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, 591 insertions, 0 deletions

diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
new file mode 100644
index 000000000..b01474717
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -0,0 +1,591 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/*
+ * Media Controller ancillary functions
+ *
+ * Copyright (c) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
+ * Copyright (C) 2016 Shuah Khan <shuahkh@osg.samsung.com>
+ * Copyright (C) 2006-2010 Nokia Corporation
+ * Copyright (c) 2016 Intel Corporation.
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/usb.h>
+#include <media/media-device.h>
+#include <media/media-entity.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-mc.h>
+#include <media/v4l2-subdev.h>
+#include <media/videobuf2-core.h>
+
+int v4l2_mc_create_media_graph(struct media_device *mdev)
+
+{
+	struct media_entity *entity;
+	struct media_entity *if_vid = NULL, *if_aud = NULL;
+	struct media_entity *tuner = NULL, *decoder = NULL;
+	struct media_entity *io_v4l = NULL, *io_vbi = NULL, *io_swradio = NULL;
+	bool is_webcam = false;
+	u32 flags;
+	int ret, pad_sink, pad_source;
+
+	if (!mdev)
+		return 0;
+
+	media_device_for_each_entity(entity, mdev) {
+		switch (entity->function) {
+		case MEDIA_ENT_F_IF_VID_DECODER:
+			if_vid = entity;
+			break;
+		case MEDIA_ENT_F_IF_AUD_DECODER:
+			if_aud = entity;
+			break;
+		case MEDIA_ENT_F_TUNER:
+			tuner = entity;
+			break;
+		case MEDIA_ENT_F_ATV_DECODER:
+			decoder = entity;
+			break;
+		case MEDIA_ENT_F_IO_V4L:
+			io_v4l = entity;
+			break;
+		case MEDIA_ENT_F_IO_VBI:
+			io_vbi = entity;
+			break;
+		case MEDIA_ENT_F_IO_SWRADIO:
+			io_swradio = entity;
+			break;
+		case MEDIA_ENT_F_CAM_SENSOR:
+			is_webcam = true;
+			break;
+		}
+	}
+
+	/* It should have at least one I/O entity */
+	if (!io_v4l && !io_vbi && !io_swradio) {
+		dev_warn(mdev->dev, "Didn't find any I/O entity\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Here, webcams are modelled on a very simple way: the sensor is
+	 * connected directly to the I/O entity. All dirty details, like
+	 * scaler and crop HW are hidden. While such mapping is not enough
+	 * for mc-centric hardware, it is enough for v4l2 interface centric
+	 * PC-consumer's hardware.
+	 */
+	if (is_webcam) {
+		if (!io_v4l) {
+			dev_warn(mdev->dev, "Didn't find a MEDIA_ENT_F_IO_V4L\n");
+			return -EINVAL;
+		}
+
+		media_device_for_each_entity(entity, mdev) {
+			if (entity->function != MEDIA_ENT_F_CAM_SENSOR)
+				continue;
+			ret = media_create_pad_link(entity, 0,
+						    io_v4l, 0,
+						    MEDIA_LNK_FL_ENABLED);
+			if (ret) {
+				dev_warn(mdev->dev, "Failed to create a sensor link\n");
+				return ret;
+			}
+		}
+		if (!decoder)
+			return 0;
+	}
+
+	/* The device isn't a webcam. So, it should have a decoder */
+	if (!decoder) {
+		dev_warn(mdev->dev, "Decoder not found\n");
+		return -EINVAL;
+	}
+
+	/* Link the tuner and IF video output pads */
+	if (tuner) {
+		if (if_vid) {
+			pad_source = media_get_pad_index(tuner, false,
+							 PAD_SIGNAL_ANALOG);
+			pad_sink = media_get_pad_index(if_vid, true,
+						       PAD_SIGNAL_ANALOG);
+			if (pad_source < 0 || pad_sink < 0) {
+				dev_warn(mdev->dev, "Couldn't get tuner and/or PLL pad(s): (%d, %d)\n",
+					 pad_source, pad_sink);
+				return -EINVAL;
+			}
+			ret = media_create_pad_link(tuner, pad_source,
+						    if_vid, pad_sink,
+						    MEDIA_LNK_FL_ENABLED);
+			if (ret) {
+				dev_warn(mdev->dev, "Couldn't create tuner->PLL link)\n");
+				return ret;
+			}
+
+			pad_source = media_get_pad_index(if_vid, false,
+							 PAD_SIGNAL_ANALOG);
+			pad_sink = media_get_pad_index(decoder, true,
+						       PAD_SIGNAL_ANALOG);
+			if (pad_source < 0 || pad_sink < 0) {
+				dev_warn(mdev->dev, "get decoder and/or PLL pad(s): (%d, %d)\n",
+					 pad_source, pad_sink);
+				return -EINVAL;
+			}
+			ret = media_create_pad_link(if_vid, pad_source,
+						    decoder, pad_sink,
+						    MEDIA_LNK_FL_ENABLED);
+			if (ret) {
+				dev_warn(mdev->dev, "couldn't link PLL to decoder\n");
+				return ret;
+			}
+		} else {
+			pad_source = media_get_pad_index(tuner, false,
+							 PAD_SIGNAL_ANALOG);
+			pad_sink = media_get_pad_index(decoder, true,
+						       PAD_SIGNAL_ANALOG);
+			if (pad_source < 0 || pad_sink < 0) {
+				dev_warn(mdev->dev, "couldn't get tuner and/or decoder pad(s): (%d, %d)\n",
+					 pad_source, pad_sink);
+				return -EINVAL;
+			}
+			ret = media_create_pad_link(tuner, pad_source,
+						    decoder, pad_sink,
+						    MEDIA_LNK_FL_ENABLED);
+			if (ret)
+				return ret;
+		}
+
+		if (if_aud) {
+			pad_source = media_get_pad_index(tuner, false,
+							 PAD_SIGNAL_AUDIO);
+			pad_sink = media_get_pad_index(if_aud, true,
+						       PAD_SIGNAL_AUDIO);
+			if (pad_source < 0 || pad_sink < 0) {
+				dev_warn(mdev->dev, "couldn't get tuner and/or decoder pad(s) for audio: (%d, %d)\n",
+					 pad_source, pad_sink);
+				return -EINVAL;
+			}
+			ret = media_create_pad_link(tuner, pad_source,
+						    if_aud, pad_sink,
+						    MEDIA_LNK_FL_ENABLED);
+			if (ret) {
+				dev_warn(mdev->dev, "couldn't link tuner->audio PLL\n");
+				return ret;
+			}
+		} else {
+			if_aud = tuner;
+		}
+
+	}
+
+	/* Create demod to V4L, VBI and SDR radio links */
+	if (io_v4l) {
+		pad_source = media_get_pad_index(decoder, false, PAD_SIGNAL_DV);
+		if (pad_source < 0) {
+			dev_warn(mdev->dev, "couldn't get decoder output pad for V4L I/O\n");
+			return -EINVAL;
+		}
+		ret = media_create_pad_link(decoder, pad_source,
+					    io_v4l, 0,
+					    MEDIA_LNK_FL_ENABLED);
+		if (ret) {
+			dev_warn(mdev->dev, "couldn't link decoder output to V4L I/O\n");
+			return ret;
+		}
+	}
+
+	if (io_swradio) {
+		pad_source = media_get_pad_index(decoder, false, PAD_SIGNAL_DV);
+		if (pad_source < 0) {
+			dev_warn(mdev->dev, "couldn't get decoder output pad for SDR\n");
+			return -EINVAL;
+		}
+		ret = media_create_pad_link(decoder, pad_source,
+					    io_swradio, 0,
+					    MEDIA_LNK_FL_ENABLED);
+		if (ret) {
+			dev_warn(mdev->dev, "couldn't link decoder output to SDR\n");
+			return ret;
+		}
+	}
+
+	if (io_vbi) {
+		pad_source = media_get_pad_index(decoder, false, PAD_SIGNAL_DV);
+		if (pad_source < 0) {
+			dev_warn(mdev->dev, "couldn't get decoder output pad for VBI\n");
+			return -EINVAL;
+		}
+		ret = media_create_pad_link(decoder, pad_source,
+					    io_vbi, 0,
+					    MEDIA_LNK_FL_ENABLED);
+		if (ret) {
+			dev_warn(mdev->dev, "couldn't link decoder output to VBI\n");
+			return ret;
+		}
+	}
+
+	/* Create links for the media connectors */
+	flags = MEDIA_LNK_FL_ENABLED;
+	media_device_for_each_entity(entity, mdev) {
+		switch (entity->function) {
+		case MEDIA_ENT_F_CONN_RF:
+			if (!tuner)
+				continue;
+			pad_sink = media_get_pad_index(tuner, true,
+						       PAD_SIGNAL_ANALOG);
+			if (pad_sink < 0) {
+				dev_warn(mdev->dev, "couldn't get tuner analog pad sink\n");
+				return -EINVAL;
+			}
+			ret = media_create_pad_link(entity, 0, tuner,
+						    pad_sink,
+						    flags);
+			break;
+		case MEDIA_ENT_F_CONN_SVIDEO:
+		case MEDIA_ENT_F_CONN_COMPOSITE:
+			pad_sink = media_get_pad_index(decoder, true,
+						       PAD_SIGNAL_ANALOG);
+			if (pad_sink < 0) {
+				dev_warn(mdev->dev, "couldn't get decoder analog pad sink\n");
+				return -EINVAL;
+			}
+			ret = media_create_pad_link(entity, 0, decoder,
+						    pad_sink,
+						    flags);
+			break;
+		default:
+			continue;
+		}
+		if (ret)
+			return ret;
+
+		flags = 0;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);
+
+int v4l_enable_media_source(struct video_device *vdev)
+{
+	struct media_device *mdev = vdev->entity.graph_obj.mdev;
+	int ret = 0, err;
+
+	if (!mdev)
+		return 0;
+
+	mutex_lock(&mdev->graph_mutex);
+	if (!mdev->enable_source)
+		goto end;
+	err = mdev->enable_source(&vdev->entity, &vdev->pipe);
+	if (err)
+		ret = -EBUSY;
+end:
+	mutex_unlock(&mdev->graph_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l_enable_media_source);
+
+void v4l_disable_media_source(struct video_device *vdev)
+{
+	struct media_device *mdev = vdev->entity.graph_obj.mdev;
+
+	if (mdev) {
+		mutex_lock(&mdev->graph_mutex);
+		if (mdev->disable_source)
+			mdev->disable_source(&vdev->entity);
+		mutex_unlock(&mdev->graph_mutex);
+	}
+}
+EXPORT_SYMBOL_GPL(v4l_disable_media_source);
+
+int v4l_vb2q_enable_media_source(struct vb2_queue *q)
+{
+	struct v4l2_fh *fh = q->owner;
+
+	if (fh && fh->vdev)
+		return v4l_enable_media_source(fh->vdev);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
+
+int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
+				    struct media_pad *sink, u32 flags)
+{
+	struct fwnode_handle *endpoint;
+	struct v4l2_subdev *sink_sd;
+
+	if (!(sink->flags & MEDIA_PAD_FL_SINK) ||
+	    !is_media_entity_v4l2_subdev(sink->entity))
+		return -EINVAL;
+
+	sink_sd = media_entity_to_v4l2_subdev(sink->entity);
+
+	fwnode_graph_for_each_endpoint(dev_fwnode(src_sd->dev), endpoint) {
+		struct fwnode_handle *remote_ep;
+		int src_idx, sink_idx, ret;
+		struct media_pad *src;
+
+		src_idx = media_entity_get_fwnode_pad(&src_sd->entity,
+						      endpoint,
+						      MEDIA_PAD_FL_SOURCE);
+		if (src_idx < 0)
+			continue;
+
+		remote_ep = fwnode_graph_get_remote_endpoint(endpoint);
+		if (!remote_ep)
+			continue;
+
+		/*
+		 * ask the sink to verify it owns the remote endpoint,
+		 * and translate to a sink pad.
+		 */
+		sink_idx = media_entity_get_fwnode_pad(&sink_sd->entity,
+						       remote_ep,
+						       MEDIA_PAD_FL_SINK);
+		fwnode_handle_put(remote_ep);
+
+		if (sink_idx < 0 || sink_idx != sink->index)
+			continue;
+
+		/*
+		 * the source endpoint corresponds to one of its source pads,
+		 * the source endpoint connects to an endpoint at the sink
+		 * entity, and the sink endpoint corresponds to the sink
+		 * pad requested, so we have found an endpoint connection
+		 * that works, create the media link for it.
+		 */
+
+		src = &src_sd->entity.pads[src_idx];
+
+		/* skip if link already exists */
+		if (media_entity_find_link(src, sink))
+			continue;
+
+		dev_dbg(sink_sd->dev, "creating link %s:%d -> %s:%d\n",
+			src_sd->entity.name, src_idx,
+			sink_sd->entity.name, sink_idx);
+
+		ret = media_create_pad_link(&src_sd->entity, src_idx,
+					    &sink_sd->entity, sink_idx, flags);
+		if (ret) {
+			dev_err(sink_sd->dev,
+				"link %s:%d -> %s:%d failed with %d\n",
+				src_sd->entity.name, src_idx,
+				sink_sd->entity.name, sink_idx, ret);
+
+			fwnode_handle_put(endpoint);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_create_fwnode_links_to_pad);
+
+int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
+			     struct v4l2_subdev *sink_sd)
+{
+	unsigned int i;
+
+	for (i = 0; i < sink_sd->entity.num_pads; i++) {
+		struct media_pad *pad = &sink_sd->entity.pads[i];
+		int ret;
+
+		if (!(pad->flags & MEDIA_PAD_FL_SINK))
+			continue;
+
+		ret = v4l2_create_fwnode_links_to_pad(src_sd, pad, 0);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_create_fwnode_links);
+
+/* -----------------------------------------------------------------------------
+ * Pipeline power management
+ *
+ * Entities must be powered up when part of a pipeline that contains at least
+ * one open video device node.
+ *
+ * To achieve this use the entity use_count field to track the number of users.
+ * For entities corresponding to video device nodes the use_count field stores
+ * the users count of the node. For entities corresponding to subdevs the
+ * use_count field stores the total number of users of all video device nodes
+ * in the pipeline.
+ *
+ * The v4l2_pipeline_pm_{get, put}() functions must be called in the open() and
+ * close() handlers of video device nodes. It increments or decrements the use
+ * count of all subdev entities in the pipeline.
+ *
+ * To react to link management on powered pipelines, the link setup notification
+ * callback updates the use count of all entities in the source and sink sides
+ * of the link.
+ */
+
+/*
+ * pipeline_pm_use_count - Count the number of users of a pipeline
+ * @entity: The entity
+ *
+ * Return the total number of users of all video device nodes in the pipeline.
+ */
+static int pipeline_pm_use_count(struct media_entity *entity,
+	struct media_graph *graph)
+{
+	int use = 0;
+
+	media_graph_walk_start(graph, entity);
+
+	while ((entity = media_graph_walk_next(graph))) {
+		if (is_media_entity_v4l2_video_device(entity))
+			use += entity->use_count;
+	}
+
+	return use;
+}
+
+/*
+ * pipeline_pm_power_one - Apply power change to an entity
+ * @entity: The entity
+ * @change: Use count change
+ *
+ * Change the entity use count by @change. If the entity is a subdev update its
+ * power state by calling the core::s_power operation when the use count goes
+ * from 0 to != 0 or from != 0 to 0.
+ *
+ * Return 0 on success or a negative error code on failure.
+ */
+static int pipeline_pm_power_one(struct media_entity *entity, int change)
+{
+	struct v4l2_subdev *subdev;
+	int ret;
+
+	subdev = is_media_entity_v4l2_subdev(entity)
+	       ? media_entity_to_v4l2_subdev(entity) : NULL;
+
+	if (entity->use_count == 0 && change > 0 && subdev != NULL) {
+		ret = v4l2_subdev_call(subdev, core, s_power, 1);
+		if (ret < 0 && ret != -ENOIOCTLCMD)
+			return ret;
+	}
+
+	entity->use_count += change;
+	WARN_ON(entity->use_count < 0);
+
+	if (entity->use_count == 0 && change < 0 && subdev != NULL)
+		v4l2_subdev_call(subdev, core, s_power, 0);
+
+	return 0;
+}
+
+/*
+ * pipeline_pm_power - Apply power change to all entities in a pipeline
+ * @entity: The entity
+ * @change: Use count change
+ *
+ * Walk the pipeline to update the use count and the power state of all non-node
+ * entities.
+ *
+ * Return 0 on success or a negative error code on failure.
+ */
+static int pipeline_pm_power(struct media_entity *entity, int change,
+	struct media_graph *graph)
+{
+	struct media_entity *first = entity;
+	int ret = 0;
+
+	if (!change)
+		return 0;
+
+	media_graph_walk_start(graph, entity);
+
+	while (!ret && (entity = media_graph_walk_next(graph)))
+		if (is_media_entity_v4l2_subdev(entity))
+			ret = pipeline_pm_power_one(entity, change);
+
+	if (!ret)
+		return ret;
+
+	media_graph_walk_start(graph, first);
+
+	while ((first = media_graph_walk_next(graph))
+	       && first != entity)
+		if (is_media_entity_v4l2_subdev(first))
+			pipeline_pm_power_one(first, -change);
+
+	return ret;
+}
+
+static int v4l2_pipeline_pm_use(struct media_entity *entity, unsigned int use)
+{
+	struct media_device *mdev = entity->graph_obj.mdev;
+	int change = use ? 1 : -1;
+	int ret;
+
+	mutex_lock(&mdev->graph_mutex);
+
+	/* Apply use count to node. */
+	entity->use_count += change;
+	WARN_ON(entity->use_count < 0);
+
+	/* Apply power change to connected non-nodes. */
+	ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
+	if (ret < 0)
+		entity->use_count -= change;
+
+	mutex_unlock(&mdev->graph_mutex);
+
+	return ret;
+}
+
+int v4l2_pipeline_pm_get(struct media_entity *entity)
+{
+	return v4l2_pipeline_pm_use(entity, 1);
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_get);
+
+void v4l2_pipeline_pm_put(struct media_entity *entity)
+{
+	/* Powering off entities shouldn't fail. */
+	WARN_ON(v4l2_pipeline_pm_use(entity, 0));
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_put);
+
+int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
+			      unsigned int notification)
+{
+	struct media_graph *graph = &link->graph_obj.mdev->pm_count_walk;
+	struct media_entity *source = link->source->entity;
+	struct media_entity *sink = link->sink->entity;
+	int source_use;
+	int sink_use;
+	int ret = 0;
+
+	source_use = pipeline_pm_use_count(source, graph);
+	sink_use = pipeline_pm_use_count(sink, graph);
+
+	if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
+	    !(flags & MEDIA_LNK_FL_ENABLED)) {
+		/* Powering off entities is assumed to never fail. */
+		pipeline_pm_power(source, -sink_use, graph);
+		pipeline_pm_power(sink, -source_use, graph);
+		return 0;
+	}
+
+	if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
+		(flags & MEDIA_LNK_FL_ENABLED)) {
+
+		ret = pipeline_pm_power(source, sink_use, graph);
+		if (ret < 0)
+			return ret;
+
+		ret = pipeline_pm_power(sink, source_use, graph);
+		if (ret < 0)
+			pipeline_pm_power(source, -sink_use, graph);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);