irq.c

来自「xen虚拟机源代码安装包」· C语言 代码 · 共 544 行 · 第 1/2 页

/******************************************************************************
 * irq.c
 * 
 * Interrupt distribution and delivery logic.
 * 
 * Copyright (c) 2006, K A Fraser, XenSource Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 */

#include <xen/config.h>
#include <xen/types.h>
#include <xen/event.h>
#include <xen/sched.h>
#include <asm/hvm/domain.h>
#include <asm/hvm/support.h>

static void __hvm_pci_intx_assert(
    struct domain *d, unsigned int device, unsigned int intx)
{
    struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
    unsigned int gsi, link, isa_irq;

    ASSERT((device <= 31) && (intx <= 3));

    if ( __test_and_set_bit(device*4 + intx, &hvm_irq->pci_intx.i) )
        return;

    gsi = hvm_pci_intx_gsi(device, intx);
    if ( hvm_irq->gsi_assert_count[gsi]++ == 0 )
        vioapic_irq_positive_edge(d, gsi);

    link    = hvm_pci_intx_link(device, intx);
    isa_irq = hvm_irq->pci_link.route[link];
    if ( (hvm_irq->pci_link_assert_count[link]++ == 0) && isa_irq &&
         (hvm_irq->gsi_assert_count[isa_irq]++ == 0) )
    {
        vioapic_irq_positive_edge(d, isa_irq);
        vpic_irq_positive_edge(d, isa_irq);
    }
}

void hvm_pci_intx_assert(
    struct domain *d, unsigned int device, unsigned int intx)
{
    spin_lock(&d->arch.hvm_domain.irq_lock);
    __hvm_pci_intx_assert(d, device, intx);
    spin_unlock(&d->arch.hvm_domain.irq_lock);
}

static void __hvm_pci_intx_deassert(
    struct domain *d, unsigned int device, unsigned int intx)
{
    struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
    unsigned int gsi, link, isa_irq;

    ASSERT((device <= 31) && (intx <= 3));

    if ( !__test_and_clear_bit(device*4 + intx, &hvm_irq->pci_intx.i) )
        return;

    gsi = hvm_pci_intx_gsi(device, intx);
    --hvm_irq->gsi_assert_count[gsi];

    link    = hvm_pci_intx_link(device, intx);
    isa_irq = hvm_irq->pci_link.route[link];
    if ( (--hvm_irq->pci_link_assert_count[link] == 0) && isa_irq &&
         (--hvm_irq->gsi_assert_count[isa_irq] == 0) )
        vpic_irq_negative_edge(d, isa_irq);
}

void hvm_pci_intx_deassert(
    struct domain *d, unsigned int device, unsigned int intx)
{
    spin_lock(&d->arch.hvm_domain.irq_lock);
    __hvm_pci_intx_deassert(d, device, intx);
    spin_unlock(&d->arch.hvm_domain.irq_lock);
}

void hvm_isa_irq_assert(
    struct domain *d, unsigned int isa_irq)
{
    struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
    unsigned int gsi = hvm_isa_irq_to_gsi(isa_irq);

    ASSERT(isa_irq <= 15);

    spin_lock(&d->arch.hvm_domain.irq_lock);

    if ( !__test_and_set_bit(isa_irq, &hvm_irq->isa_irq.i) &&
         (hvm_irq->gsi_assert_count[gsi]++ == 0) )
    {
        vioapic_irq_positive_edge(d, gsi);
        vpic_irq_positive_edge(d, isa_irq);
    }

    spin_unlock(&d->arch.hvm_domain.irq_lock);
}

void hvm_isa_irq_deassert(
    struct domain *d, unsigned int isa_irq)
{
    struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
    unsigned int gsi = hvm_isa_irq_to_gsi(isa_irq);

    ASSERT(isa_irq <= 15);

    spin_lock(&d->arch.hvm_domain.irq_lock);

    if ( __test_and_clear_bit(isa_irq, &hvm_irq->isa_irq.i) &&
         (--hvm_irq->gsi_assert_count[gsi] == 0) )
        vpic_irq_negative_edge(d, isa_irq);

    spin_unlock(&d->arch.hvm_domain.irq_lock);
}

static void hvm_set_callback_irq_level(struct vcpu *v)
{
    struct domain *d = v->domain;
    struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
    unsigned int gsi, pdev, pintx, asserted;

    ASSERT(v->vcpu_id == 0);

    spin_lock(&d->arch.hvm_domain.irq_lock);

    /* NB. Do not check the evtchn_upcall_mask. It is not used in HVM mode. */
    asserted = !!vcpu_info(v, evtchn_upcall_pending);
    if ( hvm_irq->callback_via_asserted == asserted )
        goto out;
    hvm_irq->callback_via_asserted = asserted;

    /* Callback status has changed. Update the callback via. */
    switch ( hvm_irq->callback_via_type )
    {
    case HVMIRQ_callback_gsi:
        gsi = hvm_irq->callback_via.gsi;
        if ( asserted && (hvm_irq->gsi_assert_count[gsi]++ == 0) )
        {
            vioapic_irq_positive_edge(d, gsi);
            if ( gsi <= 15 )
                vpic_irq_positive_edge(d, gsi);
        }
        else if ( !asserted && (--hvm_irq->gsi_assert_count[gsi] == 0) )
        {
            if ( gsi <= 15 )
                vpic_irq_negative_edge(d, gsi);
        }
        break;
    case HVMIRQ_callback_pci_intx:
        pdev  = hvm_irq->callback_via.pci.dev;
        pintx = hvm_irq->callback_via.pci.intx;
        if ( asserted )
            __hvm_pci_intx_assert(d, pdev, pintx);
        else
            __hvm_pci_intx_deassert(d, pdev, pintx);
    default:
        break;
    }

 out:
    spin_unlock(&d->arch.hvm_domain.irq_lock);
}

void hvm_maybe_deassert_evtchn_irq(void)
{
    struct domain *d = current->domain;
    struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;

    if ( hvm_irq->callback_via_asserted &&
         !vcpu_info(d->vcpu[0], evtchn_upcall_pending) )
        hvm_set_callback_irq_level(d->vcpu[0]);
}

void hvm_assert_evtchn_irq(struct vcpu *v)
{
    if ( v->vcpu_id == 0 )
        hvm_set_callback_irq_level(v);
}

void hvm_set_pci_link_route(struct domain *d, u8 link, u8 isa_irq)
{
    struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
    u8 old_isa_irq;
    int i;

    ASSERT((link <= 3) && (isa_irq <= 15));

    spin_lock(&d->arch.hvm_domain.irq_lock);

    old_isa_irq = hvm_irq->pci_link.route[link];
    if ( old_isa_irq == isa_irq )
        goto out;
    hvm_irq->pci_link.route[link] = isa_irq;

    /* PCI pass-through fixup. */
    if ( hvm_irq->dpci )
    {
        if ( old_isa_irq )
            clear_bit(old_isa_irq, &hvm_irq->dpci->isairq_map);

        for ( i = 0; i < NR_LINK; i++ )
            if ( hvm_irq->dpci->link_cnt[i] && hvm_irq->pci_link.route[i] )
                set_bit(hvm_irq->pci_link.route[i],
                        &hvm_irq->dpci->isairq_map);
    }

    if ( hvm_irq->pci_link_assert_count[link] == 0 )
        goto out;

    if ( old_isa_irq && (--hvm_irq->gsi_assert_count[old_isa_irq] == 0) )
        vpic_irq_negative_edge(d, old_isa_irq);

    if ( isa_irq && (hvm_irq->gsi_assert_count[isa_irq]++ == 0) )
    {
        vioapic_irq_positive_edge(d, isa_irq);
        vpic_irq_positive_edge(d, isa_irq);
    }

 out:
    spin_unlock(&d->arch.hvm_domain.irq_lock);

    dprintk(XENLOG_G_INFO, "Dom%u PCI link %u changed %u -> %u\n",
            d->domain_id, link, old_isa_irq, isa_irq);
}

void hvm_set_callback_via(struct domain *d, uint64_t via)
{
    struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
    unsigned int gsi=0, pdev=0, pintx=0;
    uint8_t via_type;

    via_type = (uint8_t)(via >> 56) + 1;
    if ( ((via_type == HVMIRQ_callback_gsi) && (via == 0)) ||
         (via_type > HVMIRQ_callback_pci_intx) )
        via_type = HVMIRQ_callback_none;

    spin_lock(&d->arch.hvm_domain.irq_lock);

    /* Tear down old callback via. */
    if ( hvm_irq->callback_via_asserted )
    {
        switch ( hvm_irq->callback_via_type )
        {
        case HVMIRQ_callback_gsi:
            gsi = hvm_irq->callback_via.gsi;
            if ( (--hvm_irq->gsi_assert_count[gsi] == 0) && (gsi <= 15) )
                vpic_irq_negative_edge(d, gsi);
            break;
        case HVMIRQ_callback_pci_intx:
            pdev  = hvm_irq->callback_via.pci.dev;
            pintx = hvm_irq->callback_via.pci.intx;
            __hvm_pci_intx_deassert(d, pdev, pintx);
            break;
        default:
            break;
        }
    }

    /* Set up new callback via. */
    switch ( hvm_irq->callback_via_type = via_type )