x86: Skip cpus with apic-ids >= 255 in !x2apic_mode
authorSuresh Siddha <suresh.b.siddha@intel.com>
Thu, 22 Dec 2011 01:45:19 +0000 (17:45 -0800)
committerH. Peter Anvin <hpa@linux.intel.com>
Fri, 23 Dec 2011 19:01:49 +0000 (11:01 -0800)
commitc284b42abadbb22083bfde24d308899c08d44ffa
treefb6890a1b3c5a4f72f52122ae652cad438fb20d2
parenta31bc32760992a2c68f3d6bf7da9f760c0fd7c41
x86: Skip cpus with apic-ids >= 255 in !x2apic_mode

If the x2apic mode is disabled for reasons like interrupt-remapping
not available etc, then we need to skip the logical cpu bringup of
apic-id's >= 255. Otherwise as the platform is in xapic mode, init/startup
IPI's will consider only the low 8-bits and there is a possibility of
re-sending init/startup IPI's to the logical cpu that is already online.

This will avoid potential reboots/unpredictable behavior etc.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/20111222014632.702932458@sbsiddha-desk.sc.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
arch/x86/kernel/smpboot.c