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authorSuresh Siddha <suresh.b.siddha@intel.com>2011-12-21 17:45:19 -0800
committerH. Peter Anvin <hpa@linux.intel.com>2011-12-23 11:01:49 -0800
commitc284b42abadbb22083bfde24d308899c08d44ffa (patch)
treefb6890a1b3c5a4f72f52122ae652cad438fb20d2
parenta31bc32760992a2c68f3d6bf7da9f760c0fd7c41 (diff)
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>
-rw-r--r--arch/x86/kernel/smpboot.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 9f548cb4a958..e38e21754eea 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -840,7 +840,8 @@ int __cpuinit native_cpu_up(unsigned int cpu)
pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);
if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
- !physid_isset(apicid, phys_cpu_present_map)) {
+ !physid_isset(apicid, phys_cpu_present_map) ||
+ (!x2apic_mode && apicid >= 255)) {
printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
return -EINVAL;
}