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/*

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

 *

 * Copyright (C) 2000, 2001 Kanoj Sarcar

 * Copyright (C) 2000, 2001 Ralf Baechle

 * Copyright (C) 2000, 2001 Silicon Graphics, Inc.

 * Copyright (C) 2000, 2001 Broadcom Corporation

 */

#include <linux/config.h>

#include <linux/cache.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/spinlock.h>

#include <linux/threads.h>

#include <linux/module.h>

#include <linux/time.h>

#include <linux/timex.h>

#include <linux/sched.h>

#include <asm/atomic.h>

#include <asm/cpu.h>

#include <asm/processor.h>

#include <asm/system.h>

#include <asm/hardirq.h>

#include <asm/softirq.h>

#include <asm/mmu_context.h>

#include <asm/smp.h>

/* The 'big kernel lock' */

spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;

int smp_threads_ready;  /* Not used */

atomic_t smp_commenced = ATOMIC_INIT(0);

atomic_t cpus_booted = ATOMIC_INIT(0);

int smp_num_cpus = 1;                   /* Number that came online.  */

cpumask_t cpu_online_map;               /* Bitmask of currently online CPUs */

int __cpu_number_map[NR_CPUS];

int __cpu_logical_map[NR_CPUS];

cycles_t cacheflush_time;

void __init smp_callin(void)

{

#if 0

        calibrate_delay();

        smp_store_cpu_info(cpuid);

#endif

}

void __init smp_commence(void)

{

        wmb();

        atomic_set(&smp_commenced, 1);

}

/*

 * this function sends a 'reschedule' IPI to another CPU.

 * it goes straight through and wastes no time serializing

 * anything. Worst case is that we lose a reschedule ...

 */

void smp_send_reschedule(int cpu)

{

        core_send_ipi(cpu, SMP_RESCHEDULE_YOURSELF);

}

spinlock_t smp_call_lock = SPIN_LOCK_UNLOCKED;

struct call_data_struct *call_data;

/*

 * Run a function on all other CPUs.

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

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

 *  <retry>     If true, keep retrying until ready.

 *  <wait>      If true, wait 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.

 */

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

                                                                int wait)

{

        struct call_data_struct data;

        int i, cpus = smp_num_cpus - 1;

        int cpu = smp_processor_id();

        if (!cpus)

                return 0;

        data.func = func;

        data.info = info;

        atomic_set(&data.started, 0);

        data.wait = wait;

        if (wait)

                atomic_set(&data.finished, 0);

        spin_lock(&smp_call_lock);

        call_data = &data;

        /* Send a message to all other CPUs and wait for them to respond */

        for (i = 0; i < smp_num_cpus; i++)

                if (i != cpu)

                        core_send_ipi(i, SMP_CALL_FUNCTION);

        /* Wait for response */

        /* FIXME: lock-up detection, backtrace on lock-up */

        while (atomic_read(&data.started) != cpus)

                barrier();

        if (wait)

                while (atomic_read(&data.finished) != cpus)

                        barrier();

        spin_unlock(&smp_call_lock);

        return 0;

}

void smp_call_function_interrupt(void)

{

        void (*func) (void *info) = call_data->func;

        void *info = call_data->info;

        int wait = call_data->wait;

        int cpu = smp_processor_id();

        irq_enter(cpu, 0);       /* XXX choose an irq number? */

        /*

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

         * about to execute the function.

         */

        mb();

        atomic_inc(&call_data->started);

        /*

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

         */

        (*func)(info);

        if (wait) {

                mb();

                atomic_inc(&call_data->finished);

        }

        irq_exit(cpu, 0);        /* XXX choose an irq number? */

}

static void stop_this_cpu(void *dummy)

{

        /*

         * Remove this CPU:

         */

        clear_bit(smp_processor_id(), &cpu_online_map);

        /* May need to service _machine_restart IPI */

        local_irq_enable();

        /* XXXKW wait if available? */

        for (;;);

}

void smp_send_stop(void)

{

        smp_call_function(stop_this_cpu, NULL, 1, 0);

        /*

         * Fix me: this prevents future IPIs, for example that would

         * cause a restart to happen on CPU0.

         */

        smp_num_cpus = 1;

}

/* Not really SMP stuff ... */

int setup_profiling_timer(unsigned int multiplier)

{

        return 0;

}

static void flush_tlb_all_ipi(void *info)

{

        local_flush_tlb_all();

}

void flush_tlb_all(void)

{

        smp_call_function(flush_tlb_all_ipi, 0, 1, 1);

        local_flush_tlb_all();

}

static void flush_tlb_mm_ipi(void *mm)

{

        local_flush_tlb_mm((struct mm_struct *)mm);

}

/*

 * The following tlb flush calls are invoked when old translations are

 * being torn down, or pte attributes are changing. For single threaded

 * address spaces, a new context is obtained on the current cpu, and tlb

 * context on other cpus are invalidated to force a new context allocation

 * at switch_mm time, should the mm ever be used on other cpus. For

 * multithreaded address spaces, intercpu interrupts have to be sent.

 * Another case where intercpu interrupts are required is when the target

 * mm might be active on another cpu (eg debuggers doing the flushes on

 * behalf of debugees, kswapd stealing pages from another process etc).

 * Kanoj 07/00.

 */

void flush_tlb_mm(struct mm_struct *mm)

{

        if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {

                smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1, 1);

        } else {

                int i;

                for (i = 0; i < smp_num_cpus; i++)

                        if (smp_processor_id() != i)

                                cpu_context(i, mm) = 0;

        }

        local_flush_tlb_mm(mm);

}

struct flush_tlb_data {

        struct mm_struct *mm;

        struct vm_area_struct *vma;

        unsigned long addr1;

        unsigned long addr2;

};

static void flush_tlb_range_ipi(void *info)

{

        struct flush_tlb_data *fd = (struct flush_tlb_data *)info;

        local_flush_tlb_range(fd->mm, fd->addr1, fd->addr2);

}

void flush_tlb_range(struct mm_struct *mm, unsigned long start, unsigned long end)

{

        if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {

                struct flush_tlb_data fd;

                fd.mm = mm;

                fd.addr1 = start;

                fd.addr2 = end;

                smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1, 1);

        } else {

                int i;

                for (i = 0; i < smp_num_cpus; i++)

                        if (smp_processor_id() != i)

                                cpu_context(i, mm) = 0;

        }

        local_flush_tlb_range(mm, start, end);

}

static void flush_tlb_page_ipi(void *info)

{

        struct flush_tlb_data *fd = (struct flush_tlb_data *)info;

        local_flush_tlb_page(fd->vma, fd->addr1);

}

void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)

{

        if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {

                struct flush_tlb_data fd;

                fd.vma = vma;

                fd.addr1 = page;

                smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1, 1);

        } else {

                int i;

                for (i = 0; i < smp_num_cpus; i++)

                        if (smp_processor_id() != i)

                                cpu_context(i, vma->vm_mm) = 0;

        }

        local_flush_tlb_page(vma, page);

}

EXPORT_SYMBOL(smp_num_cpus);

EXPORT_SYMBOL(flush_tlb_page);

EXPORT_SYMBOL(cpu_data);

EXPORT_SYMBOL(synchronize_irq);

EXPORT_SYMBOL(kernel_flag);

EXPORT_SYMBOL(__global_sti);

EXPORT_SYMBOL(__global_cli);

EXPORT_SYMBOL(__global_save_flags);

EXPORT_SYMBOL(__global_restore_flags);