From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ... --- drivers/net/loopback.c | 292 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 292 insertions(+) create mode 100644 drivers/net/loopback.c (limited to 'drivers/net/loopback.c') diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c new file mode 100644 index 000000000..1fb6ce684 --- /dev/null +++ b/drivers/net/loopback.c @@ -0,0 +1,292 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Pseudo-driver for the loopback interface. + * + * Version: @(#)loopback.c 1.0.4b 08/16/93 + * + * Authors: Ross Biro + * Fred N. van Kempen, + * Donald Becker, + * + * Alan Cox : Fixed oddments for NET3.014 + * Alan Cox : Rejig for NET3.029 snap #3 + * Alan Cox : Fixed NET3.029 bugs and sped up + * Larry McVoy : Tiny tweak to double performance + * Alan Cox : Backed out LMV's tweak - the linux mm + * can't take it... + * Michael Griffith: Don't bother computing the checksums + * on packets received on the loopback + * interface. + * Alexey Kuznetsov: Potential hang under some extreme + * cases removed. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include /* For the statistics structure. */ +#include /* For ARPHRD_ETHER */ +#include +#include +#include +#include +#include +#include +#include + +/* blackhole_netdev - a device used for dsts that are marked expired! + * This is global device (instead of per-net-ns) since it's not needed + * to be per-ns and gets initialized at boot time. + */ +struct net_device *blackhole_netdev; +EXPORT_SYMBOL(blackhole_netdev); + +/* The higher levels take care of making this non-reentrant (it's + * called with bh's disabled). + */ +static netdev_tx_t loopback_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + int len; + + skb_tx_timestamp(skb); + + /* do not fool net_timestamp_check() with various clock bases */ + skb_clear_tstamp(skb); + + skb_orphan(skb); + + /* Before queueing this packet to __netif_rx(), + * make sure dst is refcounted. + */ + skb_dst_force(skb); + + skb->protocol = eth_type_trans(skb, dev); + + len = skb->len; + if (likely(__netif_rx(skb) == NET_RX_SUCCESS)) + dev_lstats_add(dev, len); + + return NETDEV_TX_OK; +} + +void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes) +{ + int i; + + *packets = 0; + *bytes = 0; + + for_each_possible_cpu(i) { + const struct pcpu_lstats *lb_stats; + u64 tbytes, tpackets; + unsigned int start; + + lb_stats = per_cpu_ptr(dev->lstats, i); + do { + start = u64_stats_fetch_begin(&lb_stats->syncp); + tpackets = u64_stats_read(&lb_stats->packets); + tbytes = u64_stats_read(&lb_stats->bytes); + } while (u64_stats_fetch_retry(&lb_stats->syncp, start)); + *bytes += tbytes; + *packets += tpackets; + } +} +EXPORT_SYMBOL(dev_lstats_read); + +static void loopback_get_stats64(struct net_device *dev, + struct rtnl_link_stats64 *stats) +{ + u64 packets, bytes; + + dev_lstats_read(dev, &packets, &bytes); + + stats->rx_packets = packets; + stats->tx_packets = packets; + stats->rx_bytes = bytes; + stats->tx_bytes = bytes; +} + +static u32 always_on(struct net_device *dev) +{ + return 1; +} + +static const struct ethtool_ops loopback_ethtool_ops = { + .get_link = always_on, + .get_ts_info = ethtool_op_get_ts_info, +}; + +static int loopback_dev_init(struct net_device *dev) +{ + netdev_lockdep_set_classes(dev); + return 0; +} + +static void loopback_dev_free(struct net_device *dev) +{ + dev_net(dev)->loopback_dev = NULL; +} + +static const struct net_device_ops loopback_ops = { + .ndo_init = loopback_dev_init, + .ndo_start_xmit = loopback_xmit, + .ndo_get_stats64 = loopback_get_stats64, + .ndo_set_mac_address = eth_mac_addr, +}; + +static void gen_lo_setup(struct net_device *dev, + unsigned int mtu, + const struct ethtool_ops *eth_ops, + const struct header_ops *hdr_ops, + const struct net_device_ops *dev_ops, + void (*dev_destructor)(struct net_device *dev)) +{ + dev->mtu = mtu; + dev->hard_header_len = ETH_HLEN; /* 14 */ + dev->min_header_len = ETH_HLEN; /* 14 */ + dev->addr_len = ETH_ALEN; /* 6 */ + dev->type = ARPHRD_LOOPBACK; /* 0x0001*/ + dev->flags = IFF_LOOPBACK; + dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE; + dev->lltx = true; + dev->netns_immutable = true; + netif_keep_dst(dev); + dev->hw_features = NETIF_F_GSO_SOFTWARE; + dev->features = NETIF_F_SG | NETIF_F_FRAGLIST + | NETIF_F_GSO_SOFTWARE + | NETIF_F_HW_CSUM + | NETIF_F_RXCSUM + | NETIF_F_SCTP_CRC + | NETIF_F_HIGHDMA + | NETIF_F_VLAN_CHALLENGED + | NETIF_F_LOOPBACK; + dev->ethtool_ops = eth_ops; + dev->header_ops = hdr_ops; + dev->netdev_ops = dev_ops; + dev->needs_free_netdev = true; + dev->pcpu_stat_type = NETDEV_PCPU_STAT_LSTATS; + dev->priv_destructor = dev_destructor; + + netif_set_tso_max_size(dev, GSO_MAX_SIZE); +} + +/* The loopback device is special. There is only one instance + * per network namespace. + */ +static void loopback_setup(struct net_device *dev) +{ + gen_lo_setup(dev, (64 * 1024), &loopback_ethtool_ops, ð_header_ops, + &loopback_ops, loopback_dev_free); +} + +/* Setup and register the loopback device. */ +static __net_init int loopback_net_init(struct net *net) +{ + struct net_device *dev; + int err; + + err = -ENOMEM; + dev = alloc_netdev(0, "lo", NET_NAME_PREDICTABLE, loopback_setup); + if (!dev) + goto out; + + dev_net_set(dev, net); + err = register_netdev(dev); + if (err) + goto out_free_netdev; + + BUG_ON(dev->ifindex != LOOPBACK_IFINDEX); + net->loopback_dev = dev; + return 0; + +out_free_netdev: + free_netdev(dev); +out: + if (net_eq(net, &init_net)) + panic("loopback: Failed to register netdevice: %d\n", err); + return err; +} + +/* Registered in net/core/dev.c */ +struct pernet_operations __net_initdata loopback_net_ops = { + .init = loopback_net_init, +}; + +/* blackhole netdevice */ +static netdev_tx_t blackhole_netdev_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + kfree_skb(skb); + net_warn_ratelimited("%s(): Dropping skb.\n", __func__); + return NETDEV_TX_OK; +} + +static int blackhole_neigh_output(struct neighbour *n, struct sk_buff *skb) +{ + kfree_skb(skb); + return 0; +} + +static int blackhole_neigh_construct(struct net_device *dev, + struct neighbour *n) +{ + n->output = blackhole_neigh_output; + return 0; +} + +static const struct net_device_ops blackhole_netdev_ops = { + .ndo_start_xmit = blackhole_netdev_xmit, + .ndo_neigh_construct = blackhole_neigh_construct, +}; + +/* This is a dst-dummy device used specifically for invalidated + * DSTs and unlike loopback, this is not per-ns. + */ +static void blackhole_netdev_setup(struct net_device *dev) +{ + gen_lo_setup(dev, ETH_MIN_MTU, NULL, NULL, &blackhole_netdev_ops, NULL); +} + +/* Setup and register the blackhole_netdev. */ +static int __init blackhole_netdev_init(void) +{ + blackhole_netdev = alloc_netdev(0, "blackhole_dev", NET_NAME_UNKNOWN, + blackhole_netdev_setup); + if (!blackhole_netdev) + return -ENOMEM; + + rtnl_net_lock(&init_net); + dev_init_scheduler(blackhole_netdev); + dev_activate(blackhole_netdev); + rtnl_net_unlock(&init_net); + + blackhole_netdev->flags |= IFF_UP | IFF_RUNNING; + + return 0; +} + +device_initcall(blackhole_netdev_init); -- cgit v1.3.1