source: mainline/uspace/lib/virtio/virtio-pci.c@ d6f73b92

/*
 * Copyright (c) 2018 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @file VIRTIO support
 */

#include "virtio-pci.h"

#include <ddf/driver.h>
#include <ddf/log.h>
#include <pci_dev_iface.h>

static bool check_bar(virtio_dev_t *vdev, uint8_t bar)
{
        /* We must ignore the capability if bar is greater than 5 */
        if (bar >= PCI_BAR_COUNT)
                return false;

        /* This is not a mapped BAR */
        if (!vdev->bar[bar].mapped)
                return false;

        return true;
}

static void virtio_pci_common_cfg(virtio_dev_t *vdev, uint8_t bar,
    uint32_t offset, uint32_t length)
{
        if (vdev->common_cfg)
                return;

        if (!check_bar(vdev, bar))
                return;

        vdev->common_cfg = vdev->bar[bar].mapped_base + offset;

        ddf_msg(LVL_NOTE, "common_cfg=%p", vdev->common_cfg);
}

static void virtio_pci_notify_cfg(virtio_dev_t *vdev, uint8_t bar,
    uint32_t offset, uint32_t length, uint32_t multiplier)
{
        if (vdev->notify_base)
                return;

        if (!check_bar(vdev, bar))
                return;

        vdev->notify_base = vdev->bar[bar].mapped_base + offset;
        vdev->notify_off_multiplier = multiplier;

        ddf_msg(LVL_NOTE, "notify_base=%p, off_multiplier=%u",
            vdev->notify_base, vdev->notify_off_multiplier);
}

static void virtio_pci_isr_cfg(virtio_dev_t *vdev, uint8_t bar, uint32_t offset,
    uint32_t length)
{
        if (vdev->isr)
                return;

        if (!check_bar(vdev, bar))
                return;

        vdev->isr = vdev->bar[bar].mapped_base + offset;

        ddf_msg(LVL_NOTE, "isr=%p", vdev->isr);
}

static void virtio_pci_device_cfg(virtio_dev_t *vdev, uint8_t bar,
    uint32_t offset, uint32_t length)
{
        if (vdev->device_cfg)
                return;

        if (!check_bar(vdev, bar))
                return;

        vdev->device_cfg = vdev->bar[bar].mapped_base + offset;

        ddf_msg(LVL_NOTE, "device_cfg=%p", vdev->device_cfg);
}

static errno_t enable_resources(async_sess_t *pci_sess, virtio_dev_t *vdev)
{
        pio_window_t pio_window;
        errno_t rc = pio_window_get(pci_sess, &pio_window);
        if (rc != EOK)
                return rc;

        hw_resource_list_t hw_res;
        rc = hw_res_get_resource_list(pci_sess, &hw_res);
        if (rc != EOK)
                return rc;

        /*
         * Enable resources and reconstruct the mapping between BAR and resource
         * indices. We are going to need this later when the VIRTIO PCI
         * capabilities refer to specific BARs.
         *
         * XXX: The mapping should probably be provided by the PCI driver
         *      itself.
         */
        for (unsigned i = 0, j = 0; i < PCI_BAR_COUNT && j < hw_res.count;
            i++) {
                /* Detect and skip unused BARs */
                uint32_t bar;
                rc = pci_config_space_read_32(pci_sess,
                    PCI_BAR0 + i * sizeof(uint32_t), &bar);
                if (rc != EOK)
                        return rc;
                if (!bar)
                        continue;

                hw_resource_t *res = &hw_res.resources[j];
                rc = pio_enable_resource(&pio_window, res,
                    &vdev->bar[i].mapped_base, &vdev->bar[i].mapped_size);
                if (rc == EOK)
                        vdev->bar[i].mapped = true;
                j++;
        }

        return rc;
}

static errno_t disable_resources(virtio_dev_t *vdev)
{
        for (unsigned i = 0; i < PCI_BAR_COUNT; i++) {
                if (vdev->bar[i].mapped) {
                        errno_t rc = pio_disable(vdev->bar[i].mapped_base,
                            vdev->bar[i].mapped_size);
                        if (rc != EOK)
                                return rc;
                        vdev->bar[i].mapped = false;
                }
        }

        return EOK;
}

errno_t virtio_pci_dev_initialize(ddf_dev_t *dev, virtio_dev_t *vdev)
{
        memset(vdev, 0, sizeof(virtio_dev_t));

        async_sess_t *pci_sess = ddf_dev_parent_sess_get(dev);
        if (!pci_sess)
                return ENOENT;

        errno_t rc = enable_resources(pci_sess, vdev);
        if (rc != EOK)
                goto error;

        /*
         * Find the VIRTIO PCI Capabilities
         */
        uint8_t c;
        uint8_t id;
        for (rc = pci_config_space_cap_first(pci_sess, &c, &id);
            (rc == EOK) && c;
            rc = pci_config_space_cap_next(pci_sess, &c, &id)) {
                if (id != PCI_CAP_VENDORSPECID)
                        continue;

                uint8_t type;
                rc = pci_config_space_read_8(pci_sess, VIRTIO_PCI_CAP_TYPE(c),
                    &type);
                if (rc != EOK)
                        goto error;

                uint8_t bar;
                rc = pci_config_space_read_8(pci_sess, VIRTIO_PCI_CAP_BAR(c),
                    &bar);
                if (rc != EOK)
                        goto error;

                uint32_t offset;
                rc = pci_config_space_read_32(pci_sess,
                    VIRTIO_PCI_CAP_OFFSET(c), &offset);
                if (rc != EOK)
                        goto error;

                uint32_t length;
                rc = pci_config_space_read_32(pci_sess,
                    VIRTIO_PCI_CAP_LENGTH(c), &length);
                if (rc != EOK)
                        goto error;

                uint32_t multiplier;
                switch (type) {
                case VIRTIO_PCI_CAP_COMMON_CFG:
                        virtio_pci_common_cfg(vdev, bar, offset, length);
                        break;
                case VIRTIO_PCI_CAP_NOTIFY_CFG:
                        rc = pci_config_space_read_32(pci_sess,
                            VIRTIO_PCI_CAP_END(c), &multiplier);
                        if (rc != EOK)
                                goto error;
                        virtio_pci_notify_cfg(vdev, bar, offset, length,
                            multiplier);
                        break;
                case VIRTIO_PCI_CAP_ISR_CFG:
                        virtio_pci_isr_cfg(vdev, bar, offset, length);
                        break;
                case VIRTIO_PCI_CAP_DEVICE_CFG:
                        virtio_pci_device_cfg(vdev, bar, offset, length);
                        break;
                case VIRTIO_PCI_CAP_PCI_CFG:
                        break;
                default:
                        break;
                }
        }

        return rc;

error:
        (void) disable_resources(vdev);
        return rc;
}

/** @}
 */