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(). ... --- include/net/red.h | 465 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 465 insertions(+) create mode 100644 include/net/red.h (limited to 'include/net/red.h') diff --git a/include/net/red.h b/include/net/red.h new file mode 100644 index 000000000..425364de0 --- /dev/null +++ b/include/net/red.h @@ -0,0 +1,465 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_SCHED_RED_H +#define __NET_SCHED_RED_H + +#include +#include +#include +#include +#include +#include + +/* Random Early Detection (RED) algorithm. + ======================================= + + Source: Sally Floyd and Van Jacobson, "Random Early Detection Gateways + for Congestion Avoidance", 1993, IEEE/ACM Transactions on Networking. + + This file codes a "divisionless" version of RED algorithm + as written down in Fig.17 of the paper. + + Short description. + ------------------ + + When a new packet arrives we calculate the average queue length: + + avg = (1-W)*avg + W*current_queue_len, + + W is the filter time constant (chosen as 2^(-Wlog)), it controls + the inertia of the algorithm. To allow larger bursts, W should be + decreased. + + if (avg > th_max) -> packet marked (dropped). + if (avg < th_min) -> packet passes. + if (th_min < avg < th_max) we calculate probability: + + Pb = max_P * (avg - th_min)/(th_max-th_min) + + and mark (drop) packet with this probability. + Pb changes from 0 (at avg==th_min) to max_P (avg==th_max). + max_P should be small (not 1), usually 0.01..0.02 is good value. + + max_P is chosen as a number, so that max_P/(th_max-th_min) + is a negative power of two in order arithmetics to contain + only shifts. + + + Parameters, settable by user: + ----------------------------- + + qth_min - bytes (should be < qth_max/2) + qth_max - bytes (should be at least 2*qth_min and less limit) + Wlog - bits (<32) log(1/W). + Plog - bits (<32) + + Plog is related to max_P by formula: + + max_P = (qth_max-qth_min)/2^Plog; + + F.e. if qth_max=128K and qth_min=32K, then Plog=22 + corresponds to max_P=0.02 + + Scell_log + Stab + + Lookup table for log((1-W)^(t/t_ave). + + + NOTES: + + Upper bound on W. + ----------------- + + If you want to allow bursts of L packets of size S, + you should choose W: + + L + 1 - th_min/S < (1-(1-W)^L)/W + + th_min/S = 32 th_min/S = 4 + + log(W) L + -1 33 + -2 35 + -3 39 + -4 46 + -5 57 + -6 75 + -7 101 + -8 135 + -9 190 + etc. + */ + +/* + * Adaptative RED : An Algorithm for Increasing the Robustness of RED's AQM + * (Sally FLoyd, Ramakrishna Gummadi, and Scott Shenker) August 2001 + * + * Every 500 ms: + * if (avg > target and max_p <= 0.5) + * increase max_p : max_p += alpha; + * else if (avg < target and max_p >= 0.01) + * decrease max_p : max_p *= beta; + * + * target :[qth_min + 0.4*(qth_min - qth_max), + * qth_min + 0.6*(qth_min - qth_max)]. + * alpha : min(0.01, max_p / 4) + * beta : 0.9 + * max_P is a Q0.32 fixed point number (with 32 bits mantissa) + * max_P between 0.01 and 0.5 (1% - 50%) [ Its no longer a negative power of two ] + */ +#define RED_ONE_PERCENT ((u32)DIV_ROUND_CLOSEST(1ULL<<32, 100)) + +#define MAX_P_MIN (1 * RED_ONE_PERCENT) +#define MAX_P_MAX (50 * RED_ONE_PERCENT) +#define MAX_P_ALPHA(val) min(MAX_P_MIN, val / 4) + +#define RED_STAB_SIZE 256 +#define RED_STAB_MASK (RED_STAB_SIZE - 1) + +struct red_stats { + u32 prob_drop; /* Early probability drops */ + u32 prob_mark; /* Early probability marks */ + u32 forced_drop; /* Forced drops, qavg > max_thresh */ + u32 forced_mark; /* Forced marks, qavg > max_thresh */ + u32 pdrop; /* Drops due to queue limits */ +}; + +struct red_parms { + /* Parameters */ + u32 qth_min; /* Min avg length threshold: Wlog scaled */ + u32 qth_max; /* Max avg length threshold: Wlog scaled */ + u32 Scell_max; + u32 max_P; /* probability, [0 .. 1.0] 32 scaled */ + /* reciprocal_value(max_P / qth_delta) */ + struct reciprocal_value max_P_reciprocal; + u32 qth_delta; /* max_th - min_th */ + u32 target_min; /* min_th + 0.4*(max_th - min_th) */ + u32 target_max; /* min_th + 0.6*(max_th - min_th) */ + u8 Scell_log; + u8 Wlog; /* log(W) */ + u8 Plog; /* random number bits */ + u8 Stab[RED_STAB_SIZE]; +}; + +struct red_vars { + /* Variables */ + int qcount; /* Number of packets since last random + number generation */ + u32 qR; /* Cached random number */ + + unsigned long qavg; /* Average queue length: Wlog scaled */ + ktime_t qidlestart; /* Start of current idle period */ +}; + +static inline u32 red_maxp(u8 Plog) +{ + return Plog < 32 ? (~0U >> Plog) : ~0U; +} + +static inline void red_set_vars(struct red_vars *v) +{ + /* Reset average queue length, the value is strictly bound + * to the parameters below, reseting hurts a bit but leaving + * it might result in an unreasonable qavg for a while. --TGR + */ + v->qavg = 0; + + v->qcount = -1; +} + +static inline bool red_check_params(u32 qth_min, u32 qth_max, u8 Wlog, + u8 Scell_log, u8 *stab) +{ + if (fls(qth_min) + Wlog >= 32) + return false; + if (fls(qth_max) + Wlog >= 32) + return false; + if (Scell_log >= 32) + return false; + if (qth_max < qth_min) + return false; + if (stab) { + int i; + + for (i = 0; i < RED_STAB_SIZE; i++) + if (stab[i] >= 32) + return false; + } + return true; +} + +static inline int red_get_flags(unsigned char qopt_flags, + unsigned char historic_mask, + struct nlattr *flags_attr, + unsigned char supported_mask, + struct nla_bitfield32 *p_flags, + unsigned char *p_userbits, + struct netlink_ext_ack *extack) +{ + struct nla_bitfield32 flags; + + if (qopt_flags && flags_attr) { + NL_SET_ERR_MSG_MOD(extack, "flags should be passed either through qopt, or through a dedicated attribute"); + return -EINVAL; + } + + if (flags_attr) { + flags = nla_get_bitfield32(flags_attr); + } else { + flags.selector = historic_mask; + flags.value = qopt_flags & historic_mask; + } + + *p_flags = flags; + *p_userbits = qopt_flags & ~historic_mask; + return 0; +} + +static inline int red_validate_flags(unsigned char flags, + struct netlink_ext_ack *extack) +{ + if ((flags & TC_RED_NODROP) && !(flags & TC_RED_ECN)) { + NL_SET_ERR_MSG_MOD(extack, "nodrop mode is only meaningful with ECN"); + return -EINVAL; + } + + return 0; +} + +static inline void red_set_parms(struct red_parms *p, + u32 qth_min, u32 qth_max, u8 Wlog, u8 Plog, + u8 Scell_log, u8 *stab, u32 max_P) +{ + int delta = qth_max - qth_min; + u32 max_p_delta; + + p->qth_min = qth_min << Wlog; + p->qth_max = qth_max << Wlog; + p->Wlog = Wlog; + p->Plog = Plog; + if (delta <= 0) + delta = 1; + p->qth_delta = delta; + if (!max_P) { + max_P = red_maxp(Plog); + max_P *= delta; /* max_P = (qth_max - qth_min)/2^Plog */ + } + p->max_P = max_P; + max_p_delta = max_P / delta; + max_p_delta = max(max_p_delta, 1U); + p->max_P_reciprocal = reciprocal_value(max_p_delta); + + /* RED Adaptative target : + * [min_th + 0.4*(min_th - max_th), + * min_th + 0.6*(min_th - max_th)]. + */ + delta /= 5; + p->target_min = qth_min + 2*delta; + p->target_max = qth_min + 3*delta; + + p->Scell_log = Scell_log; + p->Scell_max = (255 << Scell_log); + + if (stab) + memcpy(p->Stab, stab, sizeof(p->Stab)); +} + +static inline int red_is_idling(const struct red_vars *v) +{ + return v->qidlestart != 0; +} + +static inline void red_start_of_idle_period(struct red_vars *v) +{ + v->qidlestart = ktime_get(); +} + +static inline void red_end_of_idle_period(struct red_vars *v) +{ + v->qidlestart = 0; +} + +static inline void red_restart(struct red_vars *v) +{ + red_end_of_idle_period(v); + v->qavg = 0; + v->qcount = -1; +} + +static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms *p, + const struct red_vars *v) +{ + s64 delta = ktime_us_delta(ktime_get(), v->qidlestart); + long us_idle = min_t(s64, delta, p->Scell_max); + int shift; + + /* + * The problem: ideally, average length queue recalculation should + * be done over constant clock intervals. This is too expensive, so + * that the calculation is driven by outgoing packets. + * When the queue is idle we have to model this clock by hand. + * + * SF+VJ proposed to "generate": + * + * m = idletime / (average_pkt_size / bandwidth) + * + * dummy packets as a burst after idle time, i.e. + * + * v->qavg *= (1-W)^m + * + * This is an apparently overcomplicated solution (f.e. we have to + * precompute a table to make this calculation in reasonable time) + * I believe that a simpler model may be used here, + * but it is field for experiments. + */ + + shift = p->Stab[(us_idle >> p->Scell_log) & RED_STAB_MASK]; + + if (shift) + return v->qavg >> shift; + else { + /* Approximate initial part of exponent with linear function: + * + * (1-W)^m ~= 1-mW + ... + * + * Seems, it is the best solution to + * problem of too coarse exponent tabulation. + */ + us_idle = (v->qavg * (u64)us_idle) >> p->Scell_log; + + if (us_idle < (v->qavg >> 1)) + return v->qavg - us_idle; + else + return v->qavg >> 1; + } +} + +static inline unsigned long red_calc_qavg_no_idle_time(const struct red_parms *p, + const struct red_vars *v, + unsigned int backlog) +{ + /* + * NOTE: v->qavg is fixed point number with point at Wlog. + * The formula below is equvalent to floating point + * version: + * + * qavg = qavg*(1-W) + backlog*W; + * + * --ANK (980924) + */ + return v->qavg + (backlog - (v->qavg >> p->Wlog)); +} + +static inline unsigned long red_calc_qavg(const struct red_parms *p, + const struct red_vars *v, + unsigned int backlog) +{ + if (!red_is_idling(v)) + return red_calc_qavg_no_idle_time(p, v, backlog); + else + return red_calc_qavg_from_idle_time(p, v); +} + + +static inline u32 red_random(const struct red_parms *p) +{ + return reciprocal_divide(get_random_u32(), p->max_P_reciprocal); +} + +static inline int red_mark_probability(const struct red_parms *p, + const struct red_vars *v, + unsigned long qavg) +{ + /* The formula used below causes questions. + + OK. qR is random number in the interval + (0..1/max_P)*(qth_max-qth_min) + i.e. 0..(2^Plog). If we used floating point + arithmetics, it would be: (2^Plog)*rnd_num, + where rnd_num is less 1. + + Taking into account, that qavg have fixed + point at Wlog, two lines + below have the following floating point equivalent: + + max_P*(qavg - qth_min)/(qth_max-qth_min) < rnd/qcount + + Any questions? --ANK (980924) + */ + return !(((qavg - p->qth_min) >> p->Wlog) * v->qcount < v->qR); +} + +enum { + RED_BELOW_MIN_THRESH, + RED_BETWEEN_TRESH, + RED_ABOVE_MAX_TRESH, +}; + +static inline int red_cmp_thresh(const struct red_parms *p, unsigned long qavg) +{ + if (qavg < p->qth_min) + return RED_BELOW_MIN_THRESH; + else if (qavg >= p->qth_max) + return RED_ABOVE_MAX_TRESH; + else + return RED_BETWEEN_TRESH; +} + +enum { + RED_DONT_MARK, + RED_PROB_MARK, + RED_HARD_MARK, +}; + +static inline int red_action(const struct red_parms *p, + struct red_vars *v, + unsigned long qavg) +{ + switch (red_cmp_thresh(p, qavg)) { + case RED_BELOW_MIN_THRESH: + v->qcount = -1; + return RED_DONT_MARK; + + case RED_BETWEEN_TRESH: + if (++v->qcount) { + if (red_mark_probability(p, v, qavg)) { + v->qcount = 0; + v->qR = red_random(p); + return RED_PROB_MARK; + } + } else + v->qR = red_random(p); + + return RED_DONT_MARK; + + case RED_ABOVE_MAX_TRESH: + v->qcount = -1; + return RED_HARD_MARK; + } + + BUG(); + return RED_DONT_MARK; +} + +static inline void red_adaptative_algo(struct red_parms *p, struct red_vars *v) +{ + unsigned long qavg; + u32 max_p_delta; + + qavg = v->qavg; + if (red_is_idling(v)) + qavg = red_calc_qavg_from_idle_time(p, v); + + /* v->qavg is fixed point number with point at Wlog */ + qavg >>= p->Wlog; + + if (qavg > p->target_max && p->max_P <= MAX_P_MAX) + p->max_P += MAX_P_ALPHA(p->max_P); /* maxp = maxp + alpha */ + else if (qavg < p->target_min && p->max_P >= MAX_P_MIN) + p->max_P = (p->max_P/10)*9; /* maxp = maxp * Beta */ + + max_p_delta = DIV_ROUND_CLOSEST(p->max_P, p->qth_delta); + max_p_delta = max(max_p_delta, 1U); + p->max_P_reciprocal = reciprocal_value(max_p_delta); +} +#endif -- cgit v1.2.3