]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/kern/machine.c
xnu-6153.11.26.tar.gz
[apple/xnu.git] / osfmk / kern / machine.c
index 40aa5c0b23ffc4665760ed9883bf96c15bbe1cd7..c90a8ea6dc2b4f43b4d7b1eb413fd8b3cea223f7 100644 (file)
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @OSF_COPYRIGHT@
  */
-/* 
+/*
  * Mach Operating System
  * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
  * All Rights Reserved.
- * 
+ *
  * Permission to use, copy, modify and distribute this software and its
  * documentation is hereby granted, provided that both the copyright
  * notice and this permission notice appear in all copies of the
  * software, derivative works or modified versions, and any portions
  * thereof, and that both notices appear in supporting documentation.
- * 
+ *
  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- * 
+ *
  * Carnegie Mellon requests users of this software to return to
- * 
+ *
  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  *  School of Computer Science
  *  Carnegie Mellon University
  *  Pittsburgh PA 15213-3890
- * 
+ *
  * any improvements or extensions that they make and grant Carnegie Mellon
  * the rights to redistribute these changes.
  */
 #include <kern/kern_types.h>
 #include <kern/counters.h>
 #include <kern/cpu_data.h>
+#include <kern/cpu_quiesce.h>
 #include <kern/ipc_host.h>
 #include <kern/host.h>
-#include <kern/lock.h>
 #include <kern/machine.h>
 #include <kern/misc_protos.h>
 #include <kern/processor.h>
 #include <kern/queue.h>
 #include <kern/sched.h>
+#include <kern/startup.h>
 #include <kern/task.h>
 #include <kern/thread.h>
 
+#include <machine/commpage.h>
+
+#if HIBERNATION
 #include <IOKit/IOHibernatePrivate.h>
+#endif
 #include <IOKit/IOPlatformExpert.h>
 
+#if CONFIG_DTRACE
+extern void (*dtrace_cpu_state_changed_hook)(int, boolean_t);
+#endif
+
+#if defined(__x86_64__)
+#include <i386/misc_protos.h>
+#include <libkern/OSDebug.h>
+#endif
+
 /*
  *     Exported variables:
  */
 
-struct machine_info    machine_info;
+struct machine_info     machine_info;
 
 /* Forwards */
-void                   processor_doshutdown(
-                                       processor_t                     processor);
+static void
+processor_doshutdown(processor_t processor);
+
+static void
+processor_offline(void * parameter, __unused wait_result_t result);
+
+static void
+processor_offline_intstack(processor_t processor) __dead2;
 
 /*
  *     processor_up:
@@ -109,248 +129,307 @@ void                    processor_doshutdown(
  */
 void
 processor_up(
-       processor_t             processor)
+       processor_t                     processor)
 {
-       processor_set_t         pset = &default_pset;
-       spl_t                           s;
+       processor_set_t         pset;
+       spl_t                           s;
+       boolean_t pset_online = false;
 
        s = splsched();
-       processor_lock(processor);
        init_ast_check(processor);
-       simple_lock(&pset->sched_lock);
-       pset_add_processor(pset, processor);
-       enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
-       processor->state = PROCESSOR_RUNNING;
-       simple_unlock(&pset->sched_lock);
-       hw_atomic_add(&machine_info.avail_cpus, 1);
+       pset = processor->processor_set;
+       pset_lock(pset);
+       if (pset->online_processor_count == 0) {
+               /* About to bring the first processor of a pset online */
+               pset_online = true;
+       }
+       ++pset->online_processor_count;
+       pset_update_processor_state(pset, processor, PROCESSOR_RUNNING);
+       os_atomic_inc(&processor_avail_count, relaxed);
+       if (processor->is_recommended) {
+               os_atomic_inc(&processor_avail_count_user, relaxed);
+       }
+       commpage_update_active_cpus();
+       if (pset_online) {
+               /* New pset is coming up online; callout to the
+                * scheduler in case it wants to adjust runqs.
+                */
+               SCHED(pset_made_schedulable)(processor, pset, true);
+               /* pset lock dropped */
+       } else {
+               pset_unlock(pset);
+       }
        ml_cpu_up();
-       processor_unlock(processor);
        splx(s);
+
+#if CONFIG_DTRACE
+       if (dtrace_cpu_state_changed_hook) {
+               (*dtrace_cpu_state_changed_hook)(processor->cpu_id, TRUE);
+       }
+#endif
 }
+#include <atm/atm_internal.h>
 
 kern_return_t
 host_reboot(
-       host_priv_t             host_priv,
-       int                             options)
+       host_priv_t             host_priv,
+       int                             options)
 {
-       if (host_priv == HOST_PRIV_NULL)
-               return (KERN_INVALID_HOST);
+       if (host_priv == HOST_PRIV_NULL) {
+               return KERN_INVALID_HOST;
+       }
 
        assert(host_priv == &realhost);
 
+#if DEVELOPMENT || DEBUG
        if (options & HOST_REBOOT_DEBUGGER) {
                Debugger("Debugger");
-               return (KERN_SUCCESS);
+               return KERN_SUCCESS;
        }
+#endif
 
-    if (options & HOST_REBOOT_UPSDELAY) {
-        // UPS power cutoff path
-        PEHaltRestart( kPEUPSDelayHaltCPU );
-    } else {
-       halt_all_cpus(!(options & HOST_REBOOT_HALT));
-    }
+       if (options & HOST_REBOOT_UPSDELAY) {
+               // UPS power cutoff path
+               PEHaltRestart( kPEUPSDelayHaltCPU );
+       } else {
+               halt_all_cpus(!(options & HOST_REBOOT_HALT));
+       }
 
-       return (KERN_SUCCESS);
+       return KERN_SUCCESS;
 }
 
 kern_return_t
 processor_assign(
-       __unused processor_t            processor,
-       __unused processor_set_t        new_pset,
-       __unused boolean_t              wait)
+       __unused processor_t            processor,
+       __unused processor_set_t        new_pset,
+       __unused boolean_t              wait)
 {
-       return (KERN_FAILURE);
+       return KERN_FAILURE;
 }
 
 kern_return_t
 processor_shutdown(
-       processor_t                     processor)
+       processor_t                     processor)
 {
-       processor_set_t         pset;
-       spl_t                           s;
+       processor_set_t         pset;
+       spl_t                           s;
 
        s = splsched();
-       processor_lock(processor);
+       pset = processor->processor_set;
+       pset_lock(pset);
        if (processor->state == PROCESSOR_OFF_LINE) {
                /*
                 * Success if already shutdown.
                 */
-               processor_unlock(processor);
+               pset_unlock(pset);
                splx(s);
 
-               return (KERN_SUCCESS);
+               return KERN_SUCCESS;
        }
 
        if (processor->state == PROCESSOR_START) {
                /*
                 * Failure if currently being started.
                 */
-               processor_unlock(processor);
+               pset_unlock(pset);
                splx(s);
 
-               return (KERN_FAILURE);
+               return KERN_FAILURE;
        }
 
        /*
-        * Must lock the scheduling lock
-        * to get at the processor state.
+        * If the processor is dispatching, let it finish.
         */
-       pset = processor->processor_set;
-       if (pset != PROCESSOR_SET_NULL) {
-               simple_lock(&pset->sched_lock);
-
-               /*
-                * If the processor is dispatching, let it finish.
-                */
-               while (processor->state == PROCESSOR_DISPATCHING) {
-                       simple_unlock(&pset->sched_lock);
-                       delay(1);
-                       simple_lock(&pset->sched_lock);
-               }
-
-               /*
-                * Success if already being shutdown.
-                */
-               if (processor->state == PROCESSOR_SHUTDOWN) {
-                       simple_unlock(&pset->sched_lock);
-                       processor_unlock(processor);
-                       splx(s);
-
-                       return (KERN_SUCCESS);
-               }
-       }
-       else {
-               /*
-                * Success, already being shutdown.
-                */
-               processor_unlock(processor);
+       while (processor->state == PROCESSOR_DISPATCHING) {
+               pset_unlock(pset);
                splx(s);
-
-               return (KERN_SUCCESS);
+               delay(1);
+               s = splsched();
+               pset_lock(pset);
        }
 
-       if (processor->state == PROCESSOR_IDLE) {
-               remqueue(&pset->idle_queue, (queue_entry_t)processor);
-               pset->idle_count--;
-       }
-       else
-       if (processor->state == PROCESSOR_RUNNING)
-               remqueue(&pset->active_queue, (queue_entry_t)processor);
-       else
-               panic("processor_shutdown");
-
-       processor->state = PROCESSOR_SHUTDOWN;
+       /*
+        * Success if already being shutdown.
+        */
+       if (processor->state == PROCESSOR_SHUTDOWN) {
+               pset_unlock(pset);
+               splx(s);
 
-       simple_unlock(&pset->sched_lock);
+               return KERN_SUCCESS;
+       }
 
-       processor_unlock(processor);
+       pset_update_processor_state(pset, processor, PROCESSOR_SHUTDOWN);
+       pset_unlock(pset);
 
        processor_doshutdown(processor);
        splx(s);
 
-       cpu_exit_wait(PROCESSOR_DATA(processor, slot_num));
+       cpu_exit_wait(processor->cpu_id);
 
-       return (KERN_SUCCESS);
+       return KERN_SUCCESS;
 }
 
 /*
- * Called at splsched.
+ * Called with interrupts disabled.
  */
-void
+static void
 processor_doshutdown(
-       processor_t                     processor)
+       processor_t processor)
 {
-       thread_t                        old_thread, self = current_thread();
-       processor_set_t         pset;
-       processor_t                     prev;
-       int                                     pcount;
+       thread_t self = current_thread();
 
        /*
         *      Get onto the processor to shutdown
         */
-       prev = thread_bind(self, processor);
+       processor_t prev = thread_bind(processor);
        thread_block(THREAD_CONTINUE_NULL);
 
-       processor_lock(processor);
-       pset = processor->processor_set;
-       simple_lock(&pset->sched_lock);
+       /* interrupts still disabled */
+       assert(ml_get_interrupts_enabled() == FALSE);
 
-       if ((pcount = pset->processor_count) == 1) {
-               simple_unlock(&pset->sched_lock);
-               processor_unlock(processor);
-
-               hibernate_vm_lock();
+       assert(processor == current_processor());
+       assert(processor->state == PROCESSOR_SHUTDOWN);
 
-               processor_lock(processor);
-               simple_lock(&pset->sched_lock);
+#if CONFIG_DTRACE
+       if (dtrace_cpu_state_changed_hook) {
+               (*dtrace_cpu_state_changed_hook)(processor->cpu_id, FALSE);
        }
+#endif
 
-       assert(processor->state == PROCESSOR_SHUTDOWN);
-
-       pset_remove_processor(pset, processor);
-       simple_unlock(&pset->sched_lock);
-       processor_unlock(processor);
+       ml_cpu_down();
 
-       if (pcount == 1)
+#if HIBERNATION
+       if (processor_avail_count < 2) {
+               hibernate_vm_lock();
                hibernate_vm_unlock();
+       }
+#endif
 
-       /*
-        *      Continue processor shutdown in shutdown context.
-        */
-       thread_bind(self, prev);
-       old_thread = machine_processor_shutdown(self, processor_offline, processor);
+       processor_set_t pset = processor->processor_set;
 
-       thread_begin(self, self->last_processor);
+       pset_lock(pset);
+       pset_update_processor_state(pset, processor, PROCESSOR_OFF_LINE);
+       --pset->online_processor_count;
+       os_atomic_dec(&processor_avail_count, relaxed);
+       if (processor->is_recommended) {
+               os_atomic_dec(&processor_avail_count_user, relaxed);
+       }
+       commpage_update_active_cpus();
+       SCHED(processor_queue_shutdown)(processor);
+       /* pset lock dropped */
+       SCHED(rt_queue_shutdown)(processor);
 
-       thread_dispatch(old_thread);
+       thread_bind(prev);
+
+       /* interrupts still disabled */
 
        /*
-        * If we just shutdown another processor, move the
-        * timer call outs to the current processor.
+        * Continue processor shutdown on the processor's idle thread.
+        * The handoff won't fail because the idle thread has a reserved stack.
+        * Switching to the idle thread leaves interrupts disabled,
+        * so we can't accidentally take an interrupt after the context switch.
         */
-       if (processor != current_processor()) {
-               processor_lock(processor);
-               if (    processor->state == PROCESSOR_OFF_LINE  ||
-                               processor->state == PROCESSOR_SHUTDOWN  )
-                       timer_call_shutdown(processor);
-               processor_unlock(processor);
-       }
+       thread_t shutdown_thread = processor->idle_thread;
+       shutdown_thread->continuation = processor_offline;
+       shutdown_thread->parameter = processor;
+
+       thread_run(self, NULL, NULL, shutdown_thread);
 }
 
 /*
- *     Complete the shutdown and place the processor offline.
+ * Called in the context of the idle thread to shut down the processor
  *
- *     Called at splsched in the shutdown context.
+ * A shut-down processor looks like it's 'running' the idle thread parked
+ * in this routine, but it's actually been powered off and has no hardware state.
  */
-void
+static void
 processor_offline(
-       processor_t             processor)
+       void * parameter,
+       __unused wait_result_t result)
 {
-       thread_t                thread, old_thread = processor->active_thread;
+       processor_t processor = (processor_t) parameter;
+       thread_t self = current_thread();
+       __assert_only thread_t old_thread = THREAD_NULL;
 
-       thread = processor->idle_thread;
-       processor->active_thread = thread;
-       processor->current_pri = IDLEPRI;
+       assert(processor == current_processor());
+       assert(self->state & TH_IDLE);
+       assert(processor->idle_thread == self);
+       assert(ml_get_interrupts_enabled() == FALSE);
+       assert(self->continuation == NULL);
+       assert(processor->processor_offlined == false);
 
-       processor->last_dispatch = mach_absolute_time();
-       timer_switch((uint32_t)processor->last_dispatch,
-                                                       &PROCESSOR_DATA(processor, offline_timer));
+       bool enforce_quiesce_safety = gEnforceQuiesceSafety;
 
-       thread_done(old_thread, thread, processor);
+       /*
+        * Scheduling is now disabled for this processor.
+        * Ensure that primitives that need scheduling (like mutexes) know this.
+        */
+       if (enforce_quiesce_safety) {
+               disable_preemption();
+       }
+
+       /* convince slave_main to come back here */
+       processor->processor_offlined = true;
 
-       machine_set_current_thread(thread);
+       /*
+        * Switch to the interrupt stack and shut down the processor.
+        *
+        * When the processor comes back, it will eventually call load_context which
+        * restores the context saved by machine_processor_shutdown, returning here.
+        */
+       old_thread = machine_processor_shutdown(self, processor_offline_intstack, processor);
 
-       thread_begin(thread, processor);
+       /* old_thread should be NULL because we got here through Load_context */
+       assert(old_thread == THREAD_NULL);
 
-       thread_dispatch(old_thread);
+       assert(processor == current_processor());
+       assert(processor->idle_thread == current_thread());
 
-       PMAP_DEACTIVATE_KERNEL(PROCESSOR_DATA(processor, slot_num));
+       assert(ml_get_interrupts_enabled() == FALSE);
+       assert(self->continuation == NULL);
 
-       processor_lock(processor);
-       processor->state = PROCESSOR_OFF_LINE;
-       hw_atomic_sub(&machine_info.avail_cpus, 1);
-       ml_cpu_down();
-       processor_unlock(processor);
+       /* Extract the machine_param value stashed by slave_main */
+       void * machine_param = self->parameter;
+       self->parameter = NULL;
+
+       /* Re-initialize the processor */
+       slave_machine_init(machine_param);
+
+       assert(processor->processor_offlined == true);
+       processor->processor_offlined = false;
+
+       if (enforce_quiesce_safety) {
+               enable_preemption();
+       }
+
+       /*
+        * Now that the processor is back, invoke the idle thread to find out what to do next.
+        * idle_thread will enable interrupts.
+        */
+       thread_block(idle_thread);
+       /*NOTREACHED*/
+}
+
+/*
+ * Complete the shutdown and place the processor offline.
+ *
+ * Called at splsched in the shutdown context
+ * (i.e. on the idle thread, on the interrupt stack)
+ *
+ * The onlining half of this is done in load_context().
+ */
+static void
+processor_offline_intstack(
+       processor_t processor)
+{
+       assert(processor == current_processor());
+       assert(processor->active_thread == current_thread());
+
+       timer_stop(PROCESSOR_DATA(processor, current_state), processor->last_dispatch);
+
+       cpu_quiescent_counter_leave(processor->last_dispatch);
+
+       PMAP_DEACTIVATE_KERNEL(processor->cpu_id);
 
        cpu_sleep();
        panic("zombie processor");
@@ -359,12 +438,13 @@ processor_offline(
 
 kern_return_t
 host_get_boot_info(
-        host_priv_t         host_priv,
-        kernel_boot_info_t  boot_info)
+       host_priv_t         host_priv,
+       kernel_boot_info_t  boot_info)
 {
        const char *src = "";
-       if (host_priv == HOST_PRIV_NULL)
-               return (KERN_INVALID_HOST);
+       if (host_priv == HOST_PRIV_NULL) {
+               return KERN_INVALID_HOST;
+       }
 
        assert(host_priv == &realhost);
 
@@ -373,8 +453,250 @@ host_get_boot_info(
         *      standardized strings generated from boot string.
         */
        src = machine_boot_info(boot_info, KERNEL_BOOT_INFO_MAX);
-       if (src != boot_info)
+       if (src != boot_info) {
                (void) strncpy(boot_info, src, KERNEL_BOOT_INFO_MAX);
+       }
+
+       return KERN_SUCCESS;
+}
+
+#if CONFIG_DTRACE
+#include <mach/sdt.h>
+#endif
+
+unsigned long long
+ml_io_read(uintptr_t vaddr, int size)
+{
+       unsigned long long result = 0;
+       unsigned char s1;
+       unsigned short s2;
+
+#if defined(__x86_64__)
+       uint64_t sabs, eabs;
+       boolean_t istate, timeread = FALSE;
+#if DEVELOPMENT || DEBUG
+       extern uint64_t simulate_stretched_io;
+       uintptr_t paddr = pmap_verify_noncacheable(vaddr);
+#endif /* x86_64 DEVELOPMENT || DEBUG */
+       if (__improbable(reportphyreaddelayabs != 0)) {
+               istate = ml_set_interrupts_enabled(FALSE);
+               sabs = mach_absolute_time();
+               timeread = TRUE;
+       }
+
+#if DEVELOPMENT || DEBUG
+       if (__improbable(timeread && simulate_stretched_io)) {
+               sabs -= simulate_stretched_io;
+       }
+#endif /* x86_64 DEVELOPMENT || DEBUG */
+
+#endif /* x86_64 */
+
+       switch (size) {
+       case 1:
+               s1 = *(volatile unsigned char *)vaddr;
+               result = s1;
+               break;
+       case 2:
+               s2 = *(volatile unsigned short *)vaddr;
+               result = s2;
+               break;
+       case 4:
+               result = *(volatile unsigned int *)vaddr;
+               break;
+       case 8:
+               result = *(volatile unsigned long long *)vaddr;
+               break;
+       default:
+               panic("Invalid size %d for ml_io_read(%p)", size, (void *)vaddr);
+               break;
+       }
+
+#if defined(__x86_64__)
+       if (__improbable(timeread == TRUE)) {
+               eabs = mach_absolute_time();
+
+#if DEVELOPMENT || DEBUG
+               iotrace(IOTRACE_IO_READ, vaddr, paddr, size, result, sabs, eabs - sabs);
+#endif
+
+               if (__improbable((eabs - sabs) > reportphyreaddelayabs)) {
+#if !(DEVELOPMENT || DEBUG)
+                       uintptr_t paddr = kvtophys(vaddr);
+#endif
+
+                       (void)ml_set_interrupts_enabled(istate);
+
+                       if (phyreadpanic && (machine_timeout_suspended() == FALSE)) {
+                               panic_io_port_read();
+                               panic("Read from IO vaddr 0x%lx paddr 0x%lx took %llu ns, "
+                                   "result: 0x%llx (start: %llu, end: %llu), ceiling: %llu",
+                                   vaddr, paddr, (eabs - sabs), result, sabs, eabs,
+                                   reportphyreaddelayabs);
+                       }
+
+                       if (reportphyreadosbt) {
+                               OSReportWithBacktrace("ml_io_read(v=%p, p=%p) size %d result 0x%llx "
+                                   "took %lluus",
+                                   (void *)vaddr, (void *)paddr, size, result,
+                                   (eabs - sabs) / NSEC_PER_USEC);
+                       }
+#if CONFIG_DTRACE
+                       DTRACE_PHYSLAT5(physioread, uint64_t, (eabs - sabs),
+                           uint64_t, vaddr, uint32_t, size, uint64_t, paddr, uint64_t, result);
+#endif /* CONFIG_DTRACE */
+               } else if (__improbable(tracephyreaddelayabs > 0 && (eabs - sabs) > tracephyreaddelayabs)) {
+#if !(DEVELOPMENT || DEBUG)
+                       uintptr_t paddr = kvtophys(vaddr);
+#endif
+
+                       KDBG(MACHDBG_CODE(DBG_MACH_IO, DBC_MACH_IO_MMIO_READ),
+                           (eabs - sabs), VM_KERNEL_UNSLIDE_OR_PERM(vaddr), paddr, result);
+
+                       (void)ml_set_interrupts_enabled(istate);
+               } else {
+                       (void)ml_set_interrupts_enabled(istate);
+               }
+       }
+#endif /* x86_64 */
+       return result;
+}
+
+unsigned int
+ml_io_read8(uintptr_t vaddr)
+{
+       return (unsigned) ml_io_read(vaddr, 1);
+}
 
-       return (KERN_SUCCESS);
+unsigned int
+ml_io_read16(uintptr_t vaddr)
+{
+       return (unsigned) ml_io_read(vaddr, 2);
+}
+
+unsigned int
+ml_io_read32(uintptr_t vaddr)
+{
+       return (unsigned) ml_io_read(vaddr, 4);
+}
+
+unsigned long long
+ml_io_read64(uintptr_t vaddr)
+{
+       return ml_io_read(vaddr, 8);
+}
+
+/* ml_io_write* */
+
+void
+ml_io_write(uintptr_t vaddr, uint64_t val, int size)
+{
+#if defined(__x86_64__)
+       uint64_t sabs, eabs;
+       boolean_t istate, timewrite = FALSE;
+#if DEVELOPMENT || DEBUG
+       extern uint64_t simulate_stretched_io;
+       uintptr_t paddr = pmap_verify_noncacheable(vaddr);
+#endif /* x86_64 DEVELOPMENT || DEBUG */
+       if (__improbable(reportphywritedelayabs != 0)) {
+               istate = ml_set_interrupts_enabled(FALSE);
+               sabs = mach_absolute_time();
+               timewrite = TRUE;
+       }
+
+#if DEVELOPMENT || DEBUG
+       if (__improbable(timewrite && simulate_stretched_io)) {
+               sabs -= simulate_stretched_io;
+       }
+#endif /* x86_64 DEVELOPMENT || DEBUG */
+#endif /* x86_64 */
+
+       switch (size) {
+       case 1:
+               *(volatile uint8_t *)vaddr = (uint8_t)val;
+               break;
+       case 2:
+               *(volatile uint16_t *)vaddr = (uint16_t)val;
+               break;
+       case 4:
+               *(volatile uint32_t *)vaddr = (uint32_t)val;
+               break;
+       case 8:
+               *(volatile uint64_t *)vaddr = (uint64_t)val;
+               break;
+       default:
+               panic("Invalid size %d for ml_io_write(%p, 0x%llx)", size, (void *)vaddr, val);
+               break;
+       }
+
+#if defined(__x86_64__)
+       if (__improbable(timewrite == TRUE)) {
+               eabs = mach_absolute_time();
+
+#if DEVELOPMENT || DEBUG
+               iotrace(IOTRACE_IO_WRITE, vaddr, paddr, size, val, sabs, eabs - sabs);
+#endif
+
+               if (__improbable((eabs - sabs) > reportphywritedelayabs)) {
+#if !(DEVELOPMENT || DEBUG)
+                       uintptr_t paddr = kvtophys(vaddr);
+#endif
+
+                       (void)ml_set_interrupts_enabled(istate);
+
+                       if (phywritepanic && (machine_timeout_suspended() == FALSE)) {
+                               panic_io_port_read();
+                               panic("Write to IO vaddr %p paddr %p val 0x%llx took %llu ns,"
+                                   " (start: %llu, end: %llu), ceiling: %llu",
+                                   (void *)vaddr, (void *)paddr, val, (eabs - sabs), sabs, eabs,
+                                   reportphywritedelayabs);
+                       }
+
+                       if (reportphywriteosbt) {
+                               OSReportWithBacktrace("ml_io_write size %d (v=%p, p=%p, 0x%llx) "
+                                   "took %lluus",
+                                   size, (void *)vaddr, (void *)paddr, val, (eabs - sabs) / NSEC_PER_USEC);
+                       }
+#if CONFIG_DTRACE
+                       DTRACE_PHYSLAT5(physiowrite, uint64_t, (eabs - sabs),
+                           uint64_t, vaddr, uint32_t, size, uint64_t, paddr, uint64_t, val);
+#endif /* CONFIG_DTRACE */
+               } else if (__improbable(tracephywritedelayabs > 0 && (eabs - sabs) > tracephywritedelayabs)) {
+#if !(DEVELOPMENT || DEBUG)
+                       uintptr_t paddr = kvtophys(vaddr);
+#endif
+
+                       KDBG(MACHDBG_CODE(DBG_MACH_IO, DBC_MACH_IO_MMIO_WRITE),
+                           (eabs - sabs), VM_KERNEL_UNSLIDE_OR_PERM(vaddr), paddr, val);
+
+                       (void)ml_set_interrupts_enabled(istate);
+               } else {
+                       (void)ml_set_interrupts_enabled(istate);
+               }
+       }
+#endif /* x86_64 */
+}
+
+void
+ml_io_write8(uintptr_t vaddr, uint8_t val)
+{
+       ml_io_write(vaddr, val, 1);
+}
+
+void
+ml_io_write16(uintptr_t vaddr, uint16_t val)
+{
+       ml_io_write(vaddr, val, 2);
+}
+
+void
+ml_io_write32(uintptr_t vaddr, uint32_t val)
+{
+       ml_io_write(vaddr, val, 4);
+}
+
+void
+ml_io_write64(uintptr_t vaddr, uint64_t val)
+{
+       ml_io_write(vaddr, val, 8);
 }