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, 541 insertions, 0 deletions

diff --git a/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c b/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c
new file mode 100644
index 000000000..4627847c6
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_protocol_ops.c
@@ -0,0 +1,541 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#include "iosm_ipc_protocol.h"
+#include "iosm_ipc_protocol_ops.h"
+
+/* Get the next free message element.*/
+static union ipc_mem_msg_entry *
+ipc_protocol_free_msg_get(struct iosm_protocol *ipc_protocol, int *index)
+{
+	u32 head = le32_to_cpu(ipc_protocol->p_ap_shm->msg_head);
+	u32 new_head = (head + 1) % IPC_MEM_MSG_ENTRIES;
+	union ipc_mem_msg_entry *msg;
+
+	if (new_head == le32_to_cpu(ipc_protocol->p_ap_shm->msg_tail)) {
+		dev_err(ipc_protocol->dev, "message ring is full");
+		return NULL;
+	}
+
+	/* Get the pointer to the next free message element,
+	 * reset the fields and mark is as invalid.
+	 */
+	msg = &ipc_protocol->p_ap_shm->msg_ring[head];
+	memset(msg, 0, sizeof(*msg));
+
+	/* return index in message ring */
+	*index = head;
+
+	return msg;
+}
+
+/* Updates the message ring Head pointer */
+void ipc_protocol_msg_hp_update(struct iosm_imem *ipc_imem)
+{
+	struct iosm_protocol *ipc_protocol = ipc_imem->ipc_protocol;
+	u32 head = le32_to_cpu(ipc_protocol->p_ap_shm->msg_head);
+	u32 new_head = (head + 1) % IPC_MEM_MSG_ENTRIES;
+
+	/* Update head pointer and fire doorbell. */
+	ipc_protocol->p_ap_shm->msg_head = cpu_to_le32(new_head);
+	ipc_protocol->old_msg_tail =
+		le32_to_cpu(ipc_protocol->p_ap_shm->msg_tail);
+
+	ipc_pm_signal_hpda_doorbell(&ipc_protocol->pm, IPC_HP_MR, false);
+}
+
+/* Allocate and prepare a OPEN_PIPE message.
+ * This also allocates the memory for the new TDR structure and
+ * updates the pipe structure referenced in the preparation arguments.
+ */
+static int ipc_protocol_msg_prepipe_open(struct iosm_protocol *ipc_protocol,
+					 union ipc_msg_prep_args *args)
+{
+	int index;
+	union ipc_mem_msg_entry *msg =
+		ipc_protocol_free_msg_get(ipc_protocol, &index);
+	struct ipc_pipe *pipe = args->pipe_open.pipe;
+	struct ipc_protocol_td *tdr;
+	struct sk_buff **skbr;
+
+	if (!msg) {
+		dev_err(ipc_protocol->dev, "failed to get free message");
+		return -EIO;
+	}
+
+	/* Allocate the skbuf elements for the skbuf which are on the way.
+	 * SKB ring is internal memory allocation for driver. No need to
+	 * re-calculate the start and end addresses.
+	 */
+	skbr = kcalloc(pipe->nr_of_entries, sizeof(*skbr), GFP_ATOMIC);
+	if (!skbr)
+		return -ENOMEM;
+
+	/* Allocate the transfer descriptors for the pipe. */
+	tdr = dma_alloc_coherent(&ipc_protocol->pcie->pci->dev,
+				 pipe->nr_of_entries * sizeof(*tdr),
+				 &pipe->phy_tdr_start, GFP_ATOMIC);
+	if (!tdr) {
+		kfree(skbr);
+		dev_err(ipc_protocol->dev, "tdr alloc error");
+		return -ENOMEM;
+	}
+
+	pipe->max_nr_of_queued_entries = pipe->nr_of_entries - 1;
+	pipe->nr_of_queued_entries = 0;
+	pipe->tdr_start = tdr;
+	pipe->skbr_start = skbr;
+	pipe->old_tail = 0;
+
+	ipc_protocol->p_ap_shm->head_array[pipe->pipe_nr] = 0;
+
+	msg->open_pipe.type_of_message = IPC_MEM_MSG_OPEN_PIPE;
+	msg->open_pipe.pipe_nr = pipe->pipe_nr;
+	msg->open_pipe.tdr_addr = cpu_to_le64(pipe->phy_tdr_start);
+	msg->open_pipe.tdr_entries = cpu_to_le16(pipe->nr_of_entries);
+	msg->open_pipe.accumulation_backoff =
+				cpu_to_le32(pipe->accumulation_backoff);
+	msg->open_pipe.irq_vector = cpu_to_le32(pipe->irq);
+
+	return index;
+}
+
+static int ipc_protocol_msg_prepipe_close(struct iosm_protocol *ipc_protocol,
+					  union ipc_msg_prep_args *args)
+{
+	int index = -1;
+	union ipc_mem_msg_entry *msg =
+		ipc_protocol_free_msg_get(ipc_protocol, &index);
+	struct ipc_pipe *pipe = args->pipe_close.pipe;
+
+	if (!msg)
+		return -EIO;
+
+	msg->close_pipe.type_of_message = IPC_MEM_MSG_CLOSE_PIPE;
+	msg->close_pipe.pipe_nr = pipe->pipe_nr;
+
+	dev_dbg(ipc_protocol->dev, "IPC_MEM_MSG_CLOSE_PIPE(pipe_nr=%d)",
+		msg->close_pipe.pipe_nr);
+
+	return index;
+}
+
+static int ipc_protocol_msg_prep_sleep(struct iosm_protocol *ipc_protocol,
+				       union ipc_msg_prep_args *args)
+{
+	int index = -1;
+	union ipc_mem_msg_entry *msg =
+		ipc_protocol_free_msg_get(ipc_protocol, &index);
+
+	if (!msg) {
+		dev_err(ipc_protocol->dev, "failed to get free message");
+		return -EIO;
+	}
+
+	/* Prepare and send the host sleep message to CP to enter or exit D3. */
+	msg->host_sleep.type_of_message = IPC_MEM_MSG_SLEEP;
+	msg->host_sleep.target = args->sleep.target; /* 0=host, 1=device */
+
+	/* state; 0=enter, 1=exit 2=enter w/o protocol */
+	msg->host_sleep.state = args->sleep.state;
+
+	dev_dbg(ipc_protocol->dev, "IPC_MEM_MSG_SLEEP(target=%d; state=%d)",
+		msg->host_sleep.target, msg->host_sleep.state);
+
+	return index;
+}
+
+static int ipc_protocol_msg_prep_feature_set(struct iosm_protocol *ipc_protocol,
+					     union ipc_msg_prep_args *args)
+{
+	int index = -1;
+	union ipc_mem_msg_entry *msg =
+		ipc_protocol_free_msg_get(ipc_protocol, &index);
+
+	if (!msg) {
+		dev_err(ipc_protocol->dev, "failed to get free message");
+		return -EIO;
+	}
+
+	msg->feature_set.type_of_message = IPC_MEM_MSG_FEATURE_SET;
+	msg->feature_set.reset_enable = args->feature_set.reset_enable <<
+					RESET_BIT;
+
+	dev_dbg(ipc_protocol->dev, "IPC_MEM_MSG_FEATURE_SET(reset_enable=%d)",
+		msg->feature_set.reset_enable >> RESET_BIT);
+
+	return index;
+}
+
+/* Processes the message consumed by CP. */
+bool ipc_protocol_msg_process(struct iosm_imem *ipc_imem, int irq)
+{
+	struct iosm_protocol *ipc_protocol = ipc_imem->ipc_protocol;
+	struct ipc_rsp **rsp_ring = ipc_protocol->rsp_ring;
+	bool msg_processed = false;
+	u32 i;
+
+	if (le32_to_cpu(ipc_protocol->p_ap_shm->msg_tail) >=
+			IPC_MEM_MSG_ENTRIES) {
+		dev_err(ipc_protocol->dev, "msg_tail out of range: %d",
+			le32_to_cpu(ipc_protocol->p_ap_shm->msg_tail));
+		return msg_processed;
+	}
+
+	if (irq != IMEM_IRQ_DONT_CARE &&
+	    irq != ipc_protocol->p_ap_shm->ci.msg_irq_vector)
+		return msg_processed;
+
+	for (i = ipc_protocol->old_msg_tail;
+	     i != le32_to_cpu(ipc_protocol->p_ap_shm->msg_tail);
+	     i = (i + 1) % IPC_MEM_MSG_ENTRIES) {
+		union ipc_mem_msg_entry *msg =
+			&ipc_protocol->p_ap_shm->msg_ring[i];
+
+		dev_dbg(ipc_protocol->dev, "msg[%d]: type=%u status=%d", i,
+			msg->common.type_of_message,
+			msg->common.completion_status);
+
+		/* Update response with status and wake up waiting requestor */
+		if (rsp_ring[i]) {
+			rsp_ring[i]->status =
+				le32_to_cpu(msg->common.completion_status);
+			complete(&rsp_ring[i]->completion);
+			rsp_ring[i] = NULL;
+		}
+		msg_processed = true;
+	}
+
+	ipc_protocol->old_msg_tail = i;
+	return msg_processed;
+}
+
+/* Sends data from UL list to CP for the provided pipe by updating the Head
+ * pointer of given pipe.
+ */
+bool ipc_protocol_ul_td_send(struct iosm_protocol *ipc_protocol,
+			     struct ipc_pipe *pipe,
+			     struct sk_buff_head *p_ul_list)
+{
+	struct ipc_protocol_td *td;
+	bool hpda_pending = false;
+	struct sk_buff *skb;
+	s32 free_elements;
+	u32 head;
+	u32 tail;
+
+	if (!ipc_protocol->p_ap_shm) {
+		dev_err(ipc_protocol->dev, "driver is not initialized");
+		return false;
+	}
+
+	/* Get head and tail of the td list and calculate
+	 * the number of free elements.
+	 */
+	head = le32_to_cpu(ipc_protocol->p_ap_shm->head_array[pipe->pipe_nr]);
+	tail = pipe->old_tail;
+
+	while (!skb_queue_empty(p_ul_list)) {
+		if (head < tail)
+			free_elements = tail - head - 1;
+		else
+			free_elements =
+				pipe->nr_of_entries - head + ((s32)tail - 1);
+
+		if (free_elements <= 0) {
+			dev_dbg(ipc_protocol->dev,
+				"no free td elements for UL pipe %d",
+				pipe->pipe_nr);
+			break;
+		}
+
+		/* Get the td address. */
+		td = &pipe->tdr_start[head];
+
+		/* Take the first element of the uplink list and add it
+		 * to the td list.
+		 */
+		skb = skb_dequeue(p_ul_list);
+		if (WARN_ON(!skb))
+			break;
+
+		/* Save the reference to the uplink skbuf. */
+		pipe->skbr_start[head] = skb;
+
+		td->buffer.address = IPC_CB(skb)->mapping;
+		td->scs = cpu_to_le32(skb->len) & cpu_to_le32(SIZE_MASK);
+		td->next = 0;
+
+		pipe->nr_of_queued_entries++;
+
+		/* Calculate the new head and save it. */
+		head++;
+		if (head >= pipe->nr_of_entries)
+			head = 0;
+
+		ipc_protocol->p_ap_shm->head_array[pipe->pipe_nr] =
+			cpu_to_le32(head);
+	}
+
+	if (pipe->old_head != head) {
+		dev_dbg(ipc_protocol->dev, "New UL TDs Pipe:%d", pipe->pipe_nr);
+
+		pipe->old_head = head;
+		/* Trigger doorbell because of pending UL packets. */
+		hpda_pending = true;
+	}
+
+	return hpda_pending;
+}
+
+/* Checks for Tail pointer update from CP and returns the data as SKB. */
+struct sk_buff *ipc_protocol_ul_td_process(struct iosm_protocol *ipc_protocol,
+					   struct ipc_pipe *pipe)
+{
+	struct ipc_protocol_td *p_td = &pipe->tdr_start[pipe->old_tail];
+	struct sk_buff *skb = pipe->skbr_start[pipe->old_tail];
+
+	pipe->nr_of_queued_entries--;
+	pipe->old_tail++;
+	if (pipe->old_tail >= pipe->nr_of_entries)
+		pipe->old_tail = 0;
+
+	if (!p_td->buffer.address) {
+		dev_err(ipc_protocol->dev, "Td buffer address is NULL");
+		return NULL;
+	}
+
+	if (p_td->buffer.address != IPC_CB(skb)->mapping) {
+		dev_err(ipc_protocol->dev,
+			"pipe %d: invalid buf_addr or skb_data",
+			pipe->pipe_nr);
+		return NULL;
+	}
+
+	return skb;
+}
+
+/* Allocates an SKB for CP to send data and updates the Head Pointer
+ * of the given Pipe#.
+ */
+bool ipc_protocol_dl_td_prepare(struct iosm_protocol *ipc_protocol,
+				struct ipc_pipe *pipe)
+{
+	struct ipc_protocol_td *td;
+	dma_addr_t mapping = 0;
+	u32 head, new_head;
+	struct sk_buff *skb;
+	u32 tail;
+
+	/* Get head and tail of the td list and calculate
+	 * the number of free elements.
+	 */
+	head = le32_to_cpu(ipc_protocol->p_ap_shm->head_array[pipe->pipe_nr]);
+	tail = le32_to_cpu(ipc_protocol->p_ap_shm->tail_array[pipe->pipe_nr]);
+
+	new_head = head + 1;
+	if (new_head >= pipe->nr_of_entries)
+		new_head = 0;
+
+	if (new_head == tail)
+		return false;
+
+	/* Get the td address. */
+	td = &pipe->tdr_start[head];
+
+	/* Allocate the skbuf for the descriptor. */
+	skb = ipc_pcie_alloc_skb(ipc_protocol->pcie, pipe->buf_size, GFP_ATOMIC,
+				 &mapping, DMA_FROM_DEVICE,
+				 IPC_MEM_DL_ETH_OFFSET);
+	if (!skb)
+		return false;
+
+	td->buffer.address = mapping;
+	td->scs = cpu_to_le32(pipe->buf_size) & cpu_to_le32(SIZE_MASK);
+	td->next = 0;
+
+	/* store the new head value. */
+	ipc_protocol->p_ap_shm->head_array[pipe->pipe_nr] =
+		cpu_to_le32(new_head);
+
+	/* Save the reference to the skbuf. */
+	pipe->skbr_start[head] = skb;
+
+	pipe->nr_of_queued_entries++;
+
+	return true;
+}
+
+/* Processes DL TD's */
+struct sk_buff *ipc_protocol_dl_td_process(struct iosm_protocol *ipc_protocol,
+					   struct ipc_pipe *pipe)
+{
+	struct ipc_protocol_td *p_td;
+	struct sk_buff *skb;
+
+	if (!pipe->tdr_start)
+		return NULL;
+
+	/* Copy the reference to the downlink buffer. */
+	p_td = &pipe->tdr_start[pipe->old_tail];
+	skb = pipe->skbr_start[pipe->old_tail];
+
+	/* Reset the ring elements. */
+	pipe->skbr_start[pipe->old_tail] = NULL;
+
+	pipe->nr_of_queued_entries--;
+
+	pipe->old_tail++;
+	if (pipe->old_tail >= pipe->nr_of_entries)
+		pipe->old_tail = 0;
+
+	if (!skb) {
+		dev_err(ipc_protocol->dev, "skb is null");
+		goto ret;
+	} else if (!p_td->buffer.address) {
+		dev_err(ipc_protocol->dev, "td/buffer address is null");
+		ipc_pcie_kfree_skb(ipc_protocol->pcie, skb);
+		skb = NULL;
+		goto ret;
+	}
+
+	if (p_td->buffer.address != IPC_CB(skb)->mapping) {
+		dev_err(ipc_protocol->dev, "invalid buf=%llx or skb=%p",
+			(unsigned long long)p_td->buffer.address, skb->data);
+		ipc_pcie_kfree_skb(ipc_protocol->pcie, skb);
+		skb = NULL;
+		goto ret;
+	} else if ((le32_to_cpu(p_td->scs) & SIZE_MASK) > pipe->buf_size) {
+		dev_err(ipc_protocol->dev, "invalid buffer size %d > %d",
+			le32_to_cpu(p_td->scs) & SIZE_MASK,
+			pipe->buf_size);
+		ipc_pcie_kfree_skb(ipc_protocol->pcie, skb);
+		skb = NULL;
+		goto ret;
+	} else if (le32_to_cpu(p_td->scs) >> COMPLETION_STATUS ==
+		  IPC_MEM_TD_CS_ABORT) {
+		/* Discard aborted buffers. */
+		dev_dbg(ipc_protocol->dev, "discard 'aborted' buffers");
+		ipc_pcie_kfree_skb(ipc_protocol->pcie, skb);
+		skb = NULL;
+		goto ret;
+	}
+
+	/* Set the length field in skbuf. */
+	skb_put(skb, le32_to_cpu(p_td->scs) & SIZE_MASK);
+
+ret:
+	return skb;
+}
+
+void ipc_protocol_get_head_tail_index(struct iosm_protocol *ipc_protocol,
+				      struct ipc_pipe *pipe, u32 *head,
+				      u32 *tail)
+{
+	struct ipc_protocol_ap_shm *ipc_ap_shm = ipc_protocol->p_ap_shm;
+
+	if (head)
+		*head = le32_to_cpu(ipc_ap_shm->head_array[pipe->pipe_nr]);
+
+	if (tail)
+		*tail = le32_to_cpu(ipc_ap_shm->tail_array[pipe->pipe_nr]);
+}
+
+/* Frees the TDs given to CP.  */
+void ipc_protocol_pipe_cleanup(struct iosm_protocol *ipc_protocol,
+			       struct ipc_pipe *pipe)
+{
+	struct sk_buff *skb;
+	u32 head;
+	u32 tail;
+
+	/* Get the start and the end of the buffer list. */
+	head = le32_to_cpu(ipc_protocol->p_ap_shm->head_array[pipe->pipe_nr]);
+	tail = pipe->old_tail;
+
+	/* Reset tail and head to 0. */
+	ipc_protocol->p_ap_shm->tail_array[pipe->pipe_nr] = 0;
+	ipc_protocol->p_ap_shm->head_array[pipe->pipe_nr] = 0;
+
+	/* Free pending uplink and downlink buffers. */
+	if (pipe->skbr_start) {
+		while (head != tail) {
+			/* Get the reference to the skbuf,
+			 * which is on the way and free it.
+			 */
+			skb = pipe->skbr_start[tail];
+			if (skb)
+				ipc_pcie_kfree_skb(ipc_protocol->pcie, skb);
+
+			tail++;
+			if (tail >= pipe->nr_of_entries)
+				tail = 0;
+		}
+
+		kfree(pipe->skbr_start);
+		pipe->skbr_start = NULL;
+	}
+
+	pipe->old_tail = 0;
+
+	/* Free and reset the td and skbuf circular buffers. kfree is save! */
+	if (pipe->tdr_start) {
+		dma_free_coherent(&ipc_protocol->pcie->pci->dev,
+				  sizeof(*pipe->tdr_start) * pipe->nr_of_entries,
+				  pipe->tdr_start, pipe->phy_tdr_start);
+
+		pipe->tdr_start = NULL;
+	}
+}
+
+enum ipc_mem_device_ipc_state ipc_protocol_get_ipc_status(struct iosm_protocol
+							  *ipc_protocol)
+{
+	return (enum ipc_mem_device_ipc_state)
+		le32_to_cpu(ipc_protocol->p_ap_shm->device_info.ipc_status);
+}
+
+enum ipc_mem_exec_stage
+ipc_protocol_get_ap_exec_stage(struct iosm_protocol *ipc_protocol)
+{
+	return le32_to_cpu(ipc_protocol->p_ap_shm->device_info.execution_stage);
+}
+
+int ipc_protocol_msg_prep(struct iosm_imem *ipc_imem,
+			  enum ipc_msg_prep_type msg_type,
+			  union ipc_msg_prep_args *args)
+{
+	struct iosm_protocol *ipc_protocol = ipc_imem->ipc_protocol;
+
+	switch (msg_type) {
+	case IPC_MSG_PREP_SLEEP:
+		return ipc_protocol_msg_prep_sleep(ipc_protocol, args);
+
+	case IPC_MSG_PREP_PIPE_OPEN:
+		return ipc_protocol_msg_prepipe_open(ipc_protocol, args);
+
+	case IPC_MSG_PREP_PIPE_CLOSE:
+		return ipc_protocol_msg_prepipe_close(ipc_protocol, args);
+
+	case IPC_MSG_PREP_FEATURE_SET:
+		return ipc_protocol_msg_prep_feature_set(ipc_protocol, args);
+
+		/* Unsupported messages in protocol */
+	case IPC_MSG_PREP_MAP:
+	case IPC_MSG_PREP_UNMAP:
+	default:
+		dev_err(ipc_protocol->dev,
+			"unsupported message type: %d in protocol", msg_type);
+		return -EINVAL;
+	}
+}
+
+u32
+ipc_protocol_pm_dev_get_sleep_notification(struct iosm_protocol *ipc_protocol)
+{
+	struct ipc_protocol_ap_shm *ipc_ap_shm = ipc_protocol->p_ap_shm;
+
+	return le32_to_cpu(ipc_ap_shm->device_info.device_sleep_notification);
+}