tree 8417edecc09a954bc6bb2bd7b99d4a279535dd2b
parent d6c1a9081080c6c4658acf2a06d851feb2855933
author Haren Myneni <hbabu@us.ibm.com> 1144293018 -0600
committer Paul Mackerras <paulus@samba.org> 1145695501 +1000

[PATCH] powerpc: clear IPIs on kdump

In some crash scenarios, the kexec CPU is not responding to an IPI sent by
secondary CPU after init thread is forked, causing the system to drop into
xmon during kdump boot.  This problem can be reproduced each time when the
debugger is enabled and soft-reset is used to invoke kdump boot. The first
CPU sends an IPI - setting the IPI priority for all secondary cpus
(xics_cause_ipi()). But some CPUs will enter into the xmon via soft-reset,
i.e, not executing xics_ipi_action(). Hence, IPI is not cleared. When
exited from the debugger, one of these CPUs could become the primary kexec
CPU. Since the IPI is not cleared, causing this issue in kdump boot. This
patch clears and EOI IPI for kexec CPU as well before the kdump boot
started.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>