Sending cpu 0 back to SAL slave loop

[kaos at sgi.com (Keith Owens)]

Matthew Wilcox (on Fri, 6 Oct 2006 14:44:43 -0600) wrote:
>On Fri, Oct 06, 2006 at 03:39:10PM -0500, Jack Steiner wrote:
>> For kexec, it is ESSENTIAL that all cpus except for the one doing
>> the kexec be returned to the SAL slave loop. If this is not done, our
>> chipset will misdirect IO interrupts on the newly exec'ed kernel.
>
>Could you do an IPI call to have CPU 0 do the kexec and have the CPU
>that sent the IPI fall into the SAL slave loop instead?

An IPI call will not work for MCA or INIT.  Both of those drive all
cpus into a state which has disabled interrupts.