• Vivek Goyal's avatar
    [PATCH] x86_64: ioapic virtual wire mode fix · af5b9804
    Vivek Goyal authored
    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: default avatarVivek Goyal <vgoyal@in.ibm.com>
    Signed-off-by: default avatarAndi Kleen <ak@suse.de>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
io_apic.c 52.9 KB