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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 /lib/reed_solomon/decode_rs.c
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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 '')
-rw-r--r--lib/reed_solomon/decode_rs.c326
1 files changed, 326 insertions, 0 deletions
diff --git a/lib/reed_solomon/decode_rs.c b/lib/reed_solomon/decode_rs.c
new file mode 100644
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+++ b/lib/reed_solomon/decode_rs.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic Reed Solomon encoder / decoder library
+ *
+ * Copyright 2002, Phil Karn, KA9Q
+ * May be used under the terms of the GNU General Public License (GPL)
+ *
+ * Adaption to the kernel by Thomas Gleixner (tglx@linutronix.de)
+ *
+ * Generic data width independent code which is included by the wrappers.
+ */
+{
+ struct rs_codec *rs = rsc->codec;
+ int deg_lambda, el, deg_omega;
+ int i, j, r, k, pad;
+ int nn = rs->nn;
+ int nroots = rs->nroots;
+ int fcr = rs->fcr;
+ int prim = rs->prim;
+ int iprim = rs->iprim;
+ uint16_t *alpha_to = rs->alpha_to;
+ uint16_t *index_of = rs->index_of;
+ uint16_t u, q, tmp, num1, num2, den, discr_r, syn_error;
+ int count = 0;
+ int num_corrected;
+ uint16_t msk = (uint16_t) rs->nn;
+
+ /*
+ * The decoder buffers are in the rs control struct. They are
+ * arrays sized [nroots + 1]
+ */
+ uint16_t *lambda = rsc->buffers + RS_DECODE_LAMBDA * (nroots + 1);
+ uint16_t *syn = rsc->buffers + RS_DECODE_SYN * (nroots + 1);
+ uint16_t *b = rsc->buffers + RS_DECODE_B * (nroots + 1);
+ uint16_t *t = rsc->buffers + RS_DECODE_T * (nroots + 1);
+ uint16_t *omega = rsc->buffers + RS_DECODE_OMEGA * (nroots + 1);
+ uint16_t *root = rsc->buffers + RS_DECODE_ROOT * (nroots + 1);
+ uint16_t *reg = rsc->buffers + RS_DECODE_REG * (nroots + 1);
+ uint16_t *loc = rsc->buffers + RS_DECODE_LOC * (nroots + 1);
+
+ /* Check length parameter for validity */
+ pad = nn - nroots - len;
+ BUG_ON(pad < 0 || pad >= nn - nroots);
+
+ /* Does the caller provide the syndrome ? */
+ if (s != NULL) {
+ for (i = 0; i < nroots; i++) {
+ /* The syndrome is in index form,
+ * so nn represents zero
+ */
+ if (s[i] != nn)
+ goto decode;
+ }
+
+ /* syndrome is zero, no errors to correct */
+ return 0;
+ }
+
+ /* form the syndromes; i.e., evaluate data(x) at roots of
+ * g(x) */
+ for (i = 0; i < nroots; i++)
+ syn[i] = (((uint16_t) data[0]) ^ invmsk) & msk;
+
+ for (j = 1; j < len; j++) {
+ for (i = 0; i < nroots; i++) {
+ if (syn[i] == 0) {
+ syn[i] = (((uint16_t) data[j]) ^
+ invmsk) & msk;
+ } else {
+ syn[i] = ((((uint16_t) data[j]) ^
+ invmsk) & msk) ^
+ alpha_to[rs_modnn(rs, index_of[syn[i]] +
+ (fcr + i) * prim)];
+ }
+ }
+ }
+
+ for (j = 0; j < nroots; j++) {
+ for (i = 0; i < nroots; i++) {
+ if (syn[i] == 0) {
+ syn[i] = ((uint16_t) par[j]) & msk;
+ } else {
+ syn[i] = (((uint16_t) par[j]) & msk) ^
+ alpha_to[rs_modnn(rs, index_of[syn[i]] +
+ (fcr+i)*prim)];
+ }
+ }
+ }
+ s = syn;
+
+ /* Convert syndromes to index form, checking for nonzero condition */
+ syn_error = 0;
+ for (i = 0; i < nroots; i++) {
+ syn_error |= s[i];
+ s[i] = index_of[s[i]];
+ }
+
+ if (!syn_error) {
+ /* if syndrome is zero, data[] is a codeword and there are no
+ * errors to correct. So return data[] unmodified
+ */
+ return 0;
+ }
+
+ decode:
+ memset(&lambda[1], 0, nroots * sizeof(lambda[0]));
+ lambda[0] = 1;
+
+ if (no_eras > 0) {
+ /* Init lambda to be the erasure locator polynomial */
+ lambda[1] = alpha_to[rs_modnn(rs,
+ prim * (nn - 1 - (eras_pos[0] + pad)))];
+ for (i = 1; i < no_eras; i++) {
+ u = rs_modnn(rs, prim * (nn - 1 - (eras_pos[i] + pad)));
+ for (j = i + 1; j > 0; j--) {
+ tmp = index_of[lambda[j - 1]];
+ if (tmp != nn) {
+ lambda[j] ^=
+ alpha_to[rs_modnn(rs, u + tmp)];
+ }
+ }
+ }
+ }
+
+ for (i = 0; i < nroots + 1; i++)
+ b[i] = index_of[lambda[i]];
+
+ /*
+ * Begin Berlekamp-Massey algorithm to determine error+erasure
+ * locator polynomial
+ */
+ r = no_eras;
+ el = no_eras;
+ while (++r <= nroots) { /* r is the step number */
+ /* Compute discrepancy at the r-th step in poly-form */
+ discr_r = 0;
+ for (i = 0; i < r; i++) {
+ if ((lambda[i] != 0) && (s[r - i - 1] != nn)) {
+ discr_r ^=
+ alpha_to[rs_modnn(rs,
+ index_of[lambda[i]] +
+ s[r - i - 1])];
+ }
+ }
+ discr_r = index_of[discr_r]; /* Index form */
+ if (discr_r == nn) {
+ /* 2 lines below: B(x) <-- x*B(x) */
+ memmove (&b[1], b, nroots * sizeof (b[0]));
+ b[0] = nn;
+ } else {
+ /* 7 lines below: T(x) <-- lambda(x)-discr_r*x*b(x) */
+ t[0] = lambda[0];
+ for (i = 0; i < nroots; i++) {
+ if (b[i] != nn) {
+ t[i + 1] = lambda[i + 1] ^
+ alpha_to[rs_modnn(rs, discr_r +
+ b[i])];
+ } else
+ t[i + 1] = lambda[i + 1];
+ }
+ if (2 * el <= r + no_eras - 1) {
+ el = r + no_eras - el;
+ /*
+ * 2 lines below: B(x) <-- inv(discr_r) *
+ * lambda(x)
+ */
+ for (i = 0; i <= nroots; i++) {
+ b[i] = (lambda[i] == 0) ? nn :
+ rs_modnn(rs, index_of[lambda[i]]
+ - discr_r + nn);
+ }
+ } else {
+ /* 2 lines below: B(x) <-- x*B(x) */
+ memmove(&b[1], b, nroots * sizeof(b[0]));
+ b[0] = nn;
+ }
+ memcpy(lambda, t, (nroots + 1) * sizeof(t[0]));
+ }
+ }
+
+ /* Convert lambda to index form and compute deg(lambda(x)) */
+ deg_lambda = 0;
+ for (i = 0; i < nroots + 1; i++) {
+ lambda[i] = index_of[lambda[i]];
+ if (lambda[i] != nn)
+ deg_lambda = i;
+ }
+
+ if (deg_lambda == 0) {
+ /*
+ * deg(lambda) is zero even though the syndrome is non-zero
+ * => uncorrectable error detected
+ */
+ return -EBADMSG;
+ }
+
+ /* Find roots of error+erasure locator polynomial by Chien search */
+ memcpy(&reg[1], &lambda[1], nroots * sizeof(reg[0]));
+ count = 0; /* Number of roots of lambda(x) */
+ for (i = 1, k = iprim - 1; i <= nn; i++, k = rs_modnn(rs, k + iprim)) {
+ q = 1; /* lambda[0] is always 0 */
+ for (j = deg_lambda; j > 0; j--) {
+ if (reg[j] != nn) {
+ reg[j] = rs_modnn(rs, reg[j] + j);
+ q ^= alpha_to[reg[j]];
+ }
+ }
+ if (q != 0)
+ continue; /* Not a root */
+
+ if (k < pad) {
+ /* Impossible error location. Uncorrectable error. */
+ return -EBADMSG;
+ }
+
+ /* store root (index-form) and error location number */
+ root[count] = i;
+ loc[count] = k;
+ /* If we've already found max possible roots,
+ * abort the search to save time
+ */
+ if (++count == deg_lambda)
+ break;
+ }
+ if (deg_lambda != count) {
+ /*
+ * deg(lambda) unequal to number of roots => uncorrectable
+ * error detected
+ */
+ return -EBADMSG;
+ }
+ /*
+ * Compute err+eras evaluator poly omega(x) = s(x)*lambda(x) (modulo
+ * x**nroots). in index form. Also find deg(omega).
+ */
+ deg_omega = deg_lambda - 1;
+ for (i = 0; i <= deg_omega; i++) {
+ tmp = 0;
+ for (j = i; j >= 0; j--) {
+ if ((s[i - j] != nn) && (lambda[j] != nn))
+ tmp ^=
+ alpha_to[rs_modnn(rs, s[i - j] + lambda[j])];
+ }
+ omega[i] = index_of[tmp];
+ }
+
+ /*
+ * Compute error values in poly-form. num1 = omega(inv(X(l))), num2 =
+ * inv(X(l))**(fcr-1) and den = lambda_pr(inv(X(l))) all in poly-form
+ * Note: we reuse the buffer for b to store the correction pattern
+ */
+ num_corrected = 0;
+ for (j = count - 1; j >= 0; j--) {
+ num1 = 0;
+ for (i = deg_omega; i >= 0; i--) {
+ if (omega[i] != nn)
+ num1 ^= alpha_to[rs_modnn(rs, omega[i] +
+ i * root[j])];
+ }
+
+ if (num1 == 0) {
+ /* Nothing to correct at this position */
+ b[j] = 0;
+ continue;
+ }
+
+ num2 = alpha_to[rs_modnn(rs, root[j] * (fcr - 1) + nn)];
+ den = 0;
+
+ /* lambda[i+1] for i even is the formal derivative
+ * lambda_pr of lambda[i] */
+ for (i = min(deg_lambda, nroots - 1) & ~1; i >= 0; i -= 2) {
+ if (lambda[i + 1] != nn) {
+ den ^= alpha_to[rs_modnn(rs, lambda[i + 1] +
+ i * root[j])];
+ }
+ }
+
+ b[j] = alpha_to[rs_modnn(rs, index_of[num1] +
+ index_of[num2] +
+ nn - index_of[den])];
+ num_corrected++;
+ }
+
+ /*
+ * We compute the syndrome of the 'error' and check that it matches
+ * the syndrome of the received word
+ */
+ for (i = 0; i < nroots; i++) {
+ tmp = 0;
+ for (j = 0; j < count; j++) {
+ if (b[j] == 0)
+ continue;
+
+ k = (fcr + i) * prim * (nn-loc[j]-1);
+ tmp ^= alpha_to[rs_modnn(rs, index_of[b[j]] + k)];
+ }
+
+ if (tmp != alpha_to[s[i]])
+ return -EBADMSG;
+ }
+
+ /*
+ * Store the error correction pattern, if a
+ * correction buffer is available
+ */
+ if (corr && eras_pos) {
+ j = 0;
+ for (i = 0; i < count; i++) {
+ if (b[i]) {
+ corr[j] = b[i];
+ eras_pos[j++] = loc[i] - pad;
+ }
+ }
+ } else if (data && par) {
+ /* Apply error to data and parity */
+ for (i = 0; i < count; i++) {
+ if (loc[i] < (nn - nroots))
+ data[loc[i] - pad] ^= b[i];
+ else
+ par[loc[i] - pad - len] ^= b[i];
+ }
+ }
+
+ return num_corrected;
+}