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, 724 insertions, 0 deletions

diff --git a/drivers/most/configfs.c b/drivers/most/configfs.c
new file mode 100644
index 000000000..27b0c9235
--- /dev/null
+++ b/drivers/most/configfs.c
@@ -0,0 +1,724 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * configfs.c - Implementation of configfs interface to the driver stack
+ *
+ * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/configfs.h>
+#include <linux/most.h>
+
+#define MAX_STRING_SIZE 80
+
+struct mdev_link {
+	struct config_item item;
+	struct list_head list;
+	bool create_link;
+	bool destroy_link;
+	u16 num_buffers;
+	u16 buffer_size;
+	u16 subbuffer_size;
+	u16 packets_per_xact;
+	u16 dbr_size;
+	char datatype[MAX_STRING_SIZE];
+	char direction[MAX_STRING_SIZE];
+	char name[MAX_STRING_SIZE];
+	char device[MAX_STRING_SIZE];
+	char channel[MAX_STRING_SIZE];
+	char comp[MAX_STRING_SIZE];
+	char comp_params[MAX_STRING_SIZE];
+};
+
+static struct list_head mdev_link_list;
+
+static int set_cfg_buffer_size(struct mdev_link *link)
+{
+	return most_set_cfg_buffer_size(link->device, link->channel,
+					link->buffer_size);
+}
+
+static int set_cfg_subbuffer_size(struct mdev_link *link)
+{
+	return most_set_cfg_subbuffer_size(link->device, link->channel,
+					   link->subbuffer_size);
+}
+
+static int set_cfg_dbr_size(struct mdev_link *link)
+{
+	return most_set_cfg_dbr_size(link->device, link->channel,
+				     link->dbr_size);
+}
+
+static int set_cfg_num_buffers(struct mdev_link *link)
+{
+	return most_set_cfg_num_buffers(link->device, link->channel,
+					link->num_buffers);
+}
+
+static int set_cfg_packets_xact(struct mdev_link *link)
+{
+	return most_set_cfg_packets_xact(link->device, link->channel,
+					 link->packets_per_xact);
+}
+
+static int set_cfg_direction(struct mdev_link *link)
+{
+	return most_set_cfg_direction(link->device, link->channel,
+				      link->direction);
+}
+
+static int set_cfg_datatype(struct mdev_link *link)
+{
+	return most_set_cfg_datatype(link->device, link->channel,
+				     link->datatype);
+}
+
+static int (*set_config_val[])(struct mdev_link *link) = {
+	set_cfg_buffer_size,
+	set_cfg_subbuffer_size,
+	set_cfg_dbr_size,
+	set_cfg_num_buffers,
+	set_cfg_packets_xact,
+	set_cfg_direction,
+	set_cfg_datatype,
+};
+
+static struct mdev_link *to_mdev_link(struct config_item *item)
+{
+	return container_of(item, struct mdev_link, item);
+}
+
+static int set_config_and_add_link(struct mdev_link *mdev_link)
+{
+	int i;
+	int ret;
+
+	for (i = 0; i < ARRAY_SIZE(set_config_val); i++) {
+		ret = set_config_val[i](mdev_link);
+		if (ret < 0 && ret != -ENODEV) {
+			pr_err("Config failed\n");
+			return ret;
+		}
+	}
+
+	return most_add_link(mdev_link->device, mdev_link->channel,
+			     mdev_link->comp, mdev_link->name,
+			     mdev_link->comp_params);
+}
+
+static ssize_t mdev_link_create_link_store(struct config_item *item,
+					   const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	bool tmp;
+	int ret;
+
+	ret = kstrtobool(page, &tmp);
+	if (ret)
+		return ret;
+	if (!tmp)
+		return count;
+	ret = set_config_and_add_link(mdev_link);
+	if (ret && ret != -ENODEV)
+		return ret;
+	list_add_tail(&mdev_link->list, &mdev_link_list);
+	mdev_link->create_link = tmp;
+	mdev_link->destroy_link = false;
+
+	return count;
+}
+
+static ssize_t mdev_link_destroy_link_store(struct config_item *item,
+					    const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	bool tmp;
+	int ret;
+
+	ret = kstrtobool(page, &tmp);
+	if (ret)
+		return ret;
+	if (!tmp)
+		return count;
+
+	ret = most_remove_link(mdev_link->device, mdev_link->channel,
+			       mdev_link->comp);
+	if (ret)
+		return ret;
+	if (!list_empty(&mdev_link_list))
+		list_del(&mdev_link->list);
+
+	mdev_link->destroy_link = tmp;
+
+	return count;
+}
+
+static ssize_t mdev_link_direction_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->direction);
+}
+
+static ssize_t mdev_link_direction_store(struct config_item *item,
+					 const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	if (!sysfs_streq(page, "dir_rx") && !sysfs_streq(page, "rx") &&
+	    !sysfs_streq(page, "dir_tx") && !sysfs_streq(page, "tx"))
+		return -EINVAL;
+	strcpy(mdev_link->direction, page);
+	strim(mdev_link->direction);
+	return count;
+}
+
+static ssize_t mdev_link_datatype_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->datatype);
+}
+
+static ssize_t mdev_link_datatype_store(struct config_item *item,
+					const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	if (!sysfs_streq(page, "control") && !sysfs_streq(page, "async") &&
+	    !sysfs_streq(page, "sync") && !sysfs_streq(page, "isoc") &&
+	    !sysfs_streq(page, "isoc_avp"))
+		return -EINVAL;
+	strcpy(mdev_link->datatype, page);
+	strim(mdev_link->datatype);
+	return count;
+}
+
+static ssize_t mdev_link_device_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->device);
+}
+
+static ssize_t mdev_link_device_store(struct config_item *item,
+				      const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	strlcpy(mdev_link->device, page, sizeof(mdev_link->device));
+	strim(mdev_link->device);
+	return count;
+}
+
+static ssize_t mdev_link_channel_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->channel);
+}
+
+static ssize_t mdev_link_channel_store(struct config_item *item,
+				       const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	strlcpy(mdev_link->channel, page, sizeof(mdev_link->channel));
+	strim(mdev_link->channel);
+	return count;
+}
+
+static ssize_t mdev_link_comp_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->comp);
+}
+
+static ssize_t mdev_link_comp_store(struct config_item *item,
+				    const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	strlcpy(mdev_link->comp, page, sizeof(mdev_link->comp));
+	strim(mdev_link->comp);
+	return count;
+}
+
+static ssize_t mdev_link_comp_params_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n",
+			to_mdev_link(item)->comp_params);
+}
+
+static ssize_t mdev_link_comp_params_store(struct config_item *item,
+					   const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	strlcpy(mdev_link->comp_params, page, sizeof(mdev_link->comp_params));
+	strim(mdev_link->comp_params);
+	return count;
+}
+
+static ssize_t mdev_link_num_buffers_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			to_mdev_link(item)->num_buffers);
+}
+
+static ssize_t mdev_link_num_buffers_store(struct config_item *item,
+					   const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->num_buffers);
+	if (ret)
+		return ret;
+	return count;
+}
+
+static ssize_t mdev_link_buffer_size_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			to_mdev_link(item)->buffer_size);
+}
+
+static ssize_t mdev_link_buffer_size_store(struct config_item *item,
+					   const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->buffer_size);
+	if (ret)
+		return ret;
+	return count;
+}
+
+static ssize_t mdev_link_subbuffer_size_show(struct config_item *item,
+					     char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			to_mdev_link(item)->subbuffer_size);
+}
+
+static ssize_t mdev_link_subbuffer_size_store(struct config_item *item,
+					      const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->subbuffer_size);
+	if (ret)
+		return ret;
+	return count;
+}
+
+static ssize_t mdev_link_packets_per_xact_show(struct config_item *item,
+					       char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			to_mdev_link(item)->packets_per_xact);
+}
+
+static ssize_t mdev_link_packets_per_xact_store(struct config_item *item,
+						const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->packets_per_xact);
+	if (ret)
+		return ret;
+	return count;
+}
+
+static ssize_t mdev_link_dbr_size_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n", to_mdev_link(item)->dbr_size);
+}
+
+static ssize_t mdev_link_dbr_size_store(struct config_item *item,
+					const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->dbr_size);
+	if (ret)
+		return ret;
+	return count;
+}
+
+CONFIGFS_ATTR_WO(mdev_link_, create_link);
+CONFIGFS_ATTR_WO(mdev_link_, destroy_link);
+CONFIGFS_ATTR(mdev_link_, device);
+CONFIGFS_ATTR(mdev_link_, channel);
+CONFIGFS_ATTR(mdev_link_, comp);
+CONFIGFS_ATTR(mdev_link_, comp_params);
+CONFIGFS_ATTR(mdev_link_, num_buffers);
+CONFIGFS_ATTR(mdev_link_, buffer_size);
+CONFIGFS_ATTR(mdev_link_, subbuffer_size);
+CONFIGFS_ATTR(mdev_link_, packets_per_xact);
+CONFIGFS_ATTR(mdev_link_, datatype);
+CONFIGFS_ATTR(mdev_link_, direction);
+CONFIGFS_ATTR(mdev_link_, dbr_size);
+
+static struct configfs_attribute *mdev_link_attrs[] = {
+	&mdev_link_attr_create_link,
+	&mdev_link_attr_destroy_link,
+	&mdev_link_attr_device,
+	&mdev_link_attr_channel,
+	&mdev_link_attr_comp,
+	&mdev_link_attr_comp_params,
+	&mdev_link_attr_num_buffers,
+	&mdev_link_attr_buffer_size,
+	&mdev_link_attr_subbuffer_size,
+	&mdev_link_attr_packets_per_xact,
+	&mdev_link_attr_datatype,
+	&mdev_link_attr_direction,
+	&mdev_link_attr_dbr_size,
+	NULL,
+};
+
+static void mdev_link_release(struct config_item *item)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	if (mdev_link->destroy_link)
+		goto free_item;
+
+	ret = most_remove_link(mdev_link->device, mdev_link->channel,
+			       mdev_link->comp);
+	if (ret) {
+		pr_err("Removing link failed.\n");
+		goto free_item;
+	}
+
+	if (!list_empty(&mdev_link_list))
+		list_del(&mdev_link->list);
+
+free_item:
+	kfree(to_mdev_link(item));
+}
+
+static struct configfs_item_operations mdev_link_item_ops = {
+	.release		= mdev_link_release,
+};
+
+static const struct config_item_type mdev_link_type = {
+	.ct_item_ops	= &mdev_link_item_ops,
+	.ct_attrs	= mdev_link_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+struct most_common {
+	struct config_group group;
+	struct module *mod;
+	struct configfs_subsystem subsys;
+};
+
+static struct most_common *to_most_common(struct configfs_subsystem *subsys)
+{
+	return container_of(subsys, struct most_common, subsys);
+}
+
+static struct config_item *most_common_make_item(struct config_group *group,
+						 const char *name)
+{
+	struct mdev_link *mdev_link;
+	struct most_common *mc = to_most_common(group->cg_subsys);
+
+	mdev_link = kzalloc(sizeof(*mdev_link), GFP_KERNEL);
+	if (!mdev_link)
+		return ERR_PTR(-ENOMEM);
+
+	if (!try_module_get(mc->mod)) {
+		kfree(mdev_link);
+		return ERR_PTR(-ENOLCK);
+	}
+	config_item_init_type_name(&mdev_link->item, name,
+				   &mdev_link_type);
+
+	if (!strcmp(group->cg_item.ci_namebuf, "most_cdev"))
+		strcpy(mdev_link->comp, "cdev");
+	else if (!strcmp(group->cg_item.ci_namebuf, "most_net"))
+		strcpy(mdev_link->comp, "net");
+	else if (!strcmp(group->cg_item.ci_namebuf, "most_video"))
+		strcpy(mdev_link->comp, "video");
+	strcpy(mdev_link->name, name);
+	return &mdev_link->item;
+}
+
+static void most_common_release(struct config_item *item)
+{
+	struct config_group *group = to_config_group(item);
+
+	kfree(to_most_common(group->cg_subsys));
+}
+
+static struct configfs_item_operations most_common_item_ops = {
+	.release	= most_common_release,
+};
+
+static void most_common_disconnect(struct config_group *group,
+				   struct config_item *item)
+{
+	struct most_common *mc = to_most_common(group->cg_subsys);
+
+	module_put(mc->mod);
+}
+
+static struct configfs_group_operations most_common_group_ops = {
+	.make_item	= most_common_make_item,
+	.disconnect_notify = most_common_disconnect,
+};
+
+static const struct config_item_type most_common_type = {
+	.ct_item_ops	= &most_common_item_ops,
+	.ct_group_ops	= &most_common_group_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct most_common most_cdev = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "most_cdev",
+				.ci_type = &most_common_type,
+			},
+		},
+	},
+};
+
+static struct most_common most_net = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "most_net",
+				.ci_type = &most_common_type,
+			},
+		},
+	},
+};
+
+static struct most_common most_video = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "most_video",
+				.ci_type = &most_common_type,
+			},
+		},
+	},
+};
+
+struct most_snd_grp {
+	struct config_group group;
+	bool create_card;
+	struct list_head list;
+};
+
+static struct most_snd_grp *to_most_snd_grp(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct most_snd_grp, group);
+}
+
+static struct config_item *most_snd_grp_make_item(struct config_group *group,
+						  const char *name)
+{
+	struct mdev_link *mdev_link;
+
+	mdev_link = kzalloc(sizeof(*mdev_link), GFP_KERNEL);
+	if (!mdev_link)
+		return ERR_PTR(-ENOMEM);
+
+	config_item_init_type_name(&mdev_link->item, name, &mdev_link_type);
+	mdev_link->create_link = false;
+	strcpy(mdev_link->name, name);
+	strcpy(mdev_link->comp, "sound");
+	return &mdev_link->item;
+}
+
+static ssize_t most_snd_grp_create_card_store(struct config_item *item,
+					      const char *page, size_t count)
+{
+	struct most_snd_grp *snd_grp = to_most_snd_grp(item);
+	int ret;
+	bool tmp;
+
+	ret = kstrtobool(page, &tmp);
+	if (ret)
+		return ret;
+	if (tmp) {
+		ret = most_cfg_complete("sound");
+		if (ret)
+			return ret;
+	}
+	snd_grp->create_card = tmp;
+	return count;
+}
+
+CONFIGFS_ATTR_WO(most_snd_grp_, create_card);
+
+static struct configfs_attribute *most_snd_grp_attrs[] = {
+	&most_snd_grp_attr_create_card,
+	NULL,
+};
+
+static void most_snd_grp_release(struct config_item *item)
+{
+	struct most_snd_grp *group = to_most_snd_grp(item);
+
+	list_del(&group->list);
+	kfree(group);
+}
+
+static struct configfs_item_operations most_snd_grp_item_ops = {
+	.release	= most_snd_grp_release,
+};
+
+static struct configfs_group_operations most_snd_grp_group_ops = {
+	.make_item	= most_snd_grp_make_item,
+};
+
+static const struct config_item_type most_snd_grp_type = {
+	.ct_item_ops	= &most_snd_grp_item_ops,
+	.ct_group_ops	= &most_snd_grp_group_ops,
+	.ct_attrs	= most_snd_grp_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+struct most_sound {
+	struct configfs_subsystem subsys;
+	struct list_head soundcard_list;
+	struct module *mod;
+};
+
+static struct config_group *most_sound_make_group(struct config_group *group,
+						  const char *name)
+{
+	struct most_snd_grp *most;
+	struct most_sound *ms = container_of(group->cg_subsys,
+					     struct most_sound, subsys);
+
+	list_for_each_entry(most, &ms->soundcard_list, list) {
+		if (!most->create_card) {
+			pr_info("adapter configuration still in progress.\n");
+			return ERR_PTR(-EPROTO);
+		}
+	}
+	if (!try_module_get(ms->mod))
+		return ERR_PTR(-ENOLCK);
+	most = kzalloc(sizeof(*most), GFP_KERNEL);
+	if (!most) {
+		module_put(ms->mod);
+		return ERR_PTR(-ENOMEM);
+	}
+	config_group_init_type_name(&most->group, name, &most_snd_grp_type);
+	list_add_tail(&most->list, &ms->soundcard_list);
+	return &most->group;
+}
+
+static void most_sound_disconnect(struct config_group *group,
+				  struct config_item *item)
+{
+	struct most_sound *ms = container_of(group->cg_subsys,
+					     struct most_sound, subsys);
+	module_put(ms->mod);
+}
+
+static struct configfs_group_operations most_sound_group_ops = {
+	.make_group	= most_sound_make_group,
+	.disconnect_notify = most_sound_disconnect,
+};
+
+static const struct config_item_type most_sound_type = {
+	.ct_group_ops	= &most_sound_group_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct most_sound most_sound_subsys = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "most_sound",
+				.ci_type = &most_sound_type,
+			},
+		},
+	},
+};
+
+int most_register_configfs_subsys(struct most_component *c)
+{
+	int ret;
+
+	if (!strcmp(c->name, "cdev")) {
+		most_cdev.mod = c->mod;
+		ret = configfs_register_subsystem(&most_cdev.subsys);
+	} else if (!strcmp(c->name, "net")) {
+		most_net.mod = c->mod;
+		ret = configfs_register_subsystem(&most_net.subsys);
+	} else if (!strcmp(c->name, "video")) {
+		most_video.mod = c->mod;
+		ret = configfs_register_subsystem(&most_video.subsys);
+	} else if (!strcmp(c->name, "sound")) {
+		most_sound_subsys.mod = c->mod;
+		ret = configfs_register_subsystem(&most_sound_subsys.subsys);
+	} else {
+		return -ENODEV;
+	}
+
+	if (ret) {
+		pr_err("Error %d while registering subsystem %s\n",
+		       ret, c->name);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(most_register_configfs_subsys);
+
+void most_interface_register_notify(const char *mdev)
+{
+	bool register_snd_card = false;
+	struct mdev_link *mdev_link;
+
+	list_for_each_entry(mdev_link, &mdev_link_list, list) {
+		if (!strcmp(mdev_link->device, mdev)) {
+			set_config_and_add_link(mdev_link);
+			if (!strcmp(mdev_link->comp, "sound"))
+				register_snd_card = true;
+		}
+	}
+	if (register_snd_card)
+		most_cfg_complete("sound");
+}
+
+void most_deregister_configfs_subsys(struct most_component *c)
+{
+	if (!strcmp(c->name, "cdev"))
+		configfs_unregister_subsystem(&most_cdev.subsys);
+	else if (!strcmp(c->name, "net"))
+		configfs_unregister_subsystem(&most_net.subsys);
+	else if (!strcmp(c->name, "video"))
+		configfs_unregister_subsystem(&most_video.subsys);
+	else if (!strcmp(c->name, "sound"))
+		configfs_unregister_subsystem(&most_sound_subsys.subsys);
+}
+EXPORT_SYMBOL_GPL(most_deregister_configfs_subsys);
+
+int __init configfs_init(void)
+{
+	config_group_init(&most_cdev.subsys.su_group);
+	mutex_init(&most_cdev.subsys.su_mutex);
+
+	config_group_init(&most_net.subsys.su_group);
+	mutex_init(&most_net.subsys.su_mutex);
+
+	config_group_init(&most_video.subsys.su_group);
+	mutex_init(&most_video.subsys.su_mutex);
+
+	config_group_init(&most_sound_subsys.subsys.su_group);
+	mutex_init(&most_sound_subsys.subsys.su_mutex);
+
+	INIT_LIST_HEAD(&most_sound_subsys.soundcard_list);
+	INIT_LIST_HEAD(&mdev_link_list);
+
+	return 0;
+}