diff options
| -rw-r--r-- | drivers/net/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/net/Makefile | 1 | ||||
| -rw-r--r-- | drivers/net/mhi_ep_net.c | 375 |
3 files changed, 385 insertions, 0 deletions
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 10506a4b66ef..8c3e48f2670a 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -453,6 +453,15 @@ config MHI_NET QCOM based WWAN modems for IP or QMAP/rmnet protocol (like SDX55). Say Y or M. +config MHI_EP_NET + tristate "MHI Endpoint network driver" + depends on MHI_BUS_EP + help + This is the network driver for MHI bus implementation in endpoint + devices. It is used provide the network interface for QCOM modems + such as SDX55. + Say Y or M. + endif # NET_CORE config SUNGEM_PHY diff --git a/drivers/net/Makefile b/drivers/net/Makefile index 50b23e71065f..ebe54c30651a 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -39,6 +39,7 @@ obj-$(CONFIG_NLMON) += nlmon.o obj-$(CONFIG_NET_VRF) += vrf.o obj-$(CONFIG_VSOCKMON) += vsockmon.o obj-$(CONFIG_MHI_NET) += mhi_net.o +obj-$(CONFIG_MHI_EP_NET) += mhi_ep_net.o # # Networking Drivers diff --git a/drivers/net/mhi_ep_net.c b/drivers/net/mhi_ep_net.c new file mode 100644 index 000000000000..7b3a23852457 --- /dev/null +++ b/drivers/net/mhi_ep_net.c @@ -0,0 +1,375 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * MHI Endpoint Network driver + * + * Based on drivers/net/mhi_net.c + * + * Copyright (c) 2021, Linaro Ltd. + * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> + */ + +#include <linux/if_arp.h> +#include <linux/mhi_ep.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/u64_stats_sync.h> + +#define MHI_NET_MIN_MTU ETH_MIN_MTU +#define MHI_NET_MAX_MTU 0xffff + +struct mhi_ep_net_stats { + u64_stats_t rx_packets; + u64_stats_t rx_bytes; + u64_stats_t rx_errors; + u64_stats_t tx_packets; + u64_stats_t tx_bytes; + u64_stats_t tx_errors; + u64_stats_t tx_dropped; + struct u64_stats_sync tx_syncp; + struct u64_stats_sync rx_syncp; +}; + +struct mhi_ep_net_dev { + struct mhi_ep_device *mdev; + struct net_device *ndev; + struct sk_buff *skbagg_head; + struct sk_buff *skbagg_tail; + struct mhi_ep_net_stats stats; + struct workqueue_struct *xmit_wq; + struct work_struct xmit_work; + struct sk_buff_head tx_buffers; + spinlock_t tx_lock; /* Lock for protecting tx_buffers */ +}; + +struct mhi_ep_device_info { + const char *netname; +}; + +static void mhi_ep_net_dev_process_queue_packets(struct work_struct *work) +{ + struct mhi_ep_net_dev *client = container_of(work, + struct mhi_ep_net_dev, xmit_work); + struct mhi_ep_device *mdev = client->mdev; + struct sk_buff *skb = NULL; + unsigned long flags = 0; + int ret; + + if (mhi_ep_queue_is_empty(mdev, DMA_FROM_DEVICE)) { + netif_stop_queue(client->ndev); + return; + } + + while (!skb_queue_empty(&client->tx_buffers)) { + spin_lock_irqsave(&client->tx_lock, flags); + skb = skb_dequeue(&client->tx_buffers); + if (!skb) { + spin_unlock_irqrestore(&client->tx_lock, flags); + return; + } + spin_unlock_irqrestore(&client->tx_lock, flags); + + ret = mhi_ep_queue_skb(mdev, DMA_FROM_DEVICE, skb, skb->len, MHI_EOT); + if (ret) { + kfree(skb); + return; + } + + u64_stats_update_begin(&client->stats.tx_syncp); + u64_stats_inc(&client->stats.tx_packets); + u64_stats_update_end(&client->stats.tx_syncp); + + /* Check if queue is empty */ + if (mhi_ep_queue_is_empty(mdev, DMA_FROM_DEVICE)) { + netif_stop_queue(client->ndev); + break; + } + + consume_skb(skb); + } +} + +static int mhi_ndo_open(struct net_device *ndev) +{ + /* Carrier is established via out-of-band channel (e.g. qmi) */ + netif_carrier_on(ndev); + + netif_start_queue(ndev); + + return 0; +} + +static int mhi_ndo_stop(struct net_device *ndev) +{ + netif_stop_queue(ndev); + netif_carrier_off(ndev); + + return 0; +} + +static netdev_tx_t mhi_ndo_xmit(struct sk_buff *skb, struct net_device *ndev) +{ + struct mhi_ep_net_dev *mhi_ep_netdev = netdev_priv(ndev); + unsigned long flags; + + spin_lock_irqsave(&mhi_ep_netdev->tx_lock, flags); + skb_queue_tail(&mhi_ep_netdev->tx_buffers, skb); + spin_unlock_irqrestore(&mhi_ep_netdev->tx_lock, flags); + + queue_work(mhi_ep_netdev->xmit_wq, &mhi_ep_netdev->xmit_work); + + return NETDEV_TX_OK; +} + +static void mhi_ndo_get_stats64(struct net_device *ndev, + struct rtnl_link_stats64 *stats) +{ + struct mhi_ep_net_dev *mhi_ep_netdev = netdev_priv(ndev); + unsigned int start; + + do { + start = u64_stats_fetch_begin_irq(&mhi_ep_netdev->stats.rx_syncp); + stats->rx_packets = u64_stats_read(&mhi_ep_netdev->stats.rx_packets); + stats->rx_bytes = u64_stats_read(&mhi_ep_netdev->stats.rx_bytes); + stats->rx_errors = u64_stats_read(&mhi_ep_netdev->stats.rx_errors); + } while (u64_stats_fetch_retry_irq(&mhi_ep_netdev->stats.rx_syncp, start)); + + do { + start = u64_stats_fetch_begin_irq(&mhi_ep_netdev->stats.tx_syncp); + stats->tx_packets = u64_stats_read(&mhi_ep_netdev->stats.tx_packets); + stats->tx_bytes = u64_stats_read(&mhi_ep_netdev->stats.tx_bytes); + stats->tx_errors = u64_stats_read(&mhi_ep_netdev->stats.tx_errors); + stats->tx_dropped = u64_stats_read(&mhi_ep_netdev->stats.tx_dropped); + } while (u64_stats_fetch_retry_irq(&mhi_ep_netdev->stats.tx_syncp, start)); +} + +static const struct net_device_ops mhi_ep_netdev_ops = { + .ndo_open = mhi_ndo_open, + .ndo_stop = mhi_ndo_stop, + .ndo_start_xmit = mhi_ndo_xmit, + .ndo_get_stats64 = mhi_ndo_get_stats64, +}; + +static void mhi_ep_net_setup(struct net_device *ndev) +{ + ndev->header_ops = NULL; /* No header */ + ndev->type = ARPHRD_RAWIP; + ndev->hard_header_len = 0; + ndev->addr_len = 0; + ndev->flags = IFF_POINTOPOINT | IFF_NOARP; + ndev->netdev_ops = &mhi_ep_netdev_ops; + ndev->mtu = MHI_EP_DEFAULT_MTU; + ndev->min_mtu = MHI_NET_MIN_MTU; + ndev->max_mtu = MHI_NET_MAX_MTU; + ndev->tx_queue_len = 1000; +} + +static struct sk_buff *mhi_ep_net_skb_agg(struct mhi_ep_net_dev *mhi_ep_netdev, + struct sk_buff *skb) +{ + struct sk_buff *head = mhi_ep_netdev->skbagg_head; + struct sk_buff *tail = mhi_ep_netdev->skbagg_tail; + + /* This is non-paged skb chaining using frag_list */ + if (!head) { + mhi_ep_netdev->skbagg_head = skb; + return skb; + } + + if (!skb_shinfo(head)->frag_list) + skb_shinfo(head)->frag_list = skb; + else + tail->next = skb; + + head->len += skb->len; + head->data_len += skb->len; + head->truesize += skb->truesize; + + mhi_ep_netdev->skbagg_tail = skb; + + return mhi_ep_netdev->skbagg_head; +} + +static void mhi_ep_net_ul_callback(struct mhi_ep_device *mhi_dev, + struct mhi_result *mhi_res) +{ + struct mhi_ep_net_dev *mhi_ep_netdev = dev_get_drvdata(&mhi_dev->dev); + struct net_device *ndev = mhi_ep_netdev->ndev; + struct sk_buff *skb; + + skb = netdev_alloc_skb(ndev, 8192); + if (!skb) { + u64_stats_update_begin(&mhi_ep_netdev->stats.rx_syncp); + u64_stats_inc(&mhi_ep_netdev->stats.rx_errors); + u64_stats_update_end(&mhi_ep_netdev->stats.rx_syncp); + } + + skb_copy_to_linear_data(skb, mhi_res->buf_addr, mhi_res->bytes_xferd); + skb->len = mhi_res->bytes_xferd; + skb->dev = mhi_ep_netdev->ndev; + + if (unlikely(mhi_res->transaction_status)) { + switch (mhi_res->transaction_status) { + case -EOVERFLOW: + /* Packet can not fit in one MHI buffer and has been + * split over multiple MHI transfers, do re-aggregation. + * That usually means the device side MTU is larger than + * the host side MTU/MRU. Since this is not optimal, + * print a warning (once). + */ + netdev_warn_once(mhi_ep_netdev->ndev, + "Fragmented packets received, fix MTU?\n"); + skb_put(skb, mhi_res->bytes_xferd); + mhi_ep_net_skb_agg(mhi_ep_netdev, skb); + break; + case -ENOTCONN: + /* MHI layer stopping/resetting the DL channel */ + dev_kfree_skb_any(skb); + return; + default: + /* Unknown error, simply drop */ + dev_kfree_skb_any(skb); + u64_stats_update_begin(&mhi_ep_netdev->stats.rx_syncp); + u64_stats_inc(&mhi_ep_netdev->stats.rx_errors); + u64_stats_update_end(&mhi_ep_netdev->stats.rx_syncp); + } + } else { + skb_put(skb, mhi_res->bytes_xferd); + + if (mhi_ep_netdev->skbagg_head) { + /* Aggregate the final fragment */ + skb = mhi_ep_net_skb_agg(mhi_ep_netdev, skb); + mhi_ep_netdev->skbagg_head = NULL; + } + + switch (skb->data[0] & 0xf0) { + case 0x40: + skb->protocol = htons(ETH_P_IP); + break; + case 0x60: + skb->protocol = htons(ETH_P_IPV6); + break; + default: + skb->protocol = htons(ETH_P_MAP); + break; + } + + u64_stats_update_begin(&mhi_ep_netdev->stats.rx_syncp); + u64_stats_inc(&mhi_ep_netdev->stats.rx_packets); + u64_stats_add(&mhi_ep_netdev->stats.rx_bytes, skb->len); + u64_stats_update_end(&mhi_ep_netdev->stats.rx_syncp); + netif_receive_skb(skb); + } +} + +static void mhi_ep_net_dl_callback(struct mhi_ep_device *mhi_dev, + struct mhi_result *mhi_res) +{ + struct mhi_ep_net_dev *mhi_ep_netdev = dev_get_drvdata(&mhi_dev->dev); + + if (unlikely(mhi_res->transaction_status == -ENOTCONN)) + return; + + /* Since we got enough buffers to queue, wake the queue if stopped */ + if (netif_queue_stopped(mhi_ep_netdev->ndev)) { + netif_wake_queue(mhi_ep_netdev->ndev); + queue_work(mhi_ep_netdev->xmit_wq, &mhi_ep_netdev->xmit_work); + } +} + +static int mhi_ep_net_newlink(struct mhi_ep_device *mhi_dev, struct net_device *ndev) +{ + struct mhi_ep_net_dev *mhi_ep_netdev; + int err; + + mhi_ep_netdev = netdev_priv(ndev); + + dev_set_drvdata(&mhi_dev->dev, mhi_ep_netdev); + mhi_ep_netdev->ndev = ndev; + mhi_ep_netdev->mdev = mhi_dev; + mhi_ep_netdev->skbagg_head = NULL; + + skb_queue_head_init(&mhi_ep_netdev->tx_buffers); + spin_lock_init(&mhi_ep_netdev->tx_lock); + + u64_stats_init(&mhi_ep_netdev->stats.rx_syncp); + u64_stats_init(&mhi_ep_netdev->stats.tx_syncp); + + mhi_ep_netdev->xmit_wq = create_singlethread_workqueue("mhi_ep_net_xmit_wq"); + INIT_WORK(&mhi_ep_netdev->xmit_work, mhi_ep_net_dev_process_queue_packets); + err = register_netdev(ndev); + if (err) + return err; + + return 0; +} + +static void mhi_ep_net_dellink(struct mhi_ep_device *mhi_dev, struct net_device *ndev) +{ + struct mhi_ep_net_dev *mhi_ep_netdev = netdev_priv(ndev); + + destroy_workqueue(mhi_ep_netdev->xmit_wq); + unregister_netdev(ndev); + free_netdev(ndev); + kfree_skb(mhi_ep_netdev->skbagg_head); + dev_set_drvdata(&mhi_dev->dev, NULL); +} + +static int mhi_ep_net_probe(struct mhi_ep_device *mhi_dev, const struct mhi_device_id *id) +{ + const struct mhi_ep_device_info *info = (struct mhi_ep_device_info *)id->driver_data; + struct net_device *ndev; + int err; + + ndev = alloc_netdev(sizeof(struct mhi_ep_net_dev), info->netname, + NET_NAME_PREDICTABLE, mhi_ep_net_setup); + if (!ndev) + return -ENOMEM; + + SET_NETDEV_DEV(ndev, &mhi_dev->dev); + + err = mhi_ep_net_newlink(mhi_dev, ndev); + if (err) { + free_netdev(ndev); + return err; + } + + return 0; +} + +static void mhi_ep_net_remove(struct mhi_ep_device *mhi_dev) +{ + struct mhi_ep_net_dev *mhi_ep_netdev = dev_get_drvdata(&mhi_dev->dev); + + mhi_ep_net_dellink(mhi_dev, mhi_ep_netdev->ndev); +} + +static const struct mhi_ep_device_info mhi_swip0 = { + .netname = "mhi_swip%d", +}; + +static const struct mhi_device_id mhi_ep_net_id_table[] = { + /* Software data PATH (from modem CPU) */ + { .chan = "IP_SW0", .driver_data = (kernel_ulong_t)&mhi_swip0 }, + {} +}; +MODULE_DEVICE_TABLE(mhi, mhi_ep_net_id_table); + +static struct mhi_ep_driver mhi_ep_net_driver = { + .probe = mhi_ep_net_probe, + .remove = mhi_ep_net_remove, + .dl_xfer_cb = mhi_ep_net_dl_callback, + .ul_xfer_cb = mhi_ep_net_ul_callback, + .id_table = mhi_ep_net_id_table, + .driver = { + .name = "mhi_ep_net", + .owner = THIS_MODULE, + }, +}; + +module_mhi_ep_driver(mhi_ep_net_driver); + +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>"); +MODULE_DESCRIPTION("MHI Endpoint Network driver"); +MODULE_LICENSE("GPL v2"); |