CVSROOT: /cvs
Module name: src
Changes by: v...@cvs.openbsd.org 2015/09/25 22:37:18
Modified files:
sys/arch/octeon/dev: octeon_intr.c
sys/arch/sgi/xbow: xheart.c
Log message:
xheart_splx() has to restore the interrupt mask even on secondary CPUs
because each core has a separate mask. Otherwise the IPI can be left
disabled accidentally on a non-primary CPU when the core uses the
rendezvous mutex:
1. splraise(IPL_IPI) soft-masks the IPI.
2. An IPI hits and the CPU enters the interrupt handler.
3. The handler hard-masks the IPI.
4. The interrupt is not processed because of the CPU's current IPL.
The IPI is left hard-masked on leaving the handler.
5. splx(s) lowers the IPL below IPL_IPI. However, the interrupt's
hardware mask is left unchanged because of the CPU_IS_PRIMARY()
check in xheart_splx().
After this, the system will eventually hang because the CPU does not
respond to IPI requests of other cores.
While here, fix a similar situation with CIU interrupts on octeon.
This might save a few moments of debugging once non-primary CPUs are
allowed to process CIU interrupts.
ok miod@
