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().
  ...

1 files changed, 566 insertions, 0 deletions

diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
new file mode 100644
index 000000000..4f26b0a55
--- /dev/null
+++ b/drivers/s390/char/fs3270.c
@@ -0,0 +1,566 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IBM/3270 Driver - fullscreen driver.
+ *
+ * Author(s):
+ *   Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
+ *   Rewritten for 2.5/2.6 by Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *     Copyright IBM Corp. 2003, 2009
+ */
+
+#include <linux/memblock.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/compat.h>
+#include <linux/sched/signal.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <uapi/asm/fs3270.h>
+#include <asm/ccwdev.h>
+#include <asm/cio.h>
+#include <asm/ebcdic.h>
+#include <asm/idals.h>
+
+#include "raw3270.h"
+#include "ctrlchar.h"
+
+static struct raw3270_fn fs3270_fn;
+
+struct fs3270 {
+	struct raw3270_view view;
+	struct pid *fs_pid;		/* Pid of controlling program. */
+	int read_command;		/* ccw command to use for reads. */
+	int write_command;		/* ccw command to use for writes. */
+	int attention;			/* Got attention. */
+	int active;			/* Fullscreen view is active. */
+	struct raw3270_request *init;	/* single init request. */
+	wait_queue_head_t wait;		/* Init & attention wait queue. */
+	struct idal_buffer *rdbuf;	/* full-screen-deactivate buffer */
+	size_t rdbuf_size;		/* size of data returned by RDBUF */
+};
+
+static DEFINE_MUTEX(fs3270_mutex);
+
+static void fs3270_wake_up(struct raw3270_request *rq, void *data)
+{
+	wake_up((wait_queue_head_t *)data);
+}
+
+static inline int fs3270_working(struct fs3270 *fp)
+{
+	/*
+	 * The fullscreen view is in working order if the view
+	 * has been activated AND the initial request is finished.
+	 */
+	return fp->active && raw3270_request_final(fp->init);
+}
+
+static int fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
+{
+	struct fs3270 *fp;
+	int rc;
+
+	fp = (struct fs3270 *)view;
+	rq->callback = fs3270_wake_up;
+	rq->callback_data = &fp->wait;
+
+	do {
+		if (!fs3270_working(fp)) {
+			/* Fullscreen view isn't ready yet. */
+			rc = wait_event_interruptible(fp->wait,
+						      fs3270_working(fp));
+			if (rc != 0)
+				break;
+		}
+		rc = raw3270_start(view, rq);
+		if (rc == 0) {
+			/* Started successfully. Now wait for completion. */
+			wait_event(fp->wait, raw3270_request_final(rq));
+		}
+	} while (rc == -EACCES);
+	return rc;
+}
+
+/*
+ * Switch to the fullscreen view.
+ */
+static void fs3270_reset_callback(struct raw3270_request *rq, void *data)
+{
+	struct fs3270 *fp;
+
+	fp = (struct fs3270 *)rq->view;
+	raw3270_request_reset(rq);
+	wake_up(&fp->wait);
+}
+
+static void fs3270_restore_callback(struct raw3270_request *rq, void *data)
+{
+	struct fs3270 *fp;
+
+	fp = (struct fs3270 *)rq->view;
+	if (rq->rc != 0 || rq->rescnt != 0) {
+		if (fp->fs_pid)
+			kill_pid(fp->fs_pid, SIGHUP, 1);
+	}
+	fp->rdbuf_size = 0;
+	raw3270_request_reset(rq);
+	wake_up(&fp->wait);
+}
+
+static int fs3270_activate(struct raw3270_view *view)
+{
+	struct fs3270 *fp;
+	char *cp;
+	int rc;
+
+	fp = (struct fs3270 *)view;
+
+	/* If an old init command is still running just return. */
+	if (!raw3270_request_final(fp->init))
+		return 0;
+
+	raw3270_request_set_cmd(fp->init, TC_EWRITEA);
+	raw3270_request_set_idal(fp->init, fp->rdbuf);
+	fp->init->rescnt = 0;
+	cp = fp->rdbuf->data[0];
+	if (fp->rdbuf_size == 0) {
+		/* No saved buffer. Just clear the screen. */
+		fp->init->ccw.count = 1;
+		fp->init->callback = fs3270_reset_callback;
+		cp[0] = 0;
+	} else {
+		/* Restore fullscreen buffer saved by fs3270_deactivate. */
+		fp->init->ccw.count = fp->rdbuf_size;
+		fp->init->callback = fs3270_restore_callback;
+		cp[0] = TW_KR;
+		cp[1] = TO_SBA;
+		cp[2] = cp[6];
+		cp[3] = cp[7];
+		cp[4] = TO_IC;
+		cp[5] = TO_SBA;
+		cp[6] = 0x40;
+		cp[7] = 0x40;
+	}
+	rc = raw3270_start_locked(view, fp->init);
+	fp->init->rc = rc;
+	if (rc)
+		fp->init->callback(fp->init, NULL);
+	else
+		fp->active = 1;
+	return rc;
+}
+
+/*
+ * Shutdown fullscreen view.
+ */
+static void fs3270_save_callback(struct raw3270_request *rq, void *data)
+{
+	struct fs3270 *fp;
+
+	fp = (struct fs3270 *)rq->view;
+
+	/* Correct idal buffer element 0 address. */
+	fp->rdbuf->data[0] -= 5;
+	fp->rdbuf->size += 5;
+
+	/*
+	 * If the rdbuf command failed or the idal buffer is
+	 * to small for the amount of data returned by the
+	 * rdbuf command, then we have no choice but to send
+	 * a SIGHUP to the application.
+	 */
+	if (rq->rc != 0 || rq->rescnt == 0) {
+		if (fp->fs_pid)
+			kill_pid(fp->fs_pid, SIGHUP, 1);
+		fp->rdbuf_size = 0;
+	} else {
+		fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
+	}
+	raw3270_request_reset(rq);
+	wake_up(&fp->wait);
+}
+
+static void fs3270_deactivate(struct raw3270_view *view)
+{
+	struct fs3270 *fp;
+
+	fp = (struct fs3270 *)view;
+	fp->active = 0;
+
+	/* If an old init command is still running just return. */
+	if (!raw3270_request_final(fp->init))
+		return;
+
+	/* Prepare read-buffer request. */
+	raw3270_request_set_cmd(fp->init, TC_RDBUF);
+	/*
+	 * Hackish: skip first 5 bytes of the idal buffer to make
+	 * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
+	 * in the activation command.
+	 */
+	fp->rdbuf->data[0] += 5;
+	fp->rdbuf->size -= 5;
+	raw3270_request_set_idal(fp->init, fp->rdbuf);
+	fp->init->rescnt = 0;
+	fp->init->callback = fs3270_save_callback;
+
+	/* Start I/O to read in the 3270 buffer. */
+	fp->init->rc = raw3270_start_locked(view, fp->init);
+	if (fp->init->rc)
+		fp->init->callback(fp->init, NULL);
+}
+
+static void fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq,
+		       struct irb *irb)
+{
+	/* Handle ATTN. Set indication and wake waiters for attention. */
+	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
+		fp->attention = 1;
+		wake_up(&fp->wait);
+	}
+
+	if (rq) {
+		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
+			rq->rc = -EIO;
+		else
+			/* Normal end. Copy residual count. */
+			rq->rescnt = irb->scsw.cmd.count;
+	}
+}
+
+/*
+ * Process reads from fullscreen 3270.
+ */
+static ssize_t fs3270_read(struct file *filp, char __user *data,
+			   size_t count, loff_t *off)
+{
+	struct fs3270 *fp;
+	struct raw3270_request *rq;
+	struct idal_buffer *ib;
+	ssize_t rc;
+
+	if (count == 0 || count > 65535)
+		return -EINVAL;
+	fp = filp->private_data;
+	if (!fp)
+		return -ENODEV;
+	ib = idal_buffer_alloc(count, 0);
+	if (IS_ERR(ib))
+		return -ENOMEM;
+	rq = raw3270_request_alloc(0);
+	if (!IS_ERR(rq)) {
+		if (fp->read_command == 0 && fp->write_command != 0)
+			fp->read_command = 6;
+		raw3270_request_set_cmd(rq, fp->read_command ? : 2);
+		raw3270_request_set_idal(rq, ib);
+		rc = wait_event_interruptible(fp->wait, fp->attention);
+		fp->attention = 0;
+		if (rc == 0) {
+			rc = fs3270_do_io(&fp->view, rq);
+			if (rc == 0) {
+				count -= rq->rescnt;
+				if (idal_buffer_to_user(ib, data, count) != 0)
+					rc = -EFAULT;
+				else
+					rc = count;
+			}
+		}
+		raw3270_request_free(rq);
+	} else {
+		rc = PTR_ERR(rq);
+	}
+	idal_buffer_free(ib);
+	return rc;
+}
+
+/*
+ * Process writes to fullscreen 3270.
+ */
+static ssize_t fs3270_write(struct file *filp, const char __user *data,
+			    size_t count, loff_t *off)
+{
+	struct fs3270 *fp;
+	struct raw3270_request *rq;
+	struct idal_buffer *ib;
+	int write_command;
+	ssize_t rc;
+
+	fp = filp->private_data;
+	if (!fp)
+		return -ENODEV;
+	ib = idal_buffer_alloc(count, 0);
+	if (IS_ERR(ib))
+		return -ENOMEM;
+	rq = raw3270_request_alloc(0);
+	if (!IS_ERR(rq)) {
+		if (idal_buffer_from_user(ib, data, count) == 0) {
+			write_command = fp->write_command ? : 1;
+			if (write_command == 5)
+				write_command = 13;
+			raw3270_request_set_cmd(rq, write_command);
+			raw3270_request_set_idal(rq, ib);
+			rc = fs3270_do_io(&fp->view, rq);
+			if (rc == 0)
+				rc = count - rq->rescnt;
+		} else {
+			rc = -EFAULT;
+		}
+		raw3270_request_free(rq);
+	} else {
+		rc = PTR_ERR(rq);
+	}
+	idal_buffer_free(ib);
+	return rc;
+}
+
+/*
+ * process ioctl commands for the tube driver
+ */
+static long fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	char __user *argp;
+	struct fs3270 *fp;
+	struct raw3270_iocb iocb;
+	int rc;
+
+	fp = filp->private_data;
+	if (!fp)
+		return -ENODEV;
+	if (is_compat_task())
+		argp = compat_ptr(arg);
+	else
+		argp = (char __user *)arg;
+	rc = 0;
+	mutex_lock(&fs3270_mutex);
+	switch (cmd) {
+	case TUBICMD:
+		fp->read_command = arg;
+		break;
+	case TUBOCMD:
+		fp->write_command = arg;
+		break;
+	case TUBGETI:
+		rc = put_user(fp->read_command, argp);
+		break;
+	case TUBGETO:
+		rc = put_user(fp->write_command, argp);
+		break;
+	case TUBGETMOD:
+		iocb.model = fp->view.model;
+		iocb.line_cnt = fp->view.rows;
+		iocb.col_cnt = fp->view.cols;
+		iocb.pf_cnt = 24;
+		iocb.re_cnt = 20;
+		iocb.map = 0;
+		if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
+			rc = -EFAULT;
+		break;
+	}
+	mutex_unlock(&fs3270_mutex);
+	return rc;
+}
+
+/*
+ * Allocate fs3270 structure.
+ */
+static struct fs3270 *fs3270_alloc_view(void)
+{
+	struct fs3270 *fp;
+
+	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
+	if (!fp)
+		return ERR_PTR(-ENOMEM);
+	fp->init = raw3270_request_alloc(0);
+	if (IS_ERR(fp->init)) {
+		kfree(fp);
+		return ERR_PTR(-ENOMEM);
+	}
+	return fp;
+}
+
+/*
+ * Free fs3270 structure.
+ */
+static void fs3270_free_view(struct raw3270_view *view)
+{
+	struct fs3270 *fp;
+
+	fp = (struct fs3270 *)view;
+	if (fp->rdbuf)
+		idal_buffer_free(fp->rdbuf);
+	raw3270_request_free(((struct fs3270 *)view)->init);
+	kfree(view);
+}
+
+/*
+ * Unlink fs3270 data structure from filp.
+ */
+static void fs3270_release(struct raw3270_view *view)
+{
+	struct fs3270 *fp;
+
+	fp = (struct fs3270 *)view;
+	if (fp->fs_pid)
+		kill_pid(fp->fs_pid, SIGHUP, 1);
+}
+
+/* View to a 3270 device. Can be console, tty or fullscreen. */
+static struct raw3270_fn fs3270_fn = {
+	.activate = fs3270_activate,
+	.deactivate = fs3270_deactivate,
+	.intv = (void *)fs3270_irq,
+	.release = fs3270_release,
+	.free = fs3270_free_view
+};
+
+/*
+ * This routine is called whenever a 3270 fullscreen device is opened.
+ */
+static int fs3270_open(struct inode *inode, struct file *filp)
+{
+	struct fs3270 *fp;
+	struct idal_buffer *ib;
+	int minor, rc = 0;
+
+	if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR)
+		return -ENODEV;
+	minor = iminor(file_inode(filp));
+	/* Check for minor 0 multiplexer. */
+	if (minor == 0) {
+		struct tty_struct *tty = get_current_tty();
+
+		if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
+			tty_kref_put(tty);
+			return -ENODEV;
+		}
+		minor = tty->index;
+		tty_kref_put(tty);
+	}
+	mutex_lock(&fs3270_mutex);
+	/* Check if some other program is already using fullscreen mode. */
+	fp = (struct fs3270 *)raw3270_find_view(&fs3270_fn, minor);
+	if (!IS_ERR(fp)) {
+		raw3270_put_view(&fp->view);
+		rc = -EBUSY;
+		goto out;
+	}
+	/* Allocate fullscreen view structure. */
+	fp = fs3270_alloc_view();
+	if (IS_ERR(fp)) {
+		rc = PTR_ERR(fp);
+		goto out;
+	}
+
+	init_waitqueue_head(&fp->wait);
+	fp->fs_pid = get_pid(task_pid(current));
+	rc = raw3270_add_view(&fp->view, &fs3270_fn, minor,
+			      RAW3270_VIEW_LOCK_BH);
+	if (rc) {
+		fs3270_free_view(&fp->view);
+		goto out;
+	}
+
+	/* Allocate idal-buffer. */
+	ib = idal_buffer_alloc(2 * fp->view.rows * fp->view.cols + 5, 0);
+	if (IS_ERR(ib)) {
+		raw3270_put_view(&fp->view);
+		raw3270_del_view(&fp->view);
+		rc = PTR_ERR(ib);
+		goto out;
+	}
+	fp->rdbuf = ib;
+
+	rc = raw3270_activate_view(&fp->view);
+	if (rc) {
+		raw3270_put_view(&fp->view);
+		raw3270_del_view(&fp->view);
+		goto out;
+	}
+	stream_open(inode, filp);
+	filp->private_data = fp;
+out:
+	mutex_unlock(&fs3270_mutex);
+	return rc;
+}
+
+/*
+ * This routine is called when the 3270 tty is closed. We wait
+ * for the remaining request to be completed. Then we clean up.
+ */
+static int fs3270_close(struct inode *inode, struct file *filp)
+{
+	struct fs3270 *fp;
+
+	fp = filp->private_data;
+	filp->private_data = NULL;
+	if (fp) {
+		put_pid(fp->fs_pid);
+		fp->fs_pid = NULL;
+		raw3270_reset(&fp->view);
+		raw3270_put_view(&fp->view);
+		raw3270_del_view(&fp->view);
+	}
+	return 0;
+}
+
+static const struct file_operations fs3270_fops = {
+	.owner		 = THIS_MODULE,		/* owner */
+	.read		 = fs3270_read,		/* read */
+	.write		 = fs3270_write,	/* write */
+	.unlocked_ioctl	 = fs3270_ioctl,	/* ioctl */
+	.compat_ioctl	 = fs3270_ioctl,	/* ioctl */
+	.open		 = fs3270_open,		/* open */
+	.release	 = fs3270_close,	/* release */
+	.llseek		= no_llseek,
+};
+
+static void fs3270_create_cb(int minor)
+{
+	__register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
+	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
+		      NULL, "3270/tub%d", minor);
+}
+
+static void fs3270_destroy_cb(int minor)
+{
+	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
+	__unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
+}
+
+static struct raw3270_notifier fs3270_notifier = {
+	.create = fs3270_create_cb,
+	.destroy = fs3270_destroy_cb,
+};
+
+/*
+ * 3270 fullscreen driver initialization.
+ */
+static int __init fs3270_init(void)
+{
+	int rc;
+
+	rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
+	if (rc)
+		return rc;
+	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
+		      NULL, "3270/tub");
+	raw3270_register_notifier(&fs3270_notifier);
+	return 0;
+}
+
+static void __exit fs3270_exit(void)
+{
+	raw3270_unregister_notifier(&fs3270_notifier);
+	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0));
+	__unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
+}
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
+
+module_init(fs3270_init);
+module_exit(fs3270_exit);