+
+/*
+ * HT bug: phase 2 init
+ * Called once we have valid topology information to check
+ * whether or not HT is enabled
+ * If HT is off, then we disable the workaround
+ */
+static __init int fixup_ht_bug(void)
+{
+ int cpu = smp_processor_id();
+ int w, c;
+ /*
+ * problem not present on this CPU model, nothing to do
+ */
+ if (!(x86_pmu.flags & PMU_FL_EXCL_ENABLED))
+ return 0;
+
+ w = cpumask_weight(topology_thread_cpumask(cpu));
+ if (w > 1) {
+ pr_info("PMU erratum BJ122, BV98, HSD29 worked around, HT is on\n");
+ return 0;
+ }
+
+ watchdog_nmi_disable_all();
+
+ x86_pmu.flags &= ~(PMU_FL_EXCL_CNTRS | PMU_FL_EXCL_ENABLED);
+
+ x86_pmu.commit_scheduling = NULL;
+ x86_pmu.start_scheduling = NULL;
+ x86_pmu.stop_scheduling = NULL;
+
+ watchdog_nmi_enable_all();
+
+ get_online_cpus();
+
+ for_each_online_cpu(c) {
+ free_excl_cntrs(c);
+ }
+
+ put_online_cpus();
+ pr_info("PMU erratum BJ122, BV98, HSD29 workaround disabled, HT off\n");
+ return 0;
+}
+subsys_initcall(fixup_ht_bug)