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, 483 insertions, 0 deletions

diff --git a/drivers/net/wwan/iosm/iosm_ipc_mux.c b/drivers/net/wwan/iosm/iosm_ipc_mux.c
new file mode 100644
index 000000000..fc928b298
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_mux.c
@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#include "iosm_ipc_mux_codec.h"
+
+/* At the begin of the runtime phase the IP MUX channel shall created. */
+static int ipc_mux_channel_create(struct iosm_mux *ipc_mux)
+{
+	int channel_id;
+
+	channel_id = ipc_imem_channel_alloc(ipc_mux->imem, ipc_mux->instance_id,
+					    IPC_CTYPE_WWAN);
+
+	if (channel_id < 0) {
+		dev_err(ipc_mux->dev,
+			"allocation of the MUX channel id failed");
+		ipc_mux->state = MUX_S_ERROR;
+		ipc_mux->event = MUX_E_NOT_APPLICABLE;
+		goto no_channel;
+	}
+
+	/* Establish the MUX channel in blocking mode. */
+	ipc_mux->channel = ipc_imem_channel_open(ipc_mux->imem, channel_id,
+						 IPC_HP_NET_CHANNEL_INIT);
+
+	if (!ipc_mux->channel) {
+		dev_err(ipc_mux->dev, "ipc_imem_channel_open failed");
+		ipc_mux->state = MUX_S_ERROR;
+		ipc_mux->event = MUX_E_NOT_APPLICABLE;
+		return -ENODEV; /* MUX channel is not available. */
+	}
+
+	/* Define the MUX active state properties. */
+	ipc_mux->state = MUX_S_ACTIVE;
+	ipc_mux->event = MUX_E_NO_ORDERS;
+
+no_channel:
+	return channel_id;
+}
+
+/* Reset the session/if id state. */
+static void ipc_mux_session_free(struct iosm_mux *ipc_mux, int if_id)
+{
+	struct mux_session *if_entry;
+
+	if_entry = &ipc_mux->session[if_id];
+	/* Reset the session state. */
+	if_entry->wwan = NULL;
+}
+
+/* Create and send the session open command. */
+static struct mux_cmd_open_session_resp *
+ipc_mux_session_open_send(struct iosm_mux *ipc_mux, int if_id)
+{
+	struct mux_cmd_open_session_resp *open_session_resp;
+	struct mux_acb *acb = &ipc_mux->acb;
+	union mux_cmd_param param;
+
+	/* open_session commands to one ACB and start transmission. */
+	param.open_session.flow_ctrl = 0;
+	param.open_session.ipv4v6_hints = 0;
+	param.open_session.reserved2 = 0;
+	param.open_session.dl_head_pad_len = cpu_to_le32(IPC_MEM_DL_ETH_OFFSET);
+
+	/* Finish and transfer ACB. The user thread is suspended.
+	 * It is a blocking function call, until CP responds or timeout.
+	 */
+	acb->wanted_response = MUX_CMD_OPEN_SESSION_RESP;
+	if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_OPEN_SESSION, if_id, 0,
+				     &param, sizeof(param.open_session), true,
+				 false) ||
+	    acb->got_response != MUX_CMD_OPEN_SESSION_RESP) {
+		dev_err(ipc_mux->dev, "if_id %d: OPEN_SESSION send failed",
+			if_id);
+		return NULL;
+	}
+
+	open_session_resp = &ipc_mux->acb.got_param.open_session_resp;
+	if (open_session_resp->response != cpu_to_le32(MUX_CMD_RESP_SUCCESS)) {
+		dev_err(ipc_mux->dev,
+			"if_id %d,session open failed,response=%d", if_id,
+			open_session_resp->response);
+		return NULL;
+	}
+
+	return open_session_resp;
+}
+
+/* Open the first IP session. */
+static bool ipc_mux_session_open(struct iosm_mux *ipc_mux,
+				 struct mux_session_open *session_open)
+{
+	struct mux_cmd_open_session_resp *open_session_resp;
+	int if_id;
+
+	/* Search for a free session interface id. */
+	if_id = le32_to_cpu(session_open->if_id);
+	if (if_id < 0 || if_id >= IPC_MEM_MUX_IP_SESSION_ENTRIES) {
+		dev_err(ipc_mux->dev, "invalid interface id=%d", if_id);
+		return false;
+	}
+
+	/* Create and send the session open command.
+	 * It is a blocking function call, until CP responds or timeout.
+	 */
+	open_session_resp = ipc_mux_session_open_send(ipc_mux, if_id);
+	if (!open_session_resp) {
+		ipc_mux_session_free(ipc_mux, if_id);
+		session_open->if_id = cpu_to_le32(-1);
+		return false;
+	}
+
+	/* Initialize the uplink skb accumulator. */
+	skb_queue_head_init(&ipc_mux->session[if_id].ul_list);
+
+	ipc_mux->session[if_id].dl_head_pad_len = IPC_MEM_DL_ETH_OFFSET;
+	ipc_mux->session[if_id].ul_head_pad_len =
+		le32_to_cpu(open_session_resp->ul_head_pad_len);
+	ipc_mux->session[if_id].wwan = ipc_mux->wwan;
+
+	/* Reset the flow ctrl stats of the session */
+	ipc_mux->session[if_id].flow_ctl_en_cnt = 0;
+	ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;
+	ipc_mux->session[if_id].ul_flow_credits = 0;
+	ipc_mux->session[if_id].net_tx_stop = false;
+	ipc_mux->session[if_id].flow_ctl_mask = 0;
+
+	/* Save and return the assigned if id. */
+	session_open->if_id = cpu_to_le32(if_id);
+	ipc_mux->nr_sessions++;
+
+	return true;
+}
+
+/* Free pending session UL packet. */
+static void ipc_mux_session_reset(struct iosm_mux *ipc_mux, int if_id)
+{
+	/* Reset the session/if id state. */
+	ipc_mux_session_free(ipc_mux, if_id);
+
+	/* Empty the uplink skb accumulator. */
+	skb_queue_purge(&ipc_mux->session[if_id].ul_list);
+}
+
+static void ipc_mux_session_close(struct iosm_mux *ipc_mux,
+				  struct mux_session_close *msg)
+{
+	int if_id;
+
+	/* Copy the session interface id. */
+	if_id = le32_to_cpu(msg->if_id);
+
+	if (if_id < 0 || if_id >= IPC_MEM_MUX_IP_SESSION_ENTRIES) {
+		dev_err(ipc_mux->dev, "invalid session id %d", if_id);
+		return;
+	}
+
+	/* Create and send the session close command.
+	 * It is a blocking function call, until CP responds or timeout.
+	 */
+	if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_CLOSE_SESSION, if_id, 0,
+				     NULL, 0, true, false))
+		dev_err(ipc_mux->dev, "if_id %d: CLOSE_SESSION send failed",
+			if_id);
+
+	/* Reset the flow ctrl stats of the session */
+	ipc_mux->session[if_id].flow_ctl_en_cnt = 0;
+	ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;
+	ipc_mux->session[if_id].flow_ctl_mask = 0;
+
+	ipc_mux_session_reset(ipc_mux, if_id);
+	ipc_mux->nr_sessions--;
+}
+
+static void ipc_mux_channel_close(struct iosm_mux *ipc_mux,
+				  struct mux_channel_close *channel_close_p)
+{
+	int i;
+
+	/* Free pending session UL packet. */
+	for (i = 0; i < IPC_MEM_MUX_IP_SESSION_ENTRIES; i++)
+		if (ipc_mux->session[i].wwan)
+			ipc_mux_session_reset(ipc_mux, i);
+
+	ipc_imem_channel_close(ipc_mux->imem, ipc_mux->channel_id);
+
+	/* Reset the MUX object. */
+	ipc_mux->state = MUX_S_INACTIVE;
+	ipc_mux->event = MUX_E_INACTIVE;
+}
+
+/* CP has interrupted AP. If AP is in IP MUX mode, execute the pending ops. */
+static int ipc_mux_schedule(struct iosm_mux *ipc_mux, union mux_msg *msg)
+{
+	enum mux_event order;
+	bool success;
+	int ret = -EIO;
+
+	if (!ipc_mux->initialized) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	order = msg->common.event;
+
+	switch (ipc_mux->state) {
+	case MUX_S_INACTIVE:
+		if (order != MUX_E_MUX_SESSION_OPEN)
+			goto out; /* Wait for the request to open a session */
+
+		if (ipc_mux->event == MUX_E_INACTIVE)
+			/* Establish the MUX channel and the new state. */
+			ipc_mux->channel_id = ipc_mux_channel_create(ipc_mux);
+
+		if (ipc_mux->state != MUX_S_ACTIVE) {
+			ret = ipc_mux->channel_id; /* Missing the MUX channel */
+			goto out;
+		}
+
+		/* Disable the TD update timer and open the first IP session. */
+		ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);
+		ipc_mux->event = MUX_E_MUX_SESSION_OPEN;
+		success = ipc_mux_session_open(ipc_mux, &msg->session_open);
+
+		ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);
+		if (success)
+			ret = ipc_mux->channel_id;
+		goto out;
+
+	case MUX_S_ACTIVE:
+		switch (order) {
+		case MUX_E_MUX_SESSION_OPEN:
+			/* Disable the TD update timer and open a session */
+			ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);
+			ipc_mux->event = MUX_E_MUX_SESSION_OPEN;
+			success = ipc_mux_session_open(ipc_mux,
+						       &msg->session_open);
+			ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);
+			if (success)
+				ret = ipc_mux->channel_id;
+			goto out;
+
+		case MUX_E_MUX_SESSION_CLOSE:
+			/* Release an IP session. */
+			ipc_mux->event = MUX_E_MUX_SESSION_CLOSE;
+			ipc_mux_session_close(ipc_mux, &msg->session_close);
+			if (!ipc_mux->nr_sessions) {
+				ipc_mux->event = MUX_E_MUX_CHANNEL_CLOSE;
+				ipc_mux_channel_close(ipc_mux,
+						      &msg->channel_close);
+			}
+			ret = ipc_mux->channel_id;
+			goto out;
+
+		case MUX_E_MUX_CHANNEL_CLOSE:
+			/* Close the MUX channel pipes. */
+			ipc_mux->event = MUX_E_MUX_CHANNEL_CLOSE;
+			ipc_mux_channel_close(ipc_mux, &msg->channel_close);
+			ret = ipc_mux->channel_id;
+			goto out;
+
+		default:
+			/* Invalid order. */
+			goto out;
+		}
+
+	default:
+		dev_err(ipc_mux->dev,
+			"unexpected MUX transition: state=%d, event=%d",
+			ipc_mux->state, ipc_mux->event);
+	}
+out:
+	return ret;
+}
+
+struct iosm_mux *ipc_mux_init(struct ipc_mux_config *mux_cfg,
+			      struct iosm_imem *imem)
+{
+	struct iosm_mux *ipc_mux = kzalloc(sizeof(*ipc_mux), GFP_KERNEL);
+	int i, j, ul_tds, ul_td_size;
+	struct sk_buff_head *free_list;
+	struct sk_buff *skb;
+	int qlt_size;
+
+	if (!ipc_mux)
+		return NULL;
+
+	ipc_mux->protocol = mux_cfg->protocol;
+	ipc_mux->ul_flow = mux_cfg->ul_flow;
+	ipc_mux->instance_id = mux_cfg->instance_id;
+	ipc_mux->wwan_q_offset = 0;
+
+	ipc_mux->pcie = imem->pcie;
+	ipc_mux->imem = imem;
+	ipc_mux->ipc_protocol = imem->ipc_protocol;
+	ipc_mux->dev = imem->dev;
+	ipc_mux->wwan = imem->wwan;
+
+	/* Get the reference to the UL ADB list. */
+	free_list = &ipc_mux->ul_adb.free_list;
+
+	/* Initialize the list with free ADB. */
+	skb_queue_head_init(free_list);
+
+	ul_td_size = IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE;
+
+	ul_tds = IPC_MEM_MAX_TDS_MUX_LITE_UL;
+
+	ipc_mux->ul_adb.dest_skb = NULL;
+
+	ipc_mux->initialized = true;
+	ipc_mux->adb_prep_ongoing = false;
+	ipc_mux->size_needed = 0;
+	ipc_mux->ul_data_pend_bytes = 0;
+	ipc_mux->state = MUX_S_INACTIVE;
+	ipc_mux->ev_mux_net_transmit_pending = false;
+	ipc_mux->tx_transaction_id = 0;
+	ipc_mux->rr_next_session = 0;
+	ipc_mux->event = MUX_E_INACTIVE;
+	ipc_mux->channel_id = -1;
+	ipc_mux->channel = NULL;
+
+	if (ipc_mux->protocol != MUX_LITE) {
+		qlt_size = offsetof(struct mux_qlth, ql) +
+				MUX_QUEUE_LEVEL * sizeof(struct mux_qlth_ql);
+
+		for (i = 0; i < IPC_MEM_MUX_IP_SESSION_ENTRIES; i++) {
+			ipc_mux->ul_adb.pp_qlt[i] = kzalloc(qlt_size,
+							    GFP_ATOMIC);
+			if (!ipc_mux->ul_adb.pp_qlt[i]) {
+				for (j = i - 1; j >= 0; j--)
+					kfree(ipc_mux->ul_adb.pp_qlt[j]);
+				kfree(ipc_mux);
+				return NULL;
+			}
+		}
+
+		ul_td_size = IPC_MEM_MAX_UL_ADB_BUF_SIZE;
+		ul_tds = IPC_MEM_MAX_TDS_MUX_AGGR_UL;
+	}
+
+	/* Allocate the list of UL ADB. */
+	for (i = 0; i < ul_tds; i++) {
+		dma_addr_t mapping;
+
+		skb = ipc_pcie_alloc_skb(ipc_mux->pcie, ul_td_size, GFP_ATOMIC,
+					 &mapping, DMA_TO_DEVICE, 0);
+		if (!skb) {
+			ipc_mux_deinit(ipc_mux);
+			return NULL;
+		}
+		/* Extend the UL ADB list. */
+		skb_queue_tail(free_list, skb);
+	}
+
+	return ipc_mux;
+}
+
+/* Informs the network stack to restart transmission for all opened session if
+ * Flow Control is not ON for that session.
+ */
+static void ipc_mux_restart_tx_for_all_sessions(struct iosm_mux *ipc_mux)
+{
+	struct mux_session *session;
+	int idx;
+
+	for (idx = 0; idx < IPC_MEM_MUX_IP_SESSION_ENTRIES; idx++) {
+		session = &ipc_mux->session[idx];
+
+		if (!session->wwan)
+			continue;
+
+		/* If flow control of the session is OFF and if there was tx
+		 * stop then restart. Inform the network interface to restart
+		 * sending data.
+		 */
+		if (session->flow_ctl_mask == 0) {
+			session->net_tx_stop = false;
+			ipc_mux_netif_tx_flowctrl(session, idx, false);
+		}
+	}
+}
+
+/* Informs the network stack to stop sending further pkt for all opened
+ * sessions
+ */
+static void ipc_mux_stop_netif_for_all_sessions(struct iosm_mux *ipc_mux)
+{
+	struct mux_session *session;
+	int idx;
+
+	for (idx = 0; idx < IPC_MEM_MUX_IP_SESSION_ENTRIES; idx++) {
+		session = &ipc_mux->session[idx];
+
+		if (!session->wwan)
+			continue;
+
+		ipc_mux_netif_tx_flowctrl(session, session->if_id, true);
+	}
+}
+
+void ipc_mux_check_n_restart_tx(struct iosm_mux *ipc_mux)
+{
+	if (ipc_mux->ul_flow == MUX_UL) {
+		int low_thresh = IPC_MEM_MUX_UL_FLOWCTRL_LOW_B;
+
+		if (ipc_mux->ul_data_pend_bytes < low_thresh)
+			ipc_mux_restart_tx_for_all_sessions(ipc_mux);
+	}
+}
+
+int ipc_mux_get_max_sessions(struct iosm_mux *ipc_mux)
+{
+	return ipc_mux ? IPC_MEM_MUX_IP_SESSION_ENTRIES : -EFAULT;
+}
+
+enum ipc_mux_protocol ipc_mux_get_active_protocol(struct iosm_mux *ipc_mux)
+{
+	return ipc_mux ? ipc_mux->protocol : MUX_UNKNOWN;
+}
+
+int ipc_mux_open_session(struct iosm_mux *ipc_mux, int session_nr)
+{
+	struct mux_session_open *session_open;
+	union mux_msg mux_msg;
+
+	session_open = &mux_msg.session_open;
+	session_open->event = MUX_E_MUX_SESSION_OPEN;
+
+	session_open->if_id = cpu_to_le32(session_nr);
+	ipc_mux->session[session_nr].flags |= IPC_MEM_WWAN_MUX;
+	return ipc_mux_schedule(ipc_mux, &mux_msg);
+}
+
+int ipc_mux_close_session(struct iosm_mux *ipc_mux, int session_nr)
+{
+	struct mux_session_close *session_close;
+	union mux_msg mux_msg;
+	int ret_val;
+
+	session_close = &mux_msg.session_close;
+	session_close->event = MUX_E_MUX_SESSION_CLOSE;
+
+	session_close->if_id = cpu_to_le32(session_nr);
+	ret_val = ipc_mux_schedule(ipc_mux, &mux_msg);
+	ipc_mux->session[session_nr].flags &= ~IPC_MEM_WWAN_MUX;
+
+	return ret_val;
+}
+
+void ipc_mux_deinit(struct iosm_mux *ipc_mux)
+{
+	struct mux_channel_close *channel_close;
+	struct sk_buff_head *free_list;
+	union mux_msg mux_msg;
+	struct sk_buff *skb;
+
+	if (!ipc_mux->initialized)
+		return;
+	ipc_mux_stop_netif_for_all_sessions(ipc_mux);
+
+	if (ipc_mux->state == MUX_S_ACTIVE) {
+		channel_close = &mux_msg.channel_close;
+		channel_close->event = MUX_E_MUX_CHANNEL_CLOSE;
+		ipc_mux_schedule(ipc_mux, &mux_msg);
+	}
+
+	/* Empty the ADB free list. */
+	free_list = &ipc_mux->ul_adb.free_list;
+
+	/* Remove from the head of the downlink queue. */
+	while ((skb = skb_dequeue(free_list)))
+		ipc_pcie_kfree_skb(ipc_mux->pcie, skb);
+
+	if (ipc_mux->channel) {
+		ipc_mux->channel->ul_pipe.is_open = false;
+		ipc_mux->channel->dl_pipe.is_open = false;
+	}
+
+	kfree(ipc_mux);
+}