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, 177 insertions, 0 deletions

diff --git a/Documentation/mm/memory-model.rst b/Documentation/mm/memory-model.rst
new file mode 100644
index 000000000..3779e562d
--- /dev/null
+++ b/Documentation/mm/memory-model.rst
@@ -0,0 +1,177 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _physical_memory_model:
+
+=====================
+Physical Memory Model
+=====================
+
+Physical memory in a system may be addressed in different ways. The
+simplest case is when the physical memory starts at address 0 and
+spans a contiguous range up to the maximal address. It could be,
+however, that this range contains small holes that are not accessible
+for the CPU. Then there could be several contiguous ranges at
+completely distinct addresses. And, don't forget about NUMA, where
+different memory banks are attached to different CPUs.
+
+Linux abstracts this diversity using one of the two memory models:
+FLATMEM and SPARSEMEM. Each architecture defines what
+memory models it supports, what the default memory model is and
+whether it is possible to manually override that default.
+
+All the memory models track the status of physical page frames using
+struct page arranged in one or more arrays.
+
+Regardless of the selected memory model, there exists one-to-one
+mapping between the physical page frame number (PFN) and the
+corresponding `struct page`.
+
+Each memory model defines :c:func:`pfn_to_page` and :c:func:`page_to_pfn`
+helpers that allow the conversion from PFN to `struct page` and vice
+versa.
+
+FLATMEM
+=======
+
+The simplest memory model is FLATMEM. This model is suitable for
+non-NUMA systems with contiguous, or mostly contiguous, physical
+memory.
+
+In the FLATMEM memory model, there is a global `mem_map` array that
+maps the entire physical memory. For most architectures, the holes
+have entries in the `mem_map` array. The `struct page` objects
+corresponding to the holes are never fully initialized.
+
+To allocate the `mem_map` array, architecture specific setup code should
+call :c:func:`free_area_init` function. Yet, the mappings array is not
+usable until the call to :c:func:`memblock_free_all` that hands all the
+memory to the page allocator.
+
+An architecture may free parts of the `mem_map` array that do not cover the
+actual physical pages. In such case, the architecture specific
+:c:func:`pfn_valid` implementation should take the holes in the
+`mem_map` into account.
+
+With FLATMEM, the conversion between a PFN and the `struct page` is
+straightforward: `PFN - ARCH_PFN_OFFSET` is an index to the
+`mem_map` array.
+
+The `ARCH_PFN_OFFSET` defines the first page frame number for
+systems with physical memory starting at address different from 0.
+
+SPARSEMEM
+=========
+
+SPARSEMEM is the most versatile memory model available in Linux and it
+is the only memory model that supports several advanced features such
+as hot-plug and hot-remove of the physical memory, alternative memory
+maps for non-volatile memory devices and deferred initialization of
+the memory map for larger systems.
+
+The SPARSEMEM model presents the physical memory as a collection of
+sections. A section is represented with struct mem_section
+that contains `section_mem_map` that is, logically, a pointer to an
+array of struct pages. However, it is stored with some other magic
+that aids the sections management. The section size and maximal number
+of section is specified using `SECTION_SIZE_BITS` and
+`MAX_PHYSMEM_BITS` constants defined by each architecture that
+supports SPARSEMEM. While `MAX_PHYSMEM_BITS` is an actual width of a
+physical address that an architecture supports, the
+`SECTION_SIZE_BITS` is an arbitrary value.
+
+The maximal number of sections is denoted `NR_MEM_SECTIONS` and
+defined as
+
+.. math::
+
+   NR\_MEM\_SECTIONS = 2 ^ {(MAX\_PHYSMEM\_BITS - SECTION\_SIZE\_BITS)}
+
+The `mem_section` objects are arranged in a two-dimensional array
+called `mem_sections`. The size and placement of this array depend
+on `CONFIG_SPARSEMEM_EXTREME` and the maximal possible number of
+sections:
+
+* When `CONFIG_SPARSEMEM_EXTREME` is disabled, the `mem_sections`
+  array is static and has `NR_MEM_SECTIONS` rows. Each row holds a
+  single `mem_section` object.
+* When `CONFIG_SPARSEMEM_EXTREME` is enabled, the `mem_sections`
+  array is dynamically allocated. Each row contains PAGE_SIZE worth of
+  `mem_section` objects and the number of rows is calculated to fit
+  all the memory sections.
+
+The architecture setup code should call sparse_init() to
+initialize the memory sections and the memory maps.
+
+With SPARSEMEM there are two possible ways to convert a PFN to the
+corresponding `struct page` - a "classic sparse" and "sparse
+vmemmap". The selection is made at build time and it is determined by
+the value of `CONFIG_SPARSEMEM_VMEMMAP`.
+
+The classic sparse encodes the section number of a page in page->flags
+and uses high bits of a PFN to access the section that maps that page
+frame. Inside a section, the PFN is the index to the array of pages.
+
+The sparse vmemmap uses a virtually mapped memory map to optimize
+pfn_to_page and page_to_pfn operations. There is a global `struct
+page *vmemmap` pointer that points to a virtually contiguous array of
+`struct page` objects. A PFN is an index to that array and the
+offset of the `struct page` from `vmemmap` is the PFN of that
+page.
+
+To use vmemmap, an architecture has to reserve a range of virtual
+addresses that will map the physical pages containing the memory
+map and make sure that `vmemmap` points to that range. In addition,
+the architecture should implement :c:func:`vmemmap_populate` method
+that will allocate the physical memory and create page tables for the
+virtual memory map. If an architecture does not have any special
+requirements for the vmemmap mappings, it can use default
+:c:func:`vmemmap_populate_basepages` provided by the generic memory
+management.
+
+The virtually mapped memory map allows storing `struct page` objects
+for persistent memory devices in pre-allocated storage on those
+devices. This storage is represented with struct vmem_altmap
+that is eventually passed to vmemmap_populate() through a long chain
+of function calls. The vmemmap_populate() implementation may use the
+`vmem_altmap` along with :c:func:`vmemmap_alloc_block_buf` helper to
+allocate memory map on the persistent memory device.
+
+ZONE_DEVICE
+===========
+The `ZONE_DEVICE` facility builds upon `SPARSEMEM_VMEMMAP` to offer
+`struct page` `mem_map` services for device driver identified physical
+address ranges. The "device" aspect of `ZONE_DEVICE` relates to the fact
+that the page objects for these address ranges are never marked online,
+and that a reference must be taken against the device, not just the page
+to keep the memory pinned for active use. `ZONE_DEVICE`, via
+:c:func:`devm_memremap_pages`, performs just enough memory hotplug to
+turn on :c:func:`pfn_to_page`, :c:func:`page_to_pfn`, and
+:c:func:`get_user_pages` service for the given range of pfns. Since the
+page reference count never drops below 1 the page is never tracked as
+free memory and the page's `struct list_head lru` space is repurposed
+for back referencing to the host device / driver that mapped the memory.
+
+While `SPARSEMEM` presents memory as a collection of sections,
+optionally collected into memory blocks, `ZONE_DEVICE` users have a need
+for smaller granularity of populating the `mem_map`. Given that
+`ZONE_DEVICE` memory is never marked online it is subsequently never
+subject to its memory ranges being exposed through the sysfs memory
+hotplug api on memory block boundaries. The implementation relies on
+this lack of user-api constraint to allow sub-section sized memory
+ranges to be specified to :c:func:`arch_add_memory`, the top-half of
+memory hotplug. Sub-section support allows for 2MB as the cross-arch
+common alignment granularity for :c:func:`devm_memremap_pages`.
+
+The users of `ZONE_DEVICE` are:
+
+* pmem: Map platform persistent memory to be used as a direct-I/O target
+  via DAX mappings.
+
+* hmm: Extend `ZONE_DEVICE` with `->page_fault()` and `->page_free()`
+  event callbacks to allow a device-driver to coordinate memory management
+  events related to device-memory, typically GPU memory. See
+  Documentation/mm/hmm.rst.
+
+* p2pdma: Create `struct page` objects to allow peer devices in a
+  PCI/-E topology to coordinate direct-DMA operations between themselves,
+  i.e. bypass host memory.