// SPDX-License-Identifier: GPL-2.0+ /* * Copyright (C) 2018, Tuomas Tynkkynen * Copyright (C) 2018, Bin Meng */ #include #include #include #include #include #include #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_plat(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_plat(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 = sizeof(struct virtio_net_priv), .plat_auto = sizeof(struct eth_pdata), .flags = DM_FLAG_ACTIVE_DMA, };