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/hwtracing/coresight/coresight-syscfg-configfs.c b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c
new file mode 100644
index 000000000..433ede94d
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-syscfg-configfs.c
@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Linaro Limited, All rights reserved.
+ * Author: Mike Leach <mike.leach@linaro.org>
+ */
+
+#include <linux/configfs.h>
+
+#include "coresight-config.h"
+#include "coresight-syscfg-configfs.h"
+
+/* create a default ci_type. */
+static inline struct config_item_type *cscfg_create_ci_type(void)
+{
+	struct config_item_type *ci_type;
+
+	ci_type = devm_kzalloc(cscfg_device(), sizeof(*ci_type), GFP_KERNEL);
+	if (ci_type)
+		ci_type->ct_owner = THIS_MODULE;
+
+	return ci_type;
+}
+
+/* configurations sub-group */
+
+/* attributes for the config view group */
+static ssize_t cscfg_cfg_description_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
+							 struct cscfg_fs_config, group);
+
+	return scnprintf(page, PAGE_SIZE, "%s", fs_config->config_desc->description);
+}
+CONFIGFS_ATTR_RO(cscfg_cfg_, description);
+
+static ssize_t cscfg_cfg_feature_refs_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
+							 struct cscfg_fs_config, group);
+	const struct cscfg_config_desc *config_desc = fs_config->config_desc;
+	ssize_t ch_used = 0;
+	int i;
+
+	for (i = 0; i < config_desc->nr_feat_refs; i++)
+		ch_used += scnprintf(page + ch_used, PAGE_SIZE - ch_used,
+				     "%s\n", config_desc->feat_ref_names[i]);
+	return ch_used;
+}
+CONFIGFS_ATTR_RO(cscfg_cfg_, feature_refs);
+
+/* list preset values in order of features and params */
+static ssize_t cscfg_cfg_values_show(struct config_item *item, char *page)
+{
+	const struct cscfg_feature_desc *feat_desc;
+	const struct cscfg_config_desc *config_desc;
+	struct cscfg_fs_preset *fs_preset;
+	int i, j, val_idx, preset_idx;
+	ssize_t used = 0;
+
+	fs_preset = container_of(to_config_group(item), struct cscfg_fs_preset, group);
+	config_desc = fs_preset->config_desc;
+
+	if (!config_desc->nr_presets)
+		return 0;
+
+	preset_idx = fs_preset->preset_num - 1;
+
+	/* start index on the correct array line */
+	val_idx = config_desc->nr_total_params * preset_idx;
+
+	/*
+	 * A set of presets is the sum of all params in used features,
+	 * in order of declaration of features and params in the features
+	 */
+	for (i = 0; i < config_desc->nr_feat_refs; i++) {
+		feat_desc = cscfg_get_named_feat_desc(config_desc->feat_ref_names[i]);
+		for (j = 0; j < feat_desc->nr_params; j++) {
+			used += scnprintf(page + used, PAGE_SIZE - used,
+					  "%s.%s = 0x%llx ",
+					  feat_desc->name,
+					  feat_desc->params_desc[j].name,
+					  config_desc->presets[val_idx++]);
+		}
+	}
+	used += scnprintf(page + used, PAGE_SIZE - used, "\n");
+
+	return used;
+}
+CONFIGFS_ATTR_RO(cscfg_cfg_, values);
+
+static ssize_t cscfg_cfg_enable_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
+							 struct cscfg_fs_config, group);
+
+	return scnprintf(page, PAGE_SIZE, "%d\n", fs_config->active);
+}
+
+static ssize_t cscfg_cfg_enable_store(struct config_item *item,
+					const char *page, size_t count)
+{
+	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
+							 struct cscfg_fs_config, group);
+	int err;
+	bool val;
+
+	err = kstrtobool(page, &val);
+	if (!err)
+		err = cscfg_config_sysfs_activate(fs_config->config_desc, val);
+	if (!err) {
+		fs_config->active = val;
+		if (val)
+			cscfg_config_sysfs_set_preset(fs_config->preset);
+	}
+	return err ? err : count;
+}
+CONFIGFS_ATTR(cscfg_cfg_, enable);
+
+static ssize_t cscfg_cfg_preset_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
+							 struct cscfg_fs_config, group);
+
+	return scnprintf(page, PAGE_SIZE, "%d\n", fs_config->preset);
+}
+
+static ssize_t cscfg_cfg_preset_store(struct config_item *item,
+					     const char *page, size_t count)
+{
+	struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
+							 struct cscfg_fs_config, group);
+	int preset, err;
+
+	err = kstrtoint(page, 0, &preset);
+	if (!err) {
+		/*
+		 * presets start at 1, and go up to max (15),
+		 * but the config may provide fewer.
+		 */
+		if ((preset < 1) || (preset > fs_config->config_desc->nr_presets))
+			err = -EINVAL;
+	}
+
+	if (!err) {
+		/* set new value */
+		fs_config->preset = preset;
+		/* set on system if active */
+		if (fs_config->active)
+			cscfg_config_sysfs_set_preset(fs_config->preset);
+	}
+	return err ? err : count;
+}
+CONFIGFS_ATTR(cscfg_cfg_, preset);
+
+static struct configfs_attribute *cscfg_config_view_attrs[] = {
+	&cscfg_cfg_attr_description,
+	&cscfg_cfg_attr_feature_refs,
+	&cscfg_cfg_attr_enable,
+	&cscfg_cfg_attr_preset,
+	NULL,
+};
+
+static struct config_item_type cscfg_config_view_type = {
+	.ct_owner = THIS_MODULE,
+	.ct_attrs = cscfg_config_view_attrs,
+};
+
+static struct configfs_attribute *cscfg_config_preset_attrs[] = {
+	&cscfg_cfg_attr_values,
+	NULL,
+};
+
+static struct config_item_type cscfg_config_preset_type = {
+	.ct_owner = THIS_MODULE,
+	.ct_attrs = cscfg_config_preset_attrs,
+};
+
+static int cscfg_add_preset_groups(struct cscfg_fs_config *cfg_view)
+{
+	int preset_num;
+	struct cscfg_fs_preset *cfg_fs_preset;
+	struct cscfg_config_desc *config_desc = cfg_view->config_desc;
+	char name[CONFIGFS_ITEM_NAME_LEN];
+
+	if (!config_desc->nr_presets)
+		return 0;
+
+	for (preset_num = 1; preset_num <= config_desc->nr_presets; preset_num++) {
+		cfg_fs_preset = devm_kzalloc(cscfg_device(),
+					     sizeof(struct cscfg_fs_preset), GFP_KERNEL);
+
+		if (!cfg_fs_preset)
+			return -ENOMEM;
+
+		snprintf(name, CONFIGFS_ITEM_NAME_LEN, "preset%d", preset_num);
+		cfg_fs_preset->preset_num = preset_num;
+		cfg_fs_preset->config_desc = cfg_view->config_desc;
+		config_group_init_type_name(&cfg_fs_preset->group, name,
+					    &cscfg_config_preset_type);
+		configfs_add_default_group(&cfg_fs_preset->group, &cfg_view->group);
+	}
+	return 0;
+}
+
+static struct config_group *cscfg_create_config_group(struct cscfg_config_desc *config_desc)
+{
+	struct cscfg_fs_config *cfg_view;
+	struct device *dev = cscfg_device();
+	int err;
+
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
+	cfg_view = devm_kzalloc(dev, sizeof(struct cscfg_fs_config), GFP_KERNEL);
+	if (!cfg_view)
+		return ERR_PTR(-ENOMEM);
+
+	cfg_view->config_desc = config_desc;
+	config_group_init_type_name(&cfg_view->group, config_desc->name, &cscfg_config_view_type);
+
+	/* add in a preset<n> dir for each preset */
+	err = cscfg_add_preset_groups(cfg_view);
+	if (err)
+		return ERR_PTR(err);
+
+	return &cfg_view->group;
+}
+
+/* attributes for features view */
+
+static ssize_t cscfg_feat_description_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item),
+							struct cscfg_fs_feature, group);
+
+	return scnprintf(page, PAGE_SIZE, "%s", fs_feat->feat_desc->description);
+}
+CONFIGFS_ATTR_RO(cscfg_feat_, description);
+
+static ssize_t cscfg_feat_matches_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item),
+							struct cscfg_fs_feature, group);
+	u32 match_flags = fs_feat->feat_desc->match_flags;
+	int used = 0;
+
+	if (match_flags & CS_CFG_MATCH_CLASS_SRC_ALL)
+		used = scnprintf(page, PAGE_SIZE, "SRC_ALL ");
+
+	if (match_flags & CS_CFG_MATCH_CLASS_SRC_ETM4)
+		used += scnprintf(page + used, PAGE_SIZE - used, "SRC_ETMV4 ");
+
+	used += scnprintf(page + used, PAGE_SIZE - used, "\n");
+	return used;
+}
+CONFIGFS_ATTR_RO(cscfg_feat_, matches);
+
+static ssize_t cscfg_feat_nr_params_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item),
+							struct cscfg_fs_feature, group);
+
+	return scnprintf(page, PAGE_SIZE, "%d\n", fs_feat->feat_desc->nr_params);
+}
+CONFIGFS_ATTR_RO(cscfg_feat_, nr_params);
+
+/* base feature desc attrib structures */
+static struct configfs_attribute *cscfg_feature_view_attrs[] = {
+	&cscfg_feat_attr_description,
+	&cscfg_feat_attr_matches,
+	&cscfg_feat_attr_nr_params,
+	NULL,
+};
+
+static struct config_item_type cscfg_feature_view_type = {
+	.ct_owner = THIS_MODULE,
+	.ct_attrs = cscfg_feature_view_attrs,
+};
+
+static ssize_t cscfg_param_value_show(struct config_item *item, char *page)
+{
+	struct cscfg_fs_param *param_item = container_of(to_config_group(item),
+							 struct cscfg_fs_param, group);
+	u64 value = param_item->feat_desc->params_desc[param_item->param_idx].value;
+
+	return scnprintf(page, PAGE_SIZE, "0x%llx\n", value);
+}
+
+static ssize_t cscfg_param_value_store(struct config_item *item,
+				       const char *page, size_t size)
+{
+	struct cscfg_fs_param *param_item = container_of(to_config_group(item),
+							 struct cscfg_fs_param, group);
+	struct cscfg_feature_desc *feat_desc = param_item->feat_desc;
+	int param_idx = param_item->param_idx;
+	u64 value;
+	int err;
+
+	err = kstrtoull(page, 0, &value);
+	if (!err)
+		err = cscfg_update_feat_param_val(feat_desc, param_idx, value);
+
+	return err ? err : size;
+}
+CONFIGFS_ATTR(cscfg_param_, value);
+
+static struct configfs_attribute *cscfg_param_view_attrs[] = {
+	&cscfg_param_attr_value,
+	NULL,
+};
+
+static struct config_item_type cscfg_param_view_type = {
+	.ct_owner = THIS_MODULE,
+	.ct_attrs = cscfg_param_view_attrs,
+};
+
+/*
+ * configfs has far less functionality provided to add attributes dynamically than sysfs,
+ * and the show and store fns pass the enclosing config_item so the actual attribute cannot
+ * be determined. Therefore we add each item as a group directory, with a value attribute.
+ */
+static int cscfg_create_params_group_items(struct cscfg_feature_desc *feat_desc,
+					   struct config_group *params_group)
+{
+	struct device *dev = cscfg_device();
+	struct cscfg_fs_param *param_item;
+	int i;
+
+	/* parameter items - as groups with default_value attribute */
+	for (i = 0; i < feat_desc->nr_params; i++) {
+		param_item = devm_kzalloc(dev, sizeof(struct cscfg_fs_param), GFP_KERNEL);
+		if (!param_item)
+			return -ENOMEM;
+		param_item->feat_desc = feat_desc;
+		param_item->param_idx = i;
+		config_group_init_type_name(&param_item->group,
+					    feat_desc->params_desc[i].name,
+					    &cscfg_param_view_type);
+		configfs_add_default_group(&param_item->group, params_group);
+	}
+	return 0;
+}
+
+static struct config_group *cscfg_create_feature_group(struct cscfg_feature_desc *feat_desc)
+{
+	struct cscfg_fs_feature *feat_view;
+	struct config_item_type *params_group_type;
+	struct config_group *params_group = NULL;
+	struct device *dev = cscfg_device();
+	int item_err;
+
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
+	feat_view = devm_kzalloc(dev, sizeof(struct cscfg_fs_feature), GFP_KERNEL);
+	if (!feat_view)
+		return ERR_PTR(-ENOMEM);
+
+	if (feat_desc->nr_params) {
+		params_group = devm_kzalloc(dev, sizeof(struct config_group), GFP_KERNEL);
+		if (!params_group)
+			return ERR_PTR(-ENOMEM);
+
+		params_group_type = cscfg_create_ci_type();
+		if (!params_group_type)
+			return ERR_PTR(-ENOMEM);
+	}
+
+	feat_view->feat_desc = feat_desc;
+	config_group_init_type_name(&feat_view->group,
+				    feat_desc->name,
+				    &cscfg_feature_view_type);
+	if (params_group) {
+		config_group_init_type_name(params_group, "params", params_group_type);
+		configfs_add_default_group(params_group, &feat_view->group);
+		item_err = cscfg_create_params_group_items(feat_desc, params_group);
+		if (item_err)
+			return ERR_PTR(item_err);
+	}
+	return &feat_view->group;
+}
+
+static struct config_item_type cscfg_configs_type = {
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_group cscfg_configs_grp = {
+	.cg_item = {
+		.ci_namebuf = "configurations",
+		.ci_type = &cscfg_configs_type,
+	},
+};
+
+/* add configuration to configurations group */
+int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc)
+{
+	struct config_group *new_group;
+	int err;
+
+	new_group = cscfg_create_config_group(config_desc);
+	if (IS_ERR(new_group))
+		return PTR_ERR(new_group);
+	err =  configfs_register_group(&cscfg_configs_grp, new_group);
+	if (!err)
+		config_desc->fs_group = new_group;
+	return err;
+}
+
+void cscfg_configfs_del_config(struct cscfg_config_desc *config_desc)
+{
+	if (config_desc->fs_group) {
+		configfs_unregister_group(config_desc->fs_group);
+		config_desc->fs_group = NULL;
+	}
+}
+
+static struct config_item_type cscfg_features_type = {
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_group cscfg_features_grp = {
+	.cg_item = {
+		.ci_namebuf = "features",
+		.ci_type = &cscfg_features_type,
+	},
+};
+
+/* add feature to features group */
+int cscfg_configfs_add_feature(struct cscfg_feature_desc *feat_desc)
+{
+	struct config_group *new_group;
+	int err;
+
+	new_group = cscfg_create_feature_group(feat_desc);
+	if (IS_ERR(new_group))
+		return PTR_ERR(new_group);
+	err =  configfs_register_group(&cscfg_features_grp, new_group);
+	if (!err)
+		feat_desc->fs_group = new_group;
+	return err;
+}
+
+void cscfg_configfs_del_feature(struct cscfg_feature_desc *feat_desc)
+{
+	if (feat_desc->fs_group) {
+		configfs_unregister_group(feat_desc->fs_group);
+		feat_desc->fs_group = NULL;
+	}
+}
+
+int cscfg_configfs_init(struct cscfg_manager *cscfg_mgr)
+{
+	struct configfs_subsystem *subsys;
+	struct config_item_type *ci_type;
+
+	if (!cscfg_mgr)
+		return -EINVAL;
+
+	ci_type = cscfg_create_ci_type();
+	if (!ci_type)
+		return -ENOMEM;
+
+	subsys = &cscfg_mgr->cfgfs_subsys;
+	config_item_set_name(&subsys->su_group.cg_item, CSCFG_FS_SUBSYS_NAME);
+	subsys->su_group.cg_item.ci_type = ci_type;
+
+	config_group_init(&subsys->su_group);
+	mutex_init(&subsys->su_mutex);
+
+	/* Add default groups to subsystem */
+	config_group_init(&cscfg_configs_grp);
+	configfs_add_default_group(&cscfg_configs_grp, &subsys->su_group);
+
+	config_group_init(&cscfg_features_grp);
+	configfs_add_default_group(&cscfg_features_grp, &subsys->su_group);
+
+	return configfs_register_subsystem(subsys);
+}
+
+void cscfg_configfs_release(struct cscfg_manager *cscfg_mgr)
+{
+	configfs_unregister_subsystem(&cscfg_mgr->cfgfs_subsys);
+}