Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 558 insertions, 0 deletions

diff --git a/drivers/net/usb/sr9700.c b/drivers/net/usb/sr9700.c
new file mode 100644
index 000000000..3164451e1
--- /dev/null
+++ b/drivers/net/usb/sr9700.c
@@ -0,0 +1,558 @@
+/*
+ * CoreChip-sz SR9700 one chip USB 1.1 Ethernet Devices
+ *
+ * Author : Liu Junliang <liujunliang_ljl@163.com>
+ *
+ * Based on dm9601.c
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/stddef.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/crc32.h>
+#include <linux/usb/usbnet.h>
+
+#include "sr9700.h"
+
+static int sr_read(struct usbnet *dev, u8 reg, u16 length, void *data)
+{
+	int err;
+
+	err = usbnet_read_cmd(dev, SR_RD_REGS, SR_REQ_RD_REG, 0, reg, data,
+			      length);
+	if ((err != length) && (err >= 0))
+		err = -EINVAL;
+	return err;
+}
+
+static int sr_write(struct usbnet *dev, u8 reg, u16 length, void *data)
+{
+	int err;
+
+	err = usbnet_write_cmd(dev, SR_WR_REGS, SR_REQ_WR_REG, 0, reg, data,
+			       length);
+	if ((err >= 0) && (err < length))
+		err = -EINVAL;
+	return err;
+}
+
+static int sr_read_reg(struct usbnet *dev, u8 reg, u8 *value)
+{
+	return sr_read(dev, reg, 1, value);
+}
+
+static int sr_write_reg(struct usbnet *dev, u8 reg, u8 value)
+{
+	return usbnet_write_cmd(dev, SR_WR_REGS, SR_REQ_WR_REG,
+				value, reg, NULL, 0);
+}
+
+static void sr_write_async(struct usbnet *dev, u8 reg, u16 length,
+			   const void *data)
+{
+	usbnet_write_cmd_async(dev, SR_WR_REGS, SR_REQ_WR_REG,
+			       0, reg, data, length);
+}
+
+static void sr_write_reg_async(struct usbnet *dev, u8 reg, u8 value)
+{
+	usbnet_write_cmd_async(dev, SR_WR_REGS, SR_REQ_WR_REG,
+			       value, reg, NULL, 0);
+}
+
+static int wait_phy_eeprom_ready(struct usbnet *dev, int phy)
+{
+	int i;
+
+	for (i = 0; i < SR_SHARE_TIMEOUT; i++) {
+		u8 tmp = 0;
+		int ret;
+
+		udelay(1);
+		ret = sr_read_reg(dev, SR_EPCR, &tmp);
+		if (ret < 0)
+			return ret;
+
+		/* ready */
+		if (!(tmp & EPCR_ERRE))
+			return 0;
+	}
+
+	netdev_err(dev->net, "%s write timed out!\n", phy ? "phy" : "eeprom");
+
+	return -EIO;
+}
+
+static int sr_share_read_word(struct usbnet *dev, int phy, u8 reg,
+			      __le16 *value)
+{
+	int ret;
+
+	mutex_lock(&dev->phy_mutex);
+
+	sr_write_reg(dev, SR_EPAR, phy ? (reg | EPAR_PHY_ADR) : reg);
+	sr_write_reg(dev, SR_EPCR, phy ? (EPCR_EPOS | EPCR_ERPRR) : EPCR_ERPRR);
+
+	ret = wait_phy_eeprom_ready(dev, phy);
+	if (ret < 0)
+		goto out_unlock;
+
+	sr_write_reg(dev, SR_EPCR, 0x0);
+	ret = sr_read(dev, SR_EPDR, 2, value);
+
+	netdev_dbg(dev->net, "read shared %d 0x%02x returned 0x%04x, %d\n",
+		   phy, reg, *value, ret);
+
+out_unlock:
+	mutex_unlock(&dev->phy_mutex);
+	return ret;
+}
+
+static int sr_share_write_word(struct usbnet *dev, int phy, u8 reg,
+			       __le16 value)
+{
+	int ret;
+
+	mutex_lock(&dev->phy_mutex);
+
+	ret = sr_write(dev, SR_EPDR, 2, &value);
+	if (ret < 0)
+		goto out_unlock;
+
+	sr_write_reg(dev, SR_EPAR, phy ? (reg | EPAR_PHY_ADR) : reg);
+	sr_write_reg(dev, SR_EPCR, phy ? (EPCR_WEP | EPCR_EPOS | EPCR_ERPRW) :
+		    (EPCR_WEP | EPCR_ERPRW));
+
+	ret = wait_phy_eeprom_ready(dev, phy);
+	if (ret < 0)
+		goto out_unlock;
+
+	sr_write_reg(dev, SR_EPCR, 0x0);
+
+out_unlock:
+	mutex_unlock(&dev->phy_mutex);
+	return ret;
+}
+
+static int sr_read_eeprom_word(struct usbnet *dev, u8 offset, void *value)
+{
+	return sr_share_read_word(dev, 0, offset, value);
+}
+
+static int sr9700_get_eeprom_len(struct net_device *netdev)
+{
+	return SR_EEPROM_LEN;
+}
+
+static int sr9700_get_eeprom(struct net_device *netdev,
+			     struct ethtool_eeprom *eeprom, u8 *data)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+	__le16 *buf = (__le16 *)data;
+	int ret = 0;
+	int i;
+
+	/* access is 16bit */
+	if ((eeprom->offset & 0x01) || (eeprom->len & 0x01))
+		return -EINVAL;
+
+	for (i = 0; i < eeprom->len / 2; i++) {
+		ret = sr_read_eeprom_word(dev, eeprom->offset / 2 + i, buf + i);
+		if (ret < 0)
+			break;
+	}
+
+	return ret;
+}
+
+static int sr_mdio_read(struct net_device *netdev, int phy_id, int loc)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+	__le16 res;
+	int rc = 0;
+
+	if (phy_id) {
+		netdev_dbg(netdev, "Only internal phy supported\n");
+		return 0;
+	}
+
+	/* Access NSR_LINKST bit for link status instead of MII_BMSR */
+	if (loc == MII_BMSR) {
+		u8 value;
+
+		sr_read_reg(dev, SR_NSR, &value);
+		if (value & NSR_LINKST)
+			rc = 1;
+	}
+	sr_share_read_word(dev, 1, loc, &res);
+	if (rc == 1)
+		res = le16_to_cpu(res) | BMSR_LSTATUS;
+	else
+		res = le16_to_cpu(res) & ~BMSR_LSTATUS;
+
+	netdev_dbg(netdev, "sr_mdio_read() phy_id=0x%02x, loc=0x%02x, returns=0x%04x\n",
+		   phy_id, loc, res);
+
+	return res;
+}
+
+static void sr_mdio_write(struct net_device *netdev, int phy_id, int loc,
+			  int val)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+	__le16 res = cpu_to_le16(val);
+
+	if (phy_id) {
+		netdev_dbg(netdev, "Only internal phy supported\n");
+		return;
+	}
+
+	netdev_dbg(netdev, "sr_mdio_write() phy_id=0x%02x, loc=0x%02x, val=0x%04x\n",
+		   phy_id, loc, val);
+
+	sr_share_write_word(dev, 1, loc, res);
+}
+
+static u32 sr9700_get_link(struct net_device *netdev)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+	u8 value = 0;
+	int rc = 0;
+
+	/* Get the Link Status directly */
+	sr_read_reg(dev, SR_NSR, &value);
+	if (value & NSR_LINKST)
+		rc = 1;
+
+	return rc;
+}
+
+static int sr9700_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+
+	return generic_mii_ioctl(&dev->mii, if_mii(rq), cmd, NULL);
+}
+
+static const struct ethtool_ops sr9700_ethtool_ops = {
+	.get_drvinfo	= usbnet_get_drvinfo,
+	.get_link	= sr9700_get_link,
+	.get_msglevel	= usbnet_get_msglevel,
+	.set_msglevel	= usbnet_set_msglevel,
+	.get_eeprom_len	= sr9700_get_eeprom_len,
+	.get_eeprom	= sr9700_get_eeprom,
+	.nway_reset	= usbnet_nway_reset,
+	.get_link_ksettings	= usbnet_get_link_ksettings_mii,
+	.set_link_ksettings	= usbnet_set_link_ksettings_mii,
+};
+
+static void sr9700_set_multicast(struct net_device *netdev)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+	/* We use the 20 byte dev->data for our 8 byte filter buffer
+	 * to avoid allocating memory that is tricky to free later
+	 */
+	u8 *hashes = (u8 *)&dev->data;
+	/* rx_ctl setting : enable, disable_long, disable_crc */
+	u8 rx_ctl = RCR_RXEN | RCR_DIS_CRC | RCR_DIS_LONG;
+
+	memset(hashes, 0x00, SR_MCAST_SIZE);
+	/* broadcast address */
+	hashes[SR_MCAST_SIZE - 1] |= SR_MCAST_ADDR_FLAG;
+	if (netdev->flags & IFF_PROMISC) {
+		rx_ctl |= RCR_PRMSC;
+	} else if (netdev->flags & IFF_ALLMULTI ||
+		   netdev_mc_count(netdev) > SR_MCAST_MAX) {
+		rx_ctl |= RCR_RUNT;
+	} else if (!netdev_mc_empty(netdev)) {
+		struct netdev_hw_addr *ha;
+
+		netdev_for_each_mc_addr(ha, netdev) {
+			u32 crc = ether_crc(ETH_ALEN, ha->addr) >> 26;
+			hashes[crc >> 3] |= 1 << (crc & 0x7);
+		}
+	}
+
+	sr_write_async(dev, SR_MAR, SR_MCAST_SIZE, hashes);
+	sr_write_reg_async(dev, SR_RCR, rx_ctl);
+}
+
+static int sr9700_set_mac_address(struct net_device *netdev, void *p)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+	struct sockaddr *addr = p;
+
+	if (!is_valid_ether_addr(addr->sa_data)) {
+		netdev_err(netdev, "not setting invalid mac address %pM\n",
+			   addr->sa_data);
+		return -EINVAL;
+	}
+
+	eth_hw_addr_set(netdev, addr->sa_data);
+	sr_write_async(dev, SR_PAR, 6, netdev->dev_addr);
+
+	return 0;
+}
+
+static const struct net_device_ops sr9700_netdev_ops = {
+	.ndo_open		= usbnet_open,
+	.ndo_stop		= usbnet_stop,
+	.ndo_start_xmit		= usbnet_start_xmit,
+	.ndo_tx_timeout		= usbnet_tx_timeout,
+	.ndo_change_mtu		= usbnet_change_mtu,
+	.ndo_get_stats64	= dev_get_tstats64,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_eth_ioctl		= sr9700_ioctl,
+	.ndo_set_rx_mode	= sr9700_set_multicast,
+	.ndo_set_mac_address	= sr9700_set_mac_address,
+};
+
+static int sr9700_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	struct net_device *netdev;
+	struct mii_if_info *mii;
+	u8 addr[ETH_ALEN];
+	int ret;
+
+	ret = usbnet_get_endpoints(dev, intf);
+	if (ret)
+		goto out;
+
+	netdev = dev->net;
+
+	netdev->netdev_ops = &sr9700_netdev_ops;
+	netdev->ethtool_ops = &sr9700_ethtool_ops;
+	netdev->hard_header_len += SR_TX_OVERHEAD;
+	dev->hard_mtu = netdev->mtu + netdev->hard_header_len;
+	/* bulkin buffer is preferably not less than 3K */
+	dev->rx_urb_size = 3072;
+
+	mii = &dev->mii;
+	mii->dev = netdev;
+	mii->mdio_read = sr_mdio_read;
+	mii->mdio_write = sr_mdio_write;
+	mii->phy_id_mask = 0x1f;
+	mii->reg_num_mask = 0x1f;
+
+	sr_write_reg(dev, SR_NCR, NCR_RST);
+	udelay(20);
+
+	/* read MAC
+	 * After Chip Power on, the Chip will reload the MAC from
+	 * EEPROM automatically to PAR. In case there is no EEPROM externally,
+	 * a default MAC address is stored in PAR for making chip work properly.
+	 */
+	if (sr_read(dev, SR_PAR, ETH_ALEN, addr) < 0) {
+		netdev_err(netdev, "Error reading MAC address\n");
+		ret = -ENODEV;
+		goto out;
+	}
+	eth_hw_addr_set(netdev, addr);
+
+	/* power up and reset phy */
+	sr_write_reg(dev, SR_PRR, PRR_PHY_RST);
+	/* at least 10ms, here 20ms for safe */
+	msleep(20);
+	sr_write_reg(dev, SR_PRR, 0);
+	/* at least 1ms, here 2ms for reading right register */
+	udelay(2 * 1000);
+
+	/* receive broadcast packets */
+	sr9700_set_multicast(netdev);
+
+	sr_mdio_write(netdev, mii->phy_id, MII_BMCR, BMCR_RESET);
+	sr_mdio_write(netdev, mii->phy_id, MII_ADVERTISE, ADVERTISE_ALL |
+		      ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP);
+	mii_nway_restart(mii);
+
+out:
+	return ret;
+}
+
+static int sr9700_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+	struct sk_buff *sr_skb;
+	int len;
+
+	/* skb content (packets) format :
+	 *                    p0            p1            p2    ......    pm
+	 *                 /      \
+	 *            /                \
+	 *        /                            \
+	 *  /                                        \
+	 * p0b0 p0b1 p0b2 p0b3 ...... p0b(n-4) p0b(n-3)...p0bn
+	 *
+	 * p0 : packet 0
+	 * p0b0 : packet 0 byte 0
+	 *
+	 * b0: rx status
+	 * b1: packet length (incl crc) low
+	 * b2: packet length (incl crc) high
+	 * b3..n-4: packet data
+	 * bn-3..bn: ethernet packet crc
+	 */
+	if (unlikely(skb->len < SR_RX_OVERHEAD)) {
+		netdev_err(dev->net, "unexpected tiny rx frame\n");
+		return 0;
+	}
+
+	/* one skb may contains multiple packets */
+	while (skb->len > SR_RX_OVERHEAD) {
+		if (skb->data[0] != 0x40)
+			return 0;
+
+		/* ignore the CRC length */
+		len = (skb->data[1] | (skb->data[2] << 8)) - 4;
+
+		if (len > ETH_FRAME_LEN || len > skb->len || len < 0)
+			return 0;
+
+		/* the last packet of current skb */
+		if (skb->len == (len + SR_RX_OVERHEAD))	{
+			skb_pull(skb, 3);
+			skb->len = len;
+			skb_set_tail_pointer(skb, len);
+			skb->truesize = len + sizeof(struct sk_buff);
+			return 2;
+		}
+
+		/* skb_clone is used for address align */
+		sr_skb = skb_clone(skb, GFP_ATOMIC);
+		if (!sr_skb)
+			return 0;
+
+		sr_skb->len = len;
+		sr_skb->data = skb->data + 3;
+		skb_set_tail_pointer(sr_skb, len);
+		sr_skb->truesize = len + sizeof(struct sk_buff);
+		usbnet_skb_return(dev, sr_skb);
+
+		skb_pull(skb, len + SR_RX_OVERHEAD);
+	}
+
+	return 0;
+}
+
+static struct sk_buff *sr9700_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
+				       gfp_t flags)
+{
+	int len;
+
+	/* SR9700 can only send out one ethernet packet at once.
+	 *
+	 * b0 b1 b2 b3 ...... b(n-4) b(n-3)...bn
+	 *
+	 * b0: rx status
+	 * b1: packet length (incl crc) low
+	 * b2: packet length (incl crc) high
+	 * b3..n-4: packet data
+	 * bn-3..bn: ethernet packet crc
+	 */
+
+	len = skb->len;
+
+	if (skb_cow_head(skb, SR_TX_OVERHEAD)) {
+		dev_kfree_skb_any(skb);
+		return NULL;
+	}
+
+	__skb_push(skb, SR_TX_OVERHEAD);
+
+	/* usbnet adds padding if length is a multiple of packet size
+	 * if so, adjust length value in header
+	 */
+	if ((skb->len % dev->maxpacket) == 0)
+		len++;
+
+	skb->data[0] = len;
+	skb->data[1] = len >> 8;
+
+	return skb;
+}
+
+static void sr9700_status(struct usbnet *dev, struct urb *urb)
+{
+	int link;
+	u8 *buf;
+
+	/* format:
+	   b0: net status
+	   b1: tx status 1
+	   b2: tx status 2
+	   b3: rx status
+	   b4: rx overflow
+	   b5: rx count
+	   b6: tx count
+	   b7: gpr
+	*/
+
+	if (urb->actual_length < 8)
+		return;
+
+	buf = urb->transfer_buffer;
+
+	link = !!(buf[0] & 0x40);
+	if (netif_carrier_ok(dev->net) != link) {
+		usbnet_link_change(dev, link, 1);
+		netdev_dbg(dev->net, "Link Status is: %d\n", link);
+	}
+}
+
+static int sr9700_link_reset(struct usbnet *dev)
+{
+	struct ethtool_cmd ecmd;
+
+	mii_check_media(&dev->mii, 1, 1);
+	mii_ethtool_gset(&dev->mii, &ecmd);
+
+	netdev_dbg(dev->net, "link_reset() speed: %d duplex: %d\n",
+		   ecmd.speed, ecmd.duplex);
+
+	return 0;
+}
+
+static const struct driver_info sr9700_driver_info = {
+	.description	= "CoreChip SR9700 USB Ethernet",
+	.flags		= FLAG_ETHER,
+	.bind		= sr9700_bind,
+	.rx_fixup	= sr9700_rx_fixup,
+	.tx_fixup	= sr9700_tx_fixup,
+	.status		= sr9700_status,
+	.link_reset	= sr9700_link_reset,
+	.reset		= sr9700_link_reset,
+};
+
+static const struct usb_device_id products[] = {
+	{
+		USB_DEVICE(0x0fe6, 0x9700),	/* SR9700 device */
+		.driver_info = (unsigned long)&sr9700_driver_info,
+	},
+	{},			/* END */
+};
+
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver sr9700_usb_driver = {
+	.name		= "sr9700",
+	.id_table	= products,
+	.probe		= usbnet_probe,
+	.disconnect	= usbnet_disconnect,
+	.suspend	= usbnet_suspend,
+	.resume		= usbnet_resume,
+	.disable_hub_initiated_lpm = 1,
+};
+
+module_usb_driver(sr9700_usb_driver);
+
+MODULE_AUTHOR("liujl <liujunliang_ljl@163.com>");
+MODULE_DESCRIPTION("SR9700 one chip USB 1.1 USB to Ethernet device from http://www.corechip-sz.com/");
+MODULE_LICENSE("GPL");