/*

 * xen/common/smp.c

 *

 * Generic SMP function

 *

 * Copyright (c) 2013 Citrix Systems.

 *

 * 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.

 */

#include <asm/hardirq.h>

#include <asm/processor.h>

#include <xen/spinlock.h>

#include <xen/smp.h>

/*

 * Structure and data for smp_call_function()/on_selected_cpus().

 */

static DEFINE_SPINLOCK(call_lock);

static struct call_data_struct {

    void (*func) (void *info);

    void *info;

    int wait;

    cpumask_t selected;

} call_data;

void smp_call_function(

    void (*func) (void *info),

    void *info,

    int wait)

{

    cpumask_t allbutself;

    cpumask_andnot(&allbutself, &cpu_online_map,

                   cpumask_of(smp_processor_id()));

    on_selected_cpus(&allbutself, func, info, wait);

}

void on_selected_cpus(

    const cpumask_t *selected,

    void (*func) (void *info),

    void *info,

    int wait)

{

    unsigned int nr_cpus;

    ASSERT(local_irq_is_enabled());

    ASSERT(cpumask_subset(selected, &cpu_online_map));

    spin_lock(&call_lock);

    cpumask_copy(&call_data.selected, selected);

    nr_cpus = cpumask_weight(&call_data.selected);

    if ( nr_cpus == 0 )

        goto out;

    call_data.func = func;

    call_data.info = info;

    call_data.wait = wait;

    smp_send_call_function_mask(&call_data.selected);

    while ( !cpumask_empty(&call_data.selected) )

        cpu_relax();

out:

    spin_unlock(&call_lock);

}

void smp_call_function_interrupt(void)

{

    void (*func)(void *info) = call_data.func;

    void *info = call_data.info;

    unsigned int cpu = smp_processor_id();

    if ( !cpumask_test_cpu(cpu, &call_data.selected) )

        return;

    irq_enter();

    if ( call_data.wait )

    {

        (*func)(info);

        smp_mb();

        cpumask_clear_cpu(cpu, &call_data.selected);

    }

    else

    {

        smp_mb();

        cpumask_clear_cpu(cpu, &call_data.selected);

        (*func)(info);

    }

    irq_exit();

}

/*

 * Local variables:

 * mode: C

 * c-file-style: "BSD"

 * c-basic-offset: 4

 * indent-tabs-mode: nil

 * End:

 */