Function virtio_queue_init

components/drivers/virtio/virtio.c:90–149

}

rt_err_t virtio_queue_init(struct virtio_device *dev, rt_uint32_t queue_index, rt_size_t ring_size)
{
    int i;
    void *pages;
    rt_size_t pages_total_size;
    struct virtq *queue;

    _virtio_dev_check(dev);

    RT_ASSERT(dev->mmio_config->queue_num_max > 0);
    RT_ASSERT(dev->mmio_config->queue_num_max > queue_index);
    /* ring_size is power of 2 */
    RT_ASSERT(ring_size > 0);
    RT_ASSERT(((ring_size - 1) & ring_size) == 0);

    queue = &dev->queues[queue_index];
    pages_total_size = VIRTIO_PAGE_ALIGN(
            VIRTQ_DESC_TOTAL_SIZE(ring_size) + VIRTQ_AVAIL_TOTAL_SIZE(ring_size)) + VIRTQ_USED_TOTAL_SIZE(ring_size);

    pages = rt_malloc_align(pages_total_size, VIRTIO_PAGE_SIZE);

    if (pages == RT_NULL)
    {
        return -RT_ENOMEM;
    }

    queue->free = rt_malloc(sizeof(rt_bool_t) * ring_size);

    if (queue->free == RT_NULL)
    {
        rt_free_align(pages);
        return -RT_ENOMEM;
    }

    rt_memset(pages, 0, pages_total_size);

    dev->mmio_config->guest_page_size = VIRTIO_PAGE_SIZE;
    dev->mmio_config->queue_sel = queue_index;
    dev->mmio_config->queue_num = ring_size;
    dev->mmio_config->queue_align = VIRTIO_PAGE_SIZE;
    dev->mmio_config->queue_pfn = VIRTIO_VA2PA(pages) >> VIRTIO_PAGE_SHIFT;

    queue->num = ring_size;
    queue->desc = (struct virtq_desc *)((rt_ubase_t)pages);
    queue->avail = (struct virtq_avail *)(((rt_ubase_t)pages) + VIRTQ_DESC_TOTAL_SIZE(ring_size));
    queue->used = (struct virtq_used *)VIRTIO_PAGE_ALIGN(
            (rt_ubase_t)&queue->avail->ring[ring_size] + VIRTQ_AVAIL_RES_SIZE);

    queue->used_idx = 0;

    /* All descriptors start out unused */
    for (i = 0; i < ring_size; ++i)
    {
        queue->free[i] = RT_TRUE;
    }

    queue->free_count = ring_size;