From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- kernel/rcu/srcutiny.c | 282 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 282 insertions(+) create mode 100644 kernel/rcu/srcutiny.c (limited to 'kernel/rcu/srcutiny.c') diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c new file mode 100644 index 000000000..b12fb0cec --- /dev/null +++ b/kernel/rcu/srcutiny.c @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Sleepable Read-Copy Update mechanism for mutual exclusion, + * tiny version for non-preemptible single-CPU use. + * + * Copyright (C) IBM Corporation, 2017 + * + * Author: Paul McKenney + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include "rcu_segcblist.h" +#include "rcu.h" + +int rcu_scheduler_active __read_mostly; +static LIST_HEAD(srcu_boot_list); +static bool srcu_init_done; + +static int init_srcu_struct_fields(struct srcu_struct *ssp) +{ + ssp->srcu_lock_nesting[0] = 0; + ssp->srcu_lock_nesting[1] = 0; + init_swait_queue_head(&ssp->srcu_wq); + ssp->srcu_cb_head = NULL; + ssp->srcu_cb_tail = &ssp->srcu_cb_head; + ssp->srcu_gp_running = false; + ssp->srcu_gp_waiting = false; + ssp->srcu_idx = 0; + ssp->srcu_idx_max = 0; + INIT_WORK(&ssp->srcu_work, srcu_drive_gp); + INIT_LIST_HEAD(&ssp->srcu_work.entry); + return 0; +} + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + +int __init_srcu_struct(struct srcu_struct *ssp, const char *name, + struct lock_class_key *key) +{ + /* Don't re-initialize a lock while it is held. */ + debug_check_no_locks_freed((void *)ssp, sizeof(*ssp)); + lockdep_init_map(&ssp->dep_map, name, key, 0); + return init_srcu_struct_fields(ssp); +} +EXPORT_SYMBOL_GPL(__init_srcu_struct); + +#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ + +/* + * init_srcu_struct - initialize a sleep-RCU structure + * @ssp: structure to initialize. + * + * Must invoke this on a given srcu_struct before passing that srcu_struct + * to any other function. Each srcu_struct represents a separate domain + * of SRCU protection. + */ +int init_srcu_struct(struct srcu_struct *ssp) +{ + return init_srcu_struct_fields(ssp); +} +EXPORT_SYMBOL_GPL(init_srcu_struct); + +#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ + +/* + * cleanup_srcu_struct - deconstruct a sleep-RCU structure + * @ssp: structure to clean up. + * + * Must invoke this after you are finished using a given srcu_struct that + * was initialized via init_srcu_struct(), else you leak memory. + */ +void cleanup_srcu_struct(struct srcu_struct *ssp) +{ + WARN_ON(ssp->srcu_lock_nesting[0] || ssp->srcu_lock_nesting[1]); + flush_work(&ssp->srcu_work); + WARN_ON(ssp->srcu_gp_running); + WARN_ON(ssp->srcu_gp_waiting); + WARN_ON(ssp->srcu_cb_head); + WARN_ON(&ssp->srcu_cb_head != ssp->srcu_cb_tail); + WARN_ON(ssp->srcu_idx != ssp->srcu_idx_max); + WARN_ON(ssp->srcu_idx & 0x1); +} +EXPORT_SYMBOL_GPL(cleanup_srcu_struct); + +/* + * Removes the count for the old reader from the appropriate element of + * the srcu_struct. + */ +void __srcu_read_unlock(struct srcu_struct *ssp, int idx) +{ + int newval = READ_ONCE(ssp->srcu_lock_nesting[idx]) - 1; + + WRITE_ONCE(ssp->srcu_lock_nesting[idx], newval); + if (!newval && READ_ONCE(ssp->srcu_gp_waiting) && in_task()) + swake_up_one(&ssp->srcu_wq); +} +EXPORT_SYMBOL_GPL(__srcu_read_unlock); + +/* + * Workqueue handler to drive one grace period and invoke any callbacks + * that become ready as a result. Single-CPU and !PREEMPTION operation + * means that we get away with murder on synchronization. ;-) + */ +void srcu_drive_gp(struct work_struct *wp) +{ + int idx; + struct rcu_head *lh; + struct rcu_head *rhp; + struct srcu_struct *ssp; + + ssp = container_of(wp, struct srcu_struct, srcu_work); + if (ssp->srcu_gp_running || ULONG_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max))) + return; /* Already running or nothing to do. */ + + /* Remove recently arrived callbacks and wait for readers. */ + WRITE_ONCE(ssp->srcu_gp_running, true); + local_irq_disable(); + lh = ssp->srcu_cb_head; + ssp->srcu_cb_head = NULL; + ssp->srcu_cb_tail = &ssp->srcu_cb_head; + local_irq_enable(); + idx = (ssp->srcu_idx & 0x2) / 2; + WRITE_ONCE(ssp->srcu_idx, ssp->srcu_idx + 1); + WRITE_ONCE(ssp->srcu_gp_waiting, true); /* srcu_read_unlock() wakes! */ + swait_event_exclusive(ssp->srcu_wq, !READ_ONCE(ssp->srcu_lock_nesting[idx])); + WRITE_ONCE(ssp->srcu_gp_waiting, false); /* srcu_read_unlock() cheap. */ + WRITE_ONCE(ssp->srcu_idx, ssp->srcu_idx + 1); + + /* Invoke the callbacks we removed above. */ + while (lh) { + rhp = lh; + lh = lh->next; + local_bh_disable(); + rhp->func(rhp); + local_bh_enable(); + } + + /* + * Enable rescheduling, and if there are more callbacks, + * reschedule ourselves. This can race with a call_srcu() + * at interrupt level, but the ->srcu_gp_running checks will + * straighten that out. + */ + WRITE_ONCE(ssp->srcu_gp_running, false); + if (ULONG_CMP_LT(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max))) + schedule_work(&ssp->srcu_work); +} +EXPORT_SYMBOL_GPL(srcu_drive_gp); + +static void srcu_gp_start_if_needed(struct srcu_struct *ssp) +{ + unsigned long cookie; + + cookie = get_state_synchronize_srcu(ssp); + if (ULONG_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie)) + return; + WRITE_ONCE(ssp->srcu_idx_max, cookie); + if (!READ_ONCE(ssp->srcu_gp_running)) { + if (likely(srcu_init_done)) + schedule_work(&ssp->srcu_work); + else if (list_empty(&ssp->srcu_work.entry)) + list_add(&ssp->srcu_work.entry, &srcu_boot_list); + } +} + +/* + * Enqueue an SRCU callback on the specified srcu_struct structure, + * initiating grace-period processing if it is not already running. + */ +void call_srcu(struct srcu_struct *ssp, struct rcu_head *rhp, + rcu_callback_t func) +{ + unsigned long flags; + + rhp->func = func; + rhp->next = NULL; + local_irq_save(flags); + *ssp->srcu_cb_tail = rhp; + ssp->srcu_cb_tail = &rhp->next; + local_irq_restore(flags); + srcu_gp_start_if_needed(ssp); +} +EXPORT_SYMBOL_GPL(call_srcu); + +/* + * synchronize_srcu - wait for prior SRCU read-side critical-section completion + */ +void synchronize_srcu(struct srcu_struct *ssp) +{ + struct rcu_synchronize rs; + + RCU_LOCKDEP_WARN(lockdep_is_held(ssp) || + lock_is_held(&rcu_bh_lock_map) || + lock_is_held(&rcu_lock_map) || + lock_is_held(&rcu_sched_lock_map), + "Illegal synchronize_srcu() in same-type SRCU (or in RCU) read-side critical section"); + + if (rcu_scheduler_active == RCU_SCHEDULER_INACTIVE) + return; + + might_sleep(); + init_rcu_head_on_stack(&rs.head); + init_completion(&rs.completion); + call_srcu(ssp, &rs.head, wakeme_after_rcu); + wait_for_completion(&rs.completion); + destroy_rcu_head_on_stack(&rs.head); +} +EXPORT_SYMBOL_GPL(synchronize_srcu); + +/* + * get_state_synchronize_srcu - Provide an end-of-grace-period cookie + */ +unsigned long get_state_synchronize_srcu(struct srcu_struct *ssp) +{ + unsigned long ret; + + barrier(); + ret = (READ_ONCE(ssp->srcu_idx) + 3) & ~0x1; + barrier(); + return ret; +} +EXPORT_SYMBOL_GPL(get_state_synchronize_srcu); + +/* + * start_poll_synchronize_srcu - Provide cookie and start grace period + * + * The difference between this and get_state_synchronize_srcu() is that + * this function ensures that the poll_state_synchronize_srcu() will + * eventually return the value true. + */ +unsigned long start_poll_synchronize_srcu(struct srcu_struct *ssp) +{ + unsigned long ret = get_state_synchronize_srcu(ssp); + + srcu_gp_start_if_needed(ssp); + return ret; +} +EXPORT_SYMBOL_GPL(start_poll_synchronize_srcu); + +/* + * poll_state_synchronize_srcu - Has cookie's grace period ended? + */ +bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie) +{ + unsigned long cur_s = READ_ONCE(ssp->srcu_idx); + + barrier(); + return ULONG_CMP_GE(cur_s, cookie) || ULONG_CMP_LT(cur_s, cookie - 3); +} +EXPORT_SYMBOL_GPL(poll_state_synchronize_srcu); + +/* Lockdep diagnostics. */ +void __init rcu_scheduler_starting(void) +{ + rcu_scheduler_active = RCU_SCHEDULER_RUNNING; +} + +/* + * Queue work for srcu_struct structures with early boot callbacks. + * The work won't actually execute until the workqueue initialization + * phase that takes place after the scheduler starts. + */ +void __init srcu_init(void) +{ + struct srcu_struct *ssp; + + srcu_init_done = true; + while (!list_empty(&srcu_boot_list)) { + ssp = list_first_entry(&srcu_boot_list, + struct srcu_struct, srcu_work.entry); + list_del_init(&ssp->srcu_work.entry); + schedule_work(&ssp->srcu_work); + } +} -- cgit v1.2.3