ipi.c

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#include <linux/cpumask.h>
#include <linux/interrupt.h>
#include <linux/init.h>

#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
#include <linux/mc146818rtc.h>
#include <linux/cache.h>
#include <linux/cpu.h>
#include <linux/module.h>

#include <asm/smp.h>
#include <asm/mtrr.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/apic.h>
#include <asm/proto.h>
#include <asm/ipi.h>

void default_send_IPI_mask_sequence_phys(const struct cpumask *mask, int vector)
{
    unsigned long query_cpu;
    unsigned long flags;

    /*
     * Hack. The clustered APIC addressing mode doesn't allow us to send
     * to an arbitrary mask, so I do a unicast to each CPU instead.
     * - mbligh
     */
    local_irq_save(flags);
    for_each_cpu(query_cpu, mask) {
        __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid,
                query_cpu), vector, APIC_DEST_PHYSICAL);
    }
    local_irq_restore(flags);
}

void default_send_IPI_mask_allbutself_phys(const struct cpumask *mask,
                         int vector)
{
    unsigned int this_cpu = smp_processor_id();
    unsigned int query_cpu;
    unsigned long flags;

    /* See Hack comment above */

    local_irq_save(flags);
    for_each_cpu(query_cpu, mask) {
        if (query_cpu == this_cpu)
            continue;
        __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid,
                 query_cpu), vector, APIC_DEST_PHYSICAL);
    }
    local_irq_restore(flags);
}

#ifdef CONFIG_X86_32

void default_send_IPI_mask_sequence_logical(const struct cpumask *mask,
                         int vector)
{
    unsigned long flags;
    unsigned int query_cpu;

    /*
     * Hack. The clustered APIC addressing mode doesn't allow us to send
     * to an arbitrary mask, so I do a unicasts to each CPU instead. This
     * should be modified to do 1 message per cluster ID - mbligh
     */

    local_irq_save(flags);
    for_each_cpu(query_cpu, mask)
        __default_send_IPI_dest_field(
            early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
            vector, apic->dest_logical);
    local_irq_restore(flags);
}

void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask,
                         int vector)
{
    unsigned long flags;
    unsigned int query_cpu;
    unsigned int this_cpu = smp_processor_id();

    /* See Hack comment above */

    local_irq_save(flags);
    for_each_cpu(query_cpu, mask) {
        if (query_cpu == this_cpu)
            continue;
        __default_send_IPI_dest_field(
            early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
            vector, apic->dest_logical);
        }
    local_irq_restore(flags);
}

/*
 * This is only used on smaller machines.
 */
void default_send_IPI_mask_logical(const struct cpumask *cpumask, int vector)
{
    unsigned long mask = cpumask_bits(cpumask)[0];
    unsigned long flags;

    if (WARN_ONCE(!mask, "empty IPI mask"))
        return;

    local_irq_save(flags);
    WARN_ON(mask & ~cpumask_bits(cpu_online_mask)[0]);
    __default_send_IPI_dest_field(mask, vector, apic->dest_logical);
    local_irq_restore(flags);
}

void default_send_IPI_allbutself(int vector)
{
    /*
     * if there are no other CPUs in the system then we get an APIC send
     * error if we try to broadcast, thus avoid sending IPIs in this case.
     */
    if (!(num_online_cpus() > 1))
        return;

    __default_local_send_IPI_allbutself(vector);
}

void default_send_IPI_all(int vector)
{
    __default_local_send_IPI_all(vector);
}

void default_send_IPI_self(int vector)
{
    __default_send_IPI_shortcut(APIC_DEST_SELF, vector, apic->dest_logical);
}

/* must come after the send_IPI functions above for inlining */
static int convert_apicid_to_cpu(int apic_id)
{
    int i;

    for_each_possible_cpu(i) {
        if (per_cpu(x86_cpu_to_apicid, i) == apic_id)
            return i;
    }
    return -1;
}

int safe_smp_processor_id(void)
{
    int apicid, cpuid;

    if (!cpu_has_apic)
        return 0;

    apicid = hard_smp_processor_id();
    if (apicid == BAD_APICID)
        return 0;

    cpuid = convert_apicid_to_cpu(apicid);

    return cpuid >= 0 ? cpuid : 0;
}
#endif