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(). ... --- drivers/usb/phy/phy-tahvo.c | 440 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 440 insertions(+) create mode 100644 drivers/usb/phy/phy-tahvo.c (limited to 'drivers/usb/phy/phy-tahvo.c') diff --git a/drivers/usb/phy/phy-tahvo.c b/drivers/usb/phy/phy-tahvo.c new file mode 100644 index 000000000..f2d2cc586 --- /dev/null +++ b/drivers/usb/phy/phy-tahvo.c @@ -0,0 +1,440 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Tahvo USB transceiver driver + * + * Copyright (C) 2005-2006 Nokia Corporation + * + * Parts copied from isp1301_omap.c. + * Copyright (C) 2004 Texas Instruments + * Copyright (C) 2004 David Brownell + * + * Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs. + * Modified for Retu/Tahvo MFD by Aaro Koskinen. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRIVER_NAME "tahvo-usb" + +#define TAHVO_REG_IDSR 0x02 +#define TAHVO_REG_USBR 0x06 + +#define USBR_SLAVE_CONTROL (1 << 8) +#define USBR_VPPVIO_SW (1 << 7) +#define USBR_SPEED (1 << 6) +#define USBR_REGOUT (1 << 5) +#define USBR_MASTER_SW2 (1 << 4) +#define USBR_MASTER_SW1 (1 << 3) +#define USBR_SLAVE_SW (1 << 2) +#define USBR_NSUSPEND (1 << 1) +#define USBR_SEMODE (1 << 0) + +#define TAHVO_MODE_HOST 0 +#define TAHVO_MODE_PERIPHERAL 1 + +struct tahvo_usb { + struct platform_device *pt_dev; + struct usb_phy phy; + int vbus_state; + struct mutex serialize; + struct clk *ick; + int irq; + int tahvo_mode; + struct extcon_dev *extcon; +}; + +static const unsigned int tahvo_cable[] = { + EXTCON_USB, + EXTCON_USB_HOST, + + EXTCON_NONE, +}; + +static ssize_t vbus_show(struct device *device, + struct device_attribute *attr, char *buf) +{ + struct tahvo_usb *tu = dev_get_drvdata(device); + return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off"); +} +static DEVICE_ATTR_RO(vbus); + +static void check_vbus_state(struct tahvo_usb *tu) +{ + struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); + int reg, prev_state; + + reg = retu_read(rdev, TAHVO_REG_IDSR); + if (reg & TAHVO_STAT_VBUS) { + switch (tu->phy.otg->state) { + case OTG_STATE_B_IDLE: + /* Enable the gadget driver */ + if (tu->phy.otg->gadget) + usb_gadget_vbus_connect(tu->phy.otg->gadget); + tu->phy.otg->state = OTG_STATE_B_PERIPHERAL; + usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED); + break; + case OTG_STATE_A_IDLE: + /* + * Session is now valid assuming the USB hub is driving + * Vbus. + */ + tu->phy.otg->state = OTG_STATE_A_HOST; + break; + default: + break; + } + dev_info(&tu->pt_dev->dev, "USB cable connected\n"); + } else { + switch (tu->phy.otg->state) { + case OTG_STATE_B_PERIPHERAL: + if (tu->phy.otg->gadget) + usb_gadget_vbus_disconnect(tu->phy.otg->gadget); + tu->phy.otg->state = OTG_STATE_B_IDLE; + usb_phy_set_event(&tu->phy, USB_EVENT_NONE); + break; + case OTG_STATE_A_HOST: + tu->phy.otg->state = OTG_STATE_A_IDLE; + break; + default: + break; + } + dev_info(&tu->pt_dev->dev, "USB cable disconnected\n"); + } + + prev_state = tu->vbus_state; + tu->vbus_state = reg & TAHVO_STAT_VBUS; + if (prev_state != tu->vbus_state) { + extcon_set_state_sync(tu->extcon, EXTCON_USB, tu->vbus_state); + sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state"); + } +} + +static void tahvo_usb_become_host(struct tahvo_usb *tu) +{ + struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); + + extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, true); + + /* Power up the transceiver in USB host mode */ + retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND | + USBR_MASTER_SW2 | USBR_MASTER_SW1); + tu->phy.otg->state = OTG_STATE_A_IDLE; + + check_vbus_state(tu); +} + +static void tahvo_usb_stop_host(struct tahvo_usb *tu) +{ + tu->phy.otg->state = OTG_STATE_A_IDLE; +} + +static void tahvo_usb_become_peripheral(struct tahvo_usb *tu) +{ + struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); + + extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, false); + + /* Power up transceiver and set it in USB peripheral mode */ + retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT | + USBR_NSUSPEND | USBR_SLAVE_SW); + tu->phy.otg->state = OTG_STATE_B_IDLE; + + check_vbus_state(tu); +} + +static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu) +{ + if (tu->phy.otg->gadget) + usb_gadget_vbus_disconnect(tu->phy.otg->gadget); + tu->phy.otg->state = OTG_STATE_B_IDLE; +} + +static void tahvo_usb_power_off(struct tahvo_usb *tu) +{ + struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); + + /* Disable gadget controller if any */ + if (tu->phy.otg->gadget) + usb_gadget_vbus_disconnect(tu->phy.otg->gadget); + + /* Power off transceiver */ + retu_write(rdev, TAHVO_REG_USBR, 0); + tu->phy.otg->state = OTG_STATE_UNDEFINED; +} + +static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend) +{ + struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy); + struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent); + u16 w; + + dev_dbg(&tu->pt_dev->dev, "%s\n", __func__); + + w = retu_read(rdev, TAHVO_REG_USBR); + if (suspend) + w &= ~USBR_NSUSPEND; + else + w |= USBR_NSUSPEND; + retu_write(rdev, TAHVO_REG_USBR, w); + + return 0; +} + +static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host) +{ + struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb, + phy); + + mutex_lock(&tu->serialize); + + if (host == NULL) { + if (tu->tahvo_mode == TAHVO_MODE_HOST) + tahvo_usb_power_off(tu); + otg->host = NULL; + mutex_unlock(&tu->serialize); + return 0; + } + + if (tu->tahvo_mode == TAHVO_MODE_HOST) { + otg->host = NULL; + tahvo_usb_become_host(tu); + } + + otg->host = host; + + mutex_unlock(&tu->serialize); + + return 0; +} + +static int tahvo_usb_set_peripheral(struct usb_otg *otg, + struct usb_gadget *gadget) +{ + struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb, + phy); + + mutex_lock(&tu->serialize); + + if (!gadget) { + if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) + tahvo_usb_power_off(tu); + tu->phy.otg->gadget = NULL; + mutex_unlock(&tu->serialize); + return 0; + } + + tu->phy.otg->gadget = gadget; + if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) + tahvo_usb_become_peripheral(tu); + + mutex_unlock(&tu->serialize); + + return 0; +} + +static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu) +{ + struct tahvo_usb *tu = _tu; + + mutex_lock(&tu->serialize); + check_vbus_state(tu); + mutex_unlock(&tu->serialize); + + return IRQ_HANDLED; +} + +static ssize_t otg_mode_show(struct device *device, + struct device_attribute *attr, char *buf) +{ + struct tahvo_usb *tu = dev_get_drvdata(device); + + switch (tu->tahvo_mode) { + case TAHVO_MODE_HOST: + return sprintf(buf, "host\n"); + case TAHVO_MODE_PERIPHERAL: + return sprintf(buf, "peripheral\n"); + } + + return -EINVAL; +} + +static ssize_t otg_mode_store(struct device *device, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct tahvo_usb *tu = dev_get_drvdata(device); + int r; + + mutex_lock(&tu->serialize); + if (count >= 4 && strncmp(buf, "host", 4) == 0) { + if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL) + tahvo_usb_stop_peripheral(tu); + tu->tahvo_mode = TAHVO_MODE_HOST; + if (tu->phy.otg->host) { + dev_info(device, "HOST mode: host controller present\n"); + tahvo_usb_become_host(tu); + } else { + dev_info(device, "HOST mode: no host controller, powering off\n"); + tahvo_usb_power_off(tu); + } + r = strlen(buf); + } else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) { + if (tu->tahvo_mode == TAHVO_MODE_HOST) + tahvo_usb_stop_host(tu); + tu->tahvo_mode = TAHVO_MODE_PERIPHERAL; + if (tu->phy.otg->gadget) { + dev_info(device, "PERIPHERAL mode: gadget driver present\n"); + tahvo_usb_become_peripheral(tu); + } else { + dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n"); + tahvo_usb_power_off(tu); + } + r = strlen(buf); + } else { + r = -EINVAL; + } + mutex_unlock(&tu->serialize); + + return r; +} +static DEVICE_ATTR_RW(otg_mode); + +static struct attribute *tahvo_attrs[] = { + &dev_attr_vbus.attr, + &dev_attr_otg_mode.attr, + NULL +}; +ATTRIBUTE_GROUPS(tahvo); + +static int tahvo_usb_probe(struct platform_device *pdev) +{ + struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent); + struct tahvo_usb *tu; + int ret; + + tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL); + if (!tu) + return -ENOMEM; + + tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg), + GFP_KERNEL); + if (!tu->phy.otg) + return -ENOMEM; + + tu->pt_dev = pdev; + + /* Default mode */ +#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT + tu->tahvo_mode = TAHVO_MODE_HOST; +#else + tu->tahvo_mode = TAHVO_MODE_PERIPHERAL; +#endif + + mutex_init(&tu->serialize); + + tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick"); + if (!IS_ERR(tu->ick)) + clk_enable(tu->ick); + + /* + * Set initial state, so that we generate kevents only on state changes. + */ + tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS; + + tu->extcon = devm_extcon_dev_allocate(&pdev->dev, tahvo_cable); + if (IS_ERR(tu->extcon)) { + dev_err(&pdev->dev, "failed to allocate memory for extcon\n"); + ret = PTR_ERR(tu->extcon); + goto err_disable_clk; + } + + ret = devm_extcon_dev_register(&pdev->dev, tu->extcon); + if (ret) { + dev_err(&pdev->dev, "could not register extcon device: %d\n", + ret); + goto err_disable_clk; + } + + /* Set the initial cable state. */ + extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, + tu->tahvo_mode == TAHVO_MODE_HOST); + extcon_set_state_sync(tu->extcon, EXTCON_USB, tu->vbus_state); + + /* Create OTG interface */ + tahvo_usb_power_off(tu); + tu->phy.dev = &pdev->dev; + tu->phy.otg->state = OTG_STATE_UNDEFINED; + tu->phy.label = DRIVER_NAME; + tu->phy.set_suspend = tahvo_usb_set_suspend; + + tu->phy.otg->usb_phy = &tu->phy; + tu->phy.otg->set_host = tahvo_usb_set_host; + tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral; + + ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2); + if (ret < 0) { + dev_err(&pdev->dev, "cannot register USB transceiver: %d\n", + ret); + goto err_disable_clk; + } + + dev_set_drvdata(&pdev->dev, tu); + + tu->irq = ret = platform_get_irq(pdev, 0); + if (ret < 0) + return ret; + ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt, + IRQF_ONESHOT, + "tahvo-vbus", tu); + if (ret) { + dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n", + ret); + goto err_remove_phy; + } + + return 0; + +err_remove_phy: + usb_remove_phy(&tu->phy); +err_disable_clk: + if (!IS_ERR(tu->ick)) + clk_disable(tu->ick); + + return ret; +} + +static int tahvo_usb_remove(struct platform_device *pdev) +{ + struct tahvo_usb *tu = platform_get_drvdata(pdev); + + free_irq(tu->irq, tu); + usb_remove_phy(&tu->phy); + if (!IS_ERR(tu->ick)) + clk_disable(tu->ick); + + return 0; +} + +static struct platform_driver tahvo_usb_driver = { + .probe = tahvo_usb_probe, + .remove = tahvo_usb_remove, + .driver = { + .name = "tahvo-usb", + .dev_groups = tahvo_groups, + }, +}; +module_platform_driver(tahvo_usb_driver); + +MODULE_DESCRIPTION("Tahvo USB transceiver driver"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs"); +MODULE_AUTHOR("Aaro Koskinen "); -- cgit v1.2.3