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, 559 insertions, 0 deletions

diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c
new file mode 100644
index 000000000..2397a903d
--- /dev/null
+++ b/drivers/net/wwan/wwan_hwsim.c
@@ -0,0 +1,559 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * WWAN device simulator for WWAN framework testing.
+ *
+ * Copyright (c) 2021, Sergey Ryazanov <ryazanov.s.a@gmail.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/wwan.h>
+#include <linux/debugfs.h>
+#include <linux/workqueue.h>
+
+#include <net/arp.h>
+
+static int wwan_hwsim_devsnum = 2;
+module_param_named(devices, wwan_hwsim_devsnum, int, 0444);
+MODULE_PARM_DESC(devices, "Number of simulated devices");
+
+static struct class *wwan_hwsim_class;
+
+static struct dentry *wwan_hwsim_debugfs_topdir;
+static struct dentry *wwan_hwsim_debugfs_devcreate;
+
+static DEFINE_SPINLOCK(wwan_hwsim_devs_lock);
+static LIST_HEAD(wwan_hwsim_devs);
+static unsigned int wwan_hwsim_dev_idx;
+static struct workqueue_struct *wwan_wq;
+
+struct wwan_hwsim_dev {
+	struct list_head list;
+	unsigned int id;
+	struct device dev;
+	struct work_struct del_work;
+	struct dentry *debugfs_topdir;
+	struct dentry *debugfs_portcreate;
+	spinlock_t ports_lock;	/* Serialize ports creation/deletion */
+	unsigned int port_idx;
+	struct list_head ports;
+};
+
+struct wwan_hwsim_port {
+	struct list_head list;
+	unsigned int id;
+	struct wwan_hwsim_dev *dev;
+	struct wwan_port *wwan;
+	struct work_struct del_work;
+	struct dentry *debugfs_topdir;
+	enum {			/* AT command parser state */
+		AT_PARSER_WAIT_A,
+		AT_PARSER_WAIT_T,
+		AT_PARSER_WAIT_TERM,
+		AT_PARSER_SKIP_LINE,
+	} pstate;
+};
+
+static const struct file_operations wwan_hwsim_debugfs_portdestroy_fops;
+static const struct file_operations wwan_hwsim_debugfs_portcreate_fops;
+static const struct file_operations wwan_hwsim_debugfs_devdestroy_fops;
+static void wwan_hwsim_port_del_work(struct work_struct *work);
+static void wwan_hwsim_dev_del_work(struct work_struct *work);
+
+static netdev_tx_t wwan_hwsim_netdev_xmit(struct sk_buff *skb,
+					  struct net_device *ndev)
+{
+	ndev->stats.tx_packets++;
+	ndev->stats.tx_bytes += skb->len;
+	consume_skb(skb);
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops wwan_hwsim_netdev_ops = {
+	.ndo_start_xmit = wwan_hwsim_netdev_xmit,
+};
+
+static void wwan_hwsim_netdev_setup(struct net_device *ndev)
+{
+	ndev->netdev_ops = &wwan_hwsim_netdev_ops;
+	ndev->needs_free_netdev = true;
+
+	ndev->mtu = ETH_DATA_LEN;
+	ndev->min_mtu = ETH_MIN_MTU;
+	ndev->max_mtu = ETH_MAX_MTU;
+
+	ndev->type = ARPHRD_NONE;
+	ndev->flags = IFF_POINTOPOINT | IFF_NOARP;
+}
+
+static const struct wwan_ops wwan_hwsim_wwan_rtnl_ops = {
+	.priv_size = 0,			/* No private data */
+	.setup = wwan_hwsim_netdev_setup,
+};
+
+static int wwan_hwsim_port_start(struct wwan_port *wport)
+{
+	struct wwan_hwsim_port *port = wwan_port_get_drvdata(wport);
+
+	port->pstate = AT_PARSER_WAIT_A;
+
+	return 0;
+}
+
+static void wwan_hwsim_port_stop(struct wwan_port *wport)
+{
+}
+
+/* Implements a minimalistic AT commands parser that echo input back and
+ * reply with 'OK' to each input command. See AT command protocol details in the
+ * ITU-T V.250 recomendations document.
+ *
+ * Be aware that this processor is not fully V.250 compliant.
+ */
+static int wwan_hwsim_port_tx(struct wwan_port *wport, struct sk_buff *in)
+{
+	struct wwan_hwsim_port *port = wwan_port_get_drvdata(wport);
+	struct sk_buff *out;
+	int i, n, s;
+
+	/* Estimate a max possible number of commands by counting the number of
+	 * termination chars (S3 param, CR by default). And then allocate the
+	 * output buffer that will be enough to fit the echo and result codes of
+	 * all commands.
+	 */
+	for (i = 0, n = 0; i < in->len; ++i)
+		if (in->data[i] == '\r')
+			n++;
+	n = in->len + n * (2 + 2 + 2);	/* Output buffer size */
+	out = alloc_skb(n, GFP_KERNEL);
+	if (!out)
+		return -ENOMEM;
+
+	for (i = 0, s = 0; i < in->len; ++i) {
+		char c = in->data[i];
+
+		if (port->pstate == AT_PARSER_WAIT_A) {
+			if (c == 'A' || c == 'a')
+				port->pstate = AT_PARSER_WAIT_T;
+			else if (c != '\n')	/* Ignore formating char */
+				port->pstate = AT_PARSER_SKIP_LINE;
+		} else if (port->pstate == AT_PARSER_WAIT_T) {
+			if (c == 'T' || c == 't')
+				port->pstate = AT_PARSER_WAIT_TERM;
+			else
+				port->pstate = AT_PARSER_SKIP_LINE;
+		} else if (port->pstate == AT_PARSER_WAIT_TERM) {
+			if (c != '\r')
+				continue;
+			/* Consume the trailing formatting char as well */
+			if ((i + 1) < in->len && in->data[i + 1] == '\n')
+				i++;
+			n = i - s + 1;
+			skb_put_data(out, &in->data[s], n);/* Echo */
+			skb_put_data(out, "\r\nOK\r\n", 6);
+			s = i + 1;
+			port->pstate = AT_PARSER_WAIT_A;
+		} else if (port->pstate == AT_PARSER_SKIP_LINE) {
+			if (c != '\r')
+				continue;
+			port->pstate = AT_PARSER_WAIT_A;
+		}
+	}
+
+	if (i > s) {
+		/* Echo the processed portion of a not yet completed command */
+		n = i - s;
+		skb_put_data(out, &in->data[s], n);
+	}
+
+	consume_skb(in);
+
+	wwan_port_rx(wport, out);
+
+	return 0;
+}
+
+static const struct wwan_port_ops wwan_hwsim_port_ops = {
+	.start = wwan_hwsim_port_start,
+	.stop = wwan_hwsim_port_stop,
+	.tx = wwan_hwsim_port_tx,
+};
+
+static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev)
+{
+	struct wwan_hwsim_port *port;
+	char name[0x10];
+	int err;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return ERR_PTR(-ENOMEM);
+
+	port->dev = dev;
+
+	spin_lock(&dev->ports_lock);
+	port->id = dev->port_idx++;
+	spin_unlock(&dev->ports_lock);
+
+	port->wwan = wwan_create_port(&dev->dev, WWAN_PORT_AT,
+				      &wwan_hwsim_port_ops,
+				      port);
+	if (IS_ERR(port->wwan)) {
+		err = PTR_ERR(port->wwan);
+		goto err_free_port;
+	}
+
+	INIT_WORK(&port->del_work, wwan_hwsim_port_del_work);
+
+	snprintf(name, sizeof(name), "port%u", port->id);
+	port->debugfs_topdir = debugfs_create_dir(name, dev->debugfs_topdir);
+	debugfs_create_file("destroy", 0200, port->debugfs_topdir, port,
+			    &wwan_hwsim_debugfs_portdestroy_fops);
+
+	return port;
+
+err_free_port:
+	kfree(port);
+
+	return ERR_PTR(err);
+}
+
+static void wwan_hwsim_port_del(struct wwan_hwsim_port *port)
+{
+	debugfs_remove(port->debugfs_topdir);
+
+	/* Make sure that there is no pending deletion work */
+	if (current_work() != &port->del_work)
+		cancel_work_sync(&port->del_work);
+
+	wwan_remove_port(port->wwan);
+	kfree(port);
+}
+
+static void wwan_hwsim_port_del_work(struct work_struct *work)
+{
+	struct wwan_hwsim_port *port =
+				container_of(work, typeof(*port), del_work);
+	struct wwan_hwsim_dev *dev = port->dev;
+
+	spin_lock(&dev->ports_lock);
+	if (list_empty(&port->list)) {
+		/* Someone else deleting port at the moment */
+		spin_unlock(&dev->ports_lock);
+		return;
+	}
+	list_del_init(&port->list);
+	spin_unlock(&dev->ports_lock);
+
+	wwan_hwsim_port_del(port);
+}
+
+static void wwan_hwsim_dev_release(struct device *sysdev)
+{
+	struct wwan_hwsim_dev *dev = container_of(sysdev, typeof(*dev), dev);
+
+	kfree(dev);
+}
+
+static struct wwan_hwsim_dev *wwan_hwsim_dev_new(void)
+{
+	struct wwan_hwsim_dev *dev;
+	int err;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock(&wwan_hwsim_devs_lock);
+	dev->id = wwan_hwsim_dev_idx++;
+	spin_unlock(&wwan_hwsim_devs_lock);
+
+	dev->dev.release = wwan_hwsim_dev_release;
+	dev->dev.class = wwan_hwsim_class;
+	dev_set_name(&dev->dev, "hwsim%u", dev->id);
+
+	spin_lock_init(&dev->ports_lock);
+	INIT_LIST_HEAD(&dev->ports);
+
+	err = device_register(&dev->dev);
+	if (err)
+		goto err_free_dev;
+
+	INIT_WORK(&dev->del_work, wwan_hwsim_dev_del_work);
+
+	err = wwan_register_ops(&dev->dev, &wwan_hwsim_wwan_rtnl_ops, dev, 1);
+	if (err)
+		goto err_unreg_dev;
+
+	dev->debugfs_topdir = debugfs_create_dir(dev_name(&dev->dev),
+						 wwan_hwsim_debugfs_topdir);
+	debugfs_create_file("destroy", 0200, dev->debugfs_topdir, dev,
+			    &wwan_hwsim_debugfs_devdestroy_fops);
+	dev->debugfs_portcreate =
+		debugfs_create_file("portcreate", 0200,
+				    dev->debugfs_topdir, dev,
+				    &wwan_hwsim_debugfs_portcreate_fops);
+
+	return dev;
+
+err_unreg_dev:
+	device_unregister(&dev->dev);
+	/* Memory will be freed in the device release callback */
+
+	return ERR_PTR(err);
+
+err_free_dev:
+	put_device(&dev->dev);
+
+	return ERR_PTR(err);
+}
+
+static void wwan_hwsim_dev_del(struct wwan_hwsim_dev *dev)
+{
+	debugfs_remove(dev->debugfs_portcreate);	/* Avoid new ports */
+
+	spin_lock(&dev->ports_lock);
+	while (!list_empty(&dev->ports)) {
+		struct wwan_hwsim_port *port;
+
+		port = list_first_entry(&dev->ports, struct wwan_hwsim_port,
+					list);
+		list_del_init(&port->list);
+		spin_unlock(&dev->ports_lock);
+		wwan_hwsim_port_del(port);
+		spin_lock(&dev->ports_lock);
+	}
+	spin_unlock(&dev->ports_lock);
+
+	debugfs_remove(dev->debugfs_topdir);
+
+	/* This will remove all child netdev(s) */
+	wwan_unregister_ops(&dev->dev);
+
+	/* Make sure that there is no pending deletion work */
+	if (current_work() != &dev->del_work)
+		cancel_work_sync(&dev->del_work);
+
+	device_unregister(&dev->dev);
+	/* Memory will be freed in the device release callback */
+}
+
+static void wwan_hwsim_dev_del_work(struct work_struct *work)
+{
+	struct wwan_hwsim_dev *dev = container_of(work, typeof(*dev), del_work);
+
+	spin_lock(&wwan_hwsim_devs_lock);
+	if (list_empty(&dev->list)) {
+		/* Someone else deleting device at the moment */
+		spin_unlock(&wwan_hwsim_devs_lock);
+		return;
+	}
+	list_del_init(&dev->list);
+	spin_unlock(&wwan_hwsim_devs_lock);
+
+	wwan_hwsim_dev_del(dev);
+}
+
+static ssize_t wwan_hwsim_debugfs_portdestroy_write(struct file *file,
+						    const char __user *usrbuf,
+						    size_t count, loff_t *ppos)
+{
+	struct wwan_hwsim_port *port = file->private_data;
+
+	/* We can not delete port here since it will cause a deadlock due to
+	 * waiting this callback to finish in the debugfs_remove() call. So,
+	 * use workqueue.
+	 */
+	queue_work(wwan_wq, &port->del_work);
+
+	return count;
+}
+
+static const struct file_operations wwan_hwsim_debugfs_portdestroy_fops = {
+	.write = wwan_hwsim_debugfs_portdestroy_write,
+	.open = simple_open,
+	.llseek = noop_llseek,
+};
+
+static ssize_t wwan_hwsim_debugfs_portcreate_write(struct file *file,
+						   const char __user *usrbuf,
+						   size_t count, loff_t *ppos)
+{
+	struct wwan_hwsim_dev *dev = file->private_data;
+	struct wwan_hwsim_port *port;
+
+	port = wwan_hwsim_port_new(dev);
+	if (IS_ERR(port))
+		return PTR_ERR(port);
+
+	spin_lock(&dev->ports_lock);
+	list_add_tail(&port->list, &dev->ports);
+	spin_unlock(&dev->ports_lock);
+
+	return count;
+}
+
+static const struct file_operations wwan_hwsim_debugfs_portcreate_fops = {
+	.write = wwan_hwsim_debugfs_portcreate_write,
+	.open = simple_open,
+	.llseek = noop_llseek,
+};
+
+static ssize_t wwan_hwsim_debugfs_devdestroy_write(struct file *file,
+						   const char __user *usrbuf,
+						   size_t count, loff_t *ppos)
+{
+	struct wwan_hwsim_dev *dev = file->private_data;
+
+	/* We can not delete device here since it will cause a deadlock due to
+	 * waiting this callback to finish in the debugfs_remove() call. So,
+	 * use workqueue.
+	 */
+	queue_work(wwan_wq, &dev->del_work);
+
+	return count;
+}
+
+static const struct file_operations wwan_hwsim_debugfs_devdestroy_fops = {
+	.write = wwan_hwsim_debugfs_devdestroy_write,
+	.open = simple_open,
+	.llseek = noop_llseek,
+};
+
+static ssize_t wwan_hwsim_debugfs_devcreate_write(struct file *file,
+						  const char __user *usrbuf,
+						  size_t count, loff_t *ppos)
+{
+	struct wwan_hwsim_dev *dev;
+
+	dev = wwan_hwsim_dev_new();
+	if (IS_ERR(dev))
+		return PTR_ERR(dev);
+
+	spin_lock(&wwan_hwsim_devs_lock);
+	list_add_tail(&dev->list, &wwan_hwsim_devs);
+	spin_unlock(&wwan_hwsim_devs_lock);
+
+	return count;
+}
+
+static const struct file_operations wwan_hwsim_debugfs_devcreate_fops = {
+	.write = wwan_hwsim_debugfs_devcreate_write,
+	.open = simple_open,
+	.llseek = noop_llseek,
+};
+
+static int __init wwan_hwsim_init_devs(void)
+{
+	struct wwan_hwsim_dev *dev;
+	int i, j;
+
+	for (i = 0; i < wwan_hwsim_devsnum; ++i) {
+		dev = wwan_hwsim_dev_new();
+		if (IS_ERR(dev))
+			return PTR_ERR(dev);
+
+		spin_lock(&wwan_hwsim_devs_lock);
+		list_add_tail(&dev->list, &wwan_hwsim_devs);
+		spin_unlock(&wwan_hwsim_devs_lock);
+
+		/* Create a couple of ports per each device to accelerate
+		 * the simulator readiness time.
+		 */
+		for (j = 0; j < 2; ++j) {
+			struct wwan_hwsim_port *port;
+
+			port = wwan_hwsim_port_new(dev);
+			if (IS_ERR(port))
+				return PTR_ERR(port);
+
+			spin_lock(&dev->ports_lock);
+			list_add_tail(&port->list, &dev->ports);
+			spin_unlock(&dev->ports_lock);
+		}
+	}
+
+	return 0;
+}
+
+static void wwan_hwsim_free_devs(void)
+{
+	struct wwan_hwsim_dev *dev;
+
+	spin_lock(&wwan_hwsim_devs_lock);
+	while (!list_empty(&wwan_hwsim_devs)) {
+		dev = list_first_entry(&wwan_hwsim_devs, struct wwan_hwsim_dev,
+				       list);
+		list_del_init(&dev->list);
+		spin_unlock(&wwan_hwsim_devs_lock);
+		wwan_hwsim_dev_del(dev);
+		spin_lock(&wwan_hwsim_devs_lock);
+	}
+	spin_unlock(&wwan_hwsim_devs_lock);
+}
+
+static int __init wwan_hwsim_init(void)
+{
+	int err;
+
+	if (wwan_hwsim_devsnum < 0 || wwan_hwsim_devsnum > 128)
+		return -EINVAL;
+
+	wwan_wq = alloc_workqueue("wwan_wq", 0, 0);
+	if (!wwan_wq)
+		return -ENOMEM;
+
+	wwan_hwsim_class = class_create(THIS_MODULE, "wwan_hwsim");
+	if (IS_ERR(wwan_hwsim_class)) {
+		err = PTR_ERR(wwan_hwsim_class);
+		goto err_wq_destroy;
+	}
+
+	wwan_hwsim_debugfs_topdir = debugfs_create_dir("wwan_hwsim", NULL);
+	wwan_hwsim_debugfs_devcreate =
+			debugfs_create_file("devcreate", 0200,
+					    wwan_hwsim_debugfs_topdir, NULL,
+					    &wwan_hwsim_debugfs_devcreate_fops);
+
+	err = wwan_hwsim_init_devs();
+	if (err)
+		goto err_clean_devs;
+
+	return 0;
+
+err_clean_devs:
+	debugfs_remove(wwan_hwsim_debugfs_devcreate);	/* Avoid new devs */
+	wwan_hwsim_free_devs();
+	flush_workqueue(wwan_wq);	/* Wait deletion works completion */
+	debugfs_remove(wwan_hwsim_debugfs_topdir);
+	class_destroy(wwan_hwsim_class);
+err_wq_destroy:
+	destroy_workqueue(wwan_wq);
+
+	return err;
+}
+
+static void __exit wwan_hwsim_exit(void)
+{
+	debugfs_remove(wwan_hwsim_debugfs_devcreate);	/* Avoid new devs */
+	wwan_hwsim_free_devs();
+	flush_workqueue(wwan_wq);	/* Wait deletion works completion */
+	debugfs_remove(wwan_hwsim_debugfs_topdir);
+	class_destroy(wwan_hwsim_class);
+	destroy_workqueue(wwan_wq);
+}
+
+module_init(wwan_hwsim_init);
+module_exit(wwan_hwsim_exit);
+
+MODULE_AUTHOR("Sergey Ryazanov");
+MODULE_DESCRIPTION("Device simulator for WWAN framework");
+MODULE_LICENSE("GPL");