diff options
Diffstat (limited to 'drivers/virtio/virtio_net.c')
| -rw-r--r-- | drivers/virtio/virtio_net.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_net.c b/drivers/virtio/virtio_net.c new file mode 100644 index 0000000000..0dbbd78023 --- /dev/null +++ b/drivers/virtio/virtio_net.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> + * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com> + */ + +#include <common.h> +#include <dm.h> +#include <net.h> +#include <virtio_types.h> +#include <virtio.h> +#include <virtio_ring.h> +#include "virtio_net.h" + +/* Amount of buffers to keep in the RX virtqueue */ +#define VIRTIO_NET_NUM_RX_BUFS 32 + +/* + * This value comes from the VirtIO spec: 1500 for maximum packet size, + * 14 for the Ethernet header, 12 for virtio_net_hdr. In total 1526 bytes. + */ +#define VIRTIO_NET_RX_BUF_SIZE 1526 + +struct virtio_net_priv { + union { + struct virtqueue *vqs[2]; + struct { + struct virtqueue *rx_vq; + struct virtqueue *tx_vq; + }; + }; + + char rx_buff[VIRTIO_NET_NUM_RX_BUFS][VIRTIO_NET_RX_BUF_SIZE]; + bool rx_running; + int net_hdr_len; +}; + +/* + * For simplicity, the driver only negotiates the VIRTIO_NET_F_MAC feature. + * For the VIRTIO_NET_F_STATUS feature, we don't negotiate it, hence per spec + * we should assume the link is always active. + */ +static const u32 feature[] = { + VIRTIO_NET_F_MAC +}; + +static const u32 feature_legacy[] = { + VIRTIO_NET_F_MAC +}; + +static int virtio_net_start(struct udevice *dev) +{ + struct virtio_net_priv *priv = dev_get_priv(dev); + struct virtio_sg sg; + struct virtio_sg *sgs[] = { &sg }; + int i; + + if (!priv->rx_running) { + /* receive buffer length is always 1526 */ + sg.length = VIRTIO_NET_RX_BUF_SIZE; + + /* setup the receive buffer address */ + for (i = 0; i < VIRTIO_NET_NUM_RX_BUFS; i++) { + sg.addr = priv->rx_buff[i]; + virtqueue_add(priv->rx_vq, sgs, 0, 1); + } + + virtqueue_kick(priv->rx_vq); + + /* setup the receive queue only once */ + priv->rx_running = true; + } + + return 0; +} + +static int virtio_net_send(struct udevice *dev, void *packet, int length) +{ + struct virtio_net_priv *priv = dev_get_priv(dev); + struct virtio_net_hdr hdr; + struct virtio_net_hdr_v1 hdr_v1; + struct virtio_sg hdr_sg; + struct virtio_sg data_sg = { packet, length }; + struct virtio_sg *sgs[] = { &hdr_sg, &data_sg }; + int ret; + + if (priv->net_hdr_len == sizeof(struct virtio_net_hdr)) + hdr_sg.addr = &hdr; + else + hdr_sg.addr = &hdr_v1; + hdr_sg.length = priv->net_hdr_len; + + memset(hdr_sg.addr, 0, priv->net_hdr_len); + + ret = virtqueue_add(priv->tx_vq, sgs, 2, 0); + if (ret) + return ret; + + virtqueue_kick(priv->tx_vq); + + while (1) { + if (virtqueue_get_buf(priv->tx_vq, NULL)) + break; + } + + return 0; +} + +static int virtio_net_recv(struct udevice *dev, int flags, uchar **packetp) +{ + struct virtio_net_priv *priv = dev_get_priv(dev); + unsigned int len; + void *buf; + + buf = virtqueue_get_buf(priv->rx_vq, &len); + if (!buf) + return -EAGAIN; + + *packetp = buf + priv->net_hdr_len; + return len - priv->net_hdr_len; +} + +static int virtio_net_free_pkt(struct udevice *dev, uchar *packet, int length) +{ + struct virtio_net_priv *priv = dev_get_priv(dev); + void *buf = packet - priv->net_hdr_len; + struct virtio_sg sg = { buf, VIRTIO_NET_RX_BUF_SIZE }; + struct virtio_sg *sgs[] = { &sg }; + + /* Put the buffer back to the rx ring */ + virtqueue_add(priv->rx_vq, sgs, 0, 1); + + return 0; +} + +static void virtio_net_stop(struct udevice *dev) +{ + /* + * There is no way to stop the queue from running, unless we issue + * a reset to the virtio device, and re-do the queue initialization + * from the beginning. + */ +} + +static int virtio_net_write_hwaddr(struct udevice *dev) +{ + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent); + struct eth_pdata *pdata = dev_get_platdata(dev); + int i; + + /* + * v1.0 compliant device's MAC address is set through control channel, + * which we don't support for now. + */ + if (!uc_priv->legacy) + return -ENOSYS; + + for (i = 0; i < sizeof(pdata->enetaddr); i++) { + virtio_cwrite8(dev, + offsetof(struct virtio_net_config, mac) + i, + pdata->enetaddr[i]); + } + + return 0; +} + +static int virtio_net_read_rom_hwaddr(struct udevice *dev) +{ + struct eth_pdata *pdata = dev_get_platdata(dev); + + if (!pdata) + return -ENOSYS; + + if (virtio_has_feature(dev, VIRTIO_NET_F_MAC)) { + virtio_cread_bytes(dev, + offsetof(struct virtio_net_config, mac), + pdata->enetaddr, sizeof(pdata->enetaddr)); + } + + return 0; +} + +static int virtio_net_bind(struct udevice *dev) +{ + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent); + + /* Indicate what driver features we support */ + virtio_driver_features_init(uc_priv, feature, ARRAY_SIZE(feature), + feature_legacy, ARRAY_SIZE(feature_legacy)); + + return 0; +} + +static int virtio_net_probe(struct udevice *dev) +{ + struct virtio_net_priv *priv = dev_get_priv(dev); + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent); + int ret; + + ret = virtio_find_vqs(dev, 2, priv->vqs); + if (ret < 0) + return ret; + + /* + * For v1.0 compliant device, it always assumes the member + * 'num_buffers' exists in the struct virtio_net_hdr while + * the legacy driver only presented 'num_buffers' when + * VIRTIO_NET_F_MRG_RXBUF was negotiated. Without that feature + * the structure was 2 bytes shorter. + */ + if (uc_priv->legacy) + priv->net_hdr_len = sizeof(struct virtio_net_hdr); + else + priv->net_hdr_len = sizeof(struct virtio_net_hdr_v1); + + return 0; +} + +static const struct eth_ops virtio_net_ops = { + .start = virtio_net_start, + .send = virtio_net_send, + .recv = virtio_net_recv, + .free_pkt = virtio_net_free_pkt, + .stop = virtio_net_stop, + .write_hwaddr = virtio_net_write_hwaddr, + .read_rom_hwaddr = virtio_net_read_rom_hwaddr, +}; + +U_BOOT_DRIVER(virtio_net) = { + .name = VIRTIO_NET_DRV_NAME, + .id = UCLASS_ETH, + .bind = virtio_net_bind, + .probe = virtio_net_probe, + .remove = virtio_reset, + .ops = &virtio_net_ops, + .priv_auto_alloc_size = sizeof(struct virtio_net_priv), + .platdata_auto_alloc_size = sizeof(struct eth_pdata), + .flags = DM_FLAG_ACTIVE_DMA, +}; |