u-boot/drivers/virtio/virtio_net.c

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// 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,
};