Index: sys/amd64/conf/FIRECRACKER
===================================================================
--- sys/amd64/conf/FIRECRACKER
+++ sys/amd64/conf/FIRECRACKER
@@ -115,7 +115,6 @@
 
 # Make an SMP-capable kernel by default
 options 	SMP			# Symmetric MultiProcessor Kernel
-options 	EARLY_AP_STARTUP
 
 # Pseudo devices.
 device		crypto			# core crypto support
Index: sys/amd64/conf/GENERIC
===================================================================
--- sys/amd64/conf/GENERIC
+++ sys/amd64/conf/GENERIC
@@ -124,7 +124,6 @@
 
 # Make an SMP-capable kernel by default
 options 	SMP			# Symmetric MultiProcessor Kernel
-options 	EARLY_AP_STARTUP
 
 # CPU frequency control
 device		cpufreq
Index: sys/amd64/conf/MINIMAL
===================================================================
--- sys/amd64/conf/MINIMAL
+++ sys/amd64/conf/MINIMAL
@@ -80,7 +80,6 @@
 
 # Make an SMP-capable kernel by default
 options 	SMP			# Symmetric MultiProcessor Kernel
-options 	EARLY_AP_STARTUP
 
 # CPU frequency control
 device		cpufreq
Index: sys/cddl/dev/dtrace/amd64/dtrace_subr.c
===================================================================
--- sys/cddl/dev/dtrace/amd64/dtrace_subr.c
+++ sys/cddl/dev/dtrace/amd64/dtrace_subr.c
@@ -285,7 +285,6 @@
 		hst_cpu_tsc = rdtsc();
 }
 
-#ifdef EARLY_AP_STARTUP
 static void
 dtrace_gethrtime_init(void *arg)
 {
@@ -293,16 +292,6 @@
 	uint64_t tsc_f;
 	cpuset_t map;
 	int i;
-#else
-/*
- * Get the frequency and scale factor as early as possible so that they can be
- * used for boot-time tracing.
- */
-static void
-dtrace_gethrtime_init_early(void *arg)
-{
-	uint64_t tsc_f;
-#endif
 
 	/*
 	 * Get TSC frequency known at this moment.
@@ -331,18 +320,6 @@
 	 *   (terahertz) values;
 	 */
 	nsec_scale = ((uint64_t)NANOSEC << SCALE_SHIFT) / tsc_f;
-#ifndef EARLY_AP_STARTUP
-}
-SYSINIT(dtrace_gethrtime_init_early, SI_SUB_CPU, SI_ORDER_ANY,
-    dtrace_gethrtime_init_early, NULL);
-
-static void
-dtrace_gethrtime_init(void *arg)
-{
-	struct pcpu *pc;
-	cpuset_t map;
-	int i;
-#endif
 
 	if (vm_guest != VM_GUEST_NO)
 		return;
@@ -366,13 +343,8 @@
 	}
 	sched_unpin();
 }
-#ifdef EARLY_AP_STARTUP
 SYSINIT(dtrace_gethrtime_init, SI_SUB_DTRACE, SI_ORDER_ANY,
     dtrace_gethrtime_init, NULL);
-#else
-SYSINIT(dtrace_gethrtime_init, SI_SUB_SMP, SI_ORDER_ANY, dtrace_gethrtime_init,
-    NULL);
-#endif
 
 /*
  * DTrace needs a high resolution time function which can
Index: sys/cddl/dev/dtrace/dtrace_load.c
===================================================================
--- sys/cddl/dev/dtrace/dtrace_load.c
+++ sys/cddl/dev/dtrace/dtrace_load.c
@@ -22,35 +22,11 @@
  *
  */
 
-#ifndef EARLY_AP_STARTUP
-static void
-dtrace_ap_start(void *dummy)
-{
-	int i;
-
-	mutex_enter(&cpu_lock);
-
-	/* Setup the rest of the CPUs. */
-	CPU_FOREACH(i) {
-		if (i == 0)
-			continue;
-
-		(void) dtrace_cpu_setup(CPU_CONFIG, i);
-	}
-
-	mutex_exit(&cpu_lock);
-}
-
-SYSINIT(dtrace_ap_start, SI_SUB_SMP, SI_ORDER_ANY, dtrace_ap_start, NULL);
-#endif
-
 static void
 dtrace_load(void *dummy)
 {
 	dtrace_provider_id_t id;
-#ifdef EARLY_AP_STARTUP
 	int i;
-#endif
 
 #ifndef illumos
 	/*
@@ -152,14 +128,9 @@
 	mutex_exit(&dtrace_lock);
 	mutex_exit(&dtrace_provider_lock);
 
-#ifdef EARLY_AP_STARTUP
 	CPU_FOREACH(i) {
 		(void) dtrace_cpu_setup(CPU_CONFIG, i);
 	}
-#else
-	/* Setup the boot CPU */
-	(void) dtrace_cpu_setup(CPU_CONFIG, 0);
-#endif
 
 	mutex_exit(&cpu_lock);
 
Index: sys/cddl/dev/dtrace/i386/dtrace_subr.c
===================================================================
--- sys/cddl/dev/dtrace/i386/dtrace_subr.c
+++ sys/cddl/dev/dtrace/i386/dtrace_subr.c
@@ -285,7 +285,6 @@
 		hst_cpu_tsc = rdtsc();
 }
 
-#ifdef EARLY_AP_STARTUP
 static void
 dtrace_gethrtime_init(void *arg)
 {
@@ -293,16 +292,6 @@
 	uint64_t tsc_f;
 	cpuset_t map;
 	int i;
-#else
-/*
- * Get the frequency and scale factor as early as possible so that they can be
- * used for boot-time tracing.
- */
-static void
-dtrace_gethrtime_init_early(void *arg)
-{
-	uint64_t tsc_f;
-#endif
 
 	/*
 	 * Get TSC frequency known at this moment.
@@ -331,18 +320,6 @@
 	 *   (terahertz) values;
 	 */
 	nsec_scale = ((uint64_t)NANOSEC << SCALE_SHIFT) / tsc_f;
-#ifndef EARLY_AP_STARTUP
-}
-SYSINIT(dtrace_gethrtime_init_early, SI_SUB_CPU, SI_ORDER_ANY,
-    dtrace_gethrtime_init_early, NULL);
-
-static void
-dtrace_gethrtime_init(void *arg)
-{
-	cpuset_t map;
-	struct pcpu *pc;
-	int i;
-#endif
 
 	if (vm_guest != VM_GUEST_NO)
 		return;
@@ -366,13 +343,8 @@
 	}
 	sched_unpin();
 }
-#ifdef EARLY_AP_STARTUP
 SYSINIT(dtrace_gethrtime_init, SI_SUB_DTRACE, SI_ORDER_ANY,
     dtrace_gethrtime_init, NULL);
-#else
-SYSINIT(dtrace_gethrtime_init, SI_SUB_SMP, SI_ORDER_ANY, dtrace_gethrtime_init,
-    NULL);
-#endif
 
 /*
  * DTrace needs a high resolution time function which can
Index: sys/cddl/dev/dtrace/powerpc/dtrace_subr.c
===================================================================
--- sys/cddl/dev/dtrace/powerpc/dtrace_subr.c
+++ sys/cddl/dev/dtrace/powerpc/dtrace_subr.c
@@ -220,13 +220,8 @@
 	}
 	sched_unpin();
 }
-#ifdef EARLY_AP_STARTUP
 SYSINIT(dtrace_gethrtime_init, SI_SUB_DTRACE, SI_ORDER_ANY,
     dtrace_gethrtime_init, NULL);
-#else
-SYSINIT(dtrace_gethrtime_init, SI_SUB_SMP, SI_ORDER_ANY, dtrace_gethrtime_init,
-    NULL);
-#endif
 
 /*
  * DTrace needs a high resolution time function which can
Index: sys/conf/NOTES
===================================================================
--- sys/conf/NOTES
+++ sys/conf/NOTES
@@ -223,12 +223,6 @@
 # Mandatory:
 options 	SMP			# Symmetric MultiProcessor Kernel
 
-# EARLY_AP_STARTUP releases the Application Processors earlier in the
-# kernel startup process (before devices are probed) rather than at the
-# end.  This is a temporary option for use during the transition from
-# late to early AP startup.
-options 	EARLY_AP_STARTUP
-
 # MAXCPU defines the maximum number of CPUs that can boot in the system.
 # A default value should be already present, for every architecture.
 options 	MAXCPU=32
Index: sys/conf/options
===================================================================
--- sys/conf/options
+++ sys/conf/options
@@ -634,7 +634,6 @@
 DEBUG_REDZONE		opt_vm.h
 
 # Standard SMP options
-EARLY_AP_STARTUP	opt_global.h
 SMP			opt_global.h
 NUMA			opt_global.h
 
Index: sys/dev/acpica/acpi.c
===================================================================
--- sys/dev/acpica/acpi.c
+++ sys/dev/acpica/acpi.c
@@ -3397,18 +3397,10 @@
     suspend_all_fs();
     EVENTHANDLER_INVOKE(power_suspend);
 
-#ifdef EARLY_AP_STARTUP
     MPASS(mp_ncpus == 1 || smp_started);
     thread_lock(curthread);
     sched_bind(curthread, 0);
     thread_unlock(curthread);
-#else
-    if (smp_started) {
-	thread_lock(curthread);
-	sched_bind(curthread, 0);
-	thread_unlock(curthread);
-    }
-#endif
 
     /*
      * Be sure to hold Giant across DEVICE_SUSPEND/RESUME
@@ -3541,17 +3533,9 @@
 
     bus_topo_unlock();
 
-#ifdef EARLY_AP_STARTUP
     thread_lock(curthread);
     sched_unbind(curthread);
     thread_unlock(curthread);
-#else
-    if (smp_started) {
-	thread_lock(curthread);
-	sched_unbind(curthread);
-	thread_unlock(curthread);
-    }
-#endif
 
     resume_all_fs();
     resume_all_proc();
Index: sys/dev/acpica/acpi_cpu.c
===================================================================
--- sys/dev/acpica/acpi_cpu.c
+++ sys/dev/acpica/acpi_cpu.c
@@ -479,12 +479,7 @@
     bus_topo_unlock();
 
     if (attached) {
-#ifdef EARLY_AP_STARTUP
 	acpi_cpu_startup(NULL);
-#else
-	/* Queue post cpu-probing task handler */
-	AcpiOsExecute(OSL_NOTIFY_HANDLER, acpi_cpu_startup, NULL);
-#endif
     }
 }
 
Index: sys/dev/hwpmc/hwpmc_mod.c
===================================================================
--- sys/dev/hwpmc/hwpmc_mod.c
+++ sys/dev/hwpmc/hwpmc_mod.c
@@ -435,11 +435,7 @@
 	.priv =		&pmc_syscall_mod,
 };
 
-#ifdef EARLY_AP_STARTUP
 DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SYSCALLS, SI_ORDER_ANY);
-#else
-DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY);
-#endif
 MODULE_VERSION(pmc, PMC_VERSION);
 
 #ifdef HWPMC_DEBUG
Index: sys/dev/hyperv/vmbus/vmbus.c
===================================================================
--- sys/dev/hyperv/vmbus/vmbus.c
+++ sys/dev/hyperv/vmbus/vmbus.c
@@ -114,9 +114,7 @@
 				    device_t dev, int cpu);
 static struct taskqueue		*vmbus_get_eventtq_method(device_t, device_t,
 				    int);
-#if defined(EARLY_AP_STARTUP)
 static void			vmbus_intrhook(void *);
-#endif
 
 static int			vmbus_init(struct vmbus_softc *);
 static int			vmbus_connect(struct vmbus_softc *, uint32_t);
@@ -1482,8 +1480,6 @@
 {
 }
 
-#if defined(EARLY_AP_STARTUP)
-
 static void
 vmbus_intrhook(void *xsc)
 {
@@ -1495,8 +1491,6 @@
 	config_intrhook_disestablish(&sc->vmbus_intrhook);
 }
 
-#endif /* EARLY_AP_STARTUP */
-
 static int
 vmbus_attach(device_t dev)
 {
@@ -1511,14 +1505,12 @@
 	 */
 	vmbus_sc->vmbus_event_proc = vmbus_event_proc_dummy;
 
-#if defined(EARLY_AP_STARTUP)
 	/*
 	 * Defer the real attach until the pause(9) works as expected.
 	 */
 	vmbus_sc->vmbus_intrhook.ich_func = vmbus_intrhook;
 	vmbus_sc->vmbus_intrhook.ich_arg = vmbus_sc;
 	config_intrhook_establish(&vmbus_sc->vmbus_intrhook);
-#endif /* EARLY_AP_STARTUP  and aarch64 */
 
 	return (0);
 }
@@ -1562,23 +1554,3 @@
 #endif
 	return (0);
 }
-
-#if !defined(EARLY_AP_STARTUP)
-
-static void
-vmbus_sysinit(void *arg __unused)
-{
-	struct vmbus_softc *sc = vmbus_get_softc();
-
-	if (vm_guest != VM_GUEST_HV || sc == NULL)
-		return;
-
-	vmbus_doattach(sc);
-}
-/*
- * NOTE:
- * We have to start as the last step of SI_SUB_SMP, i.e. after SMP is
- * initialized.
- */
-SYSINIT(vmbus_initialize, SI_SUB_SMP, SI_ORDER_ANY, vmbus_sysinit, NULL);
-#endif	/* !EARLY_AP_STARTUP */
Index: sys/dev/kvm_clock/kvm_clock.c
===================================================================
--- sys/dev/kvm_clock/kvm_clock.c
+++ sys/dev/kvm_clock/kvm_clock.c
@@ -71,9 +71,6 @@
 	struct pvclock_vcpu_time_info	*timeinfos;
 	u_int				 msr_tc;
 	u_int				 msr_wc;
-#ifndef EARLY_AP_STARTUP
-	int				 firstcpu;
-#endif
 };
 
 static struct pvclock_wall_clock *kvm_clock_get_wallclock(void *arg);
@@ -109,32 +106,6 @@
 	wrmsr(sc->msr_tc, vtophys(&(sc->timeinfos)[curcpu]) | 1);
 }
 
-#ifndef EARLY_AP_STARTUP
-static void
-kvm_clock_init_smp(void *arg __unused)
-{
-	devclass_t kvm_clock_devclass;
-	cpuset_t cpus;
-	struct kvm_clock_softc *sc;
-
-	kvm_clock_devclass = devclass_find(KVM_CLOCK_DEVNAME);
-	sc = devclass_get_softc(kvm_clock_devclass, 0);
-	if (sc == NULL || mp_ncpus == 1)
-		return;
-
-	/*
-	 * Register with the hypervisor on all CPUs except the one that
-	 * registered in kvm_clock_attach().
-	 */
-	cpus = all_cpus;
-	KASSERT(CPU_ISSET(sc->firstcpu, &cpus),
-	    ("%s: invalid first CPU %d", __func__, sc->firstcpu));
-	CPU_CLR(sc->firstcpu, &cpus);
-	kvm_clock_system_time_enable(sc, &cpus);
-}
-SYSINIT(kvm_clock, SI_SUB_SMP, SI_ORDER_ANY, kvm_clock_init_smp, NULL);
-#endif
-
 static void
 kvm_clock_identify(driver_t *driver, device_t parent)
 {
@@ -181,12 +152,7 @@
 	/* Set up 'struct pvclock_vcpu_time_info' page(s): */
 	sc->timeinfos = kmem_malloc(mp_ncpus *
 	    sizeof(struct pvclock_vcpu_time_info), M_WAITOK | M_ZERO);
-#ifdef EARLY_AP_STARTUP
 	kvm_clock_system_time_enable(sc, &all_cpus);
-#else
-	sc->firstcpu = curcpu;
-	kvm_clock_system_time_enable_pcpu(sc);
-#endif
 
 	/*
 	 * Init pvclock; register KVM clock wall clock, register KVM clock
Index: sys/dev/ntb/ntb_hw/ntb_hw_intel.c
===================================================================
--- sys/dev/ntb/ntb_hw/ntb_hw_intel.c
+++ sys/dev/ntb/ntb_hw/ntb_hw_intel.c
@@ -2976,19 +2976,6 @@
 	return (uidx);
 }
 
-#ifndef EARLY_AP_STARTUP
-static int msix_ready;
-
-static void
-intel_ntb_msix_ready(void *arg __unused)
-{
-
-	msix_ready = 1;
-}
-SYSINIT(intel_ntb_msix_ready, SI_SUB_SMP, SI_ORDER_ANY,
-    intel_ntb_msix_ready, NULL);
-#endif
-
 static void
 intel_ntb_exchange_msix(void *ctx)
 {
@@ -3003,12 +2990,6 @@
 	if (ntb->peer_msix_done)
 		goto msix_done;
 
-#ifndef EARLY_AP_STARTUP
-	/* Block MSIX negotiation until SMP started and IRQ reshuffled. */
-	if (!msix_ready)
-		goto reschedule;
-#endif
-
 	intel_ntb_get_msix_info(ntb);
 	for (i = 0; i < XEON_NONLINK_DB_MSIX_BITS; i++) {
 		intel_ntb_peer_spad_write(ntb->device, NTB_MSIX_DATA0 + i,
Index: sys/dev/usb/usb_process.c
===================================================================
--- sys/dev/usb/usb_process.c
+++ sys/dev/usb/usb_process.c
@@ -435,15 +435,6 @@
 			up->up_csleep = 0;
 			cv_signal(&up->up_cv);
 		}
-#ifndef EARLY_AP_STARTUP
-		/* Check if we are still cold booted */
-		if (cold) {
-			USB_THREAD_SUSPEND(up->up_ptr);
-			printf("WARNING: A USB process has "
-			    "been left suspended\n");
-			break;
-		}
-#endif
 		cv_wait(&up->up_cv, up->up_mtx);
 	}
 	/* Check if someone is waiting - should not happen */
Index: sys/dev/xen/control/control.c
===================================================================
--- sys/dev/xen/control/control.c
+++ sys/dev/xen/control/control.c
@@ -217,18 +217,10 @@
 	suspend_all_fs();
 	EVENTHANDLER_INVOKE(power_suspend);
 
-#ifdef EARLY_AP_STARTUP
 	MPASS(mp_ncpus == 1 || smp_started);
 	thread_lock(curthread);
 	sched_bind(curthread, 0);
 	thread_unlock(curthread);
-#else
-	if (smp_started) {
-		thread_lock(curthread);
-		sched_bind(curthread, 0);
-		thread_unlock(curthread);
-	}
-#endif
 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
 
 	/*
@@ -242,7 +234,6 @@
 	}
 
 #ifdef SMP
-#ifdef EARLY_AP_STARTUP
 	/*
 	 * Suspend other CPUs. This prevents IPIs while we
 	 * are resuming, and will allow us to reset per-cpu
@@ -252,20 +243,6 @@
 	CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
 	if (!CPU_EMPTY(&cpu_suspend_map))
 		suspend_cpus(cpu_suspend_map);
-#else
-	CPU_ZERO(&cpu_suspend_map);	/* silence gcc */
-	if (smp_started) {
-		/*
-		 * Suspend other CPUs. This prevents IPIs while we
-		 * are resuming, and will allow us to reset per-cpu
-		 * vcpu_info on resume.
-		 */
-		cpu_suspend_map = all_cpus;
-		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
-		if (!CPU_EMPTY(&cpu_suspend_map))
-			suspend_cpus(cpu_suspend_map);
-	}
-#endif
 #endif
 
 	/*
@@ -317,17 +294,9 @@
 	timecounter->tc_get_timecount(timecounter);
 	inittodr(time_second);
 
-#ifdef EARLY_AP_STARTUP
 	thread_lock(curthread);
 	sched_unbind(curthread);
 	thread_unlock(curthread);
-#else
-	if (smp_started) {
-		thread_lock(curthread);
-		sched_unbind(curthread);
-		thread_unlock(curthread);
-	}
-#endif
 
 	resume_all_fs();
 	resume_all_proc();
Index: sys/geom/eli/g_eli.c
===================================================================
--- sys/geom/eli/g_eli.c
+++ sys/geom/eli/g_eli.c
@@ -665,15 +665,7 @@
 
 	wr = arg;
 	sc = wr->w_softc;
-#ifdef EARLY_AP_STARTUP
 	MPASS(!sc->sc_cpubind || smp_started);
-#elif defined(SMP)
-	/* Before sched_bind() to a CPU, wait for all CPUs to go on-line. */
-	if (sc->sc_cpubind) {
-		while (!smp_started)
-			tsleep(wr, 0, "geli:smp", hz / 4);
-	}
-#endif
 	thread_lock(curthread);
 	sched_prio(curthread, PUSER);
 	if (sc->sc_cpubind)
Index: sys/i386/conf/GENERIC
===================================================================
--- sys/i386/conf/GENERIC
+++ sys/i386/conf/GENERIC
@@ -109,7 +109,6 @@
 # To make an SMP kernel, the next two lines are needed
 options 	SMP			# Symmetric MultiProcessor Kernel
 device		apic			# I/O APIC
-options 	EARLY_AP_STARTUP
 
 # CPU frequency control
 device		cpufreq
Index: sys/i386/conf/MINIMAL
===================================================================
--- sys/i386/conf/MINIMAL
+++ sys/i386/conf/MINIMAL
@@ -88,7 +88,6 @@
 
 # Make an SMP-capable kernel by default
 options 	SMP			# Symmetric MultiProcessor Kernel
-options 	EARLY_AP_STARTUP
 device		apic
 
 # CPU frequency control
Index: sys/kern/kern_clocksource.c
===================================================================
--- sys/kern/kern_clocksource.c
+++ sys/kern/kern_clocksource.c
@@ -325,16 +325,10 @@
 	    (int)(now >> 32), (u_int)(now & 0xffffffff));
 
 #ifdef SMP
-#ifdef EARLY_AP_STARTUP
 	MPASS(mp_ncpus == 1 || smp_started);
-#endif
 	/* Prepare broadcasting to other CPUs for non-per-CPU timers. */
 	bcast = 0;
-#ifdef EARLY_AP_STARTUP
 	if ((et->et_flags & ET_FLAGS_PERCPU) == 0) {
-#else
-	if ((et->et_flags & ET_FLAGS_PERCPU) == 0 && smp_started) {
-#endif
 		CPU_FOREACH(cpu) {
 			state = DPCPU_ID_PTR(cpu, timerstate);
 			ET_HW_LOCK(state);
@@ -495,18 +489,11 @@
 			nexttick = next;
 		else
 			nexttick = -1;
-#ifdef EARLY_AP_STARTUP
 		MPASS(mp_ncpus == 1 || smp_started);
-#endif
 		CPU_FOREACH(cpu) {
 			state = DPCPU_ID_PTR(cpu, timerstate);
 			state->now = now;
-#ifndef EARLY_AP_STARTUP
-			if (!smp_started && cpu != CPU_FIRST())
-				state->nextevent = SBT_MAX;
-			else
-#endif
-				state->nextevent = next;
+			state->nextevent = next;
 			if (periodic)
 				state->nexttick = next;
 			else
@@ -528,13 +515,8 @@
 	}
 	ET_HW_UNLOCK(DPCPU_PTR(timerstate));
 #ifdef SMP
-#ifdef EARLY_AP_STARTUP
 	/* If timer is global we are done. */
 	if ((timer->et_flags & ET_FLAGS_PERCPU) == 0) {
-#else
-	/* If timer is global or there is no other CPUs yet - we are done. */
-	if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || !smp_started) {
-#endif
 		critical_exit();
 		return;
 	}
Index: sys/kern/kern_cpu.c
===================================================================
--- sys/kern/kern_cpu.c
+++ sys/kern/kern_cpu.c
@@ -255,22 +255,7 @@
 	CF_MTX_LOCK(&sc->lock);
 
 #ifdef SMP
-#ifdef EARLY_AP_STARTUP
 	MPASS(mp_ncpus == 1 || smp_started);
-#else
-	/*
-	 * If still booting and secondary CPUs not started yet, don't allow
-	 * changing the frequency until they're online.  This is because we
-	 * can't switch to them using sched_bind() and thus we'd only be
-	 * switching the main CPU.  XXXTODO: Need to think more about how to
-	 * handle having different CPUs at different frequencies.  
-	 */
-	if (mp_ncpus > 1 && !smp_started) {
-		device_printf(dev, "rejecting change, SMP not started yet\n");
-		error = ENXIO;
-		goto out;
-	}
-#endif
 #endif /* SMP */
 
 	/*
Index: sys/kern/subr_epoch.c
===================================================================
--- sys/kern/subr_epoch.c
+++ sys/kern/subr_epoch.c
@@ -330,15 +330,6 @@
 }
 SYSINIT(epoch, SI_SUB_EPOCH, SI_ORDER_FIRST, epoch_init, NULL);
 
-#if !defined(EARLY_AP_STARTUP)
-static void
-epoch_init_smp(void *dummy __unused)
-{
-	inited = 2;
-}
-SYSINIT(epoch_smp, SI_SUB_SMP + 1, SI_ORDER_FIRST, epoch_init_smp, NULL);
-#endif
-
 static void
 epoch_ctor(epoch_t epoch)
 {
@@ -788,10 +779,6 @@
 	/* too early in boot to have epoch set up */
 	if (__predict_false(epoch == NULL))
 		goto boottime;
-#if !defined(EARLY_AP_STARTUP)
-	if (__predict_false(inited < 2))
-		goto boottime;
-#endif
 
 	critical_enter();
 	*DPCPU_PTR(epoch_cb_count) += 1;
@@ -972,10 +959,6 @@
 	/* too early in boot to have epoch set up */
 	if (__predict_false(epoch == NULL))
 		return;
-#if !defined(EARLY_AP_STARTUP)
-	if (__predict_false(inited < 2))
-		return;
-#endif
 	DROP_GIANT();
 
 	sx_xlock(&epoch->e_drain_sx);
Index: sys/kern/subr_intr.c
===================================================================
--- sys/kern/subr_intr.c
+++ sys/kern/subr_intr.c
@@ -138,11 +138,7 @@
 static u_int irq_next_free;
 
 #ifdef SMP
-#ifdef EARLY_AP_STARTUP
 static bool irq_assign_cpu = true;
-#else
-static bool irq_assign_cpu = false;
-#endif
 #endif
 
 u_int intr_nirq = NIRQ;
@@ -1265,49 +1261,6 @@
 	return (last_cpu);
 }
 
-#ifndef EARLY_AP_STARTUP
-/*
- *  Distribute all the interrupt sources among the available
- *  CPUs once the AP's have been launched.
- */
-static void
-intr_irq_shuffle(void *arg __unused)
-{
-	struct intr_irqsrc *isrc;
-	u_int i;
-
-	if (mp_ncpus == 1)
-		return;
-
-	mtx_lock(&isrc_table_lock);
-	irq_assign_cpu = true;
-	for (i = 0; i < intr_nirq; i++) {
-		isrc = irq_sources[i];
-		if (isrc == NULL || isrc->isrc_handlers == 0 ||
-		    isrc->isrc_flags & (INTR_ISRCF_PPI | INTR_ISRCF_IPI))
-			continue;
-
-		if (isrc->isrc_event != NULL &&
-		    isrc->isrc_flags & INTR_ISRCF_BOUND &&
-		    isrc->isrc_event->ie_cpu != CPU_FFS(&isrc->isrc_cpu) - 1)
-			panic("%s: CPU inconsistency", __func__);
-
-		if ((isrc->isrc_flags & INTR_ISRCF_BOUND) == 0)
-			CPU_ZERO(&isrc->isrc_cpu); /* start again */
-
-		/*
-		 * We are in wicked position here if the following call fails
-		 * for bound ISRC. The best thing we can do is to clear
-		 * isrc_cpu so inconsistency with ie_cpu will be detectable.
-		 */
-		if (PIC_BIND_INTR(isrc->isrc_dev, isrc) != 0)
-			CPU_ZERO(&isrc->isrc_cpu);
-	}
-	mtx_unlock(&isrc_table_lock);
-}
-SYSINIT(intr_irq_shuffle, SI_SUB_SMP, SI_ORDER_SECOND, intr_irq_shuffle, NULL);
-#endif /* !EARLY_AP_STARTUP */
-
 #else
 u_int
 intr_irq_next_cpu(u_int current_cpu, cpuset_t *cpumask)
Index: sys/net/netisr.c
===================================================================
--- sys/net/netisr.c
+++ sys/net/netisr.c
@@ -1333,41 +1333,14 @@
 	}
 #endif
 
-#ifdef EARLY_AP_STARTUP
 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
 		if (nws_count >= netisr_maxthreads)
 			break;
 		netisr_start_swi(pc->pc_cpuid, pc);
 	}
-#else
-	pc = get_pcpu();
-	netisr_start_swi(pc->pc_cpuid, pc);
-#endif
 }
 SYSINIT(netisr_init, SI_SUB_SOFTINTR, SI_ORDER_FIRST, netisr_init, NULL);
 
-#ifndef EARLY_AP_STARTUP
-/*
- * Start worker threads for additional CPUs.  No attempt to gracefully handle
- * work reassignment, we don't yet support dynamic reconfiguration.
- */
-static void
-netisr_start(void *arg)
-{
-	struct pcpu *pc;
-
-	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
-		if (nws_count >= netisr_maxthreads)
-			break;
-		/* Worker will already be present for boot CPU. */
-		if (pc->pc_netisr != NULL)
-			continue;
-		netisr_start_swi(pc->pc_cpuid, pc);
-	}
-}
-SYSINIT(netisr_start, SI_SUB_SMP, SI_ORDER_MIDDLE, netisr_start, NULL);
-#endif
-
 /*
  * Sysctl monitoring for netisr: query a list of registered protocols.
  */
Index: sys/riscv/riscv/clock.c
===================================================================
--- sys/riscv/riscv/clock.c
+++ sys/riscv/riscv/clock.c
@@ -46,7 +46,6 @@
 void
 cpu_initclocks(void)
 {
-#ifdef EARLY_AP_STARTUP
 	struct thread *td;
 	int i;
 
@@ -64,7 +63,4 @@
 	if (sched_is_bound(td))
 		sched_unbind(td);
 	thread_unlock(td);
-#else
-	cpu_initclocks_bsp();
-#endif
 }
Index: sys/riscv/riscv/mp_machdep.c
===================================================================
--- sys/riscv/riscv/mp_machdep.c
+++ sys/riscv/riscv/mp_machdep.c
@@ -250,11 +250,6 @@
 	/* Enable software interrupts */
 	riscv_unmask_ipi();
 
-#ifndef EARLY_AP_STARTUP
-	/* Start per-CPU event timers. */
-	cpu_initclocks_ap();
-#endif
-
 	/* Enable external (PLIC) interrupts */
 	csr_set(sie, SIE_SEIE);
 
Index: sys/sys/kernel.h
===================================================================
--- sys/sys/kernel.h
+++ sys/sys/kernel.h
@@ -127,9 +127,7 @@
 	SI_SUB_INTR		= 0x2800000,	/* interrupt threads */
 	SI_SUB_TASKQ		= 0x2880000,	/* task queues */
 	SI_SUB_EPOCH		= 0x2888000,	/* epoch subsystem */
-#ifdef EARLY_AP_STARTUP
 	SI_SUB_SMP		= 0x2900000,	/* start the APs*/
-#endif
 	SI_SUB_SOFTINTR		= 0x2A00000,	/* start soft interrupt thread */
 	SI_SUB_DEVFS		= 0x2F00000,	/* devfs ready for devices */
 	SI_SUB_INIT_IF		= 0x3000000,	/* prep for net interfaces */
@@ -169,9 +167,6 @@
 	SI_SUB_KTHREAD_BUF	= 0xea00000,	/* buffer daemon*/
 	SI_SUB_KTHREAD_UPDATE	= 0xec00000,	/* update daemon*/
 	SI_SUB_KTHREAD_IDLE	= 0xee00000,	/* idle procs*/
-#ifndef EARLY_AP_STARTUP
-	SI_SUB_SMP		= 0xf000000,	/* start the APs*/
-#endif	
 	SI_SUB_RACCTD		= 0xf100000,	/* start racctd*/
 	SI_SUB_LAST		= 0xfffffff	/* final initialization */
 };
Index: sys/x86/isa/clock.c
===================================================================
--- sys/x86/isa/clock.c
+++ sys/x86/isa/clock.c
@@ -413,7 +413,6 @@
 void
 cpu_initclocks(void)
 {
-#ifdef EARLY_AP_STARTUP
 	struct thread *td;
 	int i;
 
@@ -436,13 +435,6 @@
 	if (sched_is_bound(td))
 		sched_unbind(td);
 	thread_unlock(td);
-#else
-	tsc_calibrate();
-#ifdef DEV_APIC
-	lapic_calibrate_timer();
-#endif
-	cpu_initclocks_bsp();
-#endif
 }
 
 static int
Index: sys/x86/x86/intr_machdep.c
===================================================================
--- sys/x86/x86/intr_machdep.c
+++ sys/x86/x86/intr_machdep.c
@@ -93,10 +93,6 @@
 static TAILQ_HEAD(pics_head, pic) pics;
 u_int num_io_irqs;
 
-#if defined(SMP) && !defined(EARLY_AP_STARTUP)
-static int assign_cpu;
-#endif
-
 u_long *intrcnt;
 char *intrnames;
 size_t sintrcnt = sizeof(intrcnt);
@@ -402,18 +398,10 @@
 	struct intsrc *isrc;
 	int error;
 
-#ifdef EARLY_AP_STARTUP
 	MPASS(mp_ncpus == 1 || smp_started);
 
 	/* Nothing to do if there is only a single CPU. */
 	if (mp_ncpus > 1 && cpu != NOCPU) {
-#else
-	/*
-	 * Don't do anything during early boot.  We will pick up the
-	 * assignment once the APs are started.
-	 */
-	if (assign_cpu && cpu != NOCPU) {
-#endif
 		isrc = arg;
 		sx_xlock(&intrsrc_lock);
 		error = isrc->is_pic->pic_assign_cpu(isrc, cpu_apic_ids[cpu]);
@@ -608,15 +596,9 @@
 {
 	u_int apic_id;
 
-#ifdef EARLY_AP_STARTUP
 	MPASS(mp_ncpus == 1 || smp_started);
 	if (mp_ncpus == 1)
 		return (PCPU_GET(apic_id));
-#else
-	/* Leave all interrupts on the BSP during boot. */
-	if (!assign_cpu)
-		return (PCPU_GET(apic_id));
-#endif
 
 	mtx_lock_spin(&icu_lock);
 	apic_id = cpu_apic_ids[current_cpu[domain]];
@@ -647,7 +629,6 @@
 	CPU_SET(cpu, &intr_cpus);
 }
 
-#ifdef EARLY_AP_STARTUP
 static void
 intr_smp_startup(void *arg __unused)
 {
@@ -658,52 +639,6 @@
 SYSINIT(intr_smp_startup, SI_SUB_SMP, SI_ORDER_SECOND, intr_smp_startup,
     NULL);
 
-#else
-/*
- * Distribute all the interrupt sources among the available CPUs once the
- * AP's have been launched.
- */
-static void
-intr_shuffle_irqs(void *arg __unused)
-{
-	struct intsrc *isrc;
-	u_int cpu, i;
-
-	intr_init_cpus();
-	/* Don't bother on UP. */
-	if (mp_ncpus == 1)
-		return;
-
-	/* Round-robin assign a CPU to each enabled source. */
-	sx_xlock(&intrsrc_lock);
-	assign_cpu = 1;
-	for (i = 0; i < num_io_irqs; i++) {
-		isrc = interrupt_sources[i];
-		if (isrc != NULL && isrc->is_handlers > 0) {
-			/*
-			 * If this event is already bound to a CPU,
-			 * then assign the source to that CPU instead
-			 * of picking one via round-robin.  Note that
-			 * this is careful to only advance the
-			 * round-robin if the CPU assignment succeeds.
-			 */
-			cpu = isrc->is_event->ie_cpu;
-			if (cpu == NOCPU)
-				cpu = current_cpu[isrc->is_domain];
-			if (isrc->is_pic->pic_assign_cpu(isrc,
-			    cpu_apic_ids[cpu]) == 0) {
-				isrc->is_cpu = cpu;
-				if (isrc->is_event->ie_cpu == NOCPU)
-					intr_next_cpu(isrc->is_domain);
-			}
-		}
-	}
-	sx_xunlock(&intrsrc_lock);
-}
-SYSINIT(intr_shuffle_irqs, SI_SUB_SMP, SI_ORDER_SECOND, intr_shuffle_irqs,
-    NULL);
-#endif
-
 /*
  * TODO: Export this information in a non-MD fashion, integrate with vmstat -i.
  */
Index: sys/x86/x86/local_apic.c
===================================================================
--- sys/x86/x86/local_apic.c
+++ sys/x86/x86/local_apic.c
@@ -878,22 +878,8 @@
 
 	lvts[APIC_LVT_PMC].lvt_masked = 0;
 
-#ifdef EARLY_AP_STARTUP
 	MPASS(mp_ncpus == 1 || smp_started);
 	smp_rendezvous(NULL, lapic_update_pmc, NULL, NULL);
-#else
-#ifdef SMP
-	/*
-	 * If hwpmc was loaded at boot time then the APs may not be
-	 * started yet.  In that case, don't forward the request to
-	 * them as they will program the lvt when they start.
-	 */
-	if (smp_started)
-		smp_rendezvous(NULL, lapic_update_pmc, NULL, NULL);
-	else
-#endif
-		lapic_update_pmc(NULL);
-#endif
 	return (1);
 #else
 	return (0);
Index: sys/x86/x86/mca.c
===================================================================
--- sys/x86/x86/mca.c
+++ sys/x86/x86/mca.c
@@ -1079,11 +1079,7 @@
 	taskqueue_enqueue_timeout_sbt(mca_tq, &mca_scan_task,
 	    mca_ticks * SBT_1S, 0, C_PREL(1));
 }
-#ifdef EARLY_AP_STARTUP
 SYSINIT(mca_startup, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, mca_startup, NULL);
-#else
-SYSINIT(mca_startup, SI_SUB_SMP, SI_ORDER_ANY, mca_startup, NULL);
-#endif
 
 #ifdef DEV_APIC
 static void
Index: sys/x86/x86/mp_x86.c
===================================================================
--- sys/x86/x86/mp_x86.c
+++ sys/x86/x86/mp_x86.c
@@ -1114,11 +1114,6 @@
 	while (atomic_load_acq_int(&smp_started) == 0)
 		ia32_pause();
 
-#ifndef EARLY_AP_STARTUP
-	/* Start per-CPU event timers. */
-	cpu_initclocks_ap();
-#endif
-
 	kcsan_cpu_init(cpuid);
 
 	sched_ap_entry();