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, 453 insertions, 0 deletions

diff --git a/drivers/usb/usbip/stub_tx.c b/drivers/usb/usbip/stub_tx.c
new file mode 100644
index 000000000..b1c2f6781
--- /dev/null
+++ b/drivers/usb/usbip/stub_tx.c
@@ -0,0 +1,453 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ */
+
+#include <linux/kthread.h>
+#include <linux/socket.h>
+#include <linux/scatterlist.h>
+
+#include "usbip_common.h"
+#include "stub.h"
+
+/* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
+void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
+			     __u32 status)
+{
+	struct stub_unlink *unlink;
+
+	unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
+	if (!unlink) {
+		usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
+		return;
+	}
+
+	unlink->seqnum = seqnum;
+	unlink->status = status;
+
+	list_add_tail(&unlink->list, &sdev->unlink_tx);
+}
+
+/**
+ * stub_complete - completion handler of a usbip urb
+ * @urb: pointer to the urb completed
+ *
+ * When a urb has completed, the USB core driver calls this function mostly in
+ * the interrupt context. To return the result of a urb, the completed urb is
+ * linked to the pending list of returning.
+ *
+ */
+void stub_complete(struct urb *urb)
+{
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+	struct stub_device *sdev = priv->sdev;
+	unsigned long flags;
+
+	usbip_dbg_stub_tx("complete! status %d\n", urb->status);
+
+	switch (urb->status) {
+	case 0:
+		/* OK */
+		break;
+	case -ENOENT:
+		dev_info(&urb->dev->dev,
+			 "stopped by a call to usb_kill_urb() because of cleaning up a virtual connection\n");
+		return;
+	case -ECONNRESET:
+		dev_info(&urb->dev->dev,
+			 "unlinked by a call to usb_unlink_urb()\n");
+		break;
+	case -EPIPE:
+		dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
+			 usb_pipeendpoint(urb->pipe));
+		break;
+	case -ESHUTDOWN:
+		dev_info(&urb->dev->dev, "device removed?\n");
+		break;
+	default:
+		dev_info(&urb->dev->dev,
+			 "urb completion with non-zero status %d\n",
+			 urb->status);
+		break;
+	}
+
+	/*
+	 * If the server breaks single SG request into the several URBs, the
+	 * URBs must be reassembled before sending completed URB to the vhci.
+	 * Don't wake up the tx thread until all the URBs are completed.
+	 */
+	if (priv->sgl) {
+		priv->completed_urbs++;
+
+		/* Only save the first error status */
+		if (urb->status && !priv->urb_status)
+			priv->urb_status = urb->status;
+
+		if (priv->completed_urbs < priv->num_urbs)
+			return;
+	}
+
+	/* link a urb to the queue of tx. */
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+	if (sdev->ud.tcp_socket == NULL) {
+		usbip_dbg_stub_tx("ignore urb for closed connection\n");
+		/* It will be freed in stub_device_cleanup_urbs(). */
+	} else if (priv->unlinking) {
+		stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
+		stub_free_priv_and_urb(priv);
+	} else {
+		list_move_tail(&priv->list, &sdev->priv_tx);
+	}
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	/* wake up tx_thread */
+	wake_up(&sdev->tx_waitq);
+}
+
+static inline void setup_base_pdu(struct usbip_header_basic *base,
+				  __u32 command, __u32 seqnum)
+{
+	base->command	= command;
+	base->seqnum	= seqnum;
+	base->devid	= 0;
+	base->ep	= 0;
+	base->direction = 0;
+}
+
+static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
+{
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+
+	setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
+	usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
+}
+
+static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
+				 struct stub_unlink *unlink)
+{
+	setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
+	rpdu->u.ret_unlink.status = unlink->status;
+}
+
+static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_priv *priv, *tmp;
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
+		list_move_tail(&priv->list, &sdev->priv_free);
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+		return priv;
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return NULL;
+}
+
+static int stub_send_ret_submit(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_priv *priv, *tmp;
+
+	struct msghdr msg;
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
+		struct urb *urb = priv->urbs[0];
+		struct usbip_header pdu_header;
+		struct usbip_iso_packet_descriptor *iso_buffer = NULL;
+		struct kvec *iov = NULL;
+		struct scatterlist *sg;
+		u32 actual_length = 0;
+		int iovnum = 0;
+		int ret;
+		int i;
+
+		txsize = 0;
+		memset(&pdu_header, 0, sizeof(pdu_header));
+		memset(&msg, 0, sizeof(msg));
+
+		if (urb->actual_length > 0 && !urb->transfer_buffer &&
+		   !urb->num_sgs) {
+			dev_err(&sdev->udev->dev,
+				"urb: actual_length %d transfer_buffer null\n",
+				urb->actual_length);
+			return -1;
+		}
+
+		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
+			iovnum = 2 + urb->number_of_packets;
+		else if (usb_pipein(urb->pipe) && urb->actual_length > 0 &&
+			urb->num_sgs)
+			iovnum = 1 + urb->num_sgs;
+		else if (usb_pipein(urb->pipe) && priv->sgl)
+			iovnum = 1 + priv->num_urbs;
+		else
+			iovnum = 2;
+
+		iov = kcalloc(iovnum, sizeof(struct kvec), GFP_KERNEL);
+
+		if (!iov) {
+			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
+			return -1;
+		}
+
+		iovnum = 0;
+
+		/* 1. setup usbip_header */
+		setup_ret_submit_pdu(&pdu_header, urb);
+		usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
+				  pdu_header.base.seqnum);
+
+		if (priv->sgl) {
+			for (i = 0; i < priv->num_urbs; i++)
+				actual_length += priv->urbs[i]->actual_length;
+
+			pdu_header.u.ret_submit.status = priv->urb_status;
+			pdu_header.u.ret_submit.actual_length = actual_length;
+		}
+
+		usbip_header_correct_endian(&pdu_header, 1);
+
+		iov[iovnum].iov_base = &pdu_header;
+		iov[iovnum].iov_len  = sizeof(pdu_header);
+		iovnum++;
+		txsize += sizeof(pdu_header);
+
+		/* 2. setup transfer buffer */
+		if (usb_pipein(urb->pipe) && priv->sgl) {
+			/* If the server split a single SG request into several
+			 * URBs because the server's HCD doesn't support SG,
+			 * reassemble the split URB buffers into a single
+			 * return command.
+			 */
+			for (i = 0; i < priv->num_urbs; i++) {
+				iov[iovnum].iov_base =
+					priv->urbs[i]->transfer_buffer;
+				iov[iovnum].iov_len =
+					priv->urbs[i]->actual_length;
+				iovnum++;
+			}
+			txsize += actual_length;
+		} else if (usb_pipein(urb->pipe) &&
+		    usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
+		    urb->actual_length > 0) {
+			if (urb->num_sgs) {
+				unsigned int copy = urb->actual_length;
+				int size;
+
+				for_each_sg(urb->sg, sg, urb->num_sgs, i) {
+					if (copy == 0)
+						break;
+
+					if (copy < sg->length)
+						size = copy;
+					else
+						size = sg->length;
+
+					iov[iovnum].iov_base = sg_virt(sg);
+					iov[iovnum].iov_len = size;
+
+					iovnum++;
+					copy -= size;
+				}
+			} else {
+				iov[iovnum].iov_base = urb->transfer_buffer;
+				iov[iovnum].iov_len  = urb->actual_length;
+				iovnum++;
+			}
+			txsize += urb->actual_length;
+		} else if (usb_pipein(urb->pipe) &&
+			   usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
+			/*
+			 * For isochronous packets: actual length is the sum of
+			 * the actual length of the individual, packets, but as
+			 * the packet offsets are not changed there will be
+			 * padding between the packets. To optimally use the
+			 * bandwidth the padding is not transmitted.
+			 */
+
+			int i;
+
+			for (i = 0; i < urb->number_of_packets; i++) {
+				iov[iovnum].iov_base = urb->transfer_buffer +
+					urb->iso_frame_desc[i].offset;
+				iov[iovnum].iov_len =
+					urb->iso_frame_desc[i].actual_length;
+				iovnum++;
+				txsize += urb->iso_frame_desc[i].actual_length;
+			}
+
+			if (txsize != sizeof(pdu_header) + urb->actual_length) {
+				dev_err(&sdev->udev->dev,
+					"actual length of urb %d does not match iso packet sizes %zu\n",
+					urb->actual_length,
+					txsize-sizeof(pdu_header));
+				kfree(iov);
+				usbip_event_add(&sdev->ud,
+						SDEV_EVENT_ERROR_TCP);
+				return -1;
+			}
+		}
+
+		/* 3. setup iso_packet_descriptor */
+		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
+			ssize_t len = 0;
+
+			iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
+			if (!iso_buffer) {
+				usbip_event_add(&sdev->ud,
+						SDEV_EVENT_ERROR_MALLOC);
+				kfree(iov);
+				return -1;
+			}
+
+			iov[iovnum].iov_base = iso_buffer;
+			iov[iovnum].iov_len  = len;
+			txsize += len;
+			iovnum++;
+		}
+
+		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
+						iov,  iovnum, txsize);
+		if (ret != txsize) {
+			dev_err(&sdev->udev->dev,
+				"sendmsg failed!, retval %d for %zd\n",
+				ret, txsize);
+			kfree(iov);
+			kfree(iso_buffer);
+			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+		kfree(iov);
+		kfree(iso_buffer);
+
+		total_size += txsize;
+	}
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+	list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
+		stub_free_priv_and_urb(priv);
+	}
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return total_size;
+}
+
+static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_unlink *unlink, *tmp;
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
+		list_move_tail(&unlink->list, &sdev->unlink_free);
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+		return unlink;
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return NULL;
+}
+
+static int stub_send_ret_unlink(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_unlink *unlink, *tmp;
+
+	struct msghdr msg;
+	struct kvec iov[1];
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
+		int ret;
+		struct usbip_header pdu_header;
+
+		txsize = 0;
+		memset(&pdu_header, 0, sizeof(pdu_header));
+		memset(&msg, 0, sizeof(msg));
+		memset(&iov, 0, sizeof(iov));
+
+		usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
+
+		/* 1. setup usbip_header */
+		setup_ret_unlink_pdu(&pdu_header, unlink);
+		usbip_header_correct_endian(&pdu_header, 1);
+
+		iov[0].iov_base = &pdu_header;
+		iov[0].iov_len  = sizeof(pdu_header);
+		txsize += sizeof(pdu_header);
+
+		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
+				     1, txsize);
+		if (ret != txsize) {
+			dev_err(&sdev->udev->dev,
+				"sendmsg failed!, retval %d for %zd\n",
+				ret, txsize);
+			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+		usbip_dbg_stub_tx("send txdata\n");
+		total_size += txsize;
+	}
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
+		list_del(&unlink->list);
+		kfree(unlink);
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return total_size;
+}
+
+int stub_tx_loop(void *data)
+{
+	struct usbip_device *ud = data;
+	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
+
+	while (!kthread_should_stop()) {
+		if (usbip_event_happened(ud))
+			break;
+
+		/*
+		 * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
+		 * looks at only priv_init queue. If the completion of a URB is
+		 * earlier than the receive of CMD_UNLINK, priv is moved to
+		 * priv_tx queue and stub_rx does not find the target priv. In
+		 * this case, vhci_rx receives the result of the submit request
+		 * and then receives the result of the unlink request. The
+		 * result of the submit is given back to the usbcore as the
+		 * completion of the unlink request. The request of the
+		 * unlink is ignored. This is ok because a driver who calls
+		 * usb_unlink_urb() understands the unlink was too late by
+		 * getting the status of the given-backed URB which has the
+		 * status of usb_submit_urb().
+		 */
+		if (stub_send_ret_submit(sdev) < 0)
+			break;
+
+		if (stub_send_ret_unlink(sdev) < 0)
+			break;
+
+		wait_event_interruptible(sdev->tx_waitq,
+					 (!list_empty(&sdev->priv_tx) ||
+					  !list_empty(&sdev->unlink_tx) ||
+					  kthread_should_stop()));
+	}
+
+	return 0;
+}