From ddeb9bfa59c711ccbddec1c9fb9ec190caab1a4c Mon Sep 17 00:00:00 2001 From: Loic Poulain Date: Tue, 9 Feb 2021 10:05:54 +0100 Subject: [PATCH 1/5] net: mhi: Add protocol support MHI can transport different protocols, some are handled at upper level, like IP and QMAP(rmnet/netlink), but others will need to be inside MHI net driver, like mbim. This change adds support for protocol rx and tx_fixup callbacks registration, that can be used to encode/decode the targeted protocol. Signed-off-by: Loic Poulain Signed-off-by: David S. Miller --- drivers/net/mhi_net.c | 69 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 57 insertions(+), 12 deletions(-) diff --git a/drivers/net/mhi_net.c b/drivers/net/mhi_net.c index 8800991937346..b92c2e1f107e1 100644 --- a/drivers/net/mhi_net.c +++ b/drivers/net/mhi_net.c @@ -34,11 +34,24 @@ struct mhi_net_dev { struct net_device *ndev; struct sk_buff *skbagg_head; struct sk_buff *skbagg_tail; + const struct mhi_net_proto *proto; + void *proto_data; struct delayed_work rx_refill; struct mhi_net_stats stats; u32 rx_queue_sz; }; +struct mhi_net_proto { + int (*init)(struct mhi_net_dev *mhi_netdev); + struct sk_buff * (*tx_fixup)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb); + void (*rx)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb); +}; + +struct mhi_device_info { + const char *netname; + const struct mhi_net_proto *proto; +}; + static int mhi_ndo_open(struct net_device *ndev) { struct mhi_net_dev *mhi_netdev = netdev_priv(ndev); @@ -68,26 +81,35 @@ static int mhi_ndo_stop(struct net_device *ndev) static int mhi_ndo_xmit(struct sk_buff *skb, struct net_device *ndev) { struct mhi_net_dev *mhi_netdev = netdev_priv(ndev); + const struct mhi_net_proto *proto = mhi_netdev->proto; struct mhi_device *mdev = mhi_netdev->mdev; int err; + if (proto && proto->tx_fixup) { + skb = proto->tx_fixup(mhi_netdev, skb); + if (unlikely(!skb)) + goto exit_drop; + } + 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); - - 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); - - /* drop the packet */ 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, @@ -164,6 +186,7 @@ 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); + const struct mhi_net_proto *proto = mhi_netdev->proto; struct sk_buff *skb = mhi_res->buf_addr; int free_desc_count; @@ -220,7 +243,10 @@ static void mhi_net_dl_callback(struct mhi_device *mhi_dev, break; } - netif_rx(skb); + if (proto && proto->rx) + proto->rx(mhi_netdev, skb); + else + netif_rx(skb); } /* Refill if RX buffers queue becomes low */ @@ -302,14 +328,14 @@ static struct device_type wwan_type = { static int mhi_net_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id) { - const char *netname = (char *)id->driver_data; + const struct mhi_device_info *info = (struct mhi_device_info *)id->driver_data; struct device *dev = &mhi_dev->dev; struct mhi_net_dev *mhi_netdev; struct net_device *ndev; int err; - ndev = alloc_netdev(sizeof(*mhi_netdev), netname, NET_NAME_PREDICTABLE, - mhi_net_setup); + ndev = alloc_netdev(sizeof(*mhi_netdev), info->netname, + NET_NAME_PREDICTABLE, mhi_net_setup); if (!ndev) return -ENOMEM; @@ -318,6 +344,7 @@ static int mhi_net_probe(struct mhi_device *mhi_dev, mhi_netdev->ndev = ndev; mhi_netdev->mdev = mhi_dev; mhi_netdev->skbagg_head = NULL; + mhi_netdev->proto = info->proto; SET_NETDEV_DEV(ndev, &mhi_dev->dev); SET_NETDEV_DEVTYPE(ndev, &wwan_type); @@ -337,8 +364,16 @@ static int mhi_net_probe(struct mhi_device *mhi_dev, if (err) goto out_err; + if (mhi_netdev->proto) { + err = mhi_netdev->proto->init(mhi_netdev); + if (err) + goto out_err_proto; + } + return 0; +out_err_proto: + unregister_netdev(ndev); out_err: free_netdev(ndev); return err; @@ -358,9 +393,19 @@ static void mhi_net_remove(struct mhi_device *mhi_dev) free_netdev(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[] = { - { .chan = "IP_HW0", .driver_data = (kernel_ulong_t)"mhi_hwip%d" }, - { .chan = "IP_SW0", .driver_data = (kernel_ulong_t)"mhi_swip%d" }, + /* 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); From b6ec6b8942700e855aa1a42e04ca9e1f89162de0 Mon Sep 17 00:00:00 2001 From: Loic Poulain Date: Tue, 9 Feb 2021 10:05:55 +0100 Subject: [PATCH 2/5] net: mhi: Add dedicated folder Create a dedicated mhi directory for mhi-net, mhi-net is going to be split into differente files (for additional protocol support). Signed-off-by: Loic Poulain Signed-off-by: David S. Miller --- drivers/net/Makefile | 2 +- drivers/net/mhi/Makefile | 3 +++ drivers/net/{mhi_net.c => mhi/net.c} | 0 3 files changed, 4 insertions(+), 1 deletion(-) create mode 100644 drivers/net/mhi/Makefile rename drivers/net/{mhi_net.c => mhi/net.c} (100%) diff --git a/drivers/net/Makefile b/drivers/net/Makefile index 36e2e41ed2aad..f4990ff32fa4c 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -36,7 +36,7 @@ obj-$(CONFIG_GTP) += gtp.o obj-$(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_NET) += mhi/ # # Networking Drivers diff --git a/drivers/net/mhi/Makefile b/drivers/net/mhi/Makefile new file mode 100644 index 0000000000000..0acf989a5f952 --- /dev/null +++ b/drivers/net/mhi/Makefile @@ -0,0 +1,3 @@ +obj-$(CONFIG_MHI_NET) += mhi_net.o + +mhi_net-y := net.o diff --git a/drivers/net/mhi_net.c b/drivers/net/mhi/net.c similarity index 100% rename from drivers/net/mhi_net.c rename to drivers/net/mhi/net.c From 77e8080e12721c9206aa592aa34985c897ee1a32 Mon Sep 17 00:00:00 2001 From: Loic Poulain Date: Tue, 9 Feb 2021 10:05:56 +0100 Subject: [PATCH 3/5] net: mhi: Create mhi.h Move mhi-net shared structures to mhi header, that will be used by upcoming proto(s). Signed-off-by: Loic Poulain Signed-off-by: David S. Miller --- drivers/net/mhi/mhi.h | 36 ++++++++++++++++++++++++++++++++++++ drivers/net/mhi/net.c | 33 ++------------------------------- 2 files changed, 38 insertions(+), 31 deletions(-) create mode 100644 drivers/net/mhi/mhi.h diff --git a/drivers/net/mhi/mhi.h b/drivers/net/mhi/mhi.h new file mode 100644 index 0000000000000..5050e4a220d05 --- /dev/null +++ b/drivers/net/mhi/mhi.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* MHI Network driver - Network over MHI bus + * + * Copyright (C) 2021 Linaro Ltd + */ + +struct mhi_net_stats { + u64_stats_t rx_packets; + u64_stats_t rx_bytes; + u64_stats_t rx_errors; + u64_stats_t rx_dropped; + 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; + const struct mhi_net_proto *proto; + void *proto_data; + struct delayed_work rx_refill; + struct mhi_net_stats stats; + u32 rx_queue_sz; +}; + +struct mhi_net_proto { + int (*init)(struct mhi_net_dev *mhi_netdev); + struct sk_buff * (*tx_fixup)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb); + void (*rx)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb); +}; diff --git a/drivers/net/mhi/net.c b/drivers/net/mhi/net.c index b92c2e1f107e1..58b4b7c096f78 100644 --- a/drivers/net/mhi/net.c +++ b/drivers/net/mhi/net.c @@ -12,41 +12,12 @@ #include #include +#include "mhi.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 rx_dropped; - 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; - const struct mhi_net_proto *proto; - void *proto_data; - struct delayed_work rx_refill; - struct mhi_net_stats stats; - u32 rx_queue_sz; -}; - -struct mhi_net_proto { - int (*init)(struct mhi_net_dev *mhi_netdev); - struct sk_buff * (*tx_fixup)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb); - void (*rx)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb); -}; - struct mhi_device_info { const char *netname; const struct mhi_net_proto *proto; From 84c55f16dcd74af5be525aa9c1878bfaec4e8a7a Mon Sep 17 00:00:00 2001 From: Loic Poulain Date: Tue, 9 Feb 2021 10:05:57 +0100 Subject: [PATCH 4/5] net: mhi: Add rx_length_errors stat This can be used by proto when packet len is incorrect. Signed-off-by: Loic Poulain Signed-off-by: David S. Miller --- drivers/net/mhi/mhi.h | 1 + drivers/net/mhi/net.c | 1 + 2 files changed, 2 insertions(+) diff --git a/drivers/net/mhi/mhi.h b/drivers/net/mhi/mhi.h index 5050e4a220d05..82210e0730004 100644 --- a/drivers/net/mhi/mhi.h +++ b/drivers/net/mhi/mhi.h @@ -9,6 +9,7 @@ struct mhi_net_stats { u64_stats_t rx_bytes; u64_stats_t rx_errors; u64_stats_t rx_dropped; + u64_stats_t rx_length_errors; u64_stats_t tx_packets; u64_stats_t tx_bytes; u64_stats_t tx_errors; diff --git a/drivers/net/mhi/net.c b/drivers/net/mhi/net.c index 58b4b7c096f78..44cbfb39e557b 100644 --- a/drivers/net/mhi/net.c +++ b/drivers/net/mhi/net.c @@ -95,6 +95,7 @@ static void mhi_ndo_get_stats64(struct net_device *ndev, stats->rx_bytes = u64_stats_read(&mhi_netdev->stats.rx_bytes); stats->rx_errors = u64_stats_read(&mhi_netdev->stats.rx_errors); stats->rx_dropped = u64_stats_read(&mhi_netdev->stats.rx_dropped); + stats->rx_length_errors = u64_stats_read(&mhi_netdev->stats.rx_length_errors); } while (u64_stats_fetch_retry_irq(&mhi_netdev->stats.rx_syncp, start)); do { From 163c5e6262ae5d7347801964dbd3d48490490a3d Mon Sep 17 00:00:00 2001 From: Loic Poulain Date: Tue, 9 Feb 2021 10:05:58 +0100 Subject: [PATCH 5/5] net: mhi: Add mbim proto MBIM has initially been specified by USB-IF for transporting data (IP) between a modem and a host over USB. However some modern modems also support MBIM over PCIe (via MHI). In the same way as QMAP(rmnet), it allows to aggregate IP packets and to perform context multiplexing. This change adds minimal MBIM data transport support to MHI, allowing to support MBIM only modems. MBIM being based on USB NCM, it reuses and copy some helpers/functions from the USB stack (cdc-ncm, cdc-mbim). Note that is a subset of the CDC-MBIM specification, supporting only transport of network data (IP), there is no support for DSS. Moreover the multi-session (for multi-pdn) is not supported in this initial version, but will be added latter, and aligned with the cdc-mbim solution (VLAN tags). This code has been inspired from the mhi_mbim downstream implementation (Carl Yin ). Signed-off-by: Loic Poulain Signed-off-by: David S. Miller --- drivers/net/mhi/Makefile | 2 +- drivers/net/mhi/mhi.h | 3 + drivers/net/mhi/net.c | 7 + drivers/net/mhi/proto_mbim.c | 293 +++++++++++++++++++++++++++++++++++ 4 files changed, 304 insertions(+), 1 deletion(-) create mode 100644 drivers/net/mhi/proto_mbim.c diff --git a/drivers/net/mhi/Makefile b/drivers/net/mhi/Makefile index 0acf989a5f952..f71b9f8f3c4f2 100644 --- a/drivers/net/mhi/Makefile +++ b/drivers/net/mhi/Makefile @@ -1,3 +1,3 @@ obj-$(CONFIG_MHI_NET) += mhi_net.o -mhi_net-y := net.o +mhi_net-y := net.o proto_mbim.o diff --git a/drivers/net/mhi/mhi.h b/drivers/net/mhi/mhi.h index 82210e0730004..12e7407d712ab 100644 --- a/drivers/net/mhi/mhi.h +++ b/drivers/net/mhi/mhi.h @@ -28,6 +28,7 @@ struct mhi_net_dev { struct delayed_work rx_refill; struct mhi_net_stats stats; u32 rx_queue_sz; + int msg_enable; }; struct mhi_net_proto { @@ -35,3 +36,5 @@ struct mhi_net_proto { struct sk_buff * (*tx_fixup)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb); void (*rx)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb); }; + +extern const struct mhi_net_proto proto_mbim; diff --git a/drivers/net/mhi/net.c b/drivers/net/mhi/net.c index 44cbfb39e557b..f59960876083f 100644 --- a/drivers/net/mhi/net.c +++ b/drivers/net/mhi/net.c @@ -373,11 +373,18 @@ static const struct mhi_device_info mhi_swip0 = { .netname = "mhi_swip%d", }; +static const struct mhi_device_info mhi_hwip0_mbim = { + .netname = "mhi_mbim%d", + .proto = &proto_mbim, +}; + 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 }, + /* Hardware accelerated data PATH (to modem IPA), MBIM protocol */ + { .chan = "IP_HW0_MBIM", .driver_data = (kernel_ulong_t)&mhi_hwip0_mbim }, {} }; MODULE_DEVICE_TABLE(mhi, mhi_net_id_table); diff --git a/drivers/net/mhi/proto_mbim.c b/drivers/net/mhi/proto_mbim.c new file mode 100644 index 0000000000000..75b5484c40d5d --- /dev/null +++ b/drivers/net/mhi/proto_mbim.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* MHI Network driver - Network over MHI bus + * + * Copyright (C) 2021 Linaro Ltd + * + * 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 + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "mhi.h" + +#define MBIM_NDP16_SIGN_MASK 0x00ffffff + +struct mbim_context { + u16 rx_seq; + u16 tx_seq; +}; + +static void __mbim_length_errors_inc(struct mhi_net_dev *dev) +{ + u64_stats_update_begin(&dev->stats.rx_syncp); + u64_stats_inc(&dev->stats.rx_length_errors); + u64_stats_update_end(&dev->stats.rx_syncp); +} + +static void __mbim_errors_inc(struct mhi_net_dev *dev) +{ + u64_stats_update_begin(&dev->stats.rx_syncp); + u64_stats_inc(&dev->stats.rx_errors); + u64_stats_update_end(&dev->stats.rx_syncp); +} + +static int mbim_rx_verify_nth16(struct sk_buff *skb) +{ + struct mhi_net_dev *dev = netdev_priv(skb->dev); + struct mbim_context *ctx = dev->proto_data; + struct usb_cdc_ncm_nth16 *nth16; + int len; + + if (skb->len < sizeof(struct usb_cdc_ncm_nth16) + + sizeof(struct usb_cdc_ncm_ndp16)) { + netif_dbg(dev, rx_err, dev->ndev, "frame too short\n"); + __mbim_length_errors_inc(dev); + return -EINVAL; + } + + nth16 = (struct usb_cdc_ncm_nth16 *)skb->data; + + if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) { + netif_dbg(dev, rx_err, dev->ndev, + "invalid NTH16 signature <%#010x>\n", + le32_to_cpu(nth16->dwSignature)); + __mbim_errors_inc(dev); + 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) { + netif_dbg(dev, rx_err, dev->ndev, + "NTB does not fit into the skb %u/%u\n", len, + skb->len); + __mbim_length_errors_inc(dev); + return -EINVAL; + } + + if (ctx->rx_seq + 1 != le16_to_cpu(nth16->wSequence) && + (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) && + !(ctx->rx_seq == 0xffff && !le16_to_cpu(nth16->wSequence))) { + netif_dbg(dev, rx_err, dev->ndev, + "sequence number glitch prev=%d curr=%d\n", + ctx->rx_seq, le16_to_cpu(nth16->wSequence)); + } + ctx->rx_seq = le16_to_cpu(nth16->wSequence); + + return le16_to_cpu(nth16->wNdpIndex); +} + +static int mbim_rx_verify_ndp16(struct sk_buff *skb, int ndpoffset) +{ + struct mhi_net_dev *dev = netdev_priv(skb->dev); + struct usb_cdc_ncm_ndp16 *ndp16; + int ret; + + if (ndpoffset + sizeof(struct usb_cdc_ncm_ndp16) > skb->len) { + netif_dbg(dev, rx_err, dev->ndev, "invalid NDP offset <%u>\n", + ndpoffset); + return -EINVAL; + } + + ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset); + + if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) { + netif_dbg(dev, rx_err, dev->ndev, "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) { + netif_dbg(dev, rx_err, dev->ndev, + "Invalid nframes = %d\n", ret); + return -EINVAL; + } + + return ret; +} + +static void mbim_rx(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb) +{ + struct net_device *ndev = mhi_netdev->ndev; + int ndpoffset; + + if (skb_linearize(skb)) + goto error; + + /* Check NTB header and retrieve first NDP offset */ + ndpoffset = mbim_rx_verify_nth16(skb); + if (ndpoffset < 0) { + net_err_ratelimited("%s: Incorrect NTB header\n", ndev->name); + goto error; + } + + /* Process each NDP */ + while (1) { + struct usb_cdc_ncm_ndp16 *ndp16; + struct usb_cdc_ncm_dpe16 *dpe16; + int nframes, n; + + /* Check NDP header and retrieve number of datagrams */ + nframes = mbim_rx_verify_ndp16(skb, ndpoffset); + if (nframes < 0) { + net_err_ratelimited("%s: Incorrect NDP16\n", ndev->name); + __mbim_length_errors_inc(mhi_netdev); + goto error; + } + + /* Only IP data type supported, no DSS in MHI context */ + ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset); + if ((ndp16->dwSignature & cpu_to_le32(MBIM_NDP16_SIGN_MASK)) + != cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN)) { + net_err_ratelimited("%s: Unsupported NDP type\n", ndev->name); + __mbim_errors_inc(mhi_netdev); + goto next_ndp; + } + + /* Only primary IP session 0 (0x00) supported for now */ + if (ndp16->dwSignature & ~cpu_to_le32(MBIM_NDP16_SIGN_MASK)) { + net_err_ratelimited("%s: bad packet session\n", ndev->name); + __mbim_errors_inc(mhi_netdev); + goto next_ndp; + } + + /* de-aggregate and deliver IP packets */ + dpe16 = ndp16->dpe16; + for (n = 0; n < nframes; n++, dpe16++) { + u16 dgram_offset = le16_to_cpu(dpe16->wDatagramIndex); + u16 dgram_len = le16_to_cpu(dpe16->wDatagramLength); + struct sk_buff *skbn; + + if (!dgram_offset || !dgram_len) + break; /* null terminator */ + + skbn = netdev_alloc_skb(ndev, dgram_len); + if (!skbn) + continue; + + skb_put(skbn, dgram_len); + memcpy(skbn->data, skb->data + dgram_offset, 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", + ndev->name); + __mbim_errors_inc(mhi_netdev); + dev_kfree_skb_any(skbn); + continue; + } + + netif_rx(skbn); + } +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); +} + +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 sk_buff *mbim_tx_fixup(struct mhi_net_dev *mhi_netdev, + struct sk_buff *skb) +{ + struct mbim_context *ctx = mhi_netdev->proto_data; + unsigned int dgram_size = skb->len; + struct usb_cdc_ncm_nth16 *nth16; + struct usb_cdc_ncm_ndp16 *ndp16; + struct mbim_tx_hdr *mbim_hdr; + + /* For now, this is a partial implementation of CDC MBIM, 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(ctx->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); + 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 int mbim_init(struct mhi_net_dev *mhi_netdev) +{ + struct net_device *ndev = mhi_netdev->ndev; + + mhi_netdev->proto_data = devm_kzalloc(&ndev->dev, + sizeof(struct mbim_context), + GFP_KERNEL); + if (!mhi_netdev->proto_data) + return -ENOMEM; + + ndev->needed_headroom = sizeof(struct mbim_tx_hdr); + + return 0; +} + +const struct mhi_net_proto proto_mbim = { + .init = mbim_init, + .rx = mbim_rx, + .tx_fixup = mbim_tx_fixup, +};