powerpc: powerpc_ipi_handler(): Stop first, preempt lastHEADmain

Preemption should happen last so that other IPIs have a chance to be
executed in due course, in particular hardclockintr().  So, move
handling of IPI_PREEMPT at the end.

An IPI_STOP/IPI_STOP_HARD request should be processed immediately to
avoid risks that further processing changes the system state on panic,
or worse itself causes another panic on corrupted kernel state.

While here, move IPI_AST handling just before IPI_PREEMPT.  We currently
do not need to do anything for it, but if we were to, it is likely that
would have to happen after other IPIs but IPI_PREEMPT.

Reviewed by:    jhibbits
Fixes:          9d5a22b928c2 ("MFp4: SMP support")
Fixes:          12640815f815 ("MFp4: SMP support")
Fixes:          7ed09a6778d3 ("powerpc: Rework IPI message processing")
MFC after:      1 week
Sponsored by:   The FreeBSD Foundation
Differential Revision:  https://reviews.freebsd.org/D60863

0 files changed, 0 insertions, 0 deletions