/kernel/io_apic.c +++ b/arch/x86_64/kernel/io_apic.c @@ -1307,7 +1307,8 @@ void disable_IO_APIC(void) entry.dest_mode = 0; /* Physical */ entry.delivery_mode = dest_ExtINT; /* ExtInt */ entry.vector = 0; - entry.dest.physical.physical_dest = 0; + entry.dest.physical.physical_dest = + GET_APIC_ID(apic_read(APIC_ID)); /* * Add it to the IO-APIC irq-routing table: -- 2.20.1