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, 323 insertions, 0 deletions

diff --git a/Documentation/core-api/kref.rst b/Documentation/core-api/kref.rst
new file mode 100644
index 000000000..c61eea6f1
--- /dev/null
+++ b/Documentation/core-api/kref.rst
@@ -0,0 +1,323 @@
+===================================================
+Adding reference counters (krefs) to kernel objects
+===================================================
+
+:Author: Corey Minyard <minyard@acm.org>
+:Author: Thomas Hellstrom <thellstrom@vmware.com>
+
+A lot of this was lifted from Greg Kroah-Hartman's 2004 OLS paper and
+presentation on krefs, which can be found at:
+
+  - http://www.kroah.com/linux/talks/ols_2004_kref_paper/Reprint-Kroah-Hartman-OLS2004.pdf
+  - http://www.kroah.com/linux/talks/ols_2004_kref_talk/
+
+Introduction
+============
+
+krefs allow you to add reference counters to your objects.  If you
+have objects that are used in multiple places and passed around, and
+you don't have refcounts, your code is almost certainly broken.  If
+you want refcounts, krefs are the way to go.
+
+To use a kref, add one to your data structures like::
+
+    struct my_data
+    {
+	.
+	.
+	struct kref refcount;
+	.
+	.
+    };
+
+The kref can occur anywhere within the data structure.
+
+Initialization
+==============
+
+You must initialize the kref after you allocate it.  To do this, call
+kref_init as so::
+
+     struct my_data *data;
+
+     data = kmalloc(sizeof(*data), GFP_KERNEL);
+     if (!data)
+            return -ENOMEM;
+     kref_init(&data->refcount);
+
+This sets the refcount in the kref to 1.
+
+Kref rules
+==========
+
+Once you have an initialized kref, you must follow the following
+rules:
+
+1) If you make a non-temporary copy of a pointer, especially if
+   it can be passed to another thread of execution, you must
+   increment the refcount with kref_get() before passing it off::
+
+       kref_get(&data->refcount);
+
+   If you already have a valid pointer to a kref-ed structure (the
+   refcount cannot go to zero) you may do this without a lock.
+
+2) When you are done with a pointer, you must call kref_put()::
+
+       kref_put(&data->refcount, data_release);
+
+   If this is the last reference to the pointer, the release
+   routine will be called.  If the code never tries to get
+   a valid pointer to a kref-ed structure without already
+   holding a valid pointer, it is safe to do this without
+   a lock.
+
+3) If the code attempts to gain a reference to a kref-ed structure
+   without already holding a valid pointer, it must serialize access
+   where a kref_put() cannot occur during the kref_get(), and the
+   structure must remain valid during the kref_get().
+
+For example, if you allocate some data and then pass it to another
+thread to process::
+
+    void data_release(struct kref *ref)
+    {
+	struct my_data *data = container_of(ref, struct my_data, refcount);
+	kfree(data);
+    }
+
+    void more_data_handling(void *cb_data)
+    {
+	struct my_data *data = cb_data;
+	.
+	. do stuff with data here
+	.
+	kref_put(&data->refcount, data_release);
+    }
+
+    int my_data_handler(void)
+    {
+	int rv = 0;
+	struct my_data *data;
+	struct task_struct *task;
+	data = kmalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+	kref_init(&data->refcount);
+
+	kref_get(&data->refcount);
+	task = kthread_run(more_data_handling, data, "more_data_handling");
+	if (task == ERR_PTR(-ENOMEM)) {
+		rv = -ENOMEM;
+	        kref_put(&data->refcount, data_release);
+		goto out;
+	}
+
+	.
+	. do stuff with data here
+	.
+    out:
+	kref_put(&data->refcount, data_release);
+	return rv;
+    }
+
+This way, it doesn't matter what order the two threads handle the
+data, the kref_put() handles knowing when the data is not referenced
+any more and releasing it.  The kref_get() does not require a lock,
+since we already have a valid pointer that we own a refcount for.  The
+put needs no lock because nothing tries to get the data without
+already holding a pointer.
+
+In the above example, kref_put() will be called 2 times in both success
+and error paths. This is necessary because the reference count got
+incremented 2 times by kref_init() and kref_get().
+
+Note that the "before" in rule 1 is very important.  You should never
+do something like::
+
+	task = kthread_run(more_data_handling, data, "more_data_handling");
+	if (task == ERR_PTR(-ENOMEM)) {
+		rv = -ENOMEM;
+		goto out;
+	} else
+		/* BAD BAD BAD - get is after the handoff */
+		kref_get(&data->refcount);
+
+Don't assume you know what you are doing and use the above construct.
+First of all, you may not know what you are doing.  Second, you may
+know what you are doing (there are some situations where locking is
+involved where the above may be legal) but someone else who doesn't
+know what they are doing may change the code or copy the code.  It's
+bad style.  Don't do it.
+
+There are some situations where you can optimize the gets and puts.
+For instance, if you are done with an object and enqueuing it for
+something else or passing it off to something else, there is no reason
+to do a get then a put::
+
+	/* Silly extra get and put */
+	kref_get(&obj->ref);
+	enqueue(obj);
+	kref_put(&obj->ref, obj_cleanup);
+
+Just do the enqueue.  A comment about this is always welcome::
+
+	enqueue(obj);
+	/* We are done with obj, so we pass our refcount off
+	   to the queue.  DON'T TOUCH obj AFTER HERE! */
+
+The last rule (rule 3) is the nastiest one to handle.  Say, for
+instance, you have a list of items that are each kref-ed, and you wish
+to get the first one.  You can't just pull the first item off the list
+and kref_get() it.  That violates rule 3 because you are not already
+holding a valid pointer.  You must add a mutex (or some other lock).
+For instance::
+
+	static DEFINE_MUTEX(mutex);
+	static LIST_HEAD(q);
+	struct my_data
+	{
+		struct kref      refcount;
+		struct list_head link;
+	};
+
+	static struct my_data *get_entry()
+	{
+		struct my_data *entry = NULL;
+		mutex_lock(&mutex);
+		if (!list_empty(&q)) {
+			entry = container_of(q.next, struct my_data, link);
+			kref_get(&entry->refcount);
+		}
+		mutex_unlock(&mutex);
+		return entry;
+	}
+
+	static void release_entry(struct kref *ref)
+	{
+		struct my_data *entry = container_of(ref, struct my_data, refcount);
+
+		list_del(&entry->link);
+		kfree(entry);
+	}
+
+	static void put_entry(struct my_data *entry)
+	{
+		mutex_lock(&mutex);
+		kref_put(&entry->refcount, release_entry);
+		mutex_unlock(&mutex);
+	}
+
+The kref_put() return value is useful if you do not want to hold the
+lock during the whole release operation.  Say you didn't want to call
+kfree() with the lock held in the example above (since it is kind of
+pointless to do so).  You could use kref_put() as follows::
+
+	static void release_entry(struct kref *ref)
+	{
+		/* All work is done after the return from kref_put(). */
+	}
+
+	static void put_entry(struct my_data *entry)
+	{
+		mutex_lock(&mutex);
+		if (kref_put(&entry->refcount, release_entry)) {
+			list_del(&entry->link);
+			mutex_unlock(&mutex);
+			kfree(entry);
+		} else
+			mutex_unlock(&mutex);
+	}
+
+This is really more useful if you have to call other routines as part
+of the free operations that could take a long time or might claim the
+same lock.  Note that doing everything in the release routine is still
+preferred as it is a little neater.
+
+The above example could also be optimized using kref_get_unless_zero() in
+the following way::
+
+	static struct my_data *get_entry()
+	{
+		struct my_data *entry = NULL;
+		mutex_lock(&mutex);
+		if (!list_empty(&q)) {
+			entry = container_of(q.next, struct my_data, link);
+			if (!kref_get_unless_zero(&entry->refcount))
+				entry = NULL;
+		}
+		mutex_unlock(&mutex);
+		return entry;
+	}
+
+	static void release_entry(struct kref *ref)
+	{
+		struct my_data *entry = container_of(ref, struct my_data, refcount);
+
+		mutex_lock(&mutex);
+		list_del(&entry->link);
+		mutex_unlock(&mutex);
+		kfree(entry);
+	}
+
+	static void put_entry(struct my_data *entry)
+	{
+		kref_put(&entry->refcount, release_entry);
+	}
+
+Which is useful to remove the mutex lock around kref_put() in put_entry(), but
+it's important that kref_get_unless_zero is enclosed in the same critical
+section that finds the entry in the lookup table,
+otherwise kref_get_unless_zero may reference already freed memory.
+Note that it is illegal to use kref_get_unless_zero without checking its
+return value. If you are sure (by already having a valid pointer) that
+kref_get_unless_zero() will return true, then use kref_get() instead.
+
+Krefs and RCU
+=============
+
+The function kref_get_unless_zero also makes it possible to use rcu
+locking for lookups in the above example::
+
+	struct my_data
+	{
+		struct rcu_head rhead;
+		.
+		struct kref refcount;
+		.
+		.
+	};
+
+	static struct my_data *get_entry_rcu()
+	{
+		struct my_data *entry = NULL;
+		rcu_read_lock();
+		if (!list_empty(&q)) {
+			entry = container_of(q.next, struct my_data, link);
+			if (!kref_get_unless_zero(&entry->refcount))
+				entry = NULL;
+		}
+		rcu_read_unlock();
+		return entry;
+	}
+
+	static void release_entry_rcu(struct kref *ref)
+	{
+		struct my_data *entry = container_of(ref, struct my_data, refcount);
+
+		mutex_lock(&mutex);
+		list_del_rcu(&entry->link);
+		mutex_unlock(&mutex);
+		kfree_rcu(entry, rhead);
+	}
+
+	static void put_entry(struct my_data *entry)
+	{
+		kref_put(&entry->refcount, release_entry_rcu);
+	}
+
+But note that the struct kref member needs to remain in valid memory for a
+rcu grace period after release_entry_rcu was called. That can be accomplished
+by using kfree_rcu(entry, rhead) as done above, or by calling synchronize_rcu()
+before using kfree, but note that synchronize_rcu() may sleep for a
+substantial amount of time.