--- /dev/null
- err = mhi_prepare_for_transfer(mhi_dev, 0);
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* MHI Network driver - Network over MHI bus
+ *
+ * Copyright (C) 2020 Linaro Ltd <loic.poulain@linaro.org>
+ */
+
+#include <linux/if_arp.h>
+#include <linux/mhi.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
+#define MHI_NET_DEFAULT_MTU 0x4000
+
+struct mhi_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_net_dev {
+ struct mhi_device *mdev;
+ struct net_device *ndev;
+ struct sk_buff *skbagg_head;
+ struct sk_buff *skbagg_tail;
+ struct delayed_work rx_refill;
+ struct mhi_net_stats stats;
+ u32 rx_queue_sz;
+ int msg_enable;
+ unsigned int mru;
+};
+
+struct mhi_device_info {
+ const char *netname;
+};
+
+static int mhi_ndo_open(struct net_device *ndev)
+{
+ struct mhi_net_dev *mhi_netdev = netdev_priv(ndev);
+
+ /* Feed the rx buffer pool */
+ schedule_delayed_work(&mhi_netdev->rx_refill, 0);
+
+ /* 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)
+{
+ struct mhi_net_dev *mhi_netdev = netdev_priv(ndev);
+
+ netif_stop_queue(ndev);
+ netif_carrier_off(ndev);
+ cancel_delayed_work_sync(&mhi_netdev->rx_refill);
+
+ return 0;
+}
+
+static netdev_tx_t mhi_ndo_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+ struct mhi_net_dev *mhi_netdev = netdev_priv(ndev);
+ struct mhi_device *mdev = mhi_netdev->mdev;
+ int err;
+
+ err = mhi_queue_skb(mdev, DMA_TO_DEVICE, skb, skb->len, MHI_EOT);
+ if (unlikely(err)) {
+ net_err_ratelimited("%s: Failed to queue TX buf (%d)\n",
+ ndev->name, err);
+ dev_kfree_skb_any(skb);
+ goto exit_drop;
+ }
+
+ if (mhi_queue_is_full(mdev, DMA_TO_DEVICE))
+ netif_stop_queue(ndev);
+
+ return NETDEV_TX_OK;
+
+exit_drop:
+ u64_stats_update_begin(&mhi_netdev->stats.tx_syncp);
+ u64_stats_inc(&mhi_netdev->stats.tx_dropped);
+ u64_stats_update_end(&mhi_netdev->stats.tx_syncp);
+
+ return NETDEV_TX_OK;
+}
+
+static void mhi_ndo_get_stats64(struct net_device *ndev,
+ struct rtnl_link_stats64 *stats)
+{
+ struct mhi_net_dev *mhi_netdev = netdev_priv(ndev);
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin_irq(&mhi_netdev->stats.rx_syncp);
+ stats->rx_packets = u64_stats_read(&mhi_netdev->stats.rx_packets);
+ stats->rx_bytes = u64_stats_read(&mhi_netdev->stats.rx_bytes);
+ stats->rx_errors = u64_stats_read(&mhi_netdev->stats.rx_errors);
+ } while (u64_stats_fetch_retry_irq(&mhi_netdev->stats.rx_syncp, start));
+
+ do {
+ start = u64_stats_fetch_begin_irq(&mhi_netdev->stats.tx_syncp);
+ stats->tx_packets = u64_stats_read(&mhi_netdev->stats.tx_packets);
+ stats->tx_bytes = u64_stats_read(&mhi_netdev->stats.tx_bytes);
+ stats->tx_errors = u64_stats_read(&mhi_netdev->stats.tx_errors);
+ stats->tx_dropped = u64_stats_read(&mhi_netdev->stats.tx_dropped);
+ } while (u64_stats_fetch_retry_irq(&mhi_netdev->stats.tx_syncp, start));
+}
+
+static const struct net_device_ops mhi_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_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_netdev_ops;
+ ndev->mtu = MHI_NET_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_net_skb_agg(struct mhi_net_dev *mhi_netdev,
+ struct sk_buff *skb)
+{
+ struct sk_buff *head = mhi_netdev->skbagg_head;
+ struct sk_buff *tail = mhi_netdev->skbagg_tail;
+
+ /* This is non-paged skb chaining using frag_list */
+ if (!head) {
+ mhi_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_netdev->skbagg_tail = skb;
+
+ return mhi_netdev->skbagg_head;
+}
+
+static void mhi_net_dl_callback(struct mhi_device *mhi_dev,
+ struct mhi_result *mhi_res)
+{
+ struct mhi_net_dev *mhi_netdev = dev_get_drvdata(&mhi_dev->dev);
+ struct sk_buff *skb = mhi_res->buf_addr;
+ int free_desc_count;
+
+ free_desc_count = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
+
+ 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_netdev->ndev,
+ "Fragmented packets received, fix MTU?\n");
+ skb_put(skb, mhi_res->bytes_xferd);
+ mhi_net_skb_agg(mhi_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_netdev->stats.rx_syncp);
+ u64_stats_inc(&mhi_netdev->stats.rx_errors);
+ u64_stats_update_end(&mhi_netdev->stats.rx_syncp);
+ }
+ } else {
+ skb_put(skb, mhi_res->bytes_xferd);
+
+ if (mhi_netdev->skbagg_head) {
+ /* Aggregate the final fragment */
+ skb = mhi_net_skb_agg(mhi_netdev, skb);
+ mhi_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_netdev->stats.rx_syncp);
+ u64_stats_inc(&mhi_netdev->stats.rx_packets);
+ u64_stats_add(&mhi_netdev->stats.rx_bytes, skb->len);
+ u64_stats_update_end(&mhi_netdev->stats.rx_syncp);
+ netif_rx(skb);
+ }
+
+ /* Refill if RX buffers queue becomes low */
+ if (free_desc_count >= mhi_netdev->rx_queue_sz / 2)
+ schedule_delayed_work(&mhi_netdev->rx_refill, 0);
+}
+
+static void mhi_net_ul_callback(struct mhi_device *mhi_dev,
+ struct mhi_result *mhi_res)
+{
+ struct mhi_net_dev *mhi_netdev = dev_get_drvdata(&mhi_dev->dev);
+ struct net_device *ndev = mhi_netdev->ndev;
+ struct mhi_device *mdev = mhi_netdev->mdev;
+ struct sk_buff *skb = mhi_res->buf_addr;
+
+ /* Hardware has consumed the buffer, so free the skb (which is not
+ * freed by the MHI stack) and perform accounting.
+ */
+ dev_consume_skb_any(skb);
+
+ u64_stats_update_begin(&mhi_netdev->stats.tx_syncp);
+ if (unlikely(mhi_res->transaction_status)) {
+ /* MHI layer stopping/resetting the UL channel */
+ if (mhi_res->transaction_status == -ENOTCONN) {
+ u64_stats_update_end(&mhi_netdev->stats.tx_syncp);
+ return;
+ }
+
+ u64_stats_inc(&mhi_netdev->stats.tx_errors);
+ } else {
+ u64_stats_inc(&mhi_netdev->stats.tx_packets);
+ u64_stats_add(&mhi_netdev->stats.tx_bytes, mhi_res->bytes_xferd);
+ }
+ u64_stats_update_end(&mhi_netdev->stats.tx_syncp);
+
+ if (netif_queue_stopped(ndev) && !mhi_queue_is_full(mdev, DMA_TO_DEVICE))
+ netif_wake_queue(ndev);
+}
+
+static void mhi_net_rx_refill_work(struct work_struct *work)
+{
+ struct mhi_net_dev *mhi_netdev = container_of(work, struct mhi_net_dev,
+ rx_refill.work);
+ struct net_device *ndev = mhi_netdev->ndev;
+ struct mhi_device *mdev = mhi_netdev->mdev;
+ struct sk_buff *skb;
+ unsigned int size;
+ int err;
+
+ size = mhi_netdev->mru ? mhi_netdev->mru : READ_ONCE(ndev->mtu);
+
+ while (!mhi_queue_is_full(mdev, DMA_FROM_DEVICE)) {
+ skb = netdev_alloc_skb(ndev, size);
+ if (unlikely(!skb))
+ break;
+
+ err = mhi_queue_skb(mdev, DMA_FROM_DEVICE, skb, size, MHI_EOT);
+ if (unlikely(err)) {
+ net_err_ratelimited("%s: Failed to queue RX buf (%d)\n",
+ ndev->name, err);
+ kfree_skb(skb);
+ break;
+ }
+
+ /* Do not hog the CPU if rx buffers are consumed faster than
+ * queued (unlikely).
+ */
+ cond_resched();
+ }
+
+ /* If we're still starved of rx buffers, reschedule later */
+ if (mhi_get_free_desc_count(mdev, DMA_FROM_DEVICE) == mhi_netdev->rx_queue_sz)
+ schedule_delayed_work(&mhi_netdev->rx_refill, HZ / 2);
+}
+
+static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev)
+{
+ struct mhi_net_dev *mhi_netdev;
+ int err;
+
+ mhi_netdev = netdev_priv(ndev);
+
+ dev_set_drvdata(&mhi_dev->dev, mhi_netdev);
+ mhi_netdev->ndev = ndev;
+ mhi_netdev->mdev = mhi_dev;
+ mhi_netdev->skbagg_head = NULL;
+ mhi_netdev->mru = mhi_dev->mhi_cntrl->mru;
+
+ INIT_DELAYED_WORK(&mhi_netdev->rx_refill, mhi_net_rx_refill_work);
+ u64_stats_init(&mhi_netdev->stats.rx_syncp);
+ u64_stats_init(&mhi_netdev->stats.tx_syncp);
+
+ /* Start MHI channels */
++ err = mhi_prepare_for_transfer(mhi_dev);
+ if (err)
+ goto out_err;
+
+ /* Number of transfer descriptors determines size of the queue */
+ mhi_netdev->rx_queue_sz = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
+
+ err = register_netdev(ndev);
+ if (err)
+ return err;
+
+ return 0;
+
+out_err:
+ free_netdev(ndev);
+ return err;
+}
+
+static void mhi_net_dellink(struct mhi_device *mhi_dev, struct net_device *ndev)
+{
+ struct mhi_net_dev *mhi_netdev = netdev_priv(ndev);
+
+ unregister_netdev(ndev);
+
+ mhi_unprepare_from_transfer(mhi_dev);
+
+ kfree_skb(mhi_netdev->skbagg_head);
+
+ dev_set_drvdata(&mhi_dev->dev, NULL);
+}
+
+static int mhi_net_probe(struct mhi_device *mhi_dev,
+ const struct mhi_device_id *id)
+{
+ const struct mhi_device_info *info = (struct mhi_device_info *)id->driver_data;
+ struct net_device *ndev;
+ int err;
+
+ ndev = alloc_netdev(sizeof(struct mhi_net_dev), info->netname,
+ NET_NAME_PREDICTABLE, mhi_net_setup);
+ if (!ndev)
+ return -ENOMEM;
+
+ SET_NETDEV_DEV(ndev, &mhi_dev->dev);
+
+ err = mhi_net_newlink(mhi_dev, ndev);
+ if (err) {
+ free_netdev(ndev);
+ return err;
+ }
+
+ return 0;
+}
+
+static void mhi_net_remove(struct mhi_device *mhi_dev)
+{
+ struct mhi_net_dev *mhi_netdev = dev_get_drvdata(&mhi_dev->dev);
+
+ mhi_net_dellink(mhi_dev, mhi_netdev->ndev);
+}
+
+static const struct mhi_device_info mhi_hwip0 = {
+ .netname = "mhi_hwip%d",
+};
+
+static const struct mhi_device_info mhi_swip0 = {
+ .netname = "mhi_swip%d",
+};
+
+static const struct mhi_device_id mhi_net_id_table[] = {
+ /* Hardware accelerated data PATH (to modem IPA), protocol agnostic */
+ { .chan = "IP_HW0", .driver_data = (kernel_ulong_t)&mhi_hwip0 },
+ /* Software data PATH (to modem CPU) */
+ { .chan = "IP_SW0", .driver_data = (kernel_ulong_t)&mhi_swip0 },
+ {}
+};
+MODULE_DEVICE_TABLE(mhi, mhi_net_id_table);
+
+static struct mhi_driver mhi_net_driver = {
+ .probe = mhi_net_probe,
+ .remove = mhi_net_remove,
+ .dl_xfer_cb = mhi_net_dl_callback,
+ .ul_xfer_cb = mhi_net_ul_callback,
+ .id_table = mhi_net_id_table,
+ .driver = {
+ .name = "mhi_net",
+ .owner = THIS_MODULE,
+ },
+};
+
+module_mhi_driver(mhi_net_driver);
+
+MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
+MODULE_DESCRIPTION("Network over MHI");
+MODULE_LICENSE("GPL v2");
--- /dev/null
- err = mhi_prepare_for_transfer(mhi_dev, 0);
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* MHI MBIM Network driver - Network/MBIM over MHI bus
+ *
+ * Copyright (C) 2021 Linaro Ltd <loic.poulain@linaro.org>
+ *
+ * This driver copy some code from cdc_ncm, which is:
+ * Copyright (C) ST-Ericsson 2010-2012
+ * and cdc_mbim, which is:
+ * Copyright (c) 2012 Smith Micro Software, Inc.
+ * Copyright (c) 2012 Bjørn Mork <bjorn@mork.no>
+ *
+ */
+
+#include <linux/ethtool.h>
+#include <linux/if_arp.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/mhi.h>
+#include <linux/mii.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/u64_stats_sync.h>
+#include <linux/usb.h>
+#include <linux/usb/cdc.h>
+#include <linux/usb/usbnet.h>
+#include <linux/usb/cdc_ncm.h>
+#include <linux/wwan.h>
+
+/* 3500 allows to optimize skb allocation, the skbs will basically fit in
+ * one 4K page. Large MBIM packets will simply be split over several MHI
+ * transfers and chained by the MHI net layer (zerocopy).
+ */
+#define MHI_DEFAULT_MRU 3500
+
+#define MHI_MBIM_DEFAULT_MTU 1500
+#define MHI_MAX_BUF_SZ 0xffff
+
+#define MBIM_NDP16_SIGN_MASK 0x00ffffff
+
+#define MHI_MBIM_LINK_HASH_SIZE 8
+#define LINK_HASH(session) ((session) % MHI_MBIM_LINK_HASH_SIZE)
+
+struct mhi_mbim_link {
+ struct mhi_mbim_context *mbim;
+ struct net_device *ndev;
+ unsigned int session;
+
+ /* 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 hlist_node hlnode;
+};
+
+struct mhi_mbim_context {
+ struct mhi_device *mdev;
+ struct sk_buff *skbagg_head;
+ struct sk_buff *skbagg_tail;
+ unsigned int mru;
+ u32 rx_queue_sz;
+ u16 rx_seq;
+ u16 tx_seq;
+ struct delayed_work rx_refill;
+ spinlock_t tx_lock;
+ struct hlist_head link_list[MHI_MBIM_LINK_HASH_SIZE];
+};
+
+struct mbim_tx_hdr {
+ struct usb_cdc_ncm_nth16 nth16;
+ struct usb_cdc_ncm_ndp16 ndp16;
+ struct usb_cdc_ncm_dpe16 dpe16[2];
+} __packed;
+
+static struct mhi_mbim_link *mhi_mbim_get_link_rcu(struct mhi_mbim_context *mbim,
+ unsigned int session)
+{
+ struct mhi_mbim_link *link;
+
+ hlist_for_each_entry_rcu(link, &mbim->link_list[LINK_HASH(session)], hlnode) {
+ if (link->session == session)
+ return link;
+ }
+
+ return NULL;
+}
+
+static struct sk_buff *mbim_tx_fixup(struct sk_buff *skb, unsigned int session,
+ u16 tx_seq)
+{
+ unsigned int dgram_size = skb->len;
+ struct usb_cdc_ncm_nth16 *nth16;
+ struct usb_cdc_ncm_ndp16 *ndp16;
+ struct mbim_tx_hdr *mbim_hdr;
+
+ /* Only one NDP is sent, containing the IP packet (no aggregation) */
+
+ /* Ensure we have enough headroom for crafting MBIM header */
+ if (skb_cow_head(skb, sizeof(struct mbim_tx_hdr))) {
+ dev_kfree_skb_any(skb);
+ return NULL;
+ }
+
+ mbim_hdr = skb_push(skb, sizeof(struct mbim_tx_hdr));
+
+ /* Fill NTB header */
+ nth16 = &mbim_hdr->nth16;
+ nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
+ nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
+ nth16->wSequence = cpu_to_le16(tx_seq);
+ nth16->wBlockLength = cpu_to_le16(skb->len);
+ nth16->wNdpIndex = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
+
+ /* Fill the unique NDP */
+ ndp16 = &mbim_hdr->ndp16;
+ ndp16->dwSignature = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN | (session << 24));
+ ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16)
+ + sizeof(struct usb_cdc_ncm_dpe16) * 2);
+ ndp16->wNextNdpIndex = 0;
+
+ /* Datagram follows the mbim header */
+ ndp16->dpe16[0].wDatagramIndex = cpu_to_le16(sizeof(struct mbim_tx_hdr));
+ ndp16->dpe16[0].wDatagramLength = cpu_to_le16(dgram_size);
+
+ /* null termination */
+ ndp16->dpe16[1].wDatagramIndex = 0;
+ ndp16->dpe16[1].wDatagramLength = 0;
+
+ return skb;
+}
+
+static netdev_tx_t mhi_mbim_ndo_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+ struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
+ struct mhi_mbim_context *mbim = link->mbim;
+ unsigned long flags;
+ int err = -ENOMEM;
+
+ /* Serialize MHI channel queuing and MBIM seq */
+ spin_lock_irqsave(&mbim->tx_lock, flags);
+
+ skb = mbim_tx_fixup(skb, link->session, mbim->tx_seq);
+ if (unlikely(!skb))
+ goto exit_unlock;
+
+ err = mhi_queue_skb(mbim->mdev, DMA_TO_DEVICE, skb, skb->len, MHI_EOT);
+
+ if (mhi_queue_is_full(mbim->mdev, DMA_TO_DEVICE))
+ netif_stop_queue(ndev);
+
+ if (!err)
+ mbim->tx_seq++;
+
+exit_unlock:
+ spin_unlock_irqrestore(&mbim->tx_lock, flags);
+
+ if (unlikely(err)) {
+ net_err_ratelimited("%s: Failed to queue TX buf (%d)\n",
+ ndev->name, err);
+ dev_kfree_skb_any(skb);
+ goto exit_drop;
+ }
+
+ return NETDEV_TX_OK;
+
+exit_drop:
+ u64_stats_update_begin(&link->tx_syncp);
+ u64_stats_inc(&link->tx_dropped);
+ u64_stats_update_end(&link->tx_syncp);
+
+ return NETDEV_TX_OK;
+}
+
+static int mbim_rx_verify_nth16(struct mhi_mbim_context *mbim, struct sk_buff *skb)
+{
+ struct usb_cdc_ncm_nth16 *nth16;
+ int len;
+
+ if (skb->len < sizeof(struct usb_cdc_ncm_nth16) +
+ sizeof(struct usb_cdc_ncm_ndp16)) {
+ net_err_ratelimited("frame too short\n");
+ return -EINVAL;
+ }
+
+ nth16 = (struct usb_cdc_ncm_nth16 *)skb->data;
+
+ if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
+ net_err_ratelimited("invalid NTH16 signature <%#010x>\n",
+ le32_to_cpu(nth16->dwSignature));
+ return -EINVAL;
+ }
+
+ /* No limit on the block length, except the size of the data pkt */
+ len = le16_to_cpu(nth16->wBlockLength);
+ if (len > skb->len) {
+ net_err_ratelimited("NTB does not fit into the skb %u/%u\n",
+ len, skb->len);
+ return -EINVAL;
+ }
+
+ if (mbim->rx_seq + 1 != le16_to_cpu(nth16->wSequence) &&
+ (mbim->rx_seq || le16_to_cpu(nth16->wSequence)) &&
+ !(mbim->rx_seq == 0xffff && !le16_to_cpu(nth16->wSequence))) {
+ net_err_ratelimited("sequence number glitch prev=%d curr=%d\n",
+ mbim->rx_seq, le16_to_cpu(nth16->wSequence));
+ }
+ mbim->rx_seq = le16_to_cpu(nth16->wSequence);
+
+ return le16_to_cpu(nth16->wNdpIndex);
+}
+
+static int mbim_rx_verify_ndp16(struct sk_buff *skb, struct usb_cdc_ncm_ndp16 *ndp16)
+{
+ int ret;
+
+ if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
+ net_err_ratelimited("invalid DPT16 length <%u>\n",
+ le16_to_cpu(ndp16->wLength));
+ return -EINVAL;
+ }
+
+ ret = ((le16_to_cpu(ndp16->wLength) - sizeof(struct usb_cdc_ncm_ndp16))
+ / sizeof(struct usb_cdc_ncm_dpe16));
+ ret--; /* Last entry is always a NULL terminator */
+
+ if (sizeof(struct usb_cdc_ncm_ndp16) +
+ ret * sizeof(struct usb_cdc_ncm_dpe16) > skb->len) {
+ net_err_ratelimited("Invalid nframes = %d\n", ret);
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static void mhi_mbim_rx(struct mhi_mbim_context *mbim, struct sk_buff *skb)
+{
+ int ndpoffset;
+
+ /* Check NTB header and retrieve first NDP offset */
+ ndpoffset = mbim_rx_verify_nth16(mbim, skb);
+ if (ndpoffset < 0) {
+ net_err_ratelimited("mbim: Incorrect NTB header\n");
+ goto error;
+ }
+
+ /* Process each NDP */
+ while (1) {
+ struct usb_cdc_ncm_ndp16 ndp16;
+ struct usb_cdc_ncm_dpe16 dpe16;
+ struct mhi_mbim_link *link;
+ int nframes, n, dpeoffset;
+ unsigned int session;
+
+ if (skb_copy_bits(skb, ndpoffset, &ndp16, sizeof(ndp16))) {
+ net_err_ratelimited("mbim: Incorrect NDP offset (%u)\n",
+ ndpoffset);
+ goto error;
+ }
+
+ /* Check NDP header and retrieve number of datagrams */
+ nframes = mbim_rx_verify_ndp16(skb, &ndp16);
+ if (nframes < 0) {
+ net_err_ratelimited("mbim: Incorrect NDP16\n");
+ goto error;
+ }
+
+ /* Only IP data type supported, no DSS in MHI context */
+ if ((ndp16.dwSignature & cpu_to_le32(MBIM_NDP16_SIGN_MASK))
+ != cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN)) {
+ net_err_ratelimited("mbim: Unsupported NDP type\n");
+ goto next_ndp;
+ }
+
+ session = (le32_to_cpu(ndp16.dwSignature) & ~MBIM_NDP16_SIGN_MASK) >> 24;
+
+ rcu_read_lock();
+
+ link = mhi_mbim_get_link_rcu(mbim, session);
+ if (!link) {
+ net_err_ratelimited("mbim: bad packet session (%u)\n", session);
+ goto unlock;
+ }
+
+ /* de-aggregate and deliver IP packets */
+ dpeoffset = ndpoffset + sizeof(struct usb_cdc_ncm_ndp16);
+ for (n = 0; n < nframes; n++, dpeoffset += sizeof(dpe16)) {
+ u16 dgram_offset, dgram_len;
+ struct sk_buff *skbn;
+
+ if (skb_copy_bits(skb, dpeoffset, &dpe16, sizeof(dpe16)))
+ break;
+
+ dgram_offset = le16_to_cpu(dpe16.wDatagramIndex);
+ dgram_len = le16_to_cpu(dpe16.wDatagramLength);
+
+ if (!dgram_offset || !dgram_len)
+ break; /* null terminator */
+
+ skbn = netdev_alloc_skb(link->ndev, dgram_len);
+ if (!skbn)
+ continue;
+
+ skb_put(skbn, dgram_len);
+ skb_copy_bits(skb, dgram_offset, skbn->data, dgram_len);
+
+ switch (skbn->data[0] & 0xf0) {
+ case 0x40:
+ skbn->protocol = htons(ETH_P_IP);
+ break;
+ case 0x60:
+ skbn->protocol = htons(ETH_P_IPV6);
+ break;
+ default:
+ net_err_ratelimited("%s: unknown protocol\n",
+ link->ndev->name);
+ dev_kfree_skb_any(skbn);
+ u64_stats_update_begin(&link->rx_syncp);
+ u64_stats_inc(&link->rx_errors);
+ u64_stats_update_end(&link->rx_syncp);
+ continue;
+ }
+
+ u64_stats_update_begin(&link->rx_syncp);
+ u64_stats_inc(&link->rx_packets);
+ u64_stats_add(&link->rx_bytes, skbn->len);
+ u64_stats_update_end(&link->rx_syncp);
+
+ netif_rx(skbn);
+ }
+unlock:
+ rcu_read_unlock();
+next_ndp:
+ /* Other NDP to process? */
+ ndpoffset = (int)le16_to_cpu(ndp16.wNextNdpIndex);
+ if (!ndpoffset)
+ break;
+ }
+
+ /* free skb */
+ dev_consume_skb_any(skb);
+ return;
+error:
+ dev_kfree_skb_any(skb);
+}
+
+static struct sk_buff *mhi_net_skb_agg(struct mhi_mbim_context *mbim,
+ struct sk_buff *skb)
+{
+ struct sk_buff *head = mbim->skbagg_head;
+ struct sk_buff *tail = mbim->skbagg_tail;
+
+ /* This is non-paged skb chaining using frag_list */
+ if (!head) {
+ mbim->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;
+
+ mbim->skbagg_tail = skb;
+
+ return mbim->skbagg_head;
+}
+
+static void mhi_net_rx_refill_work(struct work_struct *work)
+{
+ struct mhi_mbim_context *mbim = container_of(work, struct mhi_mbim_context,
+ rx_refill.work);
+ struct mhi_device *mdev = mbim->mdev;
+ int err;
+
+ while (!mhi_queue_is_full(mdev, DMA_FROM_DEVICE)) {
+ struct sk_buff *skb = alloc_skb(MHI_DEFAULT_MRU, GFP_KERNEL);
+
+ if (unlikely(!skb))
+ break;
+
+ err = mhi_queue_skb(mdev, DMA_FROM_DEVICE, skb,
+ MHI_DEFAULT_MRU, MHI_EOT);
+ if (unlikely(err)) {
+ kfree_skb(skb);
+ break;
+ }
+
+ /* Do not hog the CPU if rx buffers are consumed faster than
+ * queued (unlikely).
+ */
+ cond_resched();
+ }
+
+ /* If we're still starved of rx buffers, reschedule later */
+ if (mhi_get_free_desc_count(mdev, DMA_FROM_DEVICE) == mbim->rx_queue_sz)
+ schedule_delayed_work(&mbim->rx_refill, HZ / 2);
+}
+
+static void mhi_mbim_dl_callback(struct mhi_device *mhi_dev,
+ struct mhi_result *mhi_res)
+{
+ struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev);
+ struct sk_buff *skb = mhi_res->buf_addr;
+ int free_desc_count;
+
+ free_desc_count = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
+
+ if (unlikely(mhi_res->transaction_status)) {
+ switch (mhi_res->transaction_status) {
+ case -EOVERFLOW:
+ /* Packet has been split over multiple transfers */
+ skb_put(skb, mhi_res->bytes_xferd);
+ mhi_net_skb_agg(mbim, 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);
+ }
+ } else {
+ skb_put(skb, mhi_res->bytes_xferd);
+
+ if (mbim->skbagg_head) {
+ /* Aggregate the final fragment */
+ skb = mhi_net_skb_agg(mbim, skb);
+ mbim->skbagg_head = NULL;
+ }
+
+ mhi_mbim_rx(mbim, skb);
+ }
+
+ /* Refill if RX buffers queue becomes low */
+ if (free_desc_count >= mbim->rx_queue_sz / 2)
+ schedule_delayed_work(&mbim->rx_refill, 0);
+}
+
+static void mhi_mbim_ndo_get_stats64(struct net_device *ndev,
+ struct rtnl_link_stats64 *stats)
+{
+ struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin_irq(&link->rx_syncp);
+ stats->rx_packets = u64_stats_read(&link->rx_packets);
+ stats->rx_bytes = u64_stats_read(&link->rx_bytes);
+ stats->rx_errors = u64_stats_read(&link->rx_errors);
+ } while (u64_stats_fetch_retry_irq(&link->rx_syncp, start));
+
+ do {
+ start = u64_stats_fetch_begin_irq(&link->tx_syncp);
+ stats->tx_packets = u64_stats_read(&link->tx_packets);
+ stats->tx_bytes = u64_stats_read(&link->tx_bytes);
+ stats->tx_errors = u64_stats_read(&link->tx_errors);
+ stats->tx_dropped = u64_stats_read(&link->tx_dropped);
+ } while (u64_stats_fetch_retry_irq(&link->tx_syncp, start));
+}
+
+static void mhi_mbim_ul_callback(struct mhi_device *mhi_dev,
+ struct mhi_result *mhi_res)
+{
+ struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev);
+ struct sk_buff *skb = mhi_res->buf_addr;
+ struct net_device *ndev = skb->dev;
+ struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
+
+ /* Hardware has consumed the buffer, so free the skb (which is not
+ * freed by the MHI stack) and perform accounting.
+ */
+ dev_consume_skb_any(skb);
+
+ u64_stats_update_begin(&link->tx_syncp);
+ if (unlikely(mhi_res->transaction_status)) {
+ /* MHI layer stopping/resetting the UL channel */
+ if (mhi_res->transaction_status == -ENOTCONN) {
+ u64_stats_update_end(&link->tx_syncp);
+ return;
+ }
+
+ u64_stats_inc(&link->tx_errors);
+ } else {
+ u64_stats_inc(&link->tx_packets);
+ u64_stats_add(&link->tx_bytes, mhi_res->bytes_xferd);
+ }
+ u64_stats_update_end(&link->tx_syncp);
+
+ if (netif_queue_stopped(ndev) && !mhi_queue_is_full(mbim->mdev, DMA_TO_DEVICE))
+ netif_wake_queue(ndev);
+}
+
+static int mhi_mbim_ndo_open(struct net_device *ndev)
+{
+ struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
+
+ /* Feed the MHI rx buffer pool */
+ schedule_delayed_work(&link->mbim->rx_refill, 0);
+
+ /* Carrier is established via out-of-band channel (e.g. qmi) */
+ netif_carrier_on(ndev);
+
+ netif_start_queue(ndev);
+
+ return 0;
+}
+
+static int mhi_mbim_ndo_stop(struct net_device *ndev)
+{
+ netif_stop_queue(ndev);
+ netif_carrier_off(ndev);
+
+ return 0;
+}
+
+static const struct net_device_ops mhi_mbim_ndo = {
+ .ndo_open = mhi_mbim_ndo_open,
+ .ndo_stop = mhi_mbim_ndo_stop,
+ .ndo_start_xmit = mhi_mbim_ndo_xmit,
+ .ndo_get_stats64 = mhi_mbim_ndo_get_stats64,
+};
+
+static int mhi_mbim_newlink(void *ctxt, struct net_device *ndev, u32 if_id,
+ struct netlink_ext_ack *extack)
+{
+ struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
+ struct mhi_mbim_context *mbim = ctxt;
+
+ link->session = if_id;
+ link->mbim = mbim;
+ link->ndev = ndev;
+ u64_stats_init(&link->rx_syncp);
+ u64_stats_init(&link->tx_syncp);
+
+ rcu_read_lock();
+ if (mhi_mbim_get_link_rcu(mbim, if_id)) {
+ rcu_read_unlock();
+ return -EEXIST;
+ }
+ rcu_read_unlock();
+
+ /* Already protected by RTNL lock */
+ hlist_add_head_rcu(&link->hlnode, &mbim->link_list[LINK_HASH(if_id)]);
+
+ return register_netdevice(ndev);
+}
+
+static void mhi_mbim_dellink(void *ctxt, struct net_device *ndev,
+ struct list_head *head)
+{
+ struct mhi_mbim_link *link = wwan_netdev_drvpriv(ndev);
+
+ hlist_del_init_rcu(&link->hlnode);
+ synchronize_rcu();
+
+ unregister_netdevice_queue(ndev, head);
+}
+
+static void mhi_mbim_setup(struct net_device *ndev)
+{
+ ndev->header_ops = NULL; /* No header */
+ ndev->type = ARPHRD_RAWIP;
+ ndev->needed_headroom = sizeof(struct mbim_tx_hdr);
+ ndev->hard_header_len = 0;
+ ndev->addr_len = 0;
+ ndev->flags = IFF_POINTOPOINT | IFF_NOARP;
+ ndev->netdev_ops = &mhi_mbim_ndo;
+ ndev->mtu = MHI_MBIM_DEFAULT_MTU;
+ ndev->min_mtu = ETH_MIN_MTU;
+ ndev->max_mtu = MHI_MAX_BUF_SZ - ndev->needed_headroom;
+ ndev->tx_queue_len = 1000;
+}
+
+static const struct wwan_ops mhi_mbim_wwan_ops = {
+ .priv_size = sizeof(struct mhi_mbim_link),
+ .setup = mhi_mbim_setup,
+ .newlink = mhi_mbim_newlink,
+ .dellink = mhi_mbim_dellink,
+};
+
+static int mhi_mbim_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id)
+{
+ struct mhi_controller *cntrl = mhi_dev->mhi_cntrl;
+ struct mhi_mbim_context *mbim;
+ int err;
+
+ mbim = devm_kzalloc(&mhi_dev->dev, sizeof(*mbim), GFP_KERNEL);
+ if (!mbim)
+ return -ENOMEM;
+
+ spin_lock_init(&mbim->tx_lock);
+ dev_set_drvdata(&mhi_dev->dev, mbim);
+ mbim->mdev = mhi_dev;
+ mbim->mru = mhi_dev->mhi_cntrl->mru ? mhi_dev->mhi_cntrl->mru : MHI_DEFAULT_MRU;
+
+ INIT_DELAYED_WORK(&mbim->rx_refill, mhi_net_rx_refill_work);
+
+ /* Start MHI channels */
++ err = mhi_prepare_for_transfer(mhi_dev);
+ if (err)
+ return err;
+
+ /* Number of transfer descriptors determines size of the queue */
+ mbim->rx_queue_sz = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
+
+ /* Register wwan link ops with MHI controller representing WWAN instance */
+ return wwan_register_ops(&cntrl->mhi_dev->dev, &mhi_mbim_wwan_ops, mbim, 0);
+}
+
+static void mhi_mbim_remove(struct mhi_device *mhi_dev)
+{
+ struct mhi_mbim_context *mbim = dev_get_drvdata(&mhi_dev->dev);
+ struct mhi_controller *cntrl = mhi_dev->mhi_cntrl;
+
+ mhi_unprepare_from_transfer(mhi_dev);
+ cancel_delayed_work_sync(&mbim->rx_refill);
+ wwan_unregister_ops(&cntrl->mhi_dev->dev);
+ kfree_skb(mbim->skbagg_head);
+ dev_set_drvdata(&mhi_dev->dev, NULL);
+}
+
+static const struct mhi_device_id mhi_mbim_id_table[] = {
+ /* Hardware accelerated data PATH (to modem IPA), MBIM protocol */
+ { .chan = "IP_HW0_MBIM", .driver_data = 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(mhi, mhi_mbim_id_table);
+
+static struct mhi_driver mhi_mbim_driver = {
+ .probe = mhi_mbim_probe,
+ .remove = mhi_mbim_remove,
+ .dl_xfer_cb = mhi_mbim_dl_callback,
+ .ul_xfer_cb = mhi_mbim_ul_callback,
+ .id_table = mhi_mbim_id_table,
+ .driver = {
+ .name = "mhi_wwan_mbim",
+ .owner = THIS_MODULE,
+ },
+};
+
+module_mhi_driver(mhi_mbim_driver);
+
+MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
+MODULE_DESCRIPTION("Network/MBIM over MHI");
+MODULE_LICENSE("GPL v2");
projects / kernel.git / commitdiff