xnu-1228.0.2.tar.gz

[apple/xnu.git] / osfmk / i386 / mp.c

/*
 * Copyright (c) 2000-2007 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@
 */
/*
 * @OSF_COPYRIGHT@
 */

#include <mach_rt.h>
#include <mach_kdb.h>
#include <mach_kdp.h>
#include <mach_ldebug.h>
#include <gprof.h>

#include <mach/mach_types.h>
#include <mach/kern_return.h>

#include <kern/kern_types.h>
#include <kern/startup.h>
#include <kern/processor.h>
#include <kern/cpu_number.h>
#include <kern/cpu_data.h>
#include <kern/assert.h>
#include <kern/machine.h>
#include <kern/pms.h>

#include <vm/vm_map.h>
#include <vm/vm_kern.h>

#include <profiling/profile-mk.h>

#include <i386/mp.h>
#include <i386/mp_events.h>
#include <i386/mp_slave_boot.h>
#include <i386/apic.h>
#include <i386/ipl.h>
#include <i386/fpu.h>
#include <i386/cpuid.h>
#include <i386/proc_reg.h>
#include <i386/machine_cpu.h>
#include <i386/misc_protos.h>
#include <i386/mtrr.h>
#include <i386/vmx/vmx_cpu.h>
#include <i386/postcode.h>
#include <i386/perfmon.h>
#include <i386/cpu_threads.h>
#include <i386/mp_desc.h>
#include <i386/trap.h>
#include <i386/machine_routines.h>
#include <i386/pmCPU.h>
#include <i386/hpet.h>
#include <i386/machine_check.h>

#include <chud/chud_xnu.h>
#include <chud/chud_xnu_private.h>

#include <sys/kdebug.h>
#if MACH_KDB
#include <i386/db_machdep.h>
#include <ddb/db_aout.h>
#include <ddb/db_access.h>
#include <ddb/db_sym.h>
#include <ddb/db_variables.h>
#include <ddb/db_command.h>
#include <ddb/db_output.h>
#include <ddb/db_expr.h>
#endif

#if     MP_DEBUG
#define PAUSE           delay(1000000)
#define DBG(x...)       kprintf(x)
#else
#define DBG(x...)
#define PAUSE
#endif  /* MP_DEBUG */

/* Initialize lapic_id so cpu_number() works on non SMP systems */
unsigned long   lapic_id_initdata = 0;
unsigned long   lapic_id = (unsigned long)&lapic_id_initdata;
vm_offset_t     lapic_start;

static i386_intr_func_t lapic_timer_func;
static i386_intr_func_t lapic_pmi_func;
static i386_intr_func_t lapic_thermal_func;

/* TRUE if local APIC was enabled by the OS not by the BIOS */
static boolean_t lapic_os_enabled = FALSE;

/* Base vector for local APIC interrupt sources */
int lapic_interrupt_base = LAPIC_DEFAULT_INTERRUPT_BASE;

void            slave_boot_init(void);

#if MACH_KDB
static void     mp_kdb_wait(void);
volatile boolean_t      mp_kdb_trap = FALSE;
volatile long   mp_kdb_ncpus = 0;
#endif

static void     mp_kdp_wait(boolean_t flush);
static void     mp_rendezvous_action(void);
static void     mp_broadcast_action(void);

static int              NMIInterruptHandler(x86_saved_state_t *regs);
static boolean_t        cpu_signal_pending(int cpu, mp_event_t event);
static void             cpu_NMI_interrupt(int cpu);

boolean_t       smp_initialized = FALSE;
boolean_t       force_immediate_debugger_NMI = FALSE;

decl_simple_lock_data(,mp_kdp_lock);

decl_mutex_data(static, mp_cpu_boot_lock);

/* Variables needed for MP rendezvous. */
decl_simple_lock_data(,mp_rv_lock);
static void             (*mp_rv_setup_func)(void *arg);
static void             (*mp_rv_action_func)(void *arg);
static void             (*mp_rv_teardown_func)(void *arg);
static void             *mp_rv_func_arg;
static int              mp_rv_ncpus;
                        /* Cache-aligned barriers: */
static volatile long    mp_rv_entry    __attribute__((aligned(64)));
static volatile long    mp_rv_exit     __attribute__((aligned(64)));
static volatile long    mp_rv_complete __attribute__((aligned(64)));

/* Variables needed for MP broadcast. */
static void        (*mp_bc_action_func)(void *arg);
static void        *mp_bc_func_arg;
static int     mp_bc_ncpus;
static volatile long   mp_bc_count;
decl_mutex_data(static, mp_bc_lock);

static void     mp_cpus_call_action(void); 

int             lapic_to_cpu[MAX_CPUS];
int             cpu_to_lapic[MAX_CPUS];

static void
lapic_cpu_map_init(void)
{
        int     i;

        for (i = 0; i < MAX_CPUS; i++) {
                lapic_to_cpu[i] = -1;
                cpu_to_lapic[i] = -1;
        }
}

void
lapic_cpu_map(int apic_id, int cpu)
{
        cpu_to_lapic[cpu] = apic_id;
        lapic_to_cpu[apic_id] = cpu;
}

/*
 * Retrieve the local apic ID a cpu.
 *
 * Returns the local apic ID for the given processor.
 * If the processor does not exist or apic not configured, returns -1.
 */

uint32_t
ml_get_apicid(uint32_t cpu)
{
        if(cpu >= (uint32_t)MAX_CPUS)
                return 0xFFFFFFFF;      /* Return -1 if cpu too big */
        
        /* Return the apic ID (or -1 if not configured) */
        return (uint32_t)cpu_to_lapic[cpu];

}

#ifdef MP_DEBUG
static void
lapic_cpu_map_dump(void)
{
        int     i;

        for (i = 0; i < MAX_CPUS; i++) {
                if (cpu_to_lapic[i] == -1)
                        continue;
                kprintf("cpu_to_lapic[%d]: %d\n",
                        i, cpu_to_lapic[i]);
        }
        for (i = 0; i < MAX_CPUS; i++) {
                if (lapic_to_cpu[i] == -1)
                        continue;
                kprintf("lapic_to_cpu[%d]: %d\n",
                        i, lapic_to_cpu[i]);
        }
}
#define LAPIC_CPU_MAP_DUMP()    lapic_cpu_map_dump()
#define LAPIC_DUMP()            lapic_dump()
#else
#define LAPIC_CPU_MAP_DUMP()
#define LAPIC_DUMP()
#endif /* MP_DEBUG */

#if GPROF
/*
 * Initialize dummy structs for profiling. These aren't used but
 * allows hertz_tick() to be built with GPROF defined.
 */
struct profile_vars _profile_vars;
struct profile_vars *_profile_vars_cpus[MAX_CPUS] = { &_profile_vars };
#define GPROF_INIT()                                                    \
{                                                                       \
        int     i;                                                      \
                                                                        \
        /* Hack to initialize pointers to unused profiling structs */   \
        for (i = 1; i < MAX_CPUS; i++)                          \
                _profile_vars_cpus[i] = &_profile_vars;                 \
}
#else
#define GPROF_INIT()
#endif /* GPROF */

void
smp_init(void)
{
        int             result;
        vm_map_entry_t  entry;
        uint32_t        lo;
        uint32_t        hi;
        boolean_t       is_boot_processor;
        boolean_t       is_lapic_enabled;
        vm_offset_t     lapic_base;

        simple_lock_init(&mp_kdp_lock, 0);
        simple_lock_init(&mp_rv_lock, 0);
        mutex_init(&mp_cpu_boot_lock, 0);
        mutex_init(&mp_bc_lock, 0);
        console_init();

        /* Local APIC? */
        if (!lapic_probe())
                return;

        /* Examine the local APIC state */
        rdmsr(MSR_IA32_APIC_BASE, lo, hi);
        is_boot_processor = (lo & MSR_IA32_APIC_BASE_BSP) != 0;
        is_lapic_enabled  = (lo & MSR_IA32_APIC_BASE_ENABLE) != 0;
        lapic_base = (lo &  MSR_IA32_APIC_BASE_BASE);
        kprintf("MSR_IA32_APIC_BASE 0x%x %s %s\n", lapic_base,
                is_lapic_enabled ? "enabled" : "disabled",
                is_boot_processor ? "BSP" : "AP");
        if (!is_boot_processor || !is_lapic_enabled)
                panic("Unexpected local APIC state\n");

        /* Establish a map to the local apic */
        lapic_start = vm_map_min(kernel_map);
        result = vm_map_find_space(kernel_map,
                                   (vm_map_address_t *) &lapic_start,
                                   round_page(LAPIC_SIZE), 0,
                                   VM_MAKE_TAG(VM_MEMORY_IOKIT), &entry);
        if (result != KERN_SUCCESS) {
                panic("smp_init: vm_map_find_entry FAILED (err=%d)", result);
        }
        vm_map_unlock(kernel_map);
/* Map in the local APIC non-cacheable, as recommended by Intel
 * in section 8.4.1 of the "System Programming Guide".
 */
        pmap_enter(pmap_kernel(),
                        lapic_start,
                        (ppnum_t) i386_btop(lapic_base),
                        VM_PROT_READ|VM_PROT_WRITE,
                        VM_WIMG_IO,
                        TRUE);
        lapic_id = (unsigned long)(lapic_start + LAPIC_ID);

        if ((LAPIC_REG(VERSION)&LAPIC_VERSION_MASK) != 0x14) {
                printf("Local APIC version not 0x14 as expected\n");
        }

        /* Set up the lapic_id <-> cpu_number map and add this boot processor */
        lapic_cpu_map_init();
        lapic_cpu_map((LAPIC_REG(ID)>>LAPIC_ID_SHIFT)&LAPIC_ID_MASK, 0);
        kprintf("Boot cpu local APIC id 0x%x\n", cpu_to_lapic[0]);

        lapic_init();

        cpu_thread_init();

        GPROF_INIT();
        DBGLOG_CPU_INIT(master_cpu);

        slave_boot_init();

        smp_initialized = TRUE;

        return;
}


static int
lapic_esr_read(void)
{
        /* write-read register */
        LAPIC_REG(ERROR_STATUS) = 0;
        return LAPIC_REG(ERROR_STATUS);
}

static void 
lapic_esr_clear(void)
{
        LAPIC_REG(ERROR_STATUS) = 0;
        LAPIC_REG(ERROR_STATUS) = 0;
}

static const char *DM[8] = {
        "Fixed",
        "Lowest Priority",
        "Invalid",
        "Invalid",
        "NMI",
        "Reset",
        "Invalid",
        "ExtINT"};

void
lapic_dump(void)
{
        int     i;

#define BOOL(a) ((a)?' ':'!')

        kprintf("LAPIC %d at 0x%x version 0x%x\n", 
                (LAPIC_REG(ID)>>LAPIC_ID_SHIFT)&LAPIC_ID_MASK,
                lapic_start,
                LAPIC_REG(VERSION)&LAPIC_VERSION_MASK);
        kprintf("Priorities: Task 0x%x  Arbitration 0x%x  Processor 0x%x\n",
                LAPIC_REG(TPR)&LAPIC_TPR_MASK,
                LAPIC_REG(APR)&LAPIC_APR_MASK,
                LAPIC_REG(PPR)&LAPIC_PPR_MASK);
        kprintf("Destination Format 0x%x Logical Destination 0x%x\n",
                LAPIC_REG(DFR)>>LAPIC_DFR_SHIFT,
                LAPIC_REG(LDR)>>LAPIC_LDR_SHIFT);
        kprintf("%cEnabled %cFocusChecking SV 0x%x\n",
                BOOL(LAPIC_REG(SVR)&LAPIC_SVR_ENABLE),
                BOOL(!(LAPIC_REG(SVR)&LAPIC_SVR_FOCUS_OFF)),
                LAPIC_REG(SVR) & LAPIC_SVR_MASK);
        kprintf("LVT_TIMER:   Vector 0x%02x %s %cmasked %s\n",
                LAPIC_REG(LVT_TIMER)&LAPIC_LVT_VECTOR_MASK,
                (LAPIC_REG(LVT_TIMER)&LAPIC_LVT_DS_PENDING)?"SendPending":"Idle",
                BOOL(LAPIC_REG(LVT_TIMER)&LAPIC_LVT_MASKED),
                (LAPIC_REG(LVT_TIMER)&LAPIC_LVT_PERIODIC)?"Periodic":"OneShot");
        kprintf("  Initial Count: 0x%08x \n", LAPIC_REG(TIMER_INITIAL_COUNT));
        kprintf("  Current Count: 0x%08x \n", LAPIC_REG(TIMER_CURRENT_COUNT));
        kprintf("  Divide Config: 0x%08x \n", LAPIC_REG(TIMER_DIVIDE_CONFIG));
        kprintf("LVT_PERFCNT: Vector 0x%02x [%s] %s %cmasked\n",
                LAPIC_REG(LVT_PERFCNT)&LAPIC_LVT_VECTOR_MASK,
                DM[(LAPIC_REG(LVT_PERFCNT)>>LAPIC_LVT_DM_SHIFT)&LAPIC_LVT_DM_MASK],
                (LAPIC_REG(LVT_PERFCNT)&LAPIC_LVT_DS_PENDING)?"SendPending":"Idle",
                BOOL(LAPIC_REG(LVT_PERFCNT)&LAPIC_LVT_MASKED));
        kprintf("LVT_THERMAL: Vector 0x%02x [%s] %s %cmasked\n",
                LAPIC_REG(LVT_THERMAL)&LAPIC_LVT_VECTOR_MASK,
                DM[(LAPIC_REG(LVT_THERMAL)>>LAPIC_LVT_DM_SHIFT)&LAPIC_LVT_DM_MASK],
                (LAPIC_REG(LVT_THERMAL)&LAPIC_LVT_DS_PENDING)?"SendPending":"Idle",
                BOOL(LAPIC_REG(LVT_THERMAL)&LAPIC_LVT_MASKED));
        kprintf("LVT_LINT0:   Vector 0x%02x [%s][%s][%s] %s %cmasked\n",
                LAPIC_REG(LVT_LINT0)&LAPIC_LVT_VECTOR_MASK,
                DM[(LAPIC_REG(LVT_LINT0)>>LAPIC_LVT_DM_SHIFT)&LAPIC_LVT_DM_MASK],
                (LAPIC_REG(LVT_LINT0)&LAPIC_LVT_TM_LEVEL)?"Level":"Edge ",
                (LAPIC_REG(LVT_LINT0)&LAPIC_LVT_IP_PLRITY_LOW)?"Low ":"High",
                (LAPIC_REG(LVT_LINT0)&LAPIC_LVT_DS_PENDING)?"SendPending":"Idle",
                BOOL(LAPIC_REG(LVT_LINT0)&LAPIC_LVT_MASKED));
        kprintf("LVT_LINT1:   Vector 0x%02x [%s][%s][%s] %s %cmasked\n",
                LAPIC_REG(LVT_LINT1)&LAPIC_LVT_VECTOR_MASK,
                DM[(LAPIC_REG(LVT_LINT1)>>LAPIC_LVT_DM_SHIFT)&LAPIC_LVT_DM_MASK],
                (LAPIC_REG(LVT_LINT1)&LAPIC_LVT_TM_LEVEL)?"Level":"Edge ",
                (LAPIC_REG(LVT_LINT1)&LAPIC_LVT_IP_PLRITY_LOW)?"Low ":"High",
                (LAPIC_REG(LVT_LINT1)&LAPIC_LVT_DS_PENDING)?"SendPending":"Idle",
                BOOL(LAPIC_REG(LVT_LINT1)&LAPIC_LVT_MASKED));
        kprintf("LVT_ERROR:   Vector 0x%02x %s %cmasked\n",
                LAPIC_REG(LVT_ERROR)&LAPIC_LVT_VECTOR_MASK,
                (LAPIC_REG(LVT_ERROR)&LAPIC_LVT_DS_PENDING)?"SendPending":"Idle",
                BOOL(LAPIC_REG(LVT_ERROR)&LAPIC_LVT_MASKED));
        kprintf("ESR: %08x \n", lapic_esr_read());
        kprintf("       ");
        for(i=0xf; i>=0; i--)
                kprintf("%x%x%x%x",i,i,i,i);
        kprintf("\n");
        kprintf("TMR: 0x");
        for(i=7; i>=0; i--)
                kprintf("%08x",LAPIC_REG_OFFSET(TMR_BASE, i*0x10));
        kprintf("\n");
        kprintf("IRR: 0x");
        for(i=7; i>=0; i--)
                kprintf("%08x",LAPIC_REG_OFFSET(IRR_BASE, i*0x10));
        kprintf("\n");
        kprintf("ISR: 0x");
        for(i=7; i >= 0; i--)
                kprintf("%08x",LAPIC_REG_OFFSET(ISR_BASE, i*0x10));
        kprintf("\n");
}

#if MACH_KDB
/*
 *      Displays apic junk
 *
 *      da
 */
void 
db_apic(__unused db_expr_t addr,
        __unused int have_addr,
        __unused db_expr_t count,
        __unused char *modif)
{

        lapic_dump();

        return;
}

#endif

boolean_t
lapic_probe(void)
{
        uint32_t        lo;
        uint32_t        hi;

        if (cpuid_features() & CPUID_FEATURE_APIC)
                return TRUE;

        if (cpuid_family() == 6 || cpuid_family() == 15) {
                /*
                 * Mobile Pentiums:
                 * There may be a local APIC which wasn't enabled by BIOS.
                 * So we try to enable it explicitly.
                 */
                rdmsr(MSR_IA32_APIC_BASE, lo, hi);
                lo &= ~MSR_IA32_APIC_BASE_BASE;
                lo |= MSR_IA32_APIC_BASE_ENABLE | LAPIC_START;
                lo |= MSR_IA32_APIC_BASE_ENABLE;
                wrmsr(MSR_IA32_APIC_BASE, lo, hi);

                /*
                 * Re-initialize cpu features info and re-check.
                 */
                cpuid_set_info();
                if (cpuid_features() & CPUID_FEATURE_APIC) {
                        printf("Local APIC discovered and enabled\n");
                        lapic_os_enabled = TRUE;
                        lapic_interrupt_base = LAPIC_REDUCED_INTERRUPT_BASE;
                        return TRUE;
                }
        }

        return FALSE;
}

void
lapic_shutdown(void)
{
        uint32_t lo;
        uint32_t hi;
        uint32_t value;

        /* Shutdown if local APIC was enabled by OS */
        if (lapic_os_enabled == FALSE)
                return;

        mp_disable_preemption();

        /* ExtINT: masked */
        if (get_cpu_number() == master_cpu) {
                value = LAPIC_REG(LVT_LINT0);
                value |= LAPIC_LVT_MASKED;
                LAPIC_REG(LVT_LINT0) = value;
        }

        /* Timer: masked */
        LAPIC_REG(LVT_TIMER) |= LAPIC_LVT_MASKED;

        /* Perfmon: masked */
        LAPIC_REG(LVT_PERFCNT) |= LAPIC_LVT_MASKED;

        /* Error: masked */
        LAPIC_REG(LVT_ERROR) |= LAPIC_LVT_MASKED;

        /* APIC software disabled */
        LAPIC_REG(SVR) &= ~LAPIC_SVR_ENABLE;

        /* Bypass the APIC completely and update cpu features */
        rdmsr(MSR_IA32_APIC_BASE, lo, hi);
        lo &= ~MSR_IA32_APIC_BASE_ENABLE;
        wrmsr(MSR_IA32_APIC_BASE, lo, hi);
        cpuid_set_info();

        mp_enable_preemption();
}

void
lapic_init(void)
{
        int     value;

        /* Set flat delivery model, logical processor id */
        LAPIC_REG(DFR) = LAPIC_DFR_FLAT;
        LAPIC_REG(LDR) = (get_cpu_number()) << LAPIC_LDR_SHIFT;

        /* Accept all */
        LAPIC_REG(TPR) =  0;

        LAPIC_REG(SVR) = LAPIC_VECTOR(SPURIOUS) | LAPIC_SVR_ENABLE;

        /* ExtINT */
        if (get_cpu_number() == master_cpu) {
                value = LAPIC_REG(LVT_LINT0);
                value &= ~LAPIC_LVT_MASKED;
                value |= LAPIC_LVT_DM_EXTINT;
                LAPIC_REG(LVT_LINT0) = value;
        }

        /* Timer: unmasked, one-shot */
        LAPIC_REG(LVT_TIMER) = LAPIC_VECTOR(TIMER);

        /* Perfmon: unmasked */
        LAPIC_REG(LVT_PERFCNT) = LAPIC_VECTOR(PERFCNT);

        /* Thermal: unmasked */
        LAPIC_REG(LVT_THERMAL) = LAPIC_VECTOR(THERMAL);

        lapic_esr_clear();

        LAPIC_REG(LVT_ERROR) = LAPIC_VECTOR(ERROR);
}

void
lapic_set_timer_func(i386_intr_func_t func)
{
        lapic_timer_func = func;
}

void
lapic_set_timer(
        boolean_t               interrupt,
        lapic_timer_mode_t      mode,
        lapic_timer_divide_t    divisor,
        lapic_timer_count_t     initial_count)
{
        boolean_t       state;
        uint32_t        timer_vector;

        state = ml_set_interrupts_enabled(FALSE);
        timer_vector = LAPIC_REG(LVT_TIMER);
        timer_vector &= ~(LAPIC_LVT_MASKED|LAPIC_LVT_PERIODIC);;
        timer_vector |= interrupt ? 0 : LAPIC_LVT_MASKED;
        timer_vector |= (mode == periodic) ? LAPIC_LVT_PERIODIC : 0;
        LAPIC_REG(LVT_TIMER) = timer_vector;
        LAPIC_REG(TIMER_DIVIDE_CONFIG) = divisor;
        LAPIC_REG(TIMER_INITIAL_COUNT) = initial_count;
        ml_set_interrupts_enabled(state);
}

void
lapic_get_timer(
        lapic_timer_mode_t      *mode,
        lapic_timer_divide_t    *divisor,
        lapic_timer_count_t     *initial_count,
        lapic_timer_count_t     *current_count)
{
        boolean_t       state;

        state = ml_set_interrupts_enabled(FALSE);
        if (mode)
                *mode = (LAPIC_REG(LVT_TIMER) & LAPIC_LVT_PERIODIC) ?
                                periodic : one_shot;
        if (divisor)
                *divisor = LAPIC_REG(TIMER_DIVIDE_CONFIG) & LAPIC_TIMER_DIVIDE_MASK;
        if (initial_count)
                *initial_count = LAPIC_REG(TIMER_INITIAL_COUNT);
        if (current_count)
                *current_count = LAPIC_REG(TIMER_CURRENT_COUNT);
        ml_set_interrupts_enabled(state);
} 

void
lapic_set_pmi_func(i386_intr_func_t func)
{
        lapic_pmi_func = func;
}

void
lapic_set_thermal_func(i386_intr_func_t func)
{
        lapic_thermal_func = func;
}

static inline void
_lapic_end_of_interrupt(void)
{
        LAPIC_REG(EOI) = 0;
}

void
lapic_end_of_interrupt(void)
{
        _lapic_end_of_interrupt();
}

int
lapic_interrupt(int interrupt, x86_saved_state_t *state)
{
        int     retval = 0;

        /* Did we just field an interruption for the HPET comparator? */
        if(x86_core()->HpetVec == ((uint32_t)interrupt - 0x40)) {
                /* Yes, go handle it... */
                retval = HPETInterrupt();
                /* Was it really handled? */
                if(retval) {
                        /* If so, EOI the 'rupt */
                        _lapic_end_of_interrupt();
                        /*
                         * and then leave,
                         * indicating that this has been handled
                         */
                        return 1;
                }
        }

        interrupt -= lapic_interrupt_base;
        if (interrupt < 0) {
                if (interrupt == (LAPIC_NMI_INTERRUPT - lapic_interrupt_base)) {
                        retval = NMIInterruptHandler(state);
                        _lapic_end_of_interrupt();
                        return retval;
                }
                else
                        return 0;
        }

        switch(interrupt) {
        case LAPIC_PERFCNT_INTERRUPT:
                if (lapic_pmi_func != NULL)
                        (*lapic_pmi_func)(NULL);
                /* Clear interrupt masked */
                LAPIC_REG(LVT_PERFCNT) = LAPIC_VECTOR(PERFCNT);
                _lapic_end_of_interrupt();
                retval = 1;
                break;
        case LAPIC_TIMER_INTERRUPT:
                _lapic_end_of_interrupt();
                if (lapic_timer_func != NULL)
                        (*lapic_timer_func)(state);
                retval = 1;
                break;
        case LAPIC_THERMAL_INTERRUPT:
                if (lapic_thermal_func != NULL)
                        (*lapic_thermal_func)(NULL);
                _lapic_end_of_interrupt();
                retval = 1;
                break;
        case LAPIC_ERROR_INTERRUPT:
                lapic_dump();
                panic("Local APIC error\n");
                _lapic_end_of_interrupt();
                retval = 1;
                break;
        case LAPIC_SPURIOUS_INTERRUPT:
                kprintf("SPIV\n");
                /* No EOI required here */
                retval = 1;
                break;
        case LAPIC_INTERPROCESSOR_INTERRUPT:
                _lapic_end_of_interrupt();
                cpu_signal_handler(state);
                retval = 1;
                break;
        }

        return retval;
}

void
lapic_smm_restore(void)
{
        boolean_t state;

        if (lapic_os_enabled == FALSE)
                return;

        state = ml_set_interrupts_enabled(FALSE);

        if (LAPIC_ISR_IS_SET(LAPIC_REDUCED_INTERRUPT_BASE, TIMER)) {
                /*
                 * Bogus SMI handler enables interrupts but does not know about
                 * local APIC interrupt sources. When APIC timer counts down to
                 * zero while in SMM, local APIC will end up waiting for an EOI
                 * but no interrupt was delivered to the OS.
                 */
                _lapic_end_of_interrupt();

                /*
                 * timer is one-shot, trigger another quick countdown to trigger
                 * another timer interrupt.
                 */
                if (LAPIC_REG(TIMER_CURRENT_COUNT) == 0) {
                        LAPIC_REG(TIMER_INITIAL_COUNT) = 1;
                }

                kprintf("lapic_smm_restore\n");
        }

        ml_set_interrupts_enabled(state);
}

kern_return_t
intel_startCPU(
        int     slot_num)
{

        int     i = 1000;
        int     lapic = cpu_to_lapic[slot_num];

        assert(lapic != -1);

        DBGLOG_CPU_INIT(slot_num);

        DBG("intel_startCPU(%d) lapic_id=%d\n", slot_num, lapic);
        DBG("IdlePTD(%p): 0x%x\n", &IdlePTD, (int) IdlePTD);

        /*
         * Initialize (or re-initialize) the descriptor tables for this cpu.
         * Propagate processor mode to slave.
         */
        if (cpu_mode_is64bit())
                cpu_desc_init64(cpu_datap(slot_num), FALSE);
        else
                cpu_desc_init(cpu_datap(slot_num), FALSE);

        /* Serialize use of the slave boot stack. */
        mutex_lock(&mp_cpu_boot_lock);

        mp_disable_preemption();
        if (slot_num == get_cpu_number()) {
                mp_enable_preemption();
                mutex_unlock(&mp_cpu_boot_lock);
                return KERN_SUCCESS;
        }

        LAPIC_REG(ICRD) = lapic << LAPIC_ICRD_DEST_SHIFT;
        LAPIC_REG(ICR) = LAPIC_ICR_DM_INIT;
        delay(10000);

        LAPIC_REG(ICRD) = lapic << LAPIC_ICRD_DEST_SHIFT;
        LAPIC_REG(ICR) = LAPIC_ICR_DM_STARTUP|(MP_BOOT>>12);
        delay(200);

        LAPIC_REG(ICRD) = lapic << LAPIC_ICRD_DEST_SHIFT;
        LAPIC_REG(ICR) = LAPIC_ICR_DM_STARTUP|(MP_BOOT>>12);
        delay(200);

#ifdef  POSTCODE_DELAY
        /* Wait much longer if postcodes are displayed for a delay period. */
        i *= 10000;
#endif
        while(i-- > 0) {
                if (cpu_datap(slot_num)->cpu_running)
                        break;
                delay(10000);
        }

        mp_enable_preemption();
        mutex_unlock(&mp_cpu_boot_lock);

        if (!cpu_datap(slot_num)->cpu_running) {
                kprintf("Failed to start CPU %02d\n", slot_num);
                printf("Failed to start CPU %02d, rebooting...\n", slot_num);
                delay(1000000);
                cpu_shutdown();
                return KERN_SUCCESS;
        } else {
                kprintf("Started cpu %d (lapic id %08x)\n", slot_num, lapic);
                return KERN_SUCCESS;
        }
}

extern char     slave_boot_base[];
extern char     slave_boot_end[];
extern void     slave_pstart(void);

void
slave_boot_init(void)
{
        DBG("V(slave_boot_base)=%p P(slave_boot_base)=%p MP_BOOT=%p sz=0x%x\n",
                slave_boot_base,
                kvtophys((vm_offset_t) slave_boot_base),
                MP_BOOT,
                slave_boot_end-slave_boot_base);

        /*
         * Copy the boot entry code to the real-mode vector area MP_BOOT.
         * This is in page 1 which has been reserved for this purpose by
         * machine_startup() from the boot processor.
         * The slave boot code is responsible for switching to protected
         * mode and then jumping to the common startup, _start().
         */
        bcopy_phys(kvtophys((vm_offset_t) slave_boot_base),
                   (addr64_t) MP_BOOT,
                   slave_boot_end-slave_boot_base);

        /*
         * Zero a stack area above the boot code.
         */
        DBG("bzero_phys 0x%x sz 0x%x\n",MP_BOOTSTACK+MP_BOOT-0x400, 0x400);
        bzero_phys((addr64_t)MP_BOOTSTACK+MP_BOOT-0x400, 0x400);

        /*
         * Set the location at the base of the stack to point to the
         * common startup entry.
         */
        DBG("writing 0x%x at phys 0x%x\n",
                kvtophys((vm_offset_t) &slave_pstart), MP_MACH_START+MP_BOOT);
        ml_phys_write_word(MP_MACH_START+MP_BOOT,
                           (unsigned int)kvtophys((vm_offset_t) &slave_pstart));
        
        /* Flush caches */
        __asm__("wbinvd");
}

#if     MP_DEBUG
cpu_signal_event_log_t  *cpu_signal[MAX_CPUS];
cpu_signal_event_log_t  *cpu_handle[MAX_CPUS];

MP_EVENT_NAME_DECL();

#endif  /* MP_DEBUG */

void
cpu_signal_handler(x86_saved_state_t *regs)
{
        int             my_cpu;
        volatile int    *my_word;
#if     MACH_KDB && MACH_ASSERT
        int             i=100;
#endif  /* MACH_KDB && MACH_ASSERT */

        mp_disable_preemption();

        my_cpu = cpu_number();
        my_word = &current_cpu_datap()->cpu_signals;

        do {
#if     MACH_KDB && MACH_ASSERT
                if (i-- <= 0)
                    Debugger("cpu_signal_handler: signals did not clear");
#endif  /* MACH_KDB && MACH_ASSERT */
#if     MACH_KDP
                if (i_bit(MP_KDP, my_word)) {
                        DBGLOG(cpu_handle,my_cpu,MP_KDP);
                        i_bit_clear(MP_KDP, my_word);
/* Ensure that the i386_kernel_state at the base of the
 * current thread's stack (if any) is synchronized with the
 * context at the moment of the interrupt, to facilitate
 * access through the debugger.
 * XXX 64-bit state?
 */
                        sync_iss_to_iks(saved_state32(regs));
                        mp_kdp_wait(TRUE);
                } else
#endif  /* MACH_KDP */
                if (i_bit(MP_TLB_FLUSH, my_word)) {
                        DBGLOG(cpu_handle,my_cpu,MP_TLB_FLUSH);
                        i_bit_clear(MP_TLB_FLUSH, my_word);
                        pmap_update_interrupt();
                } else if (i_bit(MP_AST, my_word)) {
                        DBGLOG(cpu_handle,my_cpu,MP_AST);
                        i_bit_clear(MP_AST, my_word);
                        ast_check(cpu_to_processor(my_cpu));
#if     MACH_KDB
                } else if (i_bit(MP_KDB, my_word)) {

                        i_bit_clear(MP_KDB, my_word);
                        current_cpu_datap()->cpu_kdb_is_slave++;
                        mp_kdb_wait();
                        current_cpu_datap()->cpu_kdb_is_slave--;
#endif  /* MACH_KDB */
                } else if (i_bit(MP_RENDEZVOUS, my_word)) {
                        DBGLOG(cpu_handle,my_cpu,MP_RENDEZVOUS);
                        i_bit_clear(MP_RENDEZVOUS, my_word);
                        mp_rendezvous_action();
                } else if (i_bit(MP_BROADCAST, my_word)) {
                        DBGLOG(cpu_handle,my_cpu,MP_BROADCAST);
                        i_bit_clear(MP_BROADCAST, my_word);
                        mp_broadcast_action();
                } else if (i_bit(MP_CHUD, my_word)) {
                        DBGLOG(cpu_handle,my_cpu,MP_CHUD);
                        i_bit_clear(MP_CHUD, my_word);
                        chudxnu_cpu_signal_handler();
                } else if (i_bit(MP_CALL, my_word)) {
                        DBGLOG(cpu_handle,my_cpu,MP_CALL);
                        i_bit_clear(MP_CALL, my_word);
                        mp_cpus_call_action();
                }
        } while (*my_word);

        mp_enable_preemption();

}

/* We want this to show up in backtraces, hence marked noinline.
 */
static int __attribute__((noinline))
NMIInterruptHandler(x86_saved_state_t *regs)
{
        boolean_t state = ml_set_interrupts_enabled(FALSE);
        sync_iss_to_iks_unconditionally(regs);
        mp_kdp_wait(FALSE);
        (void) ml_set_interrupts_enabled(state);
        return 1;
}

#ifdef  MP_DEBUG
extern int      max_lock_loops;
int             trappedalready = 0;     /* (BRINGUP */
#endif  /* MP_DEBUG */

static void
i386_cpu_IPI(int cpu)
{
        boolean_t       state;
        
#ifdef  MP_DEBUG
        if(cpu_datap(cpu)->cpu_signals & 6) {   /* (BRINGUP) */
                kprintf("i386_cpu_IPI: sending enter debugger signal (%08X) to cpu %d\n", cpu_datap(cpu)->cpu_signals, cpu);
        }
#endif  /* MP_DEBUG */

#if MACH_KDB
#ifdef  MP_DEBUG
        if(!trappedalready && (cpu_datap(cpu)->cpu_signals & 6)) {      /* (BRINGUP) */
                if(kdb_cpu != cpu_number()) {
                        trappedalready = 1;
                        panic("i386_cpu_IPI: sending enter debugger signal (%08X) to cpu %d and I do not own debugger, owner = %08X\n", 
                                cpu_datap(cpu)->cpu_signals, cpu, kdb_cpu);
                }
        }
#endif  /* MP_DEBUG */
#endif

        /* Wait for previous interrupt to be delivered... */
#ifdef  MP_DEBUG
        int     pending_busy_count = 0;
        while (LAPIC_REG(ICR) & LAPIC_ICR_DS_PENDING) {
                if (++pending_busy_count > max_lock_loops)
                        panic("i386_cpu_IPI() deadlock\n");
#else
        while (LAPIC_REG(ICR) & LAPIC_ICR_DS_PENDING) {
#endif  /* MP_DEBUG */
                cpu_pause();
        }

        state = ml_set_interrupts_enabled(FALSE);
        LAPIC_REG(ICRD) =
                cpu_to_lapic[cpu] << LAPIC_ICRD_DEST_SHIFT;
        LAPIC_REG(ICR)  =
                LAPIC_VECTOR(INTERPROCESSOR) | LAPIC_ICR_DM_FIXED;
        (void) ml_set_interrupts_enabled(state);
}

/*
 * cpu_interrupt is really just to be used by the scheduler to
 * get a CPU's attention it may not always issue an IPI.  If an
 * IPI is always needed then use i386_cpu_IPI.
 */
void
cpu_interrupt(int cpu)
{
        if (smp_initialized
            && pmCPUExitIdle(cpu_datap(cpu))) {
                i386_cpu_IPI(cpu);
        }
}

/*
 * Send a true NMI via the local APIC to the specified CPU.
 */
static void
cpu_NMI_interrupt(int cpu)
{
        boolean_t       state;

        if (smp_initialized) {
                state = ml_set_interrupts_enabled(FALSE);
/* Program the interrupt command register */
                LAPIC_REG(ICRD) =
                        cpu_to_lapic[cpu] << LAPIC_ICRD_DEST_SHIFT;
/* The vector is ignored in this case--the target CPU will enter on the
 * NMI vector.
 */
                LAPIC_REG(ICR)  =
                        LAPIC_VECTOR(INTERPROCESSOR) | LAPIC_ICR_DM_NMI;
                (void) ml_set_interrupts_enabled(state);
        }
}

void
i386_signal_cpu(int cpu, mp_event_t event, mp_sync_t mode)
{
        volatile int    *signals = &cpu_datap(cpu)->cpu_signals;
        uint64_t        tsc_timeout;

        
        if (!cpu_datap(cpu)->cpu_running)
                return;

        if (event == MP_TLB_FLUSH)
                KERNEL_DEBUG(0xef800020 | DBG_FUNC_START, cpu, 0, 0, 0, 0);

        DBGLOG(cpu_signal, cpu, event);
        
        i_bit_set(event, signals);
        i386_cpu_IPI(cpu);
        if (mode == SYNC) {
           again:
                tsc_timeout = rdtsc64() + (1000*1000*1000);
                while (i_bit(event, signals) && rdtsc64() < tsc_timeout) {
                        cpu_pause();
                }
                if (i_bit(event, signals)) {
                        DBG("i386_signal_cpu(%d, 0x%x, SYNC) timed out\n",
                                cpu, event);
                        goto again;
                }
        }
        if (event == MP_TLB_FLUSH)
                KERNEL_DEBUG(0xef800020 | DBG_FUNC_END, cpu, 0, 0, 0, 0);
}

/*
 * Send event to all running cpus.
 * Called with the topology locked.
 */
void
i386_signal_cpus(mp_event_t event, mp_sync_t mode)
{
        unsigned int    cpu;
        unsigned int    my_cpu = cpu_number();

        assert(hw_lock_held(&x86_topo_lock));

        for (cpu = 0; cpu < real_ncpus; cpu++) {
                if (cpu == my_cpu || !cpu_datap(cpu)->cpu_running)
                        continue;
                i386_signal_cpu(cpu, event, mode);
        }
}

/*
 * Return the number of running cpus.
 * Called with the topology locked.
 */
int
i386_active_cpus(void)
{
        unsigned int    cpu;
        unsigned int    ncpus = 0;

        assert(hw_lock_held(&x86_topo_lock));

        for (cpu = 0; cpu < real_ncpus; cpu++) {
                if (cpu_datap(cpu)->cpu_running)
                        ncpus++;
        }
        return(ncpus);
}

/*
 * All-CPU rendezvous:
 *      - CPUs are signalled,
 *      - all execute the setup function (if specified),
 *      - rendezvous (i.e. all cpus reach a barrier),
 *      - all execute the action function (if specified),
 *      - rendezvous again,
 *      - execute the teardown function (if specified), and then
 *      - resume.
 *
 * Note that the supplied external functions _must_ be reentrant and aware
 * that they are running in parallel and in an unknown lock context.
 */

static void
mp_rendezvous_action(void)
{
        boolean_t intrs_enabled;

        /* setup function */
        if (mp_rv_setup_func != NULL)
                mp_rv_setup_func(mp_rv_func_arg);

        intrs_enabled = ml_get_interrupts_enabled();

        /* spin on entry rendezvous */
        atomic_incl(&mp_rv_entry, 1);
        while (mp_rv_entry < mp_rv_ncpus) {
                /* poll for pesky tlb flushes if interrupts disabled */
                if (!intrs_enabled)
                        handle_pending_TLB_flushes();
                cpu_pause();
        }
        /* action function */
        if (mp_rv_action_func != NULL)
                mp_rv_action_func(mp_rv_func_arg);
        /* spin on exit rendezvous */
        atomic_incl(&mp_rv_exit, 1);
        while (mp_rv_exit < mp_rv_ncpus) {
                if (!intrs_enabled)
                        handle_pending_TLB_flushes();
                cpu_pause();
        }

        /* teardown function */
        if (mp_rv_teardown_func != NULL)
                mp_rv_teardown_func(mp_rv_func_arg);

        /* Bump completion count */
        atomic_incl(&mp_rv_complete, 1);
}

void
mp_rendezvous(void (*setup_func)(void *), 
              void (*action_func)(void *),
              void (*teardown_func)(void *),
              void *arg)
{

        if (!smp_initialized) {
                if (setup_func != NULL)
                        setup_func(arg);
                if (action_func != NULL)
                        action_func(arg);
                if (teardown_func != NULL)
                        teardown_func(arg);
                return;
        }
                
        /* obtain rendezvous lock */
        simple_lock(&mp_rv_lock);

        /* set static function pointers */
        mp_rv_setup_func = setup_func;
        mp_rv_action_func = action_func;
        mp_rv_teardown_func = teardown_func;
        mp_rv_func_arg = arg;

        mp_rv_entry    = 0;
        mp_rv_exit     = 0;
        mp_rv_complete = 0;

        /*
         * signal other processors, which will call mp_rendezvous_action()
         * with interrupts disabled
         */
        simple_lock(&x86_topo_lock);
        mp_rv_ncpus = i386_active_cpus();
        i386_signal_cpus(MP_RENDEZVOUS, ASYNC);
        simple_unlock(&x86_topo_lock);

        /* call executor function on this cpu */
        mp_rendezvous_action();

        /*
         * Spin for everyone to complete.
         * This is necessary to ensure that all processors have proceeded
         * from the exit barrier before we release the rendezvous structure.
         */
        while (mp_rv_complete < mp_rv_ncpus) {
                cpu_pause();
        }
        
        /* Tidy up */
        mp_rv_setup_func = NULL;
        mp_rv_action_func = NULL;
        mp_rv_teardown_func = NULL;
        mp_rv_func_arg = NULL;

        /* release lock */
        simple_unlock(&mp_rv_lock);
}

void
mp_rendezvous_break_lock(void)
{
        simple_lock_init(&mp_rv_lock, 0);
}

static void
setup_disable_intrs(__unused void * param_not_used)
{
        /* disable interrupts before the first barrier */
        boolean_t intr = ml_set_interrupts_enabled(FALSE);

        current_cpu_datap()->cpu_iflag = intr;
        DBG("CPU%d: %s\n", get_cpu_number(), __FUNCTION__);
}

static void
teardown_restore_intrs(__unused void * param_not_used)
{
        /* restore interrupt flag following MTRR changes */
        ml_set_interrupts_enabled(current_cpu_datap()->cpu_iflag);
        DBG("CPU%d: %s\n", get_cpu_number(), __FUNCTION__);
}

/*
 * A wrapper to mp_rendezvous() to call action_func() with interrupts disabled.
 * This is exported for use by kexts.
 */
void
mp_rendezvous_no_intrs(
              void (*action_func)(void *),
              void *arg)
{
        mp_rendezvous(setup_disable_intrs,
                      action_func,
                      teardown_restore_intrs,
                      arg);     
}

void
handle_pending_TLB_flushes(void)
{
        volatile int    *my_word = &current_cpu_datap()->cpu_signals;

        if (i_bit(MP_TLB_FLUSH, my_word)) {
                DBGLOG(cpu_handle, cpu_number(), MP_TLB_FLUSH);
                i_bit_clear(MP_TLB_FLUSH, my_word);
                pmap_update_interrupt();
        }
}

/*
 * This is called from cpu_signal_handler() to process an MP_CALL signal.
 */
static void
mp_cpus_call_action(void)
{
        if (mp_rv_action_func != NULL)
                mp_rv_action_func(mp_rv_func_arg);
        atomic_incl(&mp_rv_complete, 1);
}

/*
 * mp_cpus_call() runs a given function on cpus specified in a given cpu mask.
 * If the mode is SYNC, the function is called serially on the target cpus
 * in logical cpu order. If the mode is ASYNC, the function is called in
 * parallel over the specified cpus.
 * The action function may be NULL.
 * The cpu mask may include the local cpu. Offline cpus are ignored.
 * Return does not occur until the function has completed on all cpus.
 * The return value is the number of cpus on which the function was called.
 */
cpu_t
mp_cpus_call(
        cpumask_t       cpus,
        mp_sync_t       mode,
        void            (*action_func)(void *),
        void            *arg)
{
        cpu_t           cpu;
        boolean_t       intrs_enabled = ml_get_interrupts_enabled();
        boolean_t       call_self = FALSE;

        if (!smp_initialized) {
                if ((cpus & CPUMASK_SELF) == 0)
                        return 0;
                if (action_func != NULL) {
                        (void) ml_set_interrupts_enabled(FALSE);
                        action_func(arg);
                        ml_set_interrupts_enabled(intrs_enabled);
                }
                return 1;
        }
                
        /* obtain rendezvous lock */
        simple_lock(&mp_rv_lock);

        /* Use the rendezvous data structures for this call */
        mp_rv_action_func = action_func;
        mp_rv_func_arg = arg;
        mp_rv_ncpus = 0;
        mp_rv_complete = 0;

        simple_lock(&x86_topo_lock);
        for (cpu = 0; cpu < (cpu_t) real_ncpus; cpu++) {
                if (((cpu_to_cpumask(cpu) & cpus) == 0) ||
                    !cpu_datap(cpu)->cpu_running)
                        continue;
                if (cpu == (cpu_t) cpu_number()) {
                        /*
                         * We don't IPI ourself and if calling asynchronously,
                         * we defer our call until we have signalled all others.
                         */
                        call_self = TRUE;
                        if (mode == SYNC && action_func != NULL) {
                                (void) ml_set_interrupts_enabled(FALSE);
                                action_func(arg);
                                ml_set_interrupts_enabled(intrs_enabled);
                        }
                } else {
                        /*
                         * Bump count of other cpus called and signal this cpu.
                         * Note: we signal asynchronously regardless of mode
                         * because we wait on mp_rv_complete either here
                         * (if mode == SYNC) or later (if mode == ASYNC).
                         * While spinning, poll for TLB flushes if interrupts
                         * are disabled.
                         */
                        mp_rv_ncpus++;
                        i386_signal_cpu(cpu, MP_CALL, ASYNC);
                        if (mode == SYNC) {
                                simple_unlock(&x86_topo_lock);
                                while (mp_rv_complete < mp_rv_ncpus) {
                                        if (!intrs_enabled)
                                                handle_pending_TLB_flushes();
                                        cpu_pause();
                                }
                                simple_lock(&x86_topo_lock);
                        }
                }
        }
        simple_unlock(&x86_topo_lock);

        /*
         * If calls are being made asynchronously,
         * make the local call now if needed, and then
         * wait for all other cpus to finish their calls.
         */
        if (mode == ASYNC) {
                if (call_self && action_func != NULL) {
                        (void) ml_set_interrupts_enabled(FALSE);
                        action_func(arg);
                        ml_set_interrupts_enabled(intrs_enabled);
                }
                while (mp_rv_complete < mp_rv_ncpus) {
                        if (!intrs_enabled)
                                handle_pending_TLB_flushes();
                        cpu_pause();
                }
        }
        
        /* Determine the number of cpus called */
        cpu = mp_rv_ncpus + (call_self ? 1 : 0);

        simple_unlock(&mp_rv_lock);

        return cpu;
}

static void
mp_broadcast_action(void)
{
   /* call action function */
   if (mp_bc_action_func != NULL)
       mp_bc_action_func(mp_bc_func_arg);

   /* if we're the last one through, wake up the instigator */
   if (atomic_decl_and_test((volatile long *)&mp_bc_count, 1))
       thread_wakeup(((event_t)(unsigned int *) &mp_bc_count));
}

/*
 * mp_broadcast() runs a given function on all active cpus.
 * The caller blocks until the functions has run on all cpus.
 * The caller will also block if there is another pending braodcast.
 */
void
mp_broadcast(
         void (*action_func)(void *),
         void *arg)
{
   if (!smp_initialized) {
       if (action_func != NULL)
                   action_func(arg);
       return;
   }
       
   /* obtain broadcast lock */
   mutex_lock(&mp_bc_lock);

   /* set static function pointers */
   mp_bc_action_func = action_func;
   mp_bc_func_arg = arg;

   assert_wait(&mp_bc_count, THREAD_UNINT);

   /*
    * signal other processors, which will call mp_broadcast_action()
    */
   simple_lock(&x86_topo_lock);
   mp_bc_ncpus = i386_active_cpus();   /* total including this cpu */
   mp_bc_count = mp_bc_ncpus;
   i386_signal_cpus(MP_BROADCAST, ASYNC);

   /* call executor function on this cpu */
   mp_broadcast_action();
   simple_unlock(&x86_topo_lock);

   /* block for all cpus to have run action_func */
   if (mp_bc_ncpus > 1)
       thread_block(THREAD_CONTINUE_NULL);
   else
       clear_wait(current_thread(), THREAD_AWAKENED);
       
   /* release lock */
   mutex_unlock(&mp_bc_lock);
}

void
i386_activate_cpu(void)
{
        cpu_data_t      *cdp = current_cpu_datap();

        assert(!ml_get_interrupts_enabled());

        if (!smp_initialized) {
                cdp->cpu_running = TRUE;
                return;
        }

        simple_lock(&x86_topo_lock);
        cdp->cpu_running = TRUE;
        simple_unlock(&x86_topo_lock);
}

void
i386_deactivate_cpu(void)
{
        cpu_data_t      *cdp = current_cpu_datap();

        assert(!ml_get_interrupts_enabled());

        simple_lock(&x86_topo_lock);
        cdp->cpu_running = FALSE;
        simple_unlock(&x86_topo_lock);

        /*
         * In case a rendezvous/braodcast/call was initiated to this cpu
         * before we cleared cpu_running, we must perform any actions due.
         */
        if (i_bit(MP_RENDEZVOUS, &cdp->cpu_signals))
                mp_rendezvous_action();
        if (i_bit(MP_BROADCAST, &cdp->cpu_signals))
                mp_broadcast_action();
        if (i_bit(MP_CALL, &cdp->cpu_signals))
                mp_cpus_call_action();
        cdp->cpu_signals = 0;                   /* all clear */
}

int     pmsafe_debug    = 1;

#if     MACH_KDP
volatile boolean_t      mp_kdp_trap = FALSE;
volatile unsigned long          mp_kdp_ncpus;
boolean_t               mp_kdp_state;


void
mp_kdp_enter(void)
{
        unsigned int    cpu;
        unsigned int    ncpus;
        unsigned int    my_cpu = cpu_number();
        uint64_t        tsc_timeout;

        DBG("mp_kdp_enter()\n");

        /*
         * Here to enter the debugger.
         * In case of races, only one cpu is allowed to enter kdp after
         * stopping others.
         */
        mp_kdp_state = ml_set_interrupts_enabled(FALSE);
        simple_lock(&mp_kdp_lock);

        if (pmsafe_debug)
            pmSafeMode(&current_cpu_datap()->lcpu, PM_SAFE_FL_SAFE);

        while (mp_kdp_trap) {
                simple_unlock(&mp_kdp_lock);
                DBG("mp_kdp_enter() race lost\n");
                mp_kdp_wait(TRUE);
                simple_lock(&mp_kdp_lock);
        }
        mp_kdp_ncpus = 1;       /* self */
        mp_kdp_trap = TRUE;
        simple_unlock(&mp_kdp_lock);

        /*
         * Deliver a nudge to other cpus, counting how many
         */
        DBG("mp_kdp_enter() signaling other processors\n");
        if (force_immediate_debugger_NMI == FALSE) {
                for (ncpus = 1, cpu = 0; cpu < real_ncpus; cpu++) {
                        if (cpu == my_cpu || !cpu_datap(cpu)->cpu_running)
                                continue;
                        ncpus++;
                        i386_signal_cpu(cpu, MP_KDP, ASYNC);
                }
                /*
                 * Wait other processors to synchronize
                 */
                DBG("mp_kdp_enter() waiting for (%d) processors to suspend\n", ncpus);

                /*
                 * This timeout is rather arbitrary; we don't want to NMI
                 * processors that are executing at potentially
                 * "unsafe-to-interrupt" points such as the trampolines,
                 * but neither do we want to lose state by waiting too long.
                 */
                tsc_timeout = rdtsc64() + (ncpus * 1000 * 1000);

                while (mp_kdp_ncpus != ncpus && rdtsc64() < tsc_timeout) {
                        /*
                         * A TLB shootdown request may be pending--this would
                         * result in the requesting processor waiting in
                         * PMAP_UPDATE_TLBS() until this processor deals with it.
                         * Process it, so it can now enter mp_kdp_wait()
                         */
                        handle_pending_TLB_flushes();
                        cpu_pause();
                }
                /* If we've timed out, and some processor(s) are still unresponsive,
                 * interrupt them with an NMI via the local APIC.
                 */
                if (mp_kdp_ncpus != ncpus) {
                        for (cpu = 0; cpu < real_ncpus; cpu++) {
                                if (cpu == my_cpu || !cpu_datap(cpu)->cpu_running)
                                        continue;
                                if (cpu_signal_pending(cpu, MP_KDP))
                                        cpu_NMI_interrupt(cpu);
                        }
                }
        }
        else
                for (cpu = 0; cpu < real_ncpus; cpu++) {
                        if (cpu == my_cpu || !cpu_datap(cpu)->cpu_running)
                                continue;
                        cpu_NMI_interrupt(cpu);
                }

        DBG("mp_kdp_enter() %u processors done %s\n",
            mp_kdp_ncpus, (mp_kdp_ncpus == ncpus) ? "OK" : "timed out");
        
        postcode(MP_KDP_ENTER);
}

static boolean_t
cpu_signal_pending(int cpu, mp_event_t event)
{
        volatile int    *signals = &cpu_datap(cpu)->cpu_signals;
        boolean_t retval = FALSE;

        if (i_bit(event, signals))
                retval = TRUE;
        return retval;
}
 

static void
mp_kdp_wait(boolean_t flush)
{
        DBG("mp_kdp_wait()\n");
        /* If an I/O port has been specified as a debugging aid, issue a read */
        panic_io_port_read();

        /* If we've trapped due to a machine-check, save MCA registers */
        mca_check_save();

        if (pmsafe_debug)
            pmSafeMode(&current_cpu_datap()->lcpu, PM_SAFE_FL_SAFE);

        atomic_incl((volatile long *)&mp_kdp_ncpus, 1);
        while (mp_kdp_trap) {
                /*
                 * A TLB shootdown request may be pending--this would result
                 * in the requesting processor waiting in PMAP_UPDATE_TLBS()
                 * until this processor handles it.
                 * Process it, so it can now enter mp_kdp_wait()
                 */
                if (flush)
                        handle_pending_TLB_flushes();
                cpu_pause();
        }

        if (pmsafe_debug)
            pmSafeMode(&current_cpu_datap()->lcpu, PM_SAFE_FL_NORMAL);

        atomic_decl((volatile long *)&mp_kdp_ncpus, 1);
        DBG("mp_kdp_wait() done\n");
}

void
mp_kdp_exit(void)
{
        DBG("mp_kdp_exit()\n");
        atomic_decl((volatile long *)&mp_kdp_ncpus, 1);
        mp_kdp_trap = FALSE;
        __asm__ volatile("mfence");

        /* Wait other processors to stop spinning. XXX needs timeout */
        DBG("mp_kdp_exit() waiting for processors to resume\n");
        while (mp_kdp_ncpus > 0) {
                /*
                 * a TLB shootdown request may be pending... this would result in the requesting
                 * processor waiting in PMAP_UPDATE_TLBS() until this processor deals with it.
                 * Process it, so it can now enter mp_kdp_wait()
                 */
                handle_pending_TLB_flushes();

                cpu_pause();
        }

        if (pmsafe_debug)
            pmSafeMode(&current_cpu_datap()->lcpu, PM_SAFE_FL_NORMAL);

        DBG("mp_kdp_exit() done\n");
        (void) ml_set_interrupts_enabled(mp_kdp_state);
        postcode(0);
}
#endif  /* MACH_KDP */

/*ARGSUSED*/
void
init_ast_check(
        __unused processor_t    processor)
{
}

void
cause_ast_check(
        processor_t     processor)
{
        int     cpu = PROCESSOR_DATA(processor, slot_num);

        if (cpu != cpu_number()) {
                i386_signal_cpu(cpu, MP_AST, ASYNC);
        }
}

#if MACH_KDB
/*
 * invoke kdb on slave processors 
 */

void
remote_kdb(void)
{
        unsigned int    my_cpu = cpu_number();
        unsigned int    cpu;
        int kdb_ncpus;
        uint64_t tsc_timeout = 0;
        
        mp_kdb_trap = TRUE;
        mp_kdb_ncpus = 1;
        for (kdb_ncpus = 1, cpu = 0; cpu < real_ncpus; cpu++) {
                if (cpu == my_cpu || !cpu_datap(cpu)->cpu_running)
                        continue;
                kdb_ncpus++;
                i386_signal_cpu(cpu, MP_KDB, ASYNC);
        }
        DBG("remote_kdb() waiting for (%d) processors to suspend\n",kdb_ncpus);

        tsc_timeout = rdtsc64() + (kdb_ncpus * 100 * 1000 * 1000);

        while (mp_kdb_ncpus != kdb_ncpus && rdtsc64() < tsc_timeout) {
                /*
                 * a TLB shootdown request may be pending... this would result in the requesting
                 * processor waiting in PMAP_UPDATE_TLBS() until this processor deals with it.
                 * Process it, so it can now enter mp_kdp_wait()
                 */
                handle_pending_TLB_flushes();

                cpu_pause();
        }
        DBG("mp_kdp_enter() %d processors done %s\n",
                mp_kdb_ncpus, (mp_kdb_ncpus == kdb_ncpus) ? "OK" : "timed out");
}

static void
mp_kdb_wait(void)
{
        DBG("mp_kdb_wait()\n");

        /* If an I/O port has been specified as a debugging aid, issue a read */
        panic_io_port_read();

        atomic_incl(&mp_kdb_ncpus, 1);
        while (mp_kdb_trap) {
                /*
                 * a TLB shootdown request may be pending... this would result in the requesting
                 * processor waiting in PMAP_UPDATE_TLBS() until this processor deals with it.
                 * Process it, so it can now enter mp_kdp_wait()
                 */
                handle_pending_TLB_flushes();

                cpu_pause();
        }
        atomic_decl((volatile long *)&mp_kdb_ncpus, 1);
        DBG("mp_kdb_wait() done\n");
}

/*
 * Clear kdb interrupt
 */

void
clear_kdb_intr(void)
{
        mp_disable_preemption();
        i_bit_clear(MP_KDB, &current_cpu_datap()->cpu_signals);
        mp_enable_preemption();
}

void
mp_kdb_exit(void)
{
        DBG("mp_kdb_exit()\n");
        atomic_decl((volatile long *)&mp_kdb_ncpus, 1);
        mp_kdb_trap = FALSE;
        __asm__ volatile("mfence");

        while (mp_kdb_ncpus > 0) {
                /*
                 * a TLB shootdown request may be pending... this would result in the requesting
                 * processor waiting in PMAP_UPDATE_TLBS() until this processor deals with it.
                 * Process it, so it can now enter mp_kdp_wait()
                 */
                handle_pending_TLB_flushes();

                cpu_pause();
        }

        DBG("mp_kdb_exit() done\n");
}

#endif /* MACH_KDB */

/*
 * i386_init_slave() is called from pstart.
 * We're in the cpu's interrupt stack with interrupts disabled.
 * At this point we are in legacy mode. We need to switch on IA32e
 * if the mode is set to 64-bits.
 */
void
i386_init_slave(void)
{
        postcode(I386_INIT_SLAVE);

        /* Ensure that caching and write-through are enabled */
        set_cr0(get_cr0() & ~(CR0_NW|CR0_CD));

        DBG("i386_init_slave() CPU%d: phys (%d) active.\n",
                get_cpu_number(), get_cpu_phys_number());

        assert(!ml_get_interrupts_enabled());

        cpu_mode_init(current_cpu_datap());

        mca_cpu_init();

        lapic_init();
        LAPIC_DUMP();
        LAPIC_CPU_MAP_DUMP();

        init_fpu();

        mtrr_update_cpu();

        /* resume VT operation */
        vmx_resume();

        pat_init();

        cpu_thread_init();      /* not strictly necessary */

        cpu_init();     /* Sets cpu_running which starter cpu waits for */ 

        slave_main();

        panic("i386_init_slave() returned from slave_main()");
}

void
slave_machine_init(void)
{
        /*
         * Here in process context, but with interrupts disabled.
         */
        DBG("slave_machine_init() CPU%d\n", get_cpu_number());

        clock_init();

        cpu_machine_init();             /* Interrupts enabled hereafter */
}

#undef cpu_number()
int cpu_number(void)
{
        return get_cpu_number();
}

#if     MACH_KDB
#include <ddb/db_output.h>

#define TRAP_DEBUG 0 /* Must match interrupt.s and spl.s */


#if     TRAP_DEBUG
#define MTRAPS 100
struct mp_trap_hist_struct {
        unsigned char type;
        unsigned char data[5];
} trap_hist[MTRAPS], *cur_trap_hist = trap_hist,
    *max_trap_hist = &trap_hist[MTRAPS];

void db_trap_hist(void);

/*
 * SPL:
 *      1: new spl
 *      2: old spl
 *      3: new tpr
 *      4: old tpr
 * INT:
 *      1: int vec
 *      2: old spl
 *      3: new spl
 *      4: post eoi tpr
 *      5: exit tpr
 */

void
db_trap_hist(void)
{
        int i,j;
        for(i=0;i<MTRAPS;i++)
            if (trap_hist[i].type == 1 || trap_hist[i].type == 2) {
                    db_printf("%s%s",
                              (&trap_hist[i]>=cur_trap_hist)?"*":" ",
                              (trap_hist[i].type == 1)?"SPL":"INT");
                    for(j=0;j<5;j++)
                        db_printf(" %02x", trap_hist[i].data[j]);
                    db_printf("\n");
            }
                
}
#endif  /* TRAP_DEBUG */
#endif  /* MACH_KDB */