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- /*
- * (c) Copyright 2010 Stefan Hajnoczi <stefanha@gmail.com>
- *
- * based on the Etherboot virtio-net driver
- *
- * (c) Copyright 2008 Bull S.A.S.
- *
- * Author: Laurent Vivier <Laurent.Vivier@bull.net>
- *
- * some parts from Linux Virtio PCI driver
- *
- * Copyright IBM Corp. 2007
- * Authors: Anthony Liguori <aliguori@us.ibm.com>
- *
- * some parts from Linux Virtio Ring
- *
- * Copyright Rusty Russell IBM Corporation 2007
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- */
-
- FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
- #include <errno.h>
- #include <stdlib.h>
- #include <ipxe/list.h>
- #include <ipxe/iobuf.h>
- #include <ipxe/netdevice.h>
- #include <ipxe/pci.h>
- #include <ipxe/if_ether.h>
- #include <ipxe/ethernet.h>
- #include <ipxe/virtio-ring.h>
- #include <ipxe/virtio-pci.h>
- #include "virtio-net.h"
-
- /*
- * Virtio network device driver
- *
- * Specification:
- * http://ozlabs.org/~rusty/virtio-spec/
- *
- * The virtio network device is supported by Linux virtualization software
- * including QEMU/KVM and lguest. This driver supports the virtio over PCI
- * transport; virtual machines have one virtio-net PCI adapter per NIC.
- *
- * Virtio-net is different from hardware NICs because virtio devices
- * communicate with the hypervisor via virtqueues, not traditional descriptor
- * rings. Virtqueues are unordered queues, they support add_buf() and
- * get_buf() operations. To transmit a packet, the driver has to add the
- * packet buffer onto the virtqueue. To receive a packet, the driver must
- * first add an empty buffer to the virtqueue and then get the filled packet
- * buffer on completion.
- *
- * Virtqueues are an abstraction that is commonly implemented using the vring
- * descriptor ring layout. The vring is the actual shared memory structure
- * that allows the virtual machine to communicate buffers with the hypervisor.
- * Because the vring layout is optimized for flexibility and performance rather
- * than space, it is heavy-weight and allocated like traditional descriptor
- * rings in the open() function of the driver and not in probe().
- *
- * There is no true interrupt enable/disable. Virtqueues have callback
- * enable/disable flags but these are only hints. The hypervisor may still
- * raise an interrupt. Nevertheless, this driver disables callbacks in the
- * hopes of avoiding interrupts.
- */
-
- /* Driver types are declared here so virtio-net.h can be easily synced with its
- * Linux source.
- */
-
- /* Virtqueue indices */
- enum {
- RX_INDEX = 0,
- TX_INDEX,
- QUEUE_NB
- };
-
- enum {
- /** Max number of pending rx packets */
- NUM_RX_BUF = 8,
-
- /** Max Ethernet frame length, including FCS and VLAN tag */
- RX_BUF_SIZE = 1522,
- };
-
- struct virtnet_nic {
- /** Base pio register address */
- unsigned long ioaddr;
-
- /** RX/TX virtqueues */
- struct vring_virtqueue *virtqueue;
-
- /** RX packets handed to the NIC waiting to be filled in */
- struct list_head rx_iobufs;
-
- /** Pending rx packet count */
- unsigned int rx_num_iobufs;
-
- /** Virtio net packet header, we only need one */
- struct virtio_net_hdr empty_header;
- };
-
- /** Add an iobuf to a virtqueue
- *
- * @v netdev Network device
- * @v vq_idx Virtqueue index (RX_INDEX or TX_INDEX)
- * @v iobuf I/O buffer
- *
- * The virtqueue is kicked after the iobuf has been added.
- */
- static void virtnet_enqueue_iob ( struct net_device *netdev,
- int vq_idx, struct io_buffer *iobuf ) {
- struct virtnet_nic *virtnet = netdev->priv;
- struct vring_virtqueue *vq = &virtnet->virtqueue[vq_idx];
- unsigned int out = ( vq_idx == TX_INDEX ) ? 2 : 0;
- unsigned int in = ( vq_idx == TX_INDEX ) ? 0 : 2;
- struct vring_list list[] = {
- {
- /* Share a single zeroed virtio net header between all
- * rx and tx packets. This works because this driver
- * does not use any advanced features so none of the
- * header fields get used.
- */
- .addr = ( char* ) &virtnet->empty_header,
- .length = sizeof ( virtnet->empty_header ),
- },
- {
- .addr = ( char* ) iobuf->data,
- .length = iob_len ( iobuf ),
- },
- };
-
- DBGC ( virtnet, "VIRTIO-NET %p enqueuing iobuf %p on vq %d\n",
- virtnet, iobuf, vq_idx );
-
- vring_add_buf ( vq, list, out, in, iobuf, 0 );
- vring_kick ( virtnet->ioaddr, vq, 1 );
- }
-
- /** Try to keep rx virtqueue filled with iobufs
- *
- * @v netdev Network device
- */
- static void virtnet_refill_rx_virtqueue ( struct net_device *netdev ) {
- struct virtnet_nic *virtnet = netdev->priv;
-
- while ( virtnet->rx_num_iobufs < NUM_RX_BUF ) {
- struct io_buffer *iobuf;
-
- /* Try to allocate a buffer, stop for now if out of memory */
- iobuf = alloc_iob ( RX_BUF_SIZE );
- if ( ! iobuf )
- break;
-
- /* Keep track of iobuf so close() can free it */
- list_add ( &iobuf->list, &virtnet->rx_iobufs );
-
- /* Mark packet length until we know the actual size */
- iob_put ( iobuf, RX_BUF_SIZE );
-
- virtnet_enqueue_iob ( netdev, RX_INDEX, iobuf );
- virtnet->rx_num_iobufs++;
- }
- }
-
- /** Open network device
- *
- * @v netdev Network device
- * @ret rc Return status code
- */
- static int virtnet_open ( struct net_device *netdev ) {
- struct virtnet_nic *virtnet = netdev->priv;
- unsigned long ioaddr = virtnet->ioaddr;
- u32 features;
- int i;
-
- /* Reset for sanity */
- vp_reset ( ioaddr );
-
- /* Allocate virtqueues */
- virtnet->virtqueue = zalloc ( QUEUE_NB *
- sizeof ( *virtnet->virtqueue ) );
- if ( ! virtnet->virtqueue )
- return -ENOMEM;
-
- /* Initialize rx/tx virtqueues */
- for ( i = 0; i < QUEUE_NB; i++ ) {
- if ( vp_find_vq ( ioaddr, i, &virtnet->virtqueue[i] ) == -1 ) {
- DBGC ( virtnet, "VIRTIO-NET %p cannot register queue %d\n",
- virtnet, i );
- free ( virtnet->virtqueue );
- virtnet->virtqueue = NULL;
- return -ENOENT;
- }
- }
-
- /* Initialize rx packets */
- INIT_LIST_HEAD ( &virtnet->rx_iobufs );
- virtnet->rx_num_iobufs = 0;
- virtnet_refill_rx_virtqueue ( netdev );
-
- /* Disable interrupts before starting */
- netdev_irq ( netdev, 0 );
-
- /* Driver is ready */
- features = vp_get_features ( ioaddr );
- vp_set_features ( ioaddr, features & ( 1 << VIRTIO_NET_F_MAC ) );
- vp_set_status ( ioaddr, VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK );
- return 0;
- }
-
- /** Close network device
- *
- * @v netdev Network device
- */
- static void virtnet_close ( struct net_device *netdev ) {
- struct virtnet_nic *virtnet = netdev->priv;
- struct io_buffer *iobuf;
- struct io_buffer *next_iobuf;
-
- vp_reset ( virtnet->ioaddr );
-
- /* Virtqueues can be freed now that NIC is reset */
- free ( virtnet->virtqueue );
- virtnet->virtqueue = NULL;
-
- /* Free rx iobufs */
- list_for_each_entry_safe ( iobuf, next_iobuf, &virtnet->rx_iobufs, list ) {
- free_iob ( iobuf );
- }
- INIT_LIST_HEAD ( &virtnet->rx_iobufs );
- virtnet->rx_num_iobufs = 0;
- }
-
- /** Transmit packet
- *
- * @v netdev Network device
- * @v iobuf I/O buffer
- * @ret rc Return status code
- */
- static int virtnet_transmit ( struct net_device *netdev,
- struct io_buffer *iobuf ) {
- virtnet_enqueue_iob ( netdev, TX_INDEX, iobuf );
- return 0;
- }
-
- /** Complete packet transmission
- *
- * @v netdev Network device
- */
- static void virtnet_process_tx_packets ( struct net_device *netdev ) {
- struct virtnet_nic *virtnet = netdev->priv;
- struct vring_virtqueue *tx_vq = &virtnet->virtqueue[TX_INDEX];
-
- while ( vring_more_used ( tx_vq ) ) {
- struct io_buffer *iobuf = vring_get_buf ( tx_vq, NULL );
-
- DBGC ( virtnet, "VIRTIO-NET %p tx complete iobuf %p\n",
- virtnet, iobuf );
-
- netdev_tx_complete ( netdev, iobuf );
- }
- }
-
- /** Complete packet reception
- *
- * @v netdev Network device
- */
- static void virtnet_process_rx_packets ( struct net_device *netdev ) {
- struct virtnet_nic *virtnet = netdev->priv;
- struct vring_virtqueue *rx_vq = &virtnet->virtqueue[RX_INDEX];
-
- while ( vring_more_used ( rx_vq ) ) {
- unsigned int len;
- struct io_buffer *iobuf = vring_get_buf ( rx_vq, &len );
-
- /* Release ownership of iobuf */
- list_del ( &iobuf->list );
- virtnet->rx_num_iobufs--;
-
- /* Update iobuf length */
- iob_unput ( iobuf, RX_BUF_SIZE );
- iob_put ( iobuf, len - sizeof ( struct virtio_net_hdr ) );
-
- DBGC ( virtnet, "VIRTIO-NET %p rx complete iobuf %p len %zd\n",
- virtnet, iobuf, iob_len ( iobuf ) );
-
- /* Pass completed packet to the network stack */
- netdev_rx ( netdev, iobuf );
- }
-
- virtnet_refill_rx_virtqueue ( netdev );
- }
-
- /** Poll for completed and received packets
- *
- * @v netdev Network device
- */
- static void virtnet_poll ( struct net_device *netdev ) {
- struct virtnet_nic *virtnet = netdev->priv;
-
- /* Acknowledge interrupt. This is necessary for UNDI operation and
- * interrupts that are raised despite VRING_AVAIL_F_NO_INTERRUPT being
- * set (that flag is just a hint and the hypervisor not not have to
- * honor it).
- */
- vp_get_isr ( virtnet->ioaddr );
-
- virtnet_process_tx_packets ( netdev );
- virtnet_process_rx_packets ( netdev );
- }
-
- /** Enable or disable interrupts
- *
- * @v netdev Network device
- * @v enable Interrupts should be enabled
- */
- static void virtnet_irq ( struct net_device *netdev, int enable ) {
- struct virtnet_nic *virtnet = netdev->priv;
- int i;
-
- for ( i = 0; i < QUEUE_NB; i++ ) {
- if ( enable )
- vring_enable_cb ( &virtnet->virtqueue[i] );
- else
- vring_disable_cb ( &virtnet->virtqueue[i] );
- }
- }
-
- /** virtio-net device operations */
- static struct net_device_operations virtnet_operations = {
- .open = virtnet_open,
- .close = virtnet_close,
- .transmit = virtnet_transmit,
- .poll = virtnet_poll,
- .irq = virtnet_irq,
- };
-
- /**
- * Probe PCI device
- *
- * @v pci PCI device
- * @v id PCI ID
- * @ret rc Return status code
- */
- static int virtnet_probe ( struct pci_device *pci ) {
- unsigned long ioaddr = pci->ioaddr;
- struct net_device *netdev;
- struct virtnet_nic *virtnet;
- u32 features;
- int rc;
-
- /* Allocate and hook up net device */
- netdev = alloc_etherdev ( sizeof ( *virtnet ) );
- if ( ! netdev )
- return -ENOMEM;
- netdev_init ( netdev, &virtnet_operations );
- virtnet = netdev->priv;
- virtnet->ioaddr = ioaddr;
- pci_set_drvdata ( pci, netdev );
- netdev->dev = &pci->dev;
-
- DBGC ( virtnet, "VIRTIO-NET %p busaddr=%s ioaddr=%#lx irq=%d\n",
- virtnet, pci->dev.name, ioaddr, pci->irq );
-
- /* Enable PCI bus master and reset NIC */
- adjust_pci_device ( pci );
- vp_reset ( ioaddr );
-
- /* Load MAC address */
- features = vp_get_features ( ioaddr );
- if ( features & ( 1 << VIRTIO_NET_F_MAC ) ) {
- vp_get ( ioaddr, offsetof ( struct virtio_net_config, mac ),
- netdev->hw_addr, ETH_ALEN );
- DBGC ( virtnet, "VIRTIO-NET %p mac=%s\n", virtnet,
- eth_ntoa ( netdev->hw_addr ) );
- }
-
- /* Register network device */
- if ( ( rc = register_netdev ( netdev ) ) != 0 )
- goto err_register_netdev;
-
- /* Mark link as up, control virtqueue is not used */
- netdev_link_up ( netdev );
-
- return 0;
-
- unregister_netdev ( netdev );
- err_register_netdev:
- vp_reset ( ioaddr );
- netdev_nullify ( netdev );
- netdev_put ( netdev );
- return rc;
- }
-
- /**
- * Remove device
- *
- * @v pci PCI device
- */
- static void virtnet_remove ( struct pci_device *pci ) {
- struct net_device *netdev = pci_get_drvdata ( pci );
-
- unregister_netdev ( netdev );
- netdev_nullify ( netdev );
- netdev_put ( netdev );
- }
-
- static struct pci_device_id virtnet_nics[] = {
- PCI_ROM(0x1af4, 0x1000, "virtio-net", "Virtio Network Interface", 0),
- };
-
- struct pci_driver virtnet_driver __pci_driver = {
- .ids = virtnet_nics,
- .id_count = ( sizeof ( virtnet_nics ) / sizeof ( virtnet_nics[0] ) ),
- .probe = virtnet_probe,
- .remove = virtnet_remove,
- };
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