+ cpu_data_t *cdp = cpu_datap(cpu);
+ boolean_t intrs_enabled;
+ uint64_t tsc_timeout;
+
+ /*
+ * Wait until the CPU indicates that it has stopped.
+ * Disable interrupts while the topo lock is held -- arguably
+ * this should always be done but in this instance it can lead to
+ * a timeout if long-running interrupt were to occur here.
+ */
+ intrs_enabled = ml_set_interrupts_enabled(FALSE);
+ mp_safe_spin_lock(&x86_topo_lock);
+ /* Set a generous timeout of several seconds (in TSC ticks) */
+ tsc_timeout = rdtsc64() + (10ULL * 1000 * 1000 * 1000);
+ while ((cdp->lcpu.state != LCPU_HALT)
+ && (cdp->lcpu.state != LCPU_OFF)
+ && !cdp->lcpu.stopped) {
+ simple_unlock(&x86_topo_lock);
+ ml_set_interrupts_enabled(intrs_enabled);
+ cpu_pause();
+ if (rdtsc64() > tsc_timeout)
+ panic("cpu_exit_wait(%d) timeout", cpu);
+ ml_set_interrupts_enabled(FALSE);
+ mp_safe_spin_lock(&x86_topo_lock);
+ }
+ simple_unlock(&x86_topo_lock);
+ ml_set_interrupts_enabled(intrs_enabled);