/*
 * SMP support for ppc.
 *
 * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
 * deal of code from the sparc and intel versions.
 *
 * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
 *
 * PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and
 * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/cache.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
#include <linux/topology.h>

#include <asm/ptrace.h>
#include <linux/atomic.h>
#include <asm/irq.h>
#include <asm/hw_irq.h>
#include <asm/kvm_ppc.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/time.h>
#include <asm/machdep.h>
#include <asm/cputhreads.h>
#include <asm/cputable.h>
#include <asm/mpic.h>
#include <asm/vdso_datapage.h>
#ifdef CONFIG_PPC64
#include <asm/paca.h>
#endif
#include <asm/vdso.h>
#include <asm/debug.h>
#include <asm/kexec.h>

#ifdef DEBUG
#include <asm/udbg.h>
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

#ifdef CONFIG_HOTPLUG_CPU
/* State of each CPU during hotplug phases */
static DEFINE_PER_CPU(int, cpu_state) = { 0 };
#endif

struct thread_info *secondary_ti;

DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);

EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
EXPORT_PER_CPU_SYMBOL(cpu_core_map);

/* SMP operations for this machine */
struct smp_ops_t *smp_ops;

/* Can't be static due to PowerMac hackery */
volatile unsigned int cpu_callin_map[NR_CPUS];

int smt_enabled_at_boot = 1;

static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;

/*
 * Returns 1 if the specified cpu should be brought up during boot.
 * Used to inhibit booting threads if they've been disabled or
 * limited on the command line
 */
int smp_generic_cpu_bootable(unsigned int nr)
{
        /* Special case - we inhibit secondary thread startup
         * during boot if the user requests it.
         */
        if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
                if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
                        return 0;
                if (smt_enabled_at_boot
                    && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
                        return 0;
        }

        return 1;
}


#ifdef CONFIG_PPC64
int smp_generic_kick_cpu(int nr)
{
        BUG_ON(nr < 0 || nr >= NR_CPUS);

        /*
         * The processor is currently spinning, waiting for the
         * cpu_start field to become non-zero After we set cpu_start,
         * the processor will continue on to secondary_start
         */
        if (!paca[nr].cpu_start) {
                paca[nr].cpu_start = 1;
                smp_mb();
                return 0;
        }

#ifdef CONFIG_HOTPLUG_CPU
        /*
         * Ok it's not there, so it might be soft-unplugged, let's
         * try to bring it back
         */
        generic_set_cpu_up(nr);
        smp_wmb();
        smp_send_reschedule(nr);
#endif /* CONFIG_HOTPLUG_CPU */

        return 0;
}
#endif /* CONFIG_PPC64 */

static irqreturn_t call_function_action(int irq, void *data)
{
        generic_smp_call_function_interrupt();
        return IRQ_HANDLED;
}

static irqreturn_t reschedule_action(int irq, void *data)
{
        scheduler_ipi();
        return IRQ_HANDLED;
}

static irqreturn_t tick_broadcast_ipi_action(int irq, void *data)
{
        tick_broadcast_ipi_handler();
        return IRQ_HANDLED;
}

static irqreturn_t debug_ipi_action(int irq, void *data)
{
        if (crash_ipi_function_ptr) {
                crash_ipi_function_ptr(get_irq_regs());
                return IRQ_HANDLED;
        }

#ifdef CONFIG_DEBUGGER
        debugger_ipi(get_irq_regs());
#endif /* CONFIG_DEBUGGER */

        return IRQ_HANDLED;
}

static irq_handler_t smp_ipi_action[] = {
        [PPC_MSG_CALL_FUNCTION] =  call_function_action,
        [PPC_MSG_RESCHEDULE] = reschedule_action,
        [PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action,
        [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
};

const char *smp_ipi_name[] = {
        [PPC_MSG_CALL_FUNCTION] =  "ipi call function",
        [PPC_MSG_RESCHEDULE] = "ipi reschedule",
        [PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
        [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
};

/* optional function to request ipi, for controllers with >= 4 ipis */
int smp_request_message_ipi(int virq, int msg)
{
        int err;

        if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
                return -EINVAL;
        }
#if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
        if (msg == PPC_MSG_DEBUGGER_BREAK) {
                return 1;
        }
#endif
        err = request_irq(virq, smp_ipi_action[msg],
                          IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
                          smp_ipi_name[msg], NULL);
        WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
                virq, smp_ipi_name[msg], err);

        return err;
}

#ifdef CONFIG_PPC_SMP_MUXED_IPI
struct cpu_messages {
        long messages;                  /* current messages */
        unsigned long data;             /* data for cause ipi */
};
static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);

void smp_muxed_ipi_set_data(int cpu, unsigned long data)
{
        struct cpu_messages *info = &per_cpu(ipi_message, cpu);

        info->data = data;
}

void smp_muxed_ipi_set_message(int cpu, int msg)
{
        struct cpu_messages *info = &per_cpu(ipi_message, cpu);
        char *message = (char *)&info->messages;

        /*
         * Order previous accesses before accesses in the IPI handler.
         */
        smp_mb();
        message[msg] = 1;
}

void smp_muxed_ipi_message_pass(int cpu, int msg)
{
        struct cpu_messages *info = &per_cpu(ipi_message, cpu);

        smp_muxed_ipi_set_message(cpu, msg);
        /*
         * cause_ipi functions are required to include a full barrier
         * before doing whatever causes the IPI.
         */
        smp_ops->cause_ipi(cpu, info->data);
}

#ifdef __BIG_ENDIAN__
#define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A)))
#else
#define IPI_MESSAGE(A) (1uL << (8 * (A)))
#endif

irqreturn_t smp_ipi_demux(void)
{
        struct cpu_messages *info = this_cpu_ptr(&ipi_message);
        unsigned long all;

        mb();   /* order any irq clear */

        do {
                all = xchg(&info->messages, 0);
#if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
                /*
                 * Must check for PPC_MSG_RM_HOST_ACTION messages
                 * before PPC_MSG_CALL_FUNCTION messages because when
                 * a VM is destroyed, we call kick_all_cpus_sync()
                 * to ensure that any pending PPC_MSG_RM_HOST_ACTION
                 * messages have completed before we free any VCPUs.
                 */
                if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION))
                        kvmppc_xics_ipi_action();
#endif
                if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
                        generic_smp_call_function_interrupt();
                if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
                        scheduler_ipi();
                if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
                        tick_broadcast_ipi_handler();
                if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
                        debug_ipi_action(0, NULL);
        } while (info->messages);

        return IRQ_HANDLED;
}
#endif /* CONFIG_PPC_SMP_MUXED_IPI */

static inline void do_message_pass(int cpu, int msg)
{
        if (smp_ops->message_pass)
                smp_ops->message_pass(cpu, msg);
#ifdef CONFIG_PPC_SMP_MUXED_IPI
        else
                smp_muxed_ipi_message_pass(cpu, msg);
#endif
}

void smp_send_reschedule(int cpu)
{
        if (likely(smp_ops))
                do_message_pass(cpu, PPC_MSG_RESCHEDULE);
}
EXPORT_SYMBOL_GPL(smp_send_reschedule);

void arch_send_call_function_single_ipi(int cpu)
{
        do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
}

void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
        unsigned int cpu;

        for_each_cpu(cpu, mask)
                do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
}

#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
void tick_broadcast(const struct cpumask *mask)
{
        unsigned int cpu;

        for_each_cpu(cpu, mask)
                do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
}
#endif

#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
void smp_send_debugger_break(void)
{
        int cpu;
        int me = raw_smp_processor_id();

        if (unlikely(!smp_ops))
                return;

        for_each_online_cpu(cpu)
                if (cpu != me)
                        do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
}
#endif

#ifdef CONFIG_KEXEC
void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
{
        crash_ipi_function_ptr = crash_ipi_callback;
        if (crash_ipi_callback) {
                mb();
                smp_send_debugger_break();
        }
}
#endif

static void stop_this_cpu(void *dummy)
{
        /* Remove this CPU */
        set_cpu_online(smp_processor_id(), false);

        local_irq_disable();
        while (1)
                ;
}

void smp_send_stop(void)
{
        smp_call_function(stop_this_cpu, NULL, 0);
}

struct thread_info *current_set[NR_CPUS];

static void smp_store_cpu_info(int id)
{
        per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
#ifdef CONFIG_PPC_FSL_BOOK3E
        per_cpu(next_tlbcam_idx, id)
                = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
#endif
}

void __init smp_prepare_cpus(unsigned int max_cpus)
{
        unsigned int cpu;

        DBG("smp_prepare_cpus\n");

        /* 
         * setup_cpu may need to be called on the boot cpu. We havent
         * spun any cpus up but lets be paranoid.
         */
        BUG_ON(boot_cpuid != smp_processor_id());

        /* Fixup boot cpu */
        smp_store_cpu_info(boot_cpuid);
        cpu_callin_map[boot_cpuid] = 1;

        for_each_possible_cpu(cpu) {
                zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
                                        GFP_KERNEL, cpu_to_node(cpu));
                zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
                                        GFP_KERNEL, cpu_to_node(cpu));
                /*
                 * numa_node_id() works after this.
                 */
                if (cpu_present(cpu)) {
                        set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
                        set_cpu_numa_mem(cpu,
                                local_memory_node(numa_cpu_lookup_table[cpu]));
                }
        }

        cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
        cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));

        if (smp_ops && smp_ops->probe)
                smp_ops->probe();
}

void smp_prepare_boot_cpu(void)
{
        BUG_ON(smp_processor_id() != boot_cpuid);
#ifdef CONFIG_PPC64
        paca[boot_cpuid].__current = current;
#endif
        set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
        current_set[boot_cpuid] = task_thread_info(current);
}

#ifdef CONFIG_HOTPLUG_CPU

int generic_cpu_disable(void)
{
        unsigned int cpu = smp_processor_id();

        if (cpu == boot_cpuid)
                return -EBUSY;

        set_cpu_online(cpu, false);
#ifdef CONFIG_PPC64
        vdso_data->processorCount--;
#endif
        migrate_irqs();
        return 0;
}

void generic_cpu_die(unsigned int cpu)
{
        int i;

        for (i = 0; i < 100; i++) {
                smp_rmb();
                if (is_cpu_dead(cpu))
                        return;
                msleep(100);
        }
        printk(KERN_ERR "CPU%d didn't die...\n", cpu);
}

void generic_set_cpu_dead(unsigned int cpu)
{
        per_cpu(cpu_state, cpu) = CPU_DEAD;
}

/*
 * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
 * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
 * which makes the delay in generic_cpu_die() not happen.
 */
void generic_set_cpu_up(unsigned int cpu)
{
        per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
}

int generic_check_cpu_restart(unsigned int cpu)
{
        return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
}

int is_cpu_dead(unsigned int cpu)
{
        return per_cpu(cpu_state, cpu) == CPU_DEAD;
}

static bool secondaries_inhibited(void)
{
        return kvm_hv_mode_active();
}

#else /* HOTPLUG_CPU */

#define secondaries_inhibited()         0

#endif

static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
{
        struct thread_info *ti = task_thread_info(idle);

#ifdef CONFIG_PPC64
        paca[cpu].__current = idle;
        paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
#endif
        ti->cpu = cpu;
        secondary_ti = current_set[cpu] = ti;
}

int __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
        int rc, c;

        /*
         * Don't allow secondary threads to come online if inhibited
         */
        if (threads_per_core > 1 && secondaries_inhibited() &&
            cpu_thread_in_subcore(cpu))
                return -EBUSY;

        if (smp_ops == NULL ||
            (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
                return -EINVAL;

        cpu_idle_thread_init(cpu, tidle);

        /* Make sure callin-map entry is 0 (can be leftover a CPU
         * hotplug
         */
        cpu_callin_map[cpu] = 0;

        /* The information for processor bringup must
         * be written out to main store before we release
         * the processor.
         */
        smp_mb();

        /* wake up cpus */
        DBG("smp: kicking cpu %d\n", cpu);
        rc = smp_ops->kick_cpu(cpu);
        if (rc) {
                pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
                return rc;
        }

        /*
         * wait to see if the cpu made a callin (is actually up).
         * use this value that I found through experimentation.
         * -- Cort
         */
        if (system_state < SYSTEM_RUNNING)
                for (c = 50000; c && !cpu_callin_map[cpu]; c--)
                        udelay(100);
#ifdef CONFIG_HOTPLUG_CPU
        else
                /*
                 * CPUs can take much longer to come up in the
                 * hotplug case.  Wait five seconds.
                 */
                for (c = 5000; c && !cpu_callin_map[cpu]; c--)
                        msleep(1);
#endif

        if (!cpu_callin_map[cpu]) {
                printk(KERN_ERR "Processor %u is stuck.\n", cpu);
                return -ENOENT;
        }

        DBG("Processor %u found.\n", cpu);

        if (smp_ops->give_timebase)
                smp_ops->give_timebase();

        /* Wait until cpu puts itself in the online & active maps */
        while (!cpu_online(cpu) || !cpu_active(cpu))
                cpu_relax();

        return 0;
}

/* Return the value of the reg property corresponding to the given
 * logical cpu.
 */
int cpu_to_core_id(int cpu)
{
        struct device_node *np;
        const __be32 *reg;
        int id = -1;

        np = of_get_cpu_node(cpu, NULL);
        if (!np)
                goto out;

        reg = of_get_property(np, "reg", NULL);
        if (!reg)
                goto out;

        id = be32_to_cpup(reg);
out:
        of_node_put(np);
        return id;
}

/* Helper routines for cpu to core mapping */
int cpu_core_index_of_thread(int cpu)
{
        return cpu >> threads_shift;
}
EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);

int cpu_first_thread_of_core(int core)
{
        return core << threads_shift;
}
EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);

static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
{
        const struct cpumask *mask;
        struct device_node *np;
        int i, plen;
        const __be32 *prop;

        mask = add ? cpu_online_mask : cpu_present_mask;
        for_each_cpu(i, mask) {
                np = of_get_cpu_node(i, NULL);
                if (!np)
                        continue;
                prop = of_get_property(np, "ibm,chip-id", &plen);
                if (prop && plen == sizeof(int) &&
                    of_read_number(prop, 1) == chipid) {
                        if (add) {
                                cpumask_set_cpu(cpu, cpu_core_mask(i));
                                cpumask_set_cpu(i, cpu_core_mask(cpu));
                        } else {
                                cpumask_clear_cpu(cpu, cpu_core_mask(i));
                                cpumask_clear_cpu(i, cpu_core_mask(cpu));
                        }
                }
                of_node_put(np);
        }
}

/* Must be called when no change can occur to cpu_present_mask,
 * i.e. during cpu online or offline.
 */
static struct device_node *cpu_to_l2cache(int cpu)
{
        struct device_node *np;
        struct device_node *cache;

        if (!cpu_present(cpu))
                return NULL;

        np = of_get_cpu_node(cpu, NULL);
        if (np == NULL)
                return NULL;

        cache = of_find_next_cache_node(np);

        of_node_put(np);

        return cache;
}

static void traverse_core_siblings(int cpu, bool add)
{
        struct device_node *l2_cache, *np;
        const struct cpumask *mask;
        int i, chip, plen;
        const __be32 *prop;

        /* First see if we have ibm,chip-id properties in cpu nodes */
        np = of_get_cpu_node(cpu, NULL);
        if (np) {
                chip = -1;
                prop = of_get_property(np, "ibm,chip-id", &plen);
                if (prop && plen == sizeof(int))
                        chip = of_read_number(prop, 1);
                of_node_put(np);
                if (chip >= 0) {
                        traverse_siblings_chip_id(cpu, add, chip);
                        return;
                }
        }

        l2_cache = cpu_to_l2cache(cpu);
        mask = add ? cpu_online_mask : cpu_present_mask;
        for_each_cpu(i, mask) {
                np = cpu_to_l2cache(i);
                if (!np)
                        continue;
                if (np == l2_cache) {
                        if (add) {
                                cpumask_set_cpu(cpu, cpu_core_mask(i));
                                cpumask_set_cpu(i, cpu_core_mask(cpu));
                        } else {
                                cpumask_clear_cpu(cpu, cpu_core_mask(i));
                                cpumask_clear_cpu(i, cpu_core_mask(cpu));
                        }
                }
                of_node_put(np);
        }
        of_node_put(l2_cache);
}

/* Activate a secondary processor. */
void start_secondary(void *unused)
{
        unsigned int cpu = smp_processor_id();
        int i, base;

        atomic_inc(&init_mm.mm_count);
        current->active_mm = &init_mm;

        smp_store_cpu_info(cpu);
        set_dec(tb_ticks_per_jiffy);
        preempt_disable();
        cpu_callin_map[cpu] = 1;

        if (smp_ops->setup_cpu)
                smp_ops->setup_cpu(cpu);
        if (smp_ops->take_timebase)
                smp_ops->take_timebase();

        secondary_cpu_time_init();

#ifdef CONFIG_PPC64
        if (system_state == SYSTEM_RUNNING)
                vdso_data->processorCount++;

        vdso_getcpu_init();
#endif
        /* Update sibling maps */
        base = cpu_first_thread_sibling(cpu);
        for (i = 0; i < threads_per_core; i++) {
                if (cpu_is_offline(base + i) && (cpu != base + i))
                        continue;
                cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
                cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));

                /* cpu_core_map should be a superset of
                 * cpu_sibling_map even if we don't have cache
                 * information, so update the former here, too.
                 */
                cpumask_set_cpu(cpu, cpu_core_mask(base + i));
                cpumask_set_cpu(base + i, cpu_core_mask(cpu));
        }
        traverse_core_siblings(cpu, true);

        set_numa_node(numa_cpu_lookup_table[cpu]);
        set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));

        smp_wmb();
        notify_cpu_starting(cpu);
        set_cpu_online(cpu, true);

        local_irq_enable();

        cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

        BUG();
}

int setup_profiling_timer(unsigned int multiplier)
{
        return 0;
}

#ifdef CONFIG_SCHED_SMT
/* cpumask of CPUs with asymetric SMT dependancy */
static int powerpc_smt_flags(void)
{
        int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;

        if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
                printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
                flags |= SD_ASYM_PACKING;
        }
        return flags;
}
#endif

static struct sched_domain_topology_level powerpc_topology[] = {
#ifdef CONFIG_SCHED_SMT
        { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
#endif
        { cpu_cpu_mask, SD_INIT_NAME(DIE) },
        { NULL, },
};

void __init smp_cpus_done(unsigned int max_cpus)
{
        cpumask_var_t old_mask;

        /* We want the setup_cpu() here to be called from CPU 0, but our
         * init thread may have been "borrowed" by another CPU in the meantime
         * se we pin us down to CPU 0 for a short while
         */
        alloc_cpumask_var(&old_mask, GFP_NOWAIT);
        cpumask_copy(old_mask, tsk_cpus_allowed(current));
        set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
        
        if (smp_ops && smp_ops->setup_cpu)
                smp_ops->setup_cpu(boot_cpuid);

        set_cpus_allowed_ptr(current, old_mask);

        free_cpumask_var(old_mask);

        if (smp_ops && smp_ops->bringup_done)
                smp_ops->bringup_done();

        dump_numa_cpu_topology();

        set_sched_topology(powerpc_topology);

}

#ifdef CONFIG_HOTPLUG_CPU
int __cpu_disable(void)
{
        int cpu = smp_processor_id();
        int base, i;
        int err;

        if (!smp_ops->cpu_disable)
                return -ENOSYS;

        err = smp_ops->cpu_disable();
        if (err)
                return err;

        /* Update sibling maps */
        base = cpu_first_thread_sibling(cpu);
        for (i = 0; i < threads_per_core; i++) {
                cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
                cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
                cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
                cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
        }
        traverse_core_siblings(cpu, false);

        return 0;
}

void __cpu_die(unsigned int cpu)
{
        if (smp_ops->cpu_die)
                smp_ops->cpu_die(cpu);
}

void cpu_die(void)
{
        if (ppc_md.cpu_die)
                ppc_md.cpu_die();

        /* If we return, we re-enter start_secondary */
        start_secondary_resume();
}

#endif