/*

 * 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, see <http://www.gnu.org/licenses/>.

 */

#include <xen/sched.h>

#include <xen/pci.h>

#include <xen/pci_regs.h>

#include "../ats.h"

bool_t __read_mostly ats_enabled = 0;

boolean_param("ats", ats_enabled);

int enable_ats_device(struct pci_dev *pdev, struct list_head *ats_list)

{

    u32 value;

    u16 seg = pdev->seg;

    u8 bus = pdev->bus, devfn = pdev->devfn;

    int pos;

    pos = pci_find_ext_capability(seg, bus, devfn, PCI_EXT_CAP_ID_ATS);

    BUG_ON(!pos);

    if ( iommu_verbose )

        dprintk(XENLOG_INFO, "%04x:%02x:%02x.%u: ATS capability found\n",

                seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));

    value = pci_conf_read16(seg, bus, PCI_SLOT(devfn),

                            PCI_FUNC(devfn), pos + ATS_REG_CTL);

    if ( value & ATS_ENABLE )

    {

        struct pci_dev *other;

        list_for_each_entry ( other, ats_list, ats.list )

            if ( other == pdev )

            {

                pos = 0;

                break;

            }

    }

    if ( !(value & ATS_ENABLE) )

    {

        value |= ATS_ENABLE;

        pci_conf_write16(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),

                         pos + ATS_REG_CTL, value);

    }

    if ( pos )

    {

        pdev->ats.cap_pos = pos;

        value = pci_conf_read16(seg, bus, PCI_SLOT(devfn),

                                PCI_FUNC(devfn), pos + ATS_REG_CAP);

        pdev->ats.queue_depth = value & ATS_QUEUE_DEPTH_MASK ?:

                                ATS_QUEUE_DEPTH_MASK + 1;

        list_add(&pdev->ats.list, ats_list);

    }

    if ( iommu_verbose )

        dprintk(XENLOG_INFO, "%04x:%02x:%02x.%u: ATS %s enabled\n",

                seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),

                pos ? "is" : "was");

    return pos;

}

void disable_ats_device(struct pci_dev *pdev)

{

    u32 value;

    u16 seg = pdev->seg;

    u8 bus = pdev->bus, devfn = pdev->devfn;

    BUG_ON(!pdev->ats.cap_pos);

    value = pci_conf_read16(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),

                            pdev->ats.cap_pos + ATS_REG_CTL);

    value &= ~ATS_ENABLE;

    pci_conf_write16(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),

                     pdev->ats.cap_pos + ATS_REG_CTL, value);

    list_del(&pdev->ats.list);

    if ( iommu_verbose )

        dprintk(XENLOG_INFO, "%04x:%02x:%02x.%u: ATS is disabled\n",

                seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));

}