xnu-4570.51.1.tar.gz

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

/*
 * Copyright (c) 2007-2016 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 <arm/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/misc_protos.h>
#include <arm/rtclock.h>
#include <arm/caches_internal.h>
#include <console/serial_protos.h>
#include <kern/machine.h>
#include <prng/random.h>
#include <kern/startup.h>
#include <kern/sched.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>

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

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

static unsigned int avail_cpus = 0;

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;

void machine_conf(void);

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

        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 */
}

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

void
machine_conf(void)
{
        machine_info.memory_size = 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);
}

/* Return max offset */
vm_map_offset_t
ml_get_max_offset(
        boolean_t       is64,
        unsigned int option)
{
        unsigned int    pmap_max_offset_option = 0;

        switch (option) {
        case MACHINE_MAX_OFFSET_DEFAULT:
                pmap_max_offset_option = ARM_PMAP_MAX_OFFSET_DEFAULT;
                break;
        case MACHINE_MAX_OFFSET_MIN:
                pmap_max_offset_option =  ARM_PMAP_MAX_OFFSET_MIN;
                break;
        case MACHINE_MAX_OFFSET_MAX:
                pmap_max_offset_option = ARM_PMAP_MAX_OFFSET_MAX;
                break;
        case MACHINE_MAX_OFFSET_DEVICE:
                pmap_max_offset_option = ARM_PMAP_MAX_OFFSET_DEVICE;
                break;
        default:
                panic("ml_get_max_offset(): Illegal option 0x%x\n", option);
                break;
        }
        return pmap_max_offset(is64, pmap_max_offset_option);
}

boolean_t
ml_wants_panic_trap_to_debugger(void)
{
        return FALSE;
}

void
ml_panic_trap_to_debugger(__unused const char *panic_format_str,
                          __unused va_list *panic_args,
                          __unused unsigned int reason,
                          __unused void *ctx,
                          __unused uint64_t panic_options_mask,
                          __unused unsigned long panic_caller)
{
        return;
}

__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)
{
        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;
                rtclock_timebase_val = int_value;
        }
}

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

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

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

        while (kSuccess == DTIterateEntries(&iter, &child)) {

#if MACH_ASSERT
                unsigned int propSize;
                void *prop = NULL;
                if (avail_cpus == 0) {
                        if (kSuccess != DTGetProperty(child, "state", &prop, &propSize))
                                panic("unable to retrieve state for cpu %u", avail_cpus);

                        if (strncmp((char*)prop, "running", propSize) != 0)
                                panic("cpu 0 has not been marked as running!");
                }
                assert(kSuccess == DTGetProperty(child, "reg", &prop, &propSize));
                assert(avail_cpus == *((uint32_t*)prop));
#endif
                ++avail_cpus;
        }

        cpu_boot_arg = avail_cpus;
        if (PE_parse_boot_argn("cpus", &cpu_boot_arg, sizeof(cpu_boot_arg)) &&
            (avail_cpus > cpu_boot_arg))
                avail_cpus = cpu_boot_arg;

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

unsigned int
ml_get_cpu_count(void)
{
        return avail_cpus;
}

int
ml_get_boot_cpu_number(void)
{
        return 0;
}

cluster_type_t
ml_get_boot_cluster(void)
{
        return CLUSTER_TYPE_SMP;
}

int
ml_get_cpu_number(uint32_t phys_id)
{
        return (int)phys_id;
}

int
ml_get_max_cpu_number(void)
{
        return avail_cpus - 1;
}

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;
        boolean_t  is_boot_cpu;

        if (in_processor_info->phys_id >= MAX_CPUS) {
                /*
                 * The physical CPU ID indicates that we have more CPUs than
                 * this xnu build support.  This probably means we have an
                 * incorrect board configuration.
                 *
                 * TODO: Should this just return a failure instead?  A panic
                 * is simply a convenient way to catch bugs in the pexpert
                 * headers.
                 */
                panic("phys_id %u is too large for MAX_CPUS (%u)", in_processor_info->phys_id, MAX_CPUS);
        }

        /* Fail the registration if the number of CPUs has been limited by boot-arg. */
        if ((in_processor_info->phys_id >= avail_cpus) ||
            (in_processor_info->log_id > (uint32_t)ml_get_max_cpu_number())) 
                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;
        }

        this_cpu_datap->cpu_id = in_processor_info->cpu_id;

        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) {
                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;

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

                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);

        return KERN_SUCCESS;

processor_register_error:
#if KPC
        kpc_unregister_cpu(this_cpu_datap);
#endif
        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)
{
        boolean_t at_interrupt_context = FALSE;

        disable_preemption();
        at_interrupt_context = (getCpuDatap()->cpu_int_state != NULL);
        enable_preemption();

        return at_interrupt_context;
}

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)
                return KERN_FAILURE;

        assert((vaddr & (ARM_PGBYTES - 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);
        }

        if (!(new_prot & VM_PROT_EXECUTE)) {
                arm_prot |= ARM_PTE_NX;
                arm_block_prot |= ARM_TTE_BLOCK_NX;
        }

        for (vaddr_cur = vaddr;
             vaddr_cur < ((vaddr + size) & ~ARM_PGMASK);
             vaddr_cur += ARM_PGBYTES) {
                ppn = pmap_find_phys(kernel_pmap, vaddr_cur);
                if (ppn != (vm_offset_t) NULL) {
                        tt_entry_t     *ttp = &kernel_pmap->tte[ttenum(vaddr_cur)];
                        tt_entry_t      tte = *ttp;

                        if ((tte & ARM_TTE_TYPE_MASK) != ARM_TTE_TYPE_TABLE) {
                                if (((tte & ARM_TTE_TYPE_MASK) == ARM_TTE_TYPE_BLOCK) &&
                                    ((tte & (ARM_TTE_BLOCK_APMASK | ARM_TTE_BLOCK_NX_MASK)) == 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;
                        }

                        pt_entry_t *pte_p = (pt_entry_t *) ttetokv(tte) + ptenum(vaddr_cur);
                        pt_entry_t ptmp = *pte_p;

                        ptmp = (ptmp & ~(ARM_PTE_APMASK | ARM_PTE_NX_MASK)) | arm_prot;
                        *pte_p = ptmp;
#ifndef  __ARM_L1_PTW__
                        FlushPoC_DcacheRegion((vm_offset_t) pte_p, sizeof(*pte_p));
#endif
                }
        }

        if (vaddr_cur > vaddr)
                flush_mmu_tlb_region(vaddr, (vm_size_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_32(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;
        uint32_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;
}

/*
 * Stubs for CPU Stepper
 */
void
active_rt_threads(__unused boolean_t active)
{
}

void
thread_tell_urgency(__unused int urgency,
                    __unused uint64_t rt_period,
                    __unused uint64_t rt_deadline,
                    __unused uint64_t sched_latency,
                    __unused thread_t nthread)
{
}

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;
        vm_offset_t     intstack_top_ptr;

        intstack_top_ptr = getCpuDatap()->intstack_top;
        if ((local < intstack_top_ptr) && (local > intstack_top_ptr - INTSTACK_SIZE)) {
            return (local - (getCpuDatap()->intstack_top - INTSTACK_SIZE));
        } else {
            return (local - current_thread()->kernel_stack);
        }
}

boolean_t machine_timeout_suspended(void) {
        return FALSE;
}

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

uint64_t
ml_get_hwclock(void)
{
        uint64_t high_first = 0;
        uint64_t high_second = 0;
        uint64_t low = 0;

        __builtin_arm_isb(ISB_SY);

        do {
                high_first = __builtin_arm_mrrc(15, 0, 14) >> 32;
                low = __builtin_arm_mrrc(15, 0, 14) & 0xFFFFFFFFULL;
                high_second = __builtin_arm_mrrc(15, 0, 14) >> 32;
        } while (high_first != high_second);

        return (high_first << 32) | (low);
}

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(__unused thread_t t) {
        return 0;
}


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 */

boolean_t
user_cont_hwclock_allowed(void)
{
        return FALSE;
}

boolean_t
user_timebase_allowed(void)
{
#if __ARM_TIME__
        return TRUE;
#else
        return FALSE;
#endif
}

/*
 * 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();
}

#if __ARM_USER_PROTECT__
uintptr_t
arm_user_protect_begin(thread_t thread)
{
    uintptr_t   ttbr0, asid = 0;                //  kernel asid

    ttbr0 = __builtin_arm_mrc(15,0,2,0,0);              // Get TTBR0
    if (ttbr0 != thread->machine.kptw_ttb) {
        __builtin_arm_mcr(15,0,thread->machine.kptw_ttb,2,0,0); // Set TTBR0
        __builtin_arm_mcr(15,0,asid,13,0,1);    // Set CONTEXTIDR
        __builtin_arm_isb(ISB_SY);
    }
    return ttbr0;
}

void
arm_user_protect_end(thread_t thread, uintptr_t ttbr0, boolean_t disable_interrupts)
{
    if ((ttbr0 != thread->machine.kptw_ttb) && (thread->machine.uptw_ttb != thread->machine.kptw_ttb)) {
        if (disable_interrupts)
            __asm__ volatile ("cpsid if" ::: "memory"); // Disable FIQ/IRQ
        __builtin_arm_mcr(15,0,thread->machine.uptw_ttb,2,0,0); // Set TTBR0
        __builtin_arm_mcr(15,0,thread->machine.asid,13,0,1);    // Set CONTEXTIDR with thread asid
        __builtin_arm_dsb(DSB_ISH);
        __builtin_arm_isb(ISB_SY);
    }
}
#endif // __ARM_USER_PROTECT__

void ml_task_set_rop_pid(__unused task_t task, __unused task_t parent_task, __unused boolean_t inherit)
{
        return;
}