Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * 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/module.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/sysdev.h>

#include <linux/cpu.h>

#include <linux/notifier.h>

#include <linux/topology.h>

#include <asm/ptrace.h>

#include <asm/atomic.h>

#include <asm/irq.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/cputable.h>

#include <asm/system.h>

#include <asm/mpic.h>

#include <asm/vdso_datapage.h>

#ifdef CONFIG_PPC64

#include <asm/paca.h>

#endif

#ifdef DEBUG

#include <asm/udbg.h>

#define DBG(fmt...) udbg_printf(fmt)

#else

#define DBG(fmt...)

#endif

int smp_hw_index[NR_CPUS];

struct thread_info *secondary_ti;

cpumask_t cpu_possible_map = CPU_MASK_NONE;

cpumask_t cpu_online_map = CPU_MASK_NONE;

DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;

EXPORT_SYMBOL(cpu_online_map);

EXPORT_SYMBOL(cpu_possible_map);

EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);

/* SMP operations for this machine */

struct smp_ops_t *smp_ops;

static volatile unsigned int cpu_callin_map[NR_CPUS];

void smp_call_function_interrupt(void);

int smt_enabled_at_boot = 1;

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

#ifdef CONFIG_PPC64

void __devinit 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

         */

        paca[nr].cpu_start = 1;

        smp_mb();

}

#endif

void smp_message_recv(int msg)

{

        switch(msg) {

        case PPC_MSG_CALL_FUNCTION:

                smp_call_function_interrupt();

                break;

        case PPC_MSG_RESCHEDULE:

                /* XXX Do we have to do this? */

                set_need_resched();

                break;

        case PPC_MSG_DEBUGGER_BREAK:

                if (crash_ipi_function_ptr) {

                        crash_ipi_function_ptr(get_irq_regs());

                        break;

                }

#ifdef CONFIG_DEBUGGER

                debugger_ipi(get_irq_regs());

                break;

#endif /* CONFIG_DEBUGGER */

                /* FALLTHROUGH */

        default:

                printk("SMP %d: smp_message_recv(): unknown msg %d\n",

                       smp_processor_id(), msg);

                break;

        }

}

void smp_send_reschedule(int cpu)

{

        if (likely(smp_ops))

                smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);

}

#ifdef CONFIG_DEBUGGER

void smp_send_debugger_break(int cpu)

{

        if (likely(smp_ops))

                smp_ops->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 && smp_ops) {

                mb();

                smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK);

        }

}

#endif

static void stop_this_cpu(void *dummy)

{

        local_irq_disable();

        while (1)

                ;

}

/*

 * Structure and data for smp_call_function(). This is designed to minimise

 * static memory requirements. It also looks cleaner.

 * Stolen from the i386 version.

 */

static  __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock);

static struct call_data_struct {

        void (*func) (void *info);

        void *info;

        atomic_t started;

        atomic_t finished;

        int wait;

} *call_data;

/* delay of at least 8 seconds */

#define SMP_CALL_TIMEOUT        8

/*

 * These functions send a 'generic call function' IPI to other online

 * CPUS in the system.

 *

 * [SUMMARY] Run a function on other CPUs.

 * <func> The function to run. This must be fast and non-blocking.

 * <info> An arbitrary pointer to pass to the function.

 * <nonatomic> currently unused.

 * <wait> If true, wait (atomically) until function has completed on other CPUs.

 * [RETURNS] 0 on success, else a negative status code. Does not return until

 * remote CPUs are nearly ready to execute <<func>> or are or have executed.

 *

 * You must not call this function with disabled interrupts or from a

 * hardware interrupt handler or from a bottom half handler.

 */

int smp_call_function_map(void (*func) (void *info), void *info, int nonatomic,

                        int wait, cpumask_t map)

{

        struct call_data_struct data;

        int ret = -1, num_cpus;

        int cpu;

        u64 timeout;

        if (unlikely(smp_ops == NULL))

                return ret;

        data.func = func;

        data.info = info;

        atomic_set(&data.started, 0);

        data.wait = wait;

        if (wait)

                atomic_set(&data.finished, 0);

        spin_lock(&call_lock);

        /* remove 'self' from the map */

        if (cpu_isset(smp_processor_id(), map))

                cpu_clear(smp_processor_id(), map);

        /* sanity check the map, remove any non-online processors. */

        cpus_and(map, map, cpu_online_map);

        num_cpus = cpus_weight(map);

        if (!num_cpus)

                goto done;

        call_data = &data;

        smp_wmb();

        /* Send a message to all CPUs in the map */

        for_each_cpu_mask(cpu, map)

                smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);

        timeout = get_tb() + (u64) SMP_CALL_TIMEOUT * tb_ticks_per_sec;

        /* Wait for indication that they have received the message */

        while (atomic_read(&data.started) != num_cpus) {

                HMT_low();

                if (get_tb() >= timeout) {

                        printk("smp_call_function on cpu %d: other cpus not "

                                "responding (%d)\n", smp_processor_id(),

                                atomic_read(&data.started));

                        debugger(NULL);

                        goto out;

                }

        }

        /* optionally wait for the CPUs to complete */

        if (wait) {

                while (atomic_read(&data.finished) != num_cpus) {

                        HMT_low();

                        if (get_tb() >= timeout) {

                                printk("smp_call_function on cpu %d: other "

                                        "cpus not finishing (%d/%d)\n",

                                        smp_processor_id(),

                                        atomic_read(&data.finished),

                                        atomic_read(&data.started));

                                debugger(NULL);

                                goto out;

                        }

                }

        }

 done:

        ret = 0;

 out:

        call_data = NULL;

        HMT_medium();

        spin_unlock(&call_lock);

        return ret;

}

static int __smp_call_function(void (*func)(void *info), void *info,

                               int nonatomic, int wait)

{

        return smp_call_function_map(func,info,nonatomic,wait,cpu_online_map);

}

int smp_call_function(void (*func) (void *info), void *info, int nonatomic,

                        int wait)

{

        /* Can deadlock when called with interrupts disabled */

        WARN_ON(irqs_disabled());

        return __smp_call_function(func, info, nonatomic, wait);

}

EXPORT_SYMBOL(smp_call_function);

int smp_call_function_single(int cpu, void (*func) (void *info), void *info, int nonatomic,

                        int wait)

{

        cpumask_t map = CPU_MASK_NONE;

        int ret = 0;

        /* Can deadlock when called with interrupts disabled */

        WARN_ON(irqs_disabled());

        if (!cpu_online(cpu))

                return -EINVAL;

        cpu_set(cpu, map);

        if (cpu != get_cpu())

                ret = smp_call_function_map(func,info,nonatomic,wait,map);

        else {

                local_irq_disable();

                func(info);

                local_irq_enable();

        }

        put_cpu();

        return ret;

}

EXPORT_SYMBOL(smp_call_function_single);

void smp_send_stop(void)

{

        __smp_call_function(stop_this_cpu, NULL, 1, 0);

}

void smp_call_function_interrupt(void)

{

        void (*func) (void *info);

        void *info;

        int wait;

        /* call_data will be NULL if the sender timed out while

         * waiting on us to receive the call.

         */

        if (!call_data)

                return;

        func = call_data->func;

        info = call_data->info;

        wait = call_data->wait;

        if (!wait)

                smp_mb__before_atomic_inc();

        /*

         * Notify initiating CPU that I've grabbed the data and am

         * about to execute the function

         */

        atomic_inc(&call_data->started);

        /*

         * At this point the info structure may be out of scope unless wait==1

         */

        (*func)(info);

        if (wait) {

                smp_mb__before_atomic_inc();

                atomic_inc(&call_data->finished);

        }

}

extern struct gettimeofday_struct do_gtod;

struct thread_info *current_set[NR_CPUS];

DECLARE_PER_CPU(unsigned int, pvr);

static void __devinit smp_store_cpu_info(int id)

{

        per_cpu(pvr, id) = mfspr(SPRN_PVR);

}

static void __init smp_create_idle(unsigned int cpu)

{

        struct task_struct *p;

        /* create a process for the processor */

        p = fork_idle(cpu);

        if (IS_ERR(p))

                panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));

#ifdef CONFIG_PPC64

        paca[cpu].__current = p;

#endif

        current_set[cpu] = task_thread_info(p);

        task_thread_info(p)->cpu = cpu;

}

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;

        if (smp_ops)

                max_cpus = smp_ops->probe();

        else

                max_cpus = 1;

        smp_space_timers(max_cpus);

        for_each_possible_cpu(cpu)

                if (cpu != boot_cpuid)

                        smp_create_idle(cpu);

}

void __devinit smp_prepare_boot_cpu(void)

{

        BUG_ON(smp_processor_id() != boot_cpuid);

        cpu_set(boot_cpuid, cpu_online_map);

#ifdef CONFIG_PPC64

        paca[boot_cpuid].__current = current;

#endif

        current_set[boot_cpuid] = task_thread_info(current);

}

#ifdef CONFIG_HOTPLUG_CPU

/* State of each CPU during hotplug phases */

DEFINE_PER_CPU(int, cpu_state) = { 0 };

int generic_cpu_disable(void)

{

        unsigned int cpu = smp_processor_id();

        if (cpu == boot_cpuid)

                return -EBUSY;

        cpu_clear(cpu, cpu_online_map);

#ifdef CONFIG_PPC64

        vdso_data->processorCount--;

        fixup_irqs(cpu_online_map);

#endif

        return 0;

}

int generic_cpu_enable(unsigned int cpu)

{

        /* Do the normal bootup if we haven't

         * already bootstrapped. */

        if (system_state != SYSTEM_RUNNING)

                return -ENOSYS;

        /* get the target out of it's holding state */

        per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;

        smp_wmb();

        while (!cpu_online(cpu))

                cpu_relax();

#ifdef CONFIG_PPC64

        fixup_irqs(cpu_online_map);

        /* counter the irq disable in fixup_irqs */

        local_irq_enable();

#endif

        return 0;

}

void generic_cpu_die(unsigned int cpu)

{

        int i;

        for (i = 0; i < 100; i++) {

                smp_rmb();

                if (per_cpu(cpu_state, cpu) == CPU_DEAD)

                        return;

                msleep(100);

        }

        printk(KERN_ERR "CPU%d didn't die...\n", cpu);

}

void generic_mach_cpu_die(void)

{

        unsigned int cpu;

        local_irq_disable();

        cpu = smp_processor_id();

        printk(KERN_DEBUG "CPU%d offline\n", cpu);

        __get_cpu_var(cpu_state) = CPU_DEAD;

        smp_wmb();

        while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)

                cpu_relax();

        cpu_set(cpu, cpu_online_map);

        local_irq_enable();

}

#endif

static int __devinit cpu_enable(unsigned int cpu)

{

        if (smp_ops && smp_ops->cpu_enable)

                return smp_ops->cpu_enable(cpu);

        return -ENOSYS;

}

int __cpuinit __cpu_up(unsigned int cpu)

{

        int c;

        secondary_ti = current_set[cpu];

        if (!cpu_enable(cpu))

                return 0;

        if (smp_ops == NULL ||

            (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))

                return -EINVAL;

        /* 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);

        smp_ops->kick_cpu(cpu);

        /*

         * 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 = 25; c && !cpu_callin_map[cpu]; c--) {

                        msleep(200);

                }

#endif

        if (!cpu_callin_map[cpu]) {

                printk("Processor %u is stuck.\n", cpu);

                return -ENOENT;

        }

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

        if (smp_ops->give_timebase)

                smp_ops->give_timebase();

        /* Wait until cpu puts itself in the online map */

        while (!cpu_online(cpu))

                cpu_relax();

        return 0;

}

/* Activate a secondary processor. */

int __devinit start_secondary(void *unused)

{

        unsigned int cpu = smp_processor_id();

        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;

        smp_ops->setup_cpu(cpu);

        if (smp_ops->take_timebase)

                smp_ops->take_timebase();

        if (system_state > SYSTEM_BOOTING)

                snapshot_timebase();

        secondary_cpu_time_init();

        spin_lock(&call_lock);

        cpu_set(cpu, cpu_online_map);

        spin_unlock(&call_lock);

        local_irq_enable();

        cpu_idle();

        return 0;

}

int setup_profiling_timer(unsigned int multiplier)

{

        return 0;

}

void __init smp_cpus_done(unsigned int max_cpus)

{

        cpumask_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

         */

        old_mask = current->cpus_allowed;

        set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid));

        if (smp_ops)

                smp_ops->setup_cpu(boot_cpuid);

        set_cpus_allowed(current, old_mask);

        snapshot_timebases();

        dump_numa_cpu_topology();

}

#ifdef CONFIG_HOTPLUG_CPU

int __cpu_disable(void)

{

        if (smp_ops->cpu_disable)

                return smp_ops->cpu_disable();

        return -ENOSYS;

}

void __cpu_die(unsigned int cpu)

{

        if (smp_ops->cpu_die)

                smp_ops->cpu_die(cpu);

}

#endif