xen/arch/x86/cpu/mcheck/barrier.c


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#include "barrier.h"
#include "util.h"
#include "mce.h"

void mce_barrier_init(struct mce_softirq_barrier *bar)
{
    atomic_set(&bar->val, 0);
    atomic_set(&bar->ingen, 0);
    atomic_set(&bar->outgen, 0);
}

void mce_barrier_dec(struct mce_softirq_barrier *bar)
{
    atomic_inc(&bar->outgen);
    smp_wmb();
    atomic_dec(&bar->val);
}

void mce_barrier_enter(struct mce_softirq_barrier *bar, bool wait)
{
    int gen;

    if ( !wait )
        return;
    atomic_inc(&bar->ingen);
    gen = atomic_read(&bar->outgen);
    smp_mb();
    atomic_inc(&bar->val);
    while ( atomic_read(&bar->val) != num_online_cpus() &&
            atomic_read(&bar->outgen) == gen )
    {
            smp_mb();
            mce_panic_check();
    }
}

void mce_barrier_exit(struct mce_softirq_barrier *bar, bool wait)
{
    int gen;

    if ( !wait )
        return;
    atomic_inc(&bar->outgen);
    gen = atomic_read(&bar->ingen);
    smp_mb();
    atomic_dec(&bar->val);
    while ( atomic_read(&bar->val) != 0 &&
            atomic_read(&bar->ingen) == gen )
    {
            smp_mb();
            mce_panic_check();
    }
}

void mce_barrier(struct mce_softirq_barrier *bar)
{
    mce_barrier_enter(bar, mce_broadcast);
    mce_barrier_exit(bar, mce_broadcast);
}