[apple/xnu.git] / osfmk / arm64 / machine_routines.c

/*
 * Copyright (c) 2007-2017 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
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * 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,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * 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@
 */

#include <arm64/proc_reg.h>
#include <arm/machine_cpu.h>
#include <arm/cpu_internal.h>
#include <arm/cpuid.h>
#include <arm/io_map_entries.h>
#include <arm/cpu_data.h>
#include <arm/cpu_data_internal.h>
#include <arm/caches_internal.h>
#include <arm/misc_protos.h>
#include <arm/machdep_call.h>
#include <arm/rtclock.h>
#include <console/serial_protos.h>
#include <kern/machine.h>
#include <prng/random.h>
#include <kern/startup.h>
#include <kern/thread.h>
#include <mach/machine.h>
#include <machine/atomic.h>
#include <vm/pmap.h>
#include <vm/vm_page.h>
#include <sys/kdebug.h>
#include <kern/coalition.h>
#include <pexpert/device_tree.h>

#include <IOKit/IOPlatformExpert.h>
#include <libkern/section_keywords.h>

#if defined(KERNEL_INTEGRITY_KTRR)
#include <libkern/kernel_mach_header.h>
#endif

#if KPC
#include <kern/kpc.h>
#endif


static int max_cpus_initialized = 0;
#define MAX_CPUS_SET    0x1
#define MAX_CPUS_WAIT   0x2

uint32_t LockTimeOut;
uint32_t LockTimeOutUsec;
uint64_t MutexSpin;
boolean_t is_clock_configured = FALSE;

extern int mach_assert;
extern volatile uint32_t debug_enabled;
SECURITY_READ_ONLY_LATE(unsigned int) debug_boot_arg;


void machine_conf(void);

thread_t Idle_context(void);

static uint32_t cpu_phys_ids[MAX_CPUS] = {[0 ... MAX_CPUS - 1] = (uint32_t)-1};
static unsigned int avail_cpus = 0;
static int boot_cpu = -1;
static int max_cpu_number = 0;
cluster_type_t boot_cluster = CLUSTER_TYPE_SMP;

lockdown_handler_t lockdown_handler;
void *lockdown_this;
lck_mtx_t lockdown_handler_lck;
lck_grp_t *lockdown_handler_grp;
int lockdown_done;

void ml_lockdown_init(void);
void ml_lockdown_run_handler(void);
uint32_t get_arm_cpu_version(void);


void ml_cpu_signal(unsigned int cpu_id __unused)
{
        panic("Platform does not support ACC Fast IPI");
}

void ml_cpu_signal_deferred_adjust_timer(uint64_t nanosecs) {
        (void)nanosecs;
        panic("Platform does not support ACC Fast IPI");
}

uint64_t ml_cpu_signal_deferred_get_timer() {
        return 0;
}

void ml_cpu_signal_deferred(unsigned int cpu_id __unused)
{
        panic("Platform does not support ACC Fast IPI deferral");
}

void ml_cpu_signal_retract(unsigned int cpu_id __unused)
{
        panic("Platform does not support ACC Fast IPI retraction");
}

void machine_idle(void)
{
        __asm__ volatile ("msr DAIFSet, %[mask]" ::[mask] "i" (DAIFSC_IRQF | DAIFSC_FIQF));
        Idle_context();
        __asm__ volatile ("msr DAIFClr, %[mask]" ::[mask] "i" (DAIFSC_IRQF | DAIFSC_FIQF));
}

void init_vfp(void)
{
        return;
}

boolean_t get_vfp_enabled(void)
{
        return TRUE;
}

void OSSynchronizeIO(void)
{
        __builtin_arm_dsb(DSB_SY);
}

uint64_t get_aux_control(void)
{
        uint64_t        value;

        MRS(value, "ACTLR_EL1");
        return value;
}

uint64_t get_mmu_control(void)
{
        uint64_t        value;

        MRS(value, "SCTLR_EL1");
        return value;
}

uint64_t get_tcr(void)
{
        uint64_t        value;

        MRS(value, "TCR_EL1");
        return value;
}

boolean_t ml_get_interrupts_enabled(void)
{
        uint64_t        value;

        MRS(value, "DAIF");
        if (value & DAIF_IRQF)
                return FALSE;
        return TRUE;
}

pmap_paddr_t get_mmu_ttb(void)
{
        pmap_paddr_t    value;

        MRS(value, "TTBR0_EL1");
        return value;
}

MARK_AS_PMAP_TEXT
void set_mmu_ttb(pmap_paddr_t value)
{
        __builtin_arm_dsb(DSB_ISH);
        MSR("TTBR0_EL1", value);
        __builtin_arm_isb(ISB_SY);
}

static uint32_t get_midr_el1(void)
{
        uint64_t value;

        MRS(value, "MIDR_EL1");

        /* This is a 32-bit register. */
        return (uint32_t) value;
}

uint32_t get_arm_cpu_version(void)
{
        uint32_t value = get_midr_el1();

        /* Compose the register values into 8 bits; variant[7:4], revision[3:0]. */
        return ((value & MIDR_EL1_REV_MASK) >> MIDR_EL1_REV_SHIFT) | ((value & MIDR_EL1_VAR_MASK) >> (MIDR_EL1_VAR_SHIFT - 4));
}

/*
 * user_cont_hwclock_allowed()
 *
 * Indicates whether we allow EL0 to read the physical timebase (CNTPCT_EL0)
 * as a continuous time source (e.g. from mach_continuous_time)
 */
boolean_t user_cont_hwclock_allowed(void)
{
        return FALSE;
}

/*
 * user_timebase_allowed()
 *
 * Indicates whether we allow EL0 to read the physical timebase (CNTPCT_EL0).
 */
boolean_t user_timebase_allowed(void)
{
        return TRUE;
}

boolean_t arm64_wfe_allowed(void)
{
        return TRUE;
}

#if defined(KERNEL_INTEGRITY_KTRR)

uint64_t rorgn_begin __attribute__((section("__DATA, __const"))) = 0;
uint64_t rorgn_end   __attribute__((section("__DATA, __const"))) = 0;
vm_offset_t amcc_base;

static void assert_unlocked(void);
static void assert_amcc_cache_disabled(void);
static void lock_amcc(void);
static void lock_mmu(uint64_t begin, uint64_t end);

void rorgn_stash_range(void)
{

#if DEVELOPMENT || DEBUG
        boolean_t rorgn_disable = FALSE;

        PE_parse_boot_argn("-unsafe_kernel_text", &rorgn_disable, sizeof(rorgn_disable));

        if (rorgn_disable) {
                /* take early out if boot arg present, don't query any machine registers to avoid
                 * dependency on amcc DT entry
                 */
                return;
        }
#endif

        /* Get the AMC values, and stash them into rorgn_begin, rorgn_end. */

#if defined(KERNEL_INTEGRITY_KTRR)
        uint64_t soc_base = 0;
        DTEntry entryP = NULL;
        uintptr_t *reg_prop = NULL;
        uint32_t prop_size = 0;
        int rc;

        soc_base = pe_arm_get_soc_base_phys();
        rc = DTFindEntry("name", "mcc", &entryP);
        assert(rc == kSuccess);
        rc = DTGetProperty(entryP, "reg", (void **)&reg_prop, &prop_size);
        assert(rc == kSuccess);
        amcc_base = ml_io_map(soc_base + *reg_prop, *(reg_prop + 1));
#else
#error "KERNEL_INTEGRITY config error"
#endif

#if defined(KERNEL_INTEGRITY_KTRR)
        assert(rRORGNENDADDR > rRORGNBASEADDR);
        rorgn_begin = (rRORGNBASEADDR << ARM_PGSHIFT) + gPhysBase;
        rorgn_end   = (rRORGNENDADDR << ARM_PGSHIFT) + gPhysBase;
#else
#error KERNEL_INTEGRITY config error
#endif /* defined (KERNEL_INTEGRITY_KTRR) */
}

static void assert_unlocked() {
        uint64_t ktrr_lock = 0;
        uint32_t rorgn_lock = 0;

        assert(amcc_base);
#if defined(KERNEL_INTEGRITY_KTRR)
        rorgn_lock = rRORGNLOCK;
        ktrr_lock = __builtin_arm_rsr64(ARM64_REG_KTRR_LOCK_EL1);
#else
#error KERNEL_INTEGRITY config error
#endif /* defined(KERNEL_INTEGRITY_KTRR) */

        assert(!ktrr_lock);
        assert(!rorgn_lock);
}

static void lock_amcc() {
#if defined(KERNEL_INTEGRITY_KTRR)
        rRORGNLOCK = 1;
        __builtin_arm_isb(ISB_SY);
#else
#error KERNEL_INTEGRITY config error
#endif
}

static void lock_mmu(uint64_t begin, uint64_t end) {

#if defined(KERNEL_INTEGRITY_KTRR)

        __builtin_arm_wsr64(ARM64_REG_KTRR_LOWER_EL1, begin);
        __builtin_arm_wsr64(ARM64_REG_KTRR_UPPER_EL1, end);
        __builtin_arm_wsr64(ARM64_REG_KTRR_LOCK_EL1,  1ULL);

        /* flush TLB */

        __builtin_arm_isb(ISB_SY);
        flush_mmu_tlb();

#else
#error KERNEL_INTEGRITY config error
#endif

}

static void assert_amcc_cache_disabled() {
#if defined(KERNEL_INTEGRITY_KTRR)
        assert((rMCCGEN & 1) == 0); /* assert M$ disabled or LLC clean will be unreliable */
#else
#error KERNEL_INTEGRITY config error
#endif
}

/*
 * void rorgn_lockdown(void)
 *
 * Lock the MMU and AMCC RORegion within lower and upper boundaries if not already locked
 *
 * [ ] - ensure this is being called ASAP on secondary CPUs: KTRR programming and lockdown handled in
 *       start.s:start_cpu() for subsequent wake/resume of all cores
 */
void rorgn_lockdown(void)
{
        vm_offset_t ktrr_begin, ktrr_end;
        unsigned long plt_segsz, last_segsz;

#if DEVELOPMENT || DEBUG
        boolean_t ktrr_disable = FALSE;

        PE_parse_boot_argn("-unsafe_kernel_text", &ktrr_disable, sizeof(ktrr_disable));

        if (ktrr_disable) {
                /*
                 * take early out if boot arg present, since we may not have amcc DT entry present
                 * we can't assert that iboot hasn't programmed the RO region lockdown registers
                 */
                goto out;
        }
#endif /* DEVELOPMENT || DEBUG */

        assert_unlocked();

        /* [x] - Use final method of determining all kernel text range or expect crashes */

        ktrr_begin = (uint64_t) getsegdatafromheader(&_mh_execute_header, "__PRELINK_TEXT", &plt_segsz);
        assert(ktrr_begin && gVirtBase && gPhysBase);

        ktrr_begin = kvtophys(ktrr_begin);

        /* __LAST is not part of the MMU KTRR region (it is however part of the AMCC KTRR region) */
        ktrr_end = (uint64_t) getsegdatafromheader(&_mh_execute_header, "__LAST", &last_segsz);
        ktrr_end = (kvtophys(ktrr_end) - 1) & ~PAGE_MASK;

        /* ensure that iboot and xnu agree on the ktrr range */
        assert(rorgn_begin == ktrr_begin && rorgn_end == (ktrr_end + last_segsz));
        /* assert that __LAST segment containing privileged insns is only a single page */
        assert(last_segsz == PAGE_SIZE);

#if DEBUG
        printf("KTRR Begin: %p End: %p, setting lockdown\n", (void *)ktrr_begin, (void *)ktrr_end);
#endif

        /* [x] - ensure all in flight writes are flushed to AMCC before enabling RO Region Lock */

        assert_amcc_cache_disabled();

        CleanPoC_DcacheRegion_Force(phystokv(ktrr_begin),
                (unsigned)((ktrr_end + last_segsz) - ktrr_begin + PAGE_MASK));

        lock_amcc();

        lock_mmu(ktrr_begin, ktrr_end);

#if DEVELOPMENT || DEBUG
out:
#endif

        /* now we can run lockdown handler */
        ml_lockdown_run_handler();
}

#endif /* defined(KERNEL_INTEGRITY_KTRR)*/

void
machine_startup(__unused boot_args * args)
{
        int boot_arg;


#if MACH_KDP
        if (PE_parse_boot_argn("debug", &debug_boot_arg, sizeof (debug_boot_arg)) &&
            debug_enabled) {
                if (debug_boot_arg & DB_HALT)
                        halt_in_debugger = 1;
                if (debug_boot_arg & DB_NMI)
                        panicDebugging = TRUE;
        } else {
                debug_boot_arg = 0;
        }

#endif

        PE_parse_boot_argn("assert", &mach_assert, sizeof (mach_assert));

        if (PE_parse_boot_argn("preempt", &boot_arg, sizeof (boot_arg))) {
                default_preemption_rate = boot_arg;
        }
        if (PE_parse_boot_argn("bg_preempt", &boot_arg, sizeof (boot_arg))) {
                default_bg_preemption_rate = boot_arg;
        }

        machine_conf();

        /*
         * Kick off the kernel bootstrap.
         */
        kernel_bootstrap();
        /* NOTREACHED */
}

void machine_lockdown_preflight(void)
{
#if CONFIG_KERNEL_INTEGRITY

#if defined(KERNEL_INTEGRITY_KTRR)
       rorgn_stash_range();
#endif

#endif
}

void machine_lockdown(void)
{
#if CONFIG_KERNEL_INTEGRITY
#if KERNEL_INTEGRITY_WT
        /* Watchtower
         *
         * Notify the monitor about the completion of early kernel bootstrap.
         * From this point forward it will enforce the integrity of kernel text,
         * rodata and page tables.
         */

#ifdef MONITOR
        monitor_call(MONITOR_LOCKDOWN, 0, 0, 0);
#endif
#endif /* KERNEL_INTEGRITY_WT */


#if defined(KERNEL_INTEGRITY_KTRR)
        /* KTRR
         *
         * Lock physical KTRR region. KTRR region is read-only. Memory outside
         * the region is not executable at EL1.
         */

         rorgn_lockdown();
#endif /* defined(KERNEL_INTEGRITY_KTRR)*/


#endif /* CONFIG_KERNEL_INTEGRITY */
}

char           *
machine_boot_info(
                  __unused char *buf,
                  __unused vm_size_t size)
{
        return (PE_boot_args());
}

void
machine_conf(void)
{
        /*
         * This is known to be inaccurate. mem_size should always be capped at 2 GB
         */
        machine_info.memory_size = (uint32_t)mem_size;
}

void
machine_init(void)
{
        debug_log_init();
        clock_config();
        is_clock_configured = TRUE;
        if (debug_enabled)
                pmap_map_globals();
}

void
slave_machine_init(__unused void *param)
{
        cpu_machine_init();     /* Initialize the processor */
        clock_init();           /* Init the clock */
}

/*
 *      Routine:        machine_processor_shutdown
 *      Function:
 */
thread_t
machine_processor_shutdown(
                           __unused thread_t thread,
                           void (*doshutdown) (processor_t),
                           processor_t processor)
{
        return (Shutdown_context(doshutdown, processor));
}

/*
 *      Routine:        ml_init_max_cpus
 *      Function:
 */
void
ml_init_max_cpus(unsigned int max_cpus)
{
        boolean_t       current_state;

        current_state = ml_set_interrupts_enabled(FALSE);
        if (max_cpus_initialized != MAX_CPUS_SET) {
                machine_info.max_cpus = max_cpus;
                machine_info.physical_cpu_max = max_cpus;
                machine_info.logical_cpu_max = max_cpus;
                if (max_cpus_initialized == MAX_CPUS_WAIT)
                        thread_wakeup((event_t) & max_cpus_initialized);
                max_cpus_initialized = MAX_CPUS_SET;
        }
        (void) ml_set_interrupts_enabled(current_state);
}

/*
 *      Routine:        ml_get_max_cpus
 *      Function:
 */
unsigned int
ml_get_max_cpus(void)
{
        boolean_t       current_state;

        current_state = ml_set_interrupts_enabled(FALSE);
        if (max_cpus_initialized != MAX_CPUS_SET) {
                max_cpus_initialized = MAX_CPUS_WAIT;
                assert_wait((event_t) & max_cpus_initialized, THREAD_UNINT);
                (void) thread_block(THREAD_CONTINUE_NULL);
        }
        (void) ml_set_interrupts_enabled(current_state);
        return (machine_info.max_cpus);
}

/*
 *      Routine:        ml_init_lock_timeout
 *      Function:
 */
void
ml_init_lock_timeout(void)
{
        uint64_t        abstime;
        uint64_t        mtxspin;
        uint64_t        default_timeout_ns = NSEC_PER_SEC>>2;
        uint32_t        slto;

        if (PE_parse_boot_argn("slto_us", &slto, sizeof (slto)))
                default_timeout_ns = slto * NSEC_PER_USEC;

        nanoseconds_to_absolutetime(default_timeout_ns, &abstime);
        LockTimeOutUsec = (uint32_t)(abstime / NSEC_PER_USEC);
        LockTimeOut = (uint32_t)abstime;

        if (PE_parse_boot_argn("mtxspin", &mtxspin, sizeof (mtxspin))) {
                if (mtxspin > USEC_PER_SEC>>4)
                        mtxspin =  USEC_PER_SEC>>4;
                        nanoseconds_to_absolutetime(mtxspin*NSEC_PER_USEC, &abstime);
        } else {
                nanoseconds_to_absolutetime(10*NSEC_PER_USEC, &abstime);
        }
        MutexSpin = abstime;
}

/*
 * This is called from the machine-independent routine cpu_up()
 * to perform machine-dependent info updates.
 */
void
ml_cpu_up(void)
{
        hw_atomic_add(&machine_info.physical_cpu, 1);
        hw_atomic_add(&machine_info.logical_cpu, 1);
}

/*
 * This is called from the machine-independent routine cpu_down()
 * to perform machine-dependent info updates.
 */
void
ml_cpu_down(void)
{
        cpu_data_t      *cpu_data_ptr;

        hw_atomic_sub(&machine_info.physical_cpu, 1);
        hw_atomic_sub(&machine_info.logical_cpu, 1);

        /*
         * If we want to deal with outstanding IPIs, we need to
         * do relatively early in the processor_doshutdown path,
         * as we pend decrementer interrupts using the IPI
         * mechanism if we cannot immediately service them (if
         * IRQ is masked).  Do so now.
         *
         * We aren't on the interrupt stack here; would it make
         * more sense to disable signaling and then enable
         * interrupts?  It might be a bit cleaner.
         */
        cpu_data_ptr = getCpuDatap();
        cpu_data_ptr->cpu_running = FALSE;
        cpu_signal_handler_internal(TRUE);
}

/*
 *      Routine:        ml_cpu_get_info
 *      Function:
 */
void
ml_cpu_get_info(ml_cpu_info_t * ml_cpu_info)
{
        cache_info_t   *cpuid_cache_info;

        cpuid_cache_info = cache_info();
        ml_cpu_info->vector_unit = 0;
        ml_cpu_info->cache_line_size = cpuid_cache_info->c_linesz;
        ml_cpu_info->l1_icache_size = cpuid_cache_info->c_isize;
        ml_cpu_info->l1_dcache_size = cpuid_cache_info->c_dsize;

#if (__ARM_ARCH__ >= 7)
        ml_cpu_info->l2_settings = 1;
        ml_cpu_info->l2_cache_size = cpuid_cache_info->c_l2size;
#else
        ml_cpu_info->l2_settings = 0;
        ml_cpu_info->l2_cache_size = 0xFFFFFFFF;
#endif
        ml_cpu_info->l3_settings = 0;
        ml_cpu_info->l3_cache_size = 0xFFFFFFFF;
}

unsigned int
ml_get_machine_mem(void)
{
        return (machine_info.memory_size);
}

__attribute__((noreturn))
void
halt_all_cpus(boolean_t reboot)
{
        if (reboot) {
                printf("MACH Reboot\n");
                PEHaltRestart(kPERestartCPU);
        } else {
                printf("CPU halted\n");
                PEHaltRestart(kPEHaltCPU);
        }
        while (1);
}

__attribute__((noreturn))
void
halt_cpu(void)
{
        halt_all_cpus(FALSE);
}

/*
 *      Routine:        machine_signal_idle
 *      Function:
 */
void
machine_signal_idle(
                    processor_t processor)
{
        cpu_signal(processor_to_cpu_datap(processor), SIGPnop, (void *)NULL, (void *)NULL);
        KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_REMOTE_AST), processor->cpu_id, 0 /* nop */, 0, 0, 0);
}

void
machine_signal_idle_deferred(
                          processor_t processor)
{
        cpu_signal_deferred(processor_to_cpu_datap(processor));
        KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_REMOTE_DEFERRED_AST), processor->cpu_id, 0 /* nop */, 0, 0, 0);
}

void
machine_signal_idle_cancel(
                          processor_t processor)
{
        cpu_signal_cancel(processor_to_cpu_datap(processor));
        KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_REMOTE_CANCEL_AST), processor->cpu_id, 0 /* nop */, 0, 0, 0);
}

/*
 *      Routine:        ml_install_interrupt_handler
 *      Function:       Initialize Interrupt Handler
 */
void 
ml_install_interrupt_handler(
                             void *nub,
                             int source,
                             void *target,
                             IOInterruptHandler handler,
                             void *refCon)
{
        cpu_data_t     *cpu_data_ptr;
        boolean_t       current_state;

        current_state = ml_set_interrupts_enabled(FALSE);
        cpu_data_ptr = getCpuDatap();

        cpu_data_ptr->interrupt_nub = nub;
        cpu_data_ptr->interrupt_source = source;
        cpu_data_ptr->interrupt_target = target;
        cpu_data_ptr->interrupt_handler = handler;
        cpu_data_ptr->interrupt_refCon = refCon;

        cpu_data_ptr->interrupts_enabled = TRUE;
        (void) ml_set_interrupts_enabled(current_state);

        initialize_screen(NULL, kPEAcquireScreen);
}

/*
 *      Routine:        ml_init_interrupt
 *      Function:       Initialize Interrupts
 */
void
ml_init_interrupt(void)
{
}

/*
 *      Routine:        ml_init_timebase
 *      Function:       register and setup Timebase, Decremeter services
 */
void ml_init_timebase(
        void            *args,
        tbd_ops_t       tbd_funcs,
        vm_offset_t     int_address,
        vm_offset_t     int_value __unused)
{
        cpu_data_t     *cpu_data_ptr;

        cpu_data_ptr = (cpu_data_t *)args;

        if ((cpu_data_ptr == &BootCpuData)
            && (rtclock_timebase_func.tbd_fiq_handler == (void *)NULL)) {
                rtclock_timebase_func = *tbd_funcs;
                rtclock_timebase_addr = int_address;
        }
}

void
ml_parse_cpu_topology(void)
{
        DTEntry entry, child __unused;
        OpaqueDTEntryIterator iter;
        uint32_t cpu_boot_arg;
        int err;

        cpu_boot_arg = MAX_CPUS;

        PE_parse_boot_argn("cpus", &cpu_boot_arg, sizeof(cpu_boot_arg));

        err = DTLookupEntry(NULL, "/cpus", &entry);
        assert(err == kSuccess);

        err = DTInitEntryIterator(entry, &iter);
        assert(err == kSuccess);

        while (kSuccess == DTIterateEntries(&iter, &child)) {
                unsigned int propSize;
                void *prop = NULL;
                int cpu_id = avail_cpus++;

                if (kSuccess == DTGetProperty(child, "cpu-id", &prop, &propSize))
                        cpu_id = *((int32_t*)prop);

                assert(cpu_id < MAX_CPUS);
                assert(cpu_phys_ids[cpu_id] == (uint32_t)-1);

                if (boot_cpu == -1) {
                        if (kSuccess != DTGetProperty(child, "state", &prop, &propSize))
                                panic("unable to retrieve state for cpu %d", cpu_id);

                        if (strncmp((char*)prop, "running", propSize) == 0) {
                                boot_cpu = cpu_id;
                        }
                }
                if (kSuccess != DTGetProperty(child, "reg", &prop, &propSize))
                        panic("unable to retrieve physical ID for cpu %d", cpu_id);

                cpu_phys_ids[cpu_id] = *((uint32_t*)prop);

                if ((cpu_id > max_cpu_number) && ((cpu_id == boot_cpu) || (avail_cpus <= cpu_boot_arg)))
                        max_cpu_number = cpu_id;
        }

        if (avail_cpus > cpu_boot_arg)
                avail_cpus = cpu_boot_arg;

        if (avail_cpus == 0)
                panic("No cpus found!");

        if (boot_cpu == -1)
                panic("unable to determine boot cpu!");
}

unsigned int
ml_get_cpu_count(void)
{
        return avail_cpus;
}

int
ml_get_boot_cpu_number(void)
{
        return boot_cpu;
}

cluster_type_t
ml_get_boot_cluster(void)
{
        return boot_cluster;
}

int
ml_get_cpu_number(uint32_t phys_id)
{
        for (int log_id = 0; log_id <= ml_get_max_cpu_number(); ++log_id) {
                if (cpu_phys_ids[log_id] == phys_id)
                        return log_id;
        }
        return -1;
}

int
ml_get_max_cpu_number(void)
{
        return max_cpu_number;
}


void ml_lockdown_init() {
    lockdown_handler_grp = lck_grp_alloc_init("lockdown_handler", NULL);
    assert(lockdown_handler_grp != NULL);

    lck_mtx_init(&lockdown_handler_lck, lockdown_handler_grp, NULL);
}

kern_return_t
ml_lockdown_handler_register(lockdown_handler_t f, void *this)
{
    if (lockdown_handler || !f) {
        return KERN_FAILURE;
    }

    lck_mtx_lock(&lockdown_handler_lck);
    lockdown_handler = f;
    lockdown_this = this;

#if !(defined(KERNEL_INTEGRITY_KTRR))
    lockdown_done=1;
    lockdown_handler(this);
#else
    if (lockdown_done) {
        lockdown_handler(this);
    }
#endif
    lck_mtx_unlock(&lockdown_handler_lck);

    return KERN_SUCCESS;
}

void ml_lockdown_run_handler() {
    lck_mtx_lock(&lockdown_handler_lck);
    assert(!lockdown_done);

    lockdown_done = 1;
    if (lockdown_handler) {
        lockdown_handler(lockdown_this);
    }
    lck_mtx_unlock(&lockdown_handler_lck);
}

kern_return_t
ml_processor_register(
                      ml_processor_info_t * in_processor_info,
                      processor_t * processor_out,
                      ipi_handler_t * ipi_handler)
{
        cpu_data_t *this_cpu_datap;
        processor_set_t pset;
        boolean_t  is_boot_cpu;
        static unsigned int reg_cpu_count = 0;

        if (in_processor_info->log_id > (uint32_t)ml_get_max_cpu_number())
                return KERN_FAILURE;

        if ((unsigned int)OSIncrementAtomic((SInt32*)&reg_cpu_count) >= avail_cpus)
                return KERN_FAILURE;

        if (in_processor_info->log_id != (uint32_t)ml_get_boot_cpu_number()) {
                is_boot_cpu = FALSE;
                this_cpu_datap = cpu_data_alloc(FALSE);
                cpu_data_init(this_cpu_datap);
        } else {
                this_cpu_datap = &BootCpuData;
                is_boot_cpu = TRUE;
        }

        assert(in_processor_info->log_id < MAX_CPUS);

        this_cpu_datap->cpu_id = in_processor_info->cpu_id;

        this_cpu_datap->cpu_chud = chudxnu_cpu_alloc(is_boot_cpu);
        if (this_cpu_datap->cpu_chud == (void *)NULL)
                goto processor_register_error;
        this_cpu_datap->cpu_console_buf = console_cpu_alloc(is_boot_cpu);
        if (this_cpu_datap->cpu_console_buf == (void *)(NULL))
                goto processor_register_error;

        if (!is_boot_cpu) {
                this_cpu_datap->cpu_number = in_processor_info->log_id;

                if (cpu_data_register(this_cpu_datap) != KERN_SUCCESS)
                        goto processor_register_error;
        }

        this_cpu_datap->cpu_idle_notify = (void *) in_processor_info->processor_idle;
        this_cpu_datap->cpu_cache_dispatch = in_processor_info->platform_cache_dispatch;
        nanoseconds_to_absolutetime((uint64_t) in_processor_info->powergate_latency, &this_cpu_datap->cpu_idle_latency);
        this_cpu_datap->cpu_reset_assist = kvtophys(in_processor_info->powergate_stub_addr);

        this_cpu_datap->idle_timer_notify = (void *) in_processor_info->idle_timer;
        this_cpu_datap->idle_timer_refcon = in_processor_info->idle_timer_refcon;

        this_cpu_datap->platform_error_handler = (void *) in_processor_info->platform_error_handler;
        this_cpu_datap->cpu_regmap_paddr = in_processor_info->regmap_paddr;
        this_cpu_datap->cpu_phys_id = in_processor_info->phys_id;
        this_cpu_datap->cpu_l2_access_penalty = in_processor_info->l2_access_penalty;

        this_cpu_datap->cpu_cluster_type = in_processor_info->cluster_type;
        this_cpu_datap->cpu_cluster_id = in_processor_info->cluster_id;
        this_cpu_datap->cpu_l2_id = in_processor_info->l2_cache_id;
        this_cpu_datap->cpu_l2_size = in_processor_info->l2_cache_size;
        this_cpu_datap->cpu_l3_id = in_processor_info->l3_cache_id;
        this_cpu_datap->cpu_l3_size = in_processor_info->l3_cache_size;

        this_cpu_datap->cluster_master = is_boot_cpu;

        pset = pset_find(in_processor_info->cluster_id, processor_pset(master_processor));
        assert(pset != NULL);
        kprintf("%s>cpu_id %p cluster_id %d cpu_number %d is type %d\n", __FUNCTION__, in_processor_info->cpu_id, in_processor_info->cluster_id, this_cpu_datap->cpu_number, in_processor_info->cluster_type);

        if (!is_boot_cpu) {
                processor_init((struct processor *)this_cpu_datap->cpu_processor,
                               this_cpu_datap->cpu_number, pset);

                if (this_cpu_datap->cpu_l2_access_penalty) {
                        /*
                         * Cores that have a non-zero L2 access penalty compared
                         * to the boot processor should be de-prioritized by the
                         * scheduler, so that threads use the cores with better L2
                         * preferentially.
                         */
                        processor_set_primary(this_cpu_datap->cpu_processor,
                                              master_processor);
                }
        }

        *processor_out = this_cpu_datap->cpu_processor;
        *ipi_handler = cpu_signal_handler;
        if (in_processor_info->idle_tickle != (idle_tickle_t *) NULL)
                *in_processor_info->idle_tickle = (idle_tickle_t) cpu_idle_tickle;

#if KPC
        if (kpc_register_cpu(this_cpu_datap) != TRUE)
                goto processor_register_error;
#endif

        if (!is_boot_cpu) {
                prng_cpu_init(this_cpu_datap->cpu_number);
                // now let next CPU register itself
                OSIncrementAtomic((SInt32*)&real_ncpus);
        }

        return KERN_SUCCESS;

processor_register_error:
#if KPC
        kpc_unregister_cpu(this_cpu_datap);
#endif
        if (this_cpu_datap->cpu_chud != (void *)NULL)
                chudxnu_cpu_free(this_cpu_datap->cpu_chud);
        if (!is_boot_cpu)
                cpu_data_free(this_cpu_datap);

        return KERN_FAILURE;
}

void
ml_init_arm_debug_interface(
                            void * in_cpu_datap,
                            vm_offset_t virt_address)
{
        ((cpu_data_t *)in_cpu_datap)->cpu_debug_interface_map = virt_address;
        do_debugid();
}

/*
 *      Routine:        init_ast_check
 *      Function:
 */
void
init_ast_check(
               __unused processor_t processor)
{
}

/*
 *      Routine:        cause_ast_check
 *      Function:
 */
void
cause_ast_check(
                 processor_t processor)
{
        if (current_processor() != processor) {
                cpu_signal(processor_to_cpu_datap(processor), SIGPast, (void *)NULL, (void *)NULL);
                KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_REMOTE_AST), processor->cpu_id, 1 /* ast */, 0, 0, 0);
        }
}


/*
 *      Routine:        ml_at_interrupt_context
 *      Function:       Check if running at interrupt context
 */
boolean_t
ml_at_interrupt_context(void)
{
        unsigned int    local;
        vm_offset_t     intstack_top_ptr;

        intstack_top_ptr = getCpuDatap()->intstack_top;
        return (((vm_offset_t)(&local) < intstack_top_ptr) && ((vm_offset_t)(&local) > (intstack_top_ptr - INTSTACK_SIZE)));
}
extern uint32_t cpu_idle_count;

void ml_get_power_state(boolean_t *icp, boolean_t *pidlep) {
        *icp = ml_at_interrupt_context();
        *pidlep = (cpu_idle_count == real_ncpus);
}

/*
 *      Routine:        ml_cause_interrupt
 *      Function:       Generate a fake interrupt
 */
void
ml_cause_interrupt(void)
{
        return;                 /* BS_XXX */
}

/* Map memory map IO space */
vm_offset_t
ml_io_map(
          vm_offset_t phys_addr,
          vm_size_t size)
{
        return (io_map(phys_addr, size, VM_WIMG_IO));
}

vm_offset_t
ml_io_map_wcomb(
          vm_offset_t phys_addr,
          vm_size_t size)
{
        return (io_map(phys_addr, size, VM_WIMG_WCOMB));
}

/* boot memory allocation */
vm_offset_t
ml_static_malloc(
                 __unused vm_size_t size)
{
        return ((vm_offset_t) NULL);
}

vm_map_address_t
ml_map_high_window(
        vm_offset_t     phys_addr,
        vm_size_t       len)
{
        return pmap_map_high_window_bd(phys_addr, len, VM_PROT_READ | VM_PROT_WRITE);
}

vm_offset_t
ml_static_ptovirt(
                  vm_offset_t paddr)
{
        return phystokv(paddr);
}

vm_offset_t
ml_static_vtop(
                  vm_offset_t vaddr)
{
        if (((vm_address_t)(vaddr) - gVirtBase) >= gPhysSize)
                panic("ml_static_ptovirt(): illegal vaddr: %p\n", (void*)vaddr);
        return ((vm_address_t)(vaddr) - gVirtBase + gPhysBase);
}

kern_return_t
ml_static_protect(
        vm_offset_t vaddr, /* kernel virtual address */
        vm_size_t size,
        vm_prot_t new_prot)
{
        pt_entry_t    arm_prot = 0;
        pt_entry_t    arm_block_prot = 0;
        vm_offset_t   vaddr_cur;
        ppnum_t       ppn;
        kern_return_t result = KERN_SUCCESS;

        if (vaddr < VM_MIN_KERNEL_ADDRESS) {
                panic("ml_static_protect(): %p < %p", (void *) vaddr, (void *) VM_MIN_KERNEL_ADDRESS);
                return KERN_FAILURE;
        }

        assert((vaddr & (PAGE_SIZE - 1)) == 0); /* must be page aligned */

        if ((new_prot & VM_PROT_WRITE) && (new_prot & VM_PROT_EXECUTE)) {
                panic("ml_static_protect(): WX request on %p", (void *) vaddr);
        }

        /* Set up the protection bits, and block bits so we can validate block mappings. */
        if (new_prot & VM_PROT_WRITE) {
                arm_prot |= ARM_PTE_AP(AP_RWNA);
                arm_block_prot |= ARM_TTE_BLOCK_AP(AP_RWNA);
        } else {
                arm_prot |= ARM_PTE_AP(AP_RONA);
                arm_block_prot |= ARM_TTE_BLOCK_AP(AP_RONA);
        }

        arm_prot |= ARM_PTE_NX;
        arm_block_prot |= ARM_TTE_BLOCK_NX;

        if (!(new_prot & VM_PROT_EXECUTE)) {
                arm_prot |= ARM_PTE_PNX;
                arm_block_prot |= ARM_TTE_BLOCK_PNX;
        }

        for (vaddr_cur = vaddr;
             vaddr_cur < trunc_page_64(vaddr + size);
             vaddr_cur += PAGE_SIZE) {
                ppn = pmap_find_phys(kernel_pmap, vaddr_cur);
                if (ppn != (vm_offset_t) NULL) {
#if __ARM64_TWO_LEVEL_PMAP__
                        tt_entry_t      *tte2;
#else
                        tt_entry_t      *tte1, *tte2;
#endif
                        pt_entry_t      *pte_p;
                        pt_entry_t      ptmp;


#if __ARM64_TWO_LEVEL_PMAP__
                        tte2 = &kernel_pmap->tte[(((vaddr_cur) & ARM_TT_L2_INDEX_MASK) >> ARM_TT_L2_SHIFT)];
#else
                        tte1 = &kernel_pmap->tte[(((vaddr_cur) & ARM_TT_L1_INDEX_MASK) >> ARM_TT_L1_SHIFT)];
                        tte2 = &((tt_entry_t*) phystokv((*tte1) & ARM_TTE_TABLE_MASK))[(((vaddr_cur) & ARM_TT_L2_INDEX_MASK) >> ARM_TT_L2_SHIFT)];
#endif

                        if (((*tte2) & ARM_TTE_TYPE_MASK) != ARM_TTE_TYPE_TABLE) {
                                if ((((*tte2) & ARM_TTE_TYPE_MASK) == ARM_TTE_TYPE_BLOCK) &&
                                    ((*tte2 & (ARM_TTE_BLOCK_NXMASK | ARM_TTE_BLOCK_PNXMASK | ARM_TTE_BLOCK_APMASK)) == arm_block_prot)) {
                                        /*
                                         * We can support ml_static_protect on a block mapping if the mapping already has
                                         * the desired protections.  We still want to run checks on a per-page basis.
                                         */
                                        continue;
                                }

                                result = KERN_FAILURE;
                                break;
                        }

                        pte_p = (pt_entry_t *)&((tt_entry_t*)(phystokv((*tte2) & ARM_TTE_TABLE_MASK)))[(((vaddr_cur) & ARM_TT_L3_INDEX_MASK) >> ARM_TT_L3_SHIFT)];
                        ptmp = *pte_p;

                        if ((ptmp & ARM_PTE_HINT_MASK) && ((ptmp & (ARM_PTE_APMASK | ARM_PTE_PNXMASK | ARM_PTE_NXMASK)) != arm_prot)) {
                                /*
                                 * The contiguous hint is similar to a block mapping for ml_static_protect; if the existing
                                 * protections do not match the desired protections, then we will fail (as we cannot update
                                 * this mapping without updating other mappings as well).
                                 */
                                result = KERN_FAILURE;
                                break;
                        }

                        __unreachable_ok_push
                        if (TEST_PAGE_RATIO_4) {
                                {
                                        unsigned int    i;
                                        pt_entry_t      *ptep_iter;

                                        ptep_iter = pte_p;
                                        for (i=0; i<4; i++, ptep_iter++) {
                                                /* Note that there is a hole in the HINT sanity checking here. */
                                                ptmp = *ptep_iter;

                                                /* We only need to update the page tables if the protections do not match. */
                                                if ((ptmp & (ARM_PTE_APMASK | ARM_PTE_PNXMASK | ARM_PTE_NXMASK)) != arm_prot) {
                                                        ptmp = (ptmp & ~(ARM_PTE_APMASK | ARM_PTE_PNXMASK | ARM_PTE_NXMASK)) | arm_prot;
                                                        *ptep_iter = ptmp;
                                                }
                                        }
                                }
#ifndef  __ARM_L1_PTW__
                                FlushPoC_DcacheRegion( trunc_page_32(pte_p), 4*sizeof(*pte_p));
#endif
                        } else {
                                ptmp = *pte_p;

                                /* We only need to update the page tables if the protections do not match. */
                                if ((ptmp & (ARM_PTE_APMASK | ARM_PTE_PNXMASK | ARM_PTE_NXMASK)) != arm_prot) {
                                        ptmp = (ptmp & ~(ARM_PTE_APMASK | ARM_PTE_PNXMASK | ARM_PTE_NXMASK)) | arm_prot;
                                        *pte_p = ptmp;
                                }

#ifndef  __ARM_L1_PTW__
                                FlushPoC_DcacheRegion( trunc_page_32(pte_p), sizeof(*pte_p));
#endif
                        }
                        __unreachable_ok_pop
                }
        }

        if (vaddr_cur > vaddr) {
                assert(((vaddr_cur - vaddr) & 0xFFFFFFFF00000000ULL) == 0);
                flush_mmu_tlb_region(vaddr, (uint32_t)(vaddr_cur - vaddr));
        }


        return result;
}

/*
 *      Routine:        ml_static_mfree
 *      Function:
 */
void
ml_static_mfree(
                vm_offset_t vaddr,
                vm_size_t size)
{
        vm_offset_t     vaddr_cur;
        ppnum_t         ppn;
        uint32_t freed_pages = 0;

        /* It is acceptable (if bad) to fail to free. */
        if (vaddr < VM_MIN_KERNEL_ADDRESS)
                return;

        assert((vaddr & (PAGE_SIZE - 1)) == 0); /* must be page aligned */

        for (vaddr_cur = vaddr;
             vaddr_cur < trunc_page_64(vaddr + size);
             vaddr_cur += PAGE_SIZE) {

                ppn = pmap_find_phys(kernel_pmap, vaddr_cur);
                if (ppn != (vm_offset_t) NULL) {
                        /*
                         * It is not acceptable to fail to update the protections on a page
                         * we will release to the VM.  We need to either panic or continue.
                         * For now, we'll panic (to help flag if there is memory we can
                         * reclaim).
                         */
                        if (ml_static_protect(vaddr_cur, PAGE_SIZE, VM_PROT_WRITE | VM_PROT_READ) != KERN_SUCCESS) {
                                panic("Failed ml_static_mfree on %p", (void *) vaddr_cur);
                        }

#if 0
                        /*
                         * Must NOT tear down the "V==P" mapping for vaddr_cur as the zone alias scheme
                         * relies on the persistence of these mappings for all time.
                         */
                        // pmap_remove(kernel_pmap, (addr64_t) vaddr_cur, (addr64_t) (vaddr_cur + PAGE_SIZE));
#endif

                        vm_page_create(ppn, (ppn + 1));
                        freed_pages++;
                }
        }
        vm_page_lockspin_queues();
        vm_page_wire_count -= freed_pages;
        vm_page_wire_count_initial -= freed_pages;
        vm_page_unlock_queues();
#if     DEBUG
        kprintf("ml_static_mfree: Released 0x%x pages at VA %p, size:0x%llx, last ppn: 0x%x\n", freed_pages, (void *)vaddr, (uint64_t)size, ppn);
#endif
}


/* virtual to physical on wired pages */
vm_offset_t
ml_vtophys(vm_offset_t vaddr)
{
        return kvtophys(vaddr);
}

/*
 * Routine: ml_nofault_copy
 * Function: Perform a physical mode copy if the source and destination have
 * valid translations in the kernel pmap. If translations are present, they are
 * assumed to be wired; e.g., no attempt is made to guarantee that the
 * translations obtained remain valid for the duration of the copy process.
 */
vm_size_t
ml_nofault_copy(vm_offset_t virtsrc, vm_offset_t virtdst, vm_size_t size)
{
        addr64_t        cur_phys_dst, cur_phys_src;
        vm_size_t       count, nbytes = 0;

        while (size > 0) {
                if (!(cur_phys_src = kvtophys(virtsrc)))
                        break;
                if (!(cur_phys_dst = kvtophys(virtdst)))
                        break;
                if (!pmap_valid_address(trunc_page_64(cur_phys_dst)) ||
                    !pmap_valid_address(trunc_page_64(cur_phys_src)))
                        break;
                count = PAGE_SIZE - (cur_phys_src & PAGE_MASK);
                if (count > (PAGE_SIZE - (cur_phys_dst & PAGE_MASK)))
                        count = PAGE_SIZE - (cur_phys_dst & PAGE_MASK);
                if (count > size)
                        count = size;

                bcopy_phys(cur_phys_src, cur_phys_dst, count);

                nbytes += count;
                virtsrc += count;
                virtdst += count;
                size -= count;
        }

        return nbytes;
}

/*
 *      Routine:        ml_validate_nofault
 *      Function: Validate that ths address range has a valid translations
 *                      in the kernel pmap.  If translations are present, they are
 *                      assumed to be wired; i.e. no attempt is made to guarantee
 *                      that the translation persist after the check.
 *  Returns: TRUE if the range is mapped and will not cause a fault,
 *                      FALSE otherwise.
 */

boolean_t ml_validate_nofault(
        vm_offset_t virtsrc, vm_size_t size)
{
        addr64_t cur_phys_src;
        uint32_t count;

        while (size > 0) {
                if (!(cur_phys_src = kvtophys(virtsrc)))
                        return FALSE;
                if (!pmap_valid_address(trunc_page_64(cur_phys_src)))
                        return FALSE;
                count = (uint32_t)(PAGE_SIZE - (cur_phys_src & PAGE_MASK));
                if (count > size)
                        count = (uint32_t)size;

                virtsrc += count;
                size -= count;
        }

        return TRUE;
}

void
ml_get_bouncepool_info(vm_offset_t * phys_addr, vm_size_t * size)
{
        *phys_addr = 0;
        *size = 0;
}

void
active_rt_threads(__unused boolean_t active)
{
}

static void cpu_qos_cb_default(__unused int urgency, __unused uint64_t qos_param1, __unused uint64_t qos_param2) {
        return;
}

cpu_qos_update_t cpu_qos_update = cpu_qos_cb_default;

void cpu_qos_update_register(cpu_qos_update_t cpu_qos_cb) {
        if (cpu_qos_cb != NULL) {
                cpu_qos_update = cpu_qos_cb;
        } else {
                cpu_qos_update = cpu_qos_cb_default;
        }
}

void
thread_tell_urgency(int urgency, uint64_t rt_period, uint64_t rt_deadline, uint64_t sched_latency __unused, __unused thread_t nthread)
{
        SCHED_DEBUG_PLATFORM_KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED,MACH_URGENCY) | DBG_FUNC_START, urgency, rt_period, rt_deadline, sched_latency, 0);

        cpu_qos_update(urgency, rt_period, rt_deadline);

        SCHED_DEBUG_PLATFORM_KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED,MACH_URGENCY) | DBG_FUNC_END, urgency, rt_period, rt_deadline, 0, 0);
}

void
machine_run_count(__unused uint32_t count)
{
}

processor_t
machine_choose_processor(__unused processor_set_t pset, processor_t processor)
{
        return (processor);
}

vm_offset_t
ml_stack_remaining(void)
{
        uintptr_t local = (uintptr_t) &local;

        if (ml_at_interrupt_context()) {
            return (local - (getCpuDatap()->intstack_top - INTSTACK_SIZE));
        } else {
            return (local - current_thread()->kernel_stack);
        }
}

#if KASAN
vm_offset_t ml_stack_base(void);
vm_size_t ml_stack_size(void);

vm_offset_t
ml_stack_base(void)
{
        if (ml_at_interrupt_context()) {
            return getCpuDatap()->intstack_top - INTSTACK_SIZE;
        } else {
            return current_thread()->kernel_stack;
        }
}
vm_size_t
ml_stack_size(void)
{
        if (ml_at_interrupt_context()) {
            return INTSTACK_SIZE;
        } else {
            return kernel_stack_size;
        }
}
#endif

boolean_t machine_timeout_suspended(void) {
        return FALSE;
}

kern_return_t
ml_interrupt_prewarm(__unused uint64_t deadline)
{
        return KERN_FAILURE;
}

/*
 * Assumes fiq, irq disabled.
 */
void
ml_set_decrementer(uint32_t dec_value)
{
        cpu_data_t      *cdp = getCpuDatap();

        assert(ml_get_interrupts_enabled() == FALSE);
        cdp->cpu_decrementer = dec_value;

        if (cdp->cpu_set_decrementer_func)  {
                ((void (*)(uint32_t))cdp->cpu_set_decrementer_func)(dec_value);
        } else {
                __asm__ volatile("msr CNTP_TVAL_EL0, %0" : : "r"((uint64_t)dec_value));
        }
}

uint64_t ml_get_hwclock()
{
        uint64_t timebase;

        // ISB required by ARMV7C.b section B8.1.2 & ARMv8 section D6.1.2
        // "Reads of CNTPCT[_EL0] can occur speculatively and out of order relative
        // to other instructions executed on the same processor."
        __asm__ volatile("isb\n"
                         "mrs %0, CNTPCT_EL0"
                         : "=r"(timebase));

        return timebase;
}

uint64_t
ml_get_timebase()
{
        return (ml_get_hwclock() + getCpuDatap()->cpu_base_timebase);
}

uint32_t
ml_get_decrementer()
{
        cpu_data_t *cdp = getCpuDatap();
        uint32_t dec;

        assert(ml_get_interrupts_enabled() == FALSE);

        if (cdp->cpu_get_decrementer_func) {
                dec = ((uint32_t (*)(void))cdp->cpu_get_decrementer_func)();
        } else {
                uint64_t wide_val;

                __asm__ volatile("mrs %0, CNTP_TVAL_EL0" : "=r"(wide_val));
                dec = (uint32_t)wide_val;
                assert(wide_val == (uint64_t)dec);
        }

        return dec;
}

boolean_t
ml_get_timer_pending()
{
        uint64_t cntp_ctl;

        __asm__ volatile("mrs %0, CNTP_CTL_EL0" : "=r"(cntp_ctl));
        return ((cntp_ctl & CNTP_CTL_EL0_ISTATUS) != 0) ? TRUE : FALSE;
}

boolean_t
ml_wants_panic_trap_to_debugger(void)
{
        boolean_t result = FALSE;
        return result;
}

static void
cache_trap_error(thread_t thread, vm_map_address_t fault_addr)
{
        mach_exception_data_type_t exc_data[2];
        arm_saved_state_t *regs = get_user_regs(thread);

        set_saved_state_far(regs, fault_addr);

        exc_data[0] = KERN_INVALID_ADDRESS;
        exc_data[1] = fault_addr;

        exception_triage(EXC_BAD_ACCESS, exc_data, 2);
}

static void
cache_trap_recover()
{
        vm_map_address_t fault_addr;

        __asm__ volatile("mrs %0, FAR_EL1" : "=r"(fault_addr));

        cache_trap_error(current_thread(), fault_addr);
}

static void
dcache_flush_trap(vm_map_address_t start, vm_map_size_t size)
{
        vm_map_address_t end = start + size;
        thread_t thread = current_thread();
        vm_offset_t old_recover = thread->recover;

        /* Check bounds */
        if (task_has_64BitAddr(current_task())) {
                if (end > MACH_VM_MAX_ADDRESS) {
                        cache_trap_error(thread, end & ((1 << ARM64_CLINE_SHIFT) - 1));
                }
        } else {
                if (end > VM_MAX_ADDRESS) {
                        cache_trap_error(thread, end & ((1 << ARM64_CLINE_SHIFT) - 1));
                }
        }

        if (start > end) {
                cache_trap_error(thread, start & ((1 << ARM64_CLINE_SHIFT) - 1));
        }

        /* Set recovery function */
        thread->recover = (vm_address_t)cache_trap_recover;

#if defined(APPLE_ARM64_ARCH_FAMILY)
        /*
         * We're coherent on Apple ARM64 CPUs, so this could be a nop.  However,
         * if the region given us is bad, it would be good to catch it and
         * crash, ergo we still do the flush.
         */
        assert((size & 0xFFFFFFFF00000000ULL) == 0);
        FlushPoC_DcacheRegion(start, (uint32_t)size);
#else
#error "Make sure you don't need to xcall."
#endif

        /* Restore recovery function */
        thread->recover = old_recover;

        /* Return (caller does exception return) */
}

static void
icache_invalidate_trap(vm_map_address_t start, vm_map_size_t size)
{
        vm_map_address_t end = start + size;
        thread_t thread = current_thread();
        vm_offset_t old_recover = thread->recover;

        /* Check bounds */
        if (task_has_64BitAddr(current_task())) {
                if (end > MACH_VM_MAX_ADDRESS) {
                        cache_trap_error(thread, end & ((1 << ARM64_CLINE_SHIFT) - 1));
                }
        } else {
                if (end > VM_MAX_ADDRESS) {
                        cache_trap_error(thread, end & ((1 << ARM64_CLINE_SHIFT) - 1));
                }
        }

        if (start > end) {
                cache_trap_error(thread, start & ((1 << ARM64_CLINE_SHIFT) - 1));
        }

        /* Set recovery function */
        thread->recover = (vm_address_t)cache_trap_recover;

#if defined(APPLE_ARM64_ARCH_FAMILY)
        /* Clean dcache to unification, except we're coherent on Apple ARM64 CPUs */
#else
#error Make sure not cleaning is right for this platform!
#endif

        /* Invalidate iCache to point of unification */
        assert((size & 0xFFFFFFFF00000000ULL) == 0);
        InvalidatePoU_IcacheRegion(start, (uint32_t)size);

        /* Restore recovery function */
        thread->recover = old_recover;

        /* Return (caller does exception return) */
}

__attribute__((noreturn))
void
platform_syscall(arm_saved_state_t *state)
{
        uint32_t code;

#define platform_syscall_kprintf(x...) /* kprintf("platform_syscall: " x) */

        code = (uint32_t)get_saved_state_reg(state, 3);
        switch (code) {
        case 0:
                /* I-Cache flush */
                platform_syscall_kprintf("icache flush requested.\n");
                icache_invalidate_trap(get_saved_state_reg(state, 0), get_saved_state_reg(state, 1));
                break;
        case 1:
                /* D-Cache flush */
                platform_syscall_kprintf("dcache flush requested.\n");
                dcache_flush_trap(get_saved_state_reg(state, 0), get_saved_state_reg(state, 1));
                break;
        case 2:
                /* set cthread */
                platform_syscall_kprintf("set cthread self.\n");
                thread_set_cthread_self(get_saved_state_reg(state, 0));
                break;
        case 3:
                /* get cthread */
                platform_syscall_kprintf("get cthread self.\n");
                set_saved_state_reg(state, 0, thread_get_cthread_self());
                break;
        default:
                platform_syscall_kprintf("unknown: %d\n", code);
                break;
        }

        thread_exception_return();
}

static void
_enable_timebase_event_stream(uint32_t bit_index)
{
        uint64_t cntkctl; /* One wants to use 32 bits, but "mrs" prefers it this way */

        if (bit_index >= 64) {
                panic("%s: invalid bit index (%u)", __FUNCTION__, bit_index);
        }

        __asm__ volatile ("mrs  %0, CNTKCTL_EL1" : "=r"(cntkctl));

        cntkctl |= (bit_index << CNTKCTL_EL1_EVENTI_SHIFT);
        cntkctl |= CNTKCTL_EL1_EVNTEN;
        cntkctl |= CNTKCTL_EL1_EVENTDIR; /* 1->0; why not? */

        /*
         * If the SOC supports it (and it isn't broken), enable
         * EL0 access to the physical timebase register.
         */
        if (user_timebase_allowed()) {
                cntkctl |= CNTKCTL_EL1_PL0PCTEN;
        }

        __asm__ volatile ("msr  CNTKCTL_EL1, %0" : : "r"(cntkctl));
}

/*
 * Turn timer on, unmask that interrupt.
 */
static void
_enable_virtual_timer(void)
{
        uint64_t cntvctl = CNTP_CTL_EL0_ENABLE; /* One wants to use 32 bits, but "mrs" prefers it this way */

        __asm__ volatile ("msr CNTP_CTL_EL0, %0" : : "r"(cntvctl));
}

void
fiq_context_init(boolean_t enable_fiq __unused)
{
#if defined(APPLE_ARM64_ARCH_FAMILY)
        /* Could fill in our own ops here, if we needed them */
        uint64_t        ticks_per_sec, ticks_per_event, events_per_sec;
        uint32_t        bit_index;

        ticks_per_sec = gPEClockFrequencyInfo.timebase_frequency_hz;
#if defined(ARM_BOARD_WFE_TIMEOUT_NS)
        events_per_sec = 1000000000 / ARM_BOARD_WFE_TIMEOUT_NS;
#else
        /* Default to 1usec (or as close as we can get) */
        events_per_sec = 1000000;
#endif
        ticks_per_event = ticks_per_sec / events_per_sec;
        bit_index = flsll(ticks_per_event) - 1; /* Highest bit set */

        /* Round up to power of two */
        if ((ticks_per_event & ((1 << bit_index) - 1)) != 0) {
                bit_index++;
        }

        /*
         * The timer can only trigger on rising or falling edge,
         * not both; we don't care which we trigger on, but we
         * do need to adjust which bit we are interested in to
         * account for this.
         */
        if (bit_index != 0)
                bit_index--;

        _enable_timebase_event_stream(bit_index);
#else
#error Need a board configuration.
#endif

        /* Interrupts still disabled. */
        assert(ml_get_interrupts_enabled() == FALSE);
        _enable_virtual_timer();
}

/*
 * ARM64_TODO: remove me (just a convenience while we don't have crashreporter)
 */
extern int copyinframe(vm_address_t, char *, boolean_t);
size_t          _OSUserBacktrace(char *buffer, size_t bufsize);

size_t _OSUserBacktrace(char *buffer, size_t bufsize) 
{
        thread_t thread = current_thread();
        boolean_t is64bit = thread_is_64bit(thread);
        size_t trace_size_bytes = 0, lr_size;
        vm_address_t frame_addr; // Should really by mach_vm_offset_t...

        if (bufsize < 8) {
                return 0;
        }

        if (get_threadtask(thread) == kernel_task) {
                panic("%s: Should never be called from a kernel thread.", __FUNCTION__);
        }

        frame_addr = get_saved_state_fp(thread->machine.upcb);
        if (is64bit) {
                uint64_t frame[2];
                lr_size = sizeof(frame[1]);

                *((uint64_t*)buffer) = get_saved_state_pc(thread->machine.upcb);
                trace_size_bytes = lr_size;

                while (trace_size_bytes + lr_size < bufsize) {
                        if (!(frame_addr < VM_MIN_KERNEL_AND_KEXT_ADDRESS)) {
                                break;
                        }

                        if (0 != copyinframe(frame_addr, (char*)frame, TRUE)) {
                                break;
                        }

                        *((uint64_t*)(buffer + trace_size_bytes)) = frame[1]; /* lr */
                        frame_addr = frame[0];
                        trace_size_bytes += lr_size;

                        if (frame[0] == 0x0ULL) {
                                break;
                        }
                }
        } else {
                uint32_t frame[2];
                lr_size = sizeof(frame[1]);

                *((uint32_t*)buffer) = (uint32_t)get_saved_state_pc(thread->machine.upcb);
                trace_size_bytes = lr_size;

                while (trace_size_bytes + lr_size < bufsize) {
                        if (!(frame_addr < VM_MIN_KERNEL_AND_KEXT_ADDRESS)) {
                                break;
                        }

                        if (0 != copyinframe(frame_addr, (char*)frame, FALSE)) {
                                break;
                        }

                        *((uint32_t*)(buffer + trace_size_bytes)) = frame[1]; /* lr */
                        frame_addr = frame[0];
                        trace_size_bytes += lr_size;

                        if (frame[0] == 0x0ULL) {
                                break;
                        }
                }
        }

        return trace_size_bytes;
}

boolean_t
ml_delay_should_spin(uint64_t interval)
{
        cpu_data_t     *cdp = getCpuDatap();

        if (cdp->cpu_idle_latency) {
                return (interval < cdp->cpu_idle_latency) ? TRUE : FALSE;
        } else {
                /*
                 * Early boot, latency is unknown. Err on the side of blocking,
                 * which should always be safe, even if slow
                 */
                return FALSE;
        }
}

boolean_t ml_thread_is64bit(thread_t thread) {
        return (thread_is_64bit(thread));
}

void ml_timer_evaluate(void) {
}

boolean_t
ml_timer_forced_evaluation(void) {
        return FALSE;
}

uint64_t
ml_energy_stat(thread_t t) {
        return t->machine.energy_estimate_nj;
}


void
ml_gpu_stat_update(__unused uint64_t gpu_ns_delta) {
#if CONFIG_EMBEDDED
        /*
         * For now: update the resource coalition stats of the
         * current thread's coalition
         */
        task_coalition_update_gpu_stats(current_task(), gpu_ns_delta);
#endif
}

uint64_t
ml_gpu_stat(__unused thread_t t) {
        return 0;
}

#if !CONFIG_SKIP_PRECISE_USER_KERNEL_TIME
static void
timer_state_event(boolean_t switch_to_kernel)
{
        thread_t thread = current_thread();
        if (!thread->precise_user_kernel_time) return;

        processor_data_t *pd = &getCpuDatap()->cpu_processor->processor_data;
        uint64_t now = ml_get_timebase();

        timer_stop(pd->current_state, now);
        pd->current_state = (switch_to_kernel) ? &pd->system_state : &pd->user_state;
        timer_start(pd->current_state, now);

        timer_stop(pd->thread_timer, now);
        pd->thread_timer = (switch_to_kernel) ? &thread->system_timer : &thread->user_timer;
        timer_start(pd->thread_timer, now);
}

void
timer_state_event_user_to_kernel(void)
{
        timer_state_event(TRUE);
}

void
timer_state_event_kernel_to_user(void)
{
        timer_state_event(FALSE);
}
#endif /* !CONFIG_SKIP_PRECISE_USER_KERNEL_TIME */

/*
 * The following are required for parts of the kernel
 * that cannot resolve these functions as inlines:
 */
extern thread_t current_act(void);
thread_t
current_act(void)
{
        return current_thread_fast();
}

#undef current_thread
extern thread_t current_thread(void);
thread_t
current_thread(void)
{
        return current_thread_fast();
}

typedef struct
{
        ex_cb_t         cb;
        void            *refcon;
}
ex_cb_info_t;

ex_cb_info_t ex_cb_info[EXCB_CLASS_MAX];

/*
 * Callback registration
 * Currently we support only one registered callback per class but
 * it should be possible to support more callbacks
 */
kern_return_t ex_cb_register(
        ex_cb_class_t   cb_class,
        ex_cb_t                 cb,
        void                    *refcon)
{
        ex_cb_info_t *pInfo = &ex_cb_info[cb_class];

        if ((NULL == cb) || (cb_class >= EXCB_CLASS_MAX))
        {
                return KERN_INVALID_VALUE;
        }

        if (NULL == pInfo->cb)
        {
                pInfo->cb = cb;
                pInfo->refcon = refcon;
                return KERN_SUCCESS;
        }
        return KERN_FAILURE;
}

/*
 * Called internally by platform kernel to invoke the registered callback for class
 */
ex_cb_action_t ex_cb_invoke(
        ex_cb_class_t   cb_class,
        vm_offset_t             far)
{
        ex_cb_info_t *pInfo = &ex_cb_info[cb_class];
        ex_cb_state_t state = {far};

        if (cb_class >= EXCB_CLASS_MAX)
        {
                panic("Invalid exception callback class 0x%x\n", cb_class);
        }

        if (pInfo->cb)
        {
                return pInfo->cb(cb_class, pInfo->refcon, &state);
        }
        return EXCB_ACTION_NONE;
}