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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/ia64/lib/strlen.S
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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(). ...
Diffstat (limited to 'arch/ia64/lib/strlen.S')
-rw-r--r--arch/ia64/lib/strlen.S195
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diff --git a/arch/ia64/lib/strlen.S b/arch/ia64/lib/strlen.S
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+++ b/arch/ia64/lib/strlen.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *
+ * Optimized version of the standard strlen() function
+ *
+ *
+ * Inputs:
+ * in0 address of string
+ *
+ * Outputs:
+ * ret0 the number of characters in the string (0 if empty string)
+ * does not count the \0
+ *
+ * Copyright (C) 1999, 2001 Hewlett-Packard Co
+ * Stephane Eranian <eranian@hpl.hp.com>
+ *
+ * 09/24/99 S.Eranian add speculation recovery code
+ */
+
+#include <asm/asmmacro.h>
+#include <asm/export.h>
+
+//
+//
+// This is an enhanced version of the basic strlen. it includes a combination
+// of compute zero index (czx), parallel comparisons, speculative loads and
+// loop unroll using rotating registers.
+//
+// General Ideas about the algorithm:
+// The goal is to look at the string in chunks of 8 bytes.
+// so we need to do a few extra checks at the beginning because the
+// string may not be 8-byte aligned. In this case we load the 8byte
+// quantity which includes the start of the string and mask the unused
+// bytes with 0xff to avoid confusing czx.
+// We use speculative loads and software pipelining to hide memory
+// latency and do read ahead safely. This way we defer any exception.
+//
+// Because we don't want the kernel to be relying on particular
+// settings of the DCR register, we provide recovery code in case
+// speculation fails. The recovery code is going to "redo" the work using
+// only normal loads. If we still get a fault then we generate a
+// kernel panic. Otherwise we return the strlen as usual.
+//
+// The fact that speculation may fail can be caused, for instance, by
+// the DCR.dm bit being set. In this case TLB misses are deferred, i.e.,
+// a NaT bit will be set if the translation is not present. The normal
+// load, on the other hand, will cause the translation to be inserted
+// if the mapping exists.
+//
+// It should be noted that we execute recovery code only when we need
+// to use the data that has been speculatively loaded: we don't execute
+// recovery code on pure read ahead data.
+//
+// Remarks:
+// - the cmp r0,r0 is used as a fast way to initialize a predicate
+// register to 1. This is required to make sure that we get the parallel
+// compare correct.
+//
+// - we don't use the epilogue counter to exit the loop but we need to set
+// it to zero beforehand.
+//
+// - after the loop we must test for Nat values because neither the
+// czx nor cmp instruction raise a NaT consumption fault. We must be
+// careful not to look too far for a Nat for which we don't care.
+// For instance we don't need to look at a NaT in val2 if the zero byte
+// was in val1.
+//
+// - Clearly performance tuning is required.
+//
+//
+//
+#define saved_pfs r11
+#define tmp r10
+#define base r16
+#define orig r17
+#define saved_pr r18
+#define src r19
+#define mask r20
+#define val r21
+#define val1 r22
+#define val2 r23
+
+GLOBAL_ENTRY(strlen)
+ .prologue
+ .save ar.pfs, saved_pfs
+ alloc saved_pfs=ar.pfs,11,0,0,8 // rotating must be multiple of 8
+
+ .rotr v[2], w[2] // declares our 4 aliases
+
+ extr.u tmp=in0,0,3 // tmp=least significant 3 bits
+ mov orig=in0 // keep trackof initial byte address
+ dep src=0,in0,0,3 // src=8byte-aligned in0 address
+ .save pr, saved_pr
+ mov saved_pr=pr // preserve predicates (rotation)
+ ;;
+
+ .body
+
+ ld8 v[1]=[src],8 // must not speculate: can fail here
+ shl tmp=tmp,3 // multiply by 8bits/byte
+ mov mask=-1 // our mask
+ ;;
+ ld8.s w[1]=[src],8 // speculatively load next
+ cmp.eq p6,p0=r0,r0 // sets p6 to true for cmp.and
+ sub tmp=64,tmp // how many bits to shift our mask on the right
+ ;;
+ shr.u mask=mask,tmp // zero enough bits to hold v[1] valuable part
+ mov ar.ec=r0 // clear epilogue counter (saved in ar.pfs)
+ ;;
+ add base=-16,src // keep track of aligned base
+ or v[1]=v[1],mask // now we have a safe initial byte pattern
+ ;;
+1:
+ ld8.s v[0]=[src],8 // speculatively load next
+ czx1.r val1=v[1] // search 0 byte from right
+ czx1.r val2=w[1] // search 0 byte from right following 8bytes
+ ;;
+ ld8.s w[0]=[src],8 // speculatively load next to next
+ cmp.eq.and p6,p0=8,val1 // p6 = p6 and val1==8
+ cmp.eq.and p6,p0=8,val2 // p6 = p6 and mask==8
+(p6) br.wtop.dptk 1b // loop until p6 == 0
+ ;;
+ //
+ // We must return try the recovery code iff
+ // val1_is_nat || (val1==8 && val2_is_nat)
+ //
+ // XXX Fixme
+ // - there must be a better way of doing the test
+ //
+ cmp.eq p8,p9=8,val1 // p6 = val1 had zero (disambiguate)
+ tnat.nz p6,p7=val1 // test NaT on val1
+(p6) br.cond.spnt .recover // jump to recovery if val1 is NaT
+ ;;
+ //
+ // if we come here p7 is true, i.e., initialized for // cmp
+ //
+ cmp.eq.and p7,p0=8,val1// val1==8?
+ tnat.nz.and p7,p0=val2 // test NaT if val2
+(p7) br.cond.spnt .recover // jump to recovery if val2 is NaT
+ ;;
+(p8) mov val1=val2 // the other test got us out of the loop
+(p8) adds src=-16,src // correct position when 3 ahead
+(p9) adds src=-24,src // correct position when 4 ahead
+ ;;
+ sub ret0=src,orig // distance from base
+ sub tmp=8,val1 // which byte in word
+ mov pr=saved_pr,0xffffffffffff0000
+ ;;
+ sub ret0=ret0,tmp // adjust
+ mov ar.pfs=saved_pfs // because of ar.ec, restore no matter what
+ br.ret.sptk.many rp // end of normal execution
+
+ //
+ // Outlined recovery code when speculation failed
+ //
+ // This time we don't use speculation and rely on the normal exception
+ // mechanism. that's why the loop is not as good as the previous one
+ // because read ahead is not possible
+ //
+ // IMPORTANT:
+ // Please note that in the case of strlen() as opposed to strlen_user()
+ // we don't use the exception mechanism, as this function is not
+ // supposed to fail. If that happens it means we have a bug and the
+ // code will cause of kernel fault.
+ //
+ // XXX Fixme
+ // - today we restart from the beginning of the string instead
+ // of trying to continue where we left off.
+ //
+.recover:
+ ld8 val=[base],8 // will fail if unrecoverable fault
+ ;;
+ or val=val,mask // remask first bytes
+ cmp.eq p0,p6=r0,r0 // nullify first ld8 in loop
+ ;;
+ //
+ // ar.ec is still zero here
+ //
+2:
+(p6) ld8 val=[base],8 // will fail if unrecoverable fault
+ ;;
+ czx1.r val1=val // search 0 byte from right
+ ;;
+ cmp.eq p6,p0=8,val1 // val1==8 ?
+(p6) br.wtop.dptk 2b // loop until p6 == 0
+ ;; // (avoid WAW on p63)
+ sub ret0=base,orig // distance from base
+ sub tmp=8,val1
+ mov pr=saved_pr,0xffffffffffff0000
+ ;;
+ sub ret0=ret0,tmp // length=now - back -1
+ mov ar.pfs=saved_pfs // because of ar.ec, restore no matter what
+ br.ret.sptk.many rp // end of successful recovery code
+END(strlen)
+EXPORT_SYMBOL(strlen)