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, 348 insertions, 0 deletions

diff --git a/Documentation/input/input-programming.rst b/Documentation/input/input-programming.rst
new file mode 100644
index 000000000..c9264814c
--- /dev/null
+++ b/Documentation/input/input-programming.rst
@@ -0,0 +1,348 @@
+===============================
+Creating an input device driver
+===============================
+
+The simplest example
+~~~~~~~~~~~~~~~~~~~~
+
+Here comes a very simple example of an input device driver. The device has
+just one button and the button is accessible at i/o port BUTTON_PORT. When
+pressed or released a BUTTON_IRQ happens. The driver could look like::
+
+    #include <linux/input.h>
+    #include <linux/module.h>
+    #include <linux/init.h>
+
+    #include <asm/irq.h>
+    #include <asm/io.h>
+
+    static struct input_dev *button_dev;
+
+    static irqreturn_t button_interrupt(int irq, void *dummy)
+    {
+	    input_report_key(button_dev, BTN_0, inb(BUTTON_PORT) & 1);
+	    input_sync(button_dev);
+	    return IRQ_HANDLED;
+    }
+
+    static int __init button_init(void)
+    {
+	    int error;
+
+	    if (request_irq(BUTTON_IRQ, button_interrupt, 0, "button", NULL)) {
+		    printk(KERN_ERR "button.c: Can't allocate irq %d\n", button_irq);
+		    return -EBUSY;
+	    }
+
+	    button_dev = input_allocate_device();
+	    if (!button_dev) {
+		    printk(KERN_ERR "button.c: Not enough memory\n");
+		    error = -ENOMEM;
+		    goto err_free_irq;
+	    }
+
+	    button_dev->evbit[0] = BIT_MASK(EV_KEY);
+	    button_dev->keybit[BIT_WORD(BTN_0)] = BIT_MASK(BTN_0);
+
+	    error = input_register_device(button_dev);
+	    if (error) {
+		    printk(KERN_ERR "button.c: Failed to register device\n");
+		    goto err_free_dev;
+	    }
+
+	    return 0;
+
+    err_free_dev:
+	    input_free_device(button_dev);
+    err_free_irq:
+	    free_irq(BUTTON_IRQ, button_interrupt);
+	    return error;
+    }
+
+    static void __exit button_exit(void)
+    {
+	    input_unregister_device(button_dev);
+	    free_irq(BUTTON_IRQ, button_interrupt);
+    }
+
+    module_init(button_init);
+    module_exit(button_exit);
+
+What the example does
+~~~~~~~~~~~~~~~~~~~~~
+
+First it has to include the <linux/input.h> file, which interfaces to the
+input subsystem. This provides all the definitions needed.
+
+In the _init function, which is called either upon module load or when
+booting the kernel, it grabs the required resources (it should also check
+for the presence of the device).
+
+Then it allocates a new input device structure with input_allocate_device()
+and sets up input bitfields. This way the device driver tells the other
+parts of the input systems what it is - what events can be generated or
+accepted by this input device. Our example device can only generate EV_KEY
+type events, and from those only BTN_0 event code. Thus we only set these
+two bits. We could have used::
+
+	set_bit(EV_KEY, button_dev->evbit);
+	set_bit(BTN_0, button_dev->keybit);
+
+as well, but with more than single bits the first approach tends to be
+shorter.
+
+Then the example driver registers the input device structure by calling::
+
+	input_register_device(button_dev);
+
+This adds the button_dev structure to linked lists of the input driver and
+calls device handler modules _connect functions to tell them a new input
+device has appeared. input_register_device() may sleep and therefore must
+not be called from an interrupt or with a spinlock held.
+
+While in use, the only used function of the driver is::
+
+	button_interrupt()
+
+which upon every interrupt from the button checks its state and reports it
+via the::
+
+	input_report_key()
+
+call to the input system. There is no need to check whether the interrupt
+routine isn't reporting two same value events (press, press for example) to
+the input system, because the input_report_* functions check that
+themselves.
+
+Then there is the::
+
+	input_sync()
+
+call to tell those who receive the events that we've sent a complete report.
+This doesn't seem important in the one button case, but is quite important
+for example for mouse movement, where you don't want the X and Y values
+to be interpreted separately, because that'd result in a different movement.
+
+dev->open() and dev->close()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In case the driver has to repeatedly poll the device, because it doesn't
+have an interrupt coming from it and the polling is too expensive to be done
+all the time, or if the device uses a valuable resource (e.g. interrupt), it
+can use the open and close callback to know when it can stop polling or
+release the interrupt and when it must resume polling or grab the interrupt
+again. To do that, we would add this to our example driver::
+
+    static int button_open(struct input_dev *dev)
+    {
+	    if (request_irq(BUTTON_IRQ, button_interrupt, 0, "button", NULL)) {
+		    printk(KERN_ERR "button.c: Can't allocate irq %d\n", button_irq);
+		    return -EBUSY;
+	    }
+
+	    return 0;
+    }
+
+    static void button_close(struct input_dev *dev)
+    {
+	    free_irq(IRQ_AMIGA_VERTB, button_interrupt);
+    }
+
+    static int __init button_init(void)
+    {
+	    ...
+	    button_dev->open = button_open;
+	    button_dev->close = button_close;
+	    ...
+    }
+
+Note that input core keeps track of number of users for the device and
+makes sure that dev->open() is called only when the first user connects
+to the device and that dev->close() is called when the very last user
+disconnects. Calls to both callbacks are serialized.
+
+The open() callback should return a 0 in case of success or any non-zero value
+in case of failure. The close() callback (which is void) must always succeed.
+
+Inhibiting input devices
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Inhibiting a device means ignoring input events from it. As such it is about
+maintaining relationships with input handlers - either already existing
+relationships, or relationships to be established while the device is in
+inhibited state.
+
+If a device is inhibited, no input handler will receive events from it.
+
+The fact that nobody wants events from the device is exploited further, by
+calling device's close() (if there are users) and open() (if there are users) on
+inhibit and uninhibit operations, respectively. Indeed, the meaning of close()
+is to stop providing events to the input core and that of open() is to start
+providing events to the input core.
+
+Calling the device's close() method on inhibit (if there are users) allows the
+driver to save power. Either by directly powering down the device or by
+releasing the runtime-PM reference it got in open() when the driver is using
+runtime-PM.
+
+Inhibiting and uninhibiting are orthogonal to opening and closing the device by
+input handlers. Userspace might want to inhibit a device in anticipation before
+any handler is positively matched against it.
+
+Inhibiting and uninhibiting are orthogonal to device's being a wakeup source,
+too. Being a wakeup source plays a role when the system is sleeping, not when
+the system is operating.  How drivers should program their interaction between
+inhibiting, sleeping and being a wakeup source is driver-specific.
+
+Taking the analogy with the network devices - bringing a network interface down
+doesn't mean that it should be impossible be wake the system up on LAN through
+this interface. So, there may be input drivers which should be considered wakeup
+sources even when inhibited. Actually, in many I2C input devices their interrupt
+is declared a wakeup interrupt and its handling happens in driver's core, which
+is not aware of input-specific inhibit (nor should it be).  Composite devices
+containing several interfaces can be inhibited on a per-interface basis and e.g.
+inhibiting one interface shouldn't affect the device's capability of being a
+wakeup source.
+
+If a device is to be considered a wakeup source while inhibited, special care
+must be taken when programming its suspend(), as it might need to call device's
+open(). Depending on what close() means for the device in question, not
+opening() it before going to sleep might make it impossible to provide any
+wakeup events. The device is going to sleep anyway.
+
+Basic event types
+~~~~~~~~~~~~~~~~~
+
+The most simple event type is EV_KEY, which is used for keys and buttons.
+It's reported to the input system via::
+
+	input_report_key(struct input_dev *dev, int code, int value)
+
+See uapi/linux/input-event-codes.h for the allowable values of code (from 0 to
+KEY_MAX). Value is interpreted as a truth value, i.e. any non-zero value means
+key pressed, zero value means key released. The input code generates events only
+in case the value is different from before.
+
+In addition to EV_KEY, there are two more basic event types: EV_REL and
+EV_ABS. They are used for relative and absolute values supplied by the
+device. A relative value may be for example a mouse movement in the X axis.
+The mouse reports it as a relative difference from the last position,
+because it doesn't have any absolute coordinate system to work in. Absolute
+events are namely for joysticks and digitizers - devices that do work in an
+absolute coordinate systems.
+
+Having the device report EV_REL buttons is as simple as with EV_KEY; simply
+set the corresponding bits and call the::
+
+	input_report_rel(struct input_dev *dev, int code, int value)
+
+function. Events are generated only for non-zero values.
+
+However EV_ABS requires a little special care. Before calling
+input_register_device, you have to fill additional fields in the input_dev
+struct for each absolute axis your device has. If our button device had also
+the ABS_X axis::
+
+	button_dev.absmin[ABS_X] = 0;
+	button_dev.absmax[ABS_X] = 255;
+	button_dev.absfuzz[ABS_X] = 4;
+	button_dev.absflat[ABS_X] = 8;
+
+Or, you can just say::
+
+	input_set_abs_params(button_dev, ABS_X, 0, 255, 4, 8);
+
+This setting would be appropriate for a joystick X axis, with the minimum of
+0, maximum of 255 (which the joystick *must* be able to reach, no problem if
+it sometimes reports more, but it must be able to always reach the min and
+max values), with noise in the data up to +- 4, and with a center flat
+position of size 8.
+
+If you don't need absfuzz and absflat, you can set them to zero, which mean
+that the thing is precise and always returns to exactly the center position
+(if it has any).
+
+BITS_TO_LONGS(), BIT_WORD(), BIT_MASK()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+These three macros from bitops.h help some bitfield computations::
+
+	BITS_TO_LONGS(x) - returns the length of a bitfield array in longs for
+			   x bits
+	BIT_WORD(x)	 - returns the index in the array in longs for bit x
+	BIT_MASK(x)	 - returns the index in a long for bit x
+
+The id* and name fields
+~~~~~~~~~~~~~~~~~~~~~~~
+
+The dev->name should be set before registering the input device by the input
+device driver. It's a string like 'Generic button device' containing a
+user friendly name of the device.
+
+The id* fields contain the bus ID (PCI, USB, ...), vendor ID and device ID
+of the device. The bus IDs are defined in input.h. The vendor and device IDs
+are defined in pci_ids.h, usb_ids.h and similar include files. These fields
+should be set by the input device driver before registering it.
+
+The idtype field can be used for specific information for the input device
+driver.
+
+The id and name fields can be passed to userland via the evdev interface.
+
+The keycode, keycodemax, keycodesize fields
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+These three fields should be used by input devices that have dense keymaps.
+The keycode is an array used to map from scancodes to input system keycodes.
+The keycode max should contain the size of the array and keycodesize the
+size of each entry in it (in bytes).
+
+Userspace can query and alter current scancode to keycode mappings using
+EVIOCGKEYCODE and EVIOCSKEYCODE ioctls on corresponding evdev interface.
+When a device has all 3 aforementioned fields filled in, the driver may
+rely on kernel's default implementation of setting and querying keycode
+mappings.
+
+dev->getkeycode() and dev->setkeycode()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+getkeycode() and setkeycode() callbacks allow drivers to override default
+keycode/keycodesize/keycodemax mapping mechanism provided by input core
+and implement sparse keycode maps.
+
+Key autorepeat
+~~~~~~~~~~~~~~
+
+... is simple. It is handled by the input.c module. Hardware autorepeat is
+not used, because it's not present in many devices and even where it is
+present, it is broken sometimes (at keyboards: Toshiba notebooks). To enable
+autorepeat for your device, just set EV_REP in dev->evbit. All will be
+handled by the input system.
+
+Other event types, handling output events
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The other event types up to now are:
+
+- EV_LED - used for the keyboard LEDs.
+- EV_SND - used for keyboard beeps.
+
+They are very similar to for example key events, but they go in the other
+direction - from the system to the input device driver. If your input device
+driver can handle these events, it has to set the respective bits in evbit,
+*and* also the callback routine::
+
+    button_dev->event = button_event;
+
+    int button_event(struct input_dev *dev, unsigned int type,
+		     unsigned int code, int value)
+    {
+	    if (type == EV_SND && code == SND_BELL) {
+		    outb(value, BUTTON_BELL);
+		    return 0;
+	    }
+	    return -1;
+    }
+
+This callback routine can be called from an interrupt or a BH (although that
+isn't a rule), and thus must not sleep, and must not take too long to finish.