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, 572 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_proc.c b/drivers/scsi/scsi_proc.c
new file mode 100644
index 000000000..4a6eb1741
--- /dev/null
+++ b/drivers/scsi/scsi_proc.c
@@ -0,0 +1,572 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/scsi/scsi_proc.c
+ *
+ * The functions in this file provide an interface between
+ * the PROC file system and the SCSI device drivers
+ * It is mainly used for debugging, statistics and to pass 
+ * information directly to the lowlevel driver.
+ *
+ * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de 
+ * Version: 0.99.8   last change: 95/09/13
+ * 
+ * generic command parser provided by: 
+ * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
+ *
+ * generic_proc_info() support of xxxx_info() by:
+ * Michael A. Griffith <grif@acm.org>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/proc_fs.h>
+#include <linux/errno.h>
+#include <linux/blkdev.h>
+#include <linux/seq_file.h>
+#include <linux/mutex.h>
+#include <linux/gfp.h>
+#include <linux/uaccess.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_transport.h>
+
+#include "scsi_priv.h"
+#include "scsi_logging.h"
+
+
+/* 4K page size, but our output routines, use some slack for overruns */
+#define PROC_BLOCK_SIZE (3*1024)
+
+static struct proc_dir_entry *proc_scsi;
+
+/* Protects scsi_proc_list */
+static DEFINE_MUTEX(global_host_template_mutex);
+static LIST_HEAD(scsi_proc_list);
+
+/**
+ * struct scsi_proc_entry - (host template, SCSI proc dir) association
+ * @entry: entry in scsi_proc_list.
+ * @sht: SCSI host template associated with the procfs directory.
+ * @proc_dir: procfs directory associated with the SCSI host template.
+ * @present: Number of SCSI hosts instantiated for @sht.
+ */
+struct scsi_proc_entry {
+	struct list_head	entry;
+	const struct scsi_host_template *sht;
+	struct proc_dir_entry	*proc_dir;
+	unsigned int		present;
+};
+
+static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
+                           size_t count, loff_t *ppos)
+{
+	struct Scsi_Host *shost = pde_data(file_inode(file));
+	ssize_t ret = -ENOMEM;
+	char *page;
+    
+	if (count > PROC_BLOCK_SIZE)
+		return -EOVERFLOW;
+
+	if (!shost->hostt->write_info)
+		return -EINVAL;
+
+	page = (char *)__get_free_page(GFP_KERNEL);
+	if (page) {
+		ret = -EFAULT;
+		if (copy_from_user(page, buf, count))
+			goto out;
+		ret = shost->hostt->write_info(shost, page, count);
+	}
+out:
+	free_page((unsigned long)page);
+	return ret;
+}
+
+static int proc_scsi_show(struct seq_file *m, void *v)
+{
+	struct Scsi_Host *shost = m->private;
+	return shost->hostt->show_info(m, shost);
+}
+
+static int proc_scsi_host_open(struct inode *inode, struct file *file)
+{
+	return single_open_size(file, proc_scsi_show, pde_data(inode),
+				4 * PAGE_SIZE);
+}
+
+static struct scsi_proc_entry *
+__scsi_lookup_proc_entry(const struct scsi_host_template *sht)
+{
+	struct scsi_proc_entry *e;
+
+	lockdep_assert_held(&global_host_template_mutex);
+
+	list_for_each_entry(e, &scsi_proc_list, entry)
+		if (e->sht == sht)
+			return e;
+
+	return NULL;
+}
+
+static struct scsi_proc_entry *
+scsi_lookup_proc_entry(const struct scsi_host_template *sht)
+{
+	struct scsi_proc_entry *e;
+
+	mutex_lock(&global_host_template_mutex);
+	e = __scsi_lookup_proc_entry(sht);
+	mutex_unlock(&global_host_template_mutex);
+
+	return e;
+}
+
+/**
+ * scsi_template_proc_dir() - returns the procfs dir for a SCSI host template
+ * @sht: SCSI host template pointer.
+ */
+struct proc_dir_entry *
+scsi_template_proc_dir(const struct scsi_host_template *sht)
+{
+	struct scsi_proc_entry *e = scsi_lookup_proc_entry(sht);
+
+	return e ? e->proc_dir : NULL;
+}
+EXPORT_SYMBOL_GPL(scsi_template_proc_dir);
+
+static const struct proc_ops proc_scsi_ops = {
+	.proc_open	= proc_scsi_host_open,
+	.proc_release	= single_release,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_write	= proc_scsi_host_write
+};
+
+/**
+ * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
+ * @sht: owner of this directory
+ *
+ * Sets sht->proc_dir to the new directory.
+ */
+int scsi_proc_hostdir_add(const struct scsi_host_template *sht)
+{
+	struct scsi_proc_entry *e;
+	int ret;
+
+	if (!sht->show_info)
+		return 0;
+
+	mutex_lock(&global_host_template_mutex);
+	e = __scsi_lookup_proc_entry(sht);
+	if (!e) {
+		e = kzalloc(sizeof(*e), GFP_KERNEL);
+		if (!e) {
+			ret = -ENOMEM;
+			goto unlock;
+		}
+	}
+	if (e->present++)
+		goto success;
+	e->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
+	if (!e->proc_dir) {
+		printk(KERN_ERR "%s: proc_mkdir failed for %s\n", __func__,
+		       sht->proc_name);
+		ret = -ENOMEM;
+		goto unlock;
+	}
+	e->sht = sht;
+	list_add_tail(&e->entry, &scsi_proc_list);
+success:
+	e = NULL;
+	ret = 0;
+unlock:
+	mutex_unlock(&global_host_template_mutex);
+
+	kfree(e);
+	return ret;
+}
+
+/**
+ * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
+ * @sht: owner of directory
+ */
+void scsi_proc_hostdir_rm(const struct scsi_host_template *sht)
+{
+	struct scsi_proc_entry *e;
+
+	if (!sht->show_info)
+		return;
+
+	mutex_lock(&global_host_template_mutex);
+	e = __scsi_lookup_proc_entry(sht);
+	if (e && !--e->present) {
+		remove_proc_entry(sht->proc_name, proc_scsi);
+		list_del(&e->entry);
+		kfree(e);
+	}
+	mutex_unlock(&global_host_template_mutex);
+}
+
+
+/**
+ * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
+ * @shost: host to add
+ */
+void scsi_proc_host_add(struct Scsi_Host *shost)
+{
+	const struct scsi_host_template *sht = shost->hostt;
+	struct scsi_proc_entry *e;
+	struct proc_dir_entry *p;
+	char name[10];
+
+	if (!sht->show_info)
+		return;
+
+	e = scsi_lookup_proc_entry(sht);
+	if (!e)
+		goto err;
+
+	sprintf(name,"%d", shost->host_no);
+	p = proc_create_data(name, S_IRUGO | S_IWUSR, e->proc_dir,
+			     &proc_scsi_ops, shost);
+	if (!p)
+		goto err;
+	return;
+
+err:
+	shost_printk(KERN_ERR, shost,
+		     "%s: Failed to register host (%s failed)\n", __func__,
+		     e ? "proc_create_data()" : "scsi_proc_hostdir_add()");
+}
+
+/**
+ * scsi_proc_host_rm - remove this host's entry from /proc
+ * @shost: which host
+ */
+void scsi_proc_host_rm(struct Scsi_Host *shost)
+{
+	const struct scsi_host_template *sht = shost->hostt;
+	struct scsi_proc_entry *e;
+	char name[10];
+
+	if (!sht->show_info)
+		return;
+
+	e = scsi_lookup_proc_entry(sht);
+	if (!e)
+		return;
+
+	sprintf(name,"%d", shost->host_no);
+	remove_proc_entry(name, e->proc_dir);
+}
+/**
+ * proc_print_scsidevice - return data about this host
+ * @dev: A scsi device
+ * @data: &struct seq_file to output to.
+ *
+ * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
+ * and revision.
+ */
+static int proc_print_scsidevice(struct device *dev, void *data)
+{
+	struct scsi_device *sdev;
+	struct seq_file *s = data;
+	int i;
+
+	if (!scsi_is_sdev_device(dev))
+		goto out;
+
+	sdev = to_scsi_device(dev);
+	seq_printf(s,
+		"Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n  Vendor: ",
+		sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
+	for (i = 0; i < 8; i++) {
+		if (sdev->vendor[i] >= 0x20)
+			seq_putc(s, sdev->vendor[i]);
+		else
+			seq_putc(s, ' ');
+	}
+
+	seq_puts(s, " Model: ");
+	for (i = 0; i < 16; i++) {
+		if (sdev->model[i] >= 0x20)
+			seq_putc(s, sdev->model[i]);
+		else
+			seq_putc(s, ' ');
+	}
+
+	seq_puts(s, " Rev: ");
+	for (i = 0; i < 4; i++) {
+		if (sdev->rev[i] >= 0x20)
+			seq_putc(s, sdev->rev[i]);
+		else
+			seq_putc(s, ' ');
+	}
+
+	seq_putc(s, '\n');
+
+	seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
+	seq_printf(s, "               ANSI  SCSI revision: %02x",
+			sdev->scsi_level - (sdev->scsi_level > 1));
+	if (sdev->scsi_level == 2)
+		seq_puts(s, " CCS\n");
+	else
+		seq_putc(s, '\n');
+
+out:
+	return 0;
+}
+
+/**
+ * scsi_add_single_device - Respond to user request to probe for/add device
+ * @host: user-supplied decimal integer
+ * @channel: user-supplied decimal integer
+ * @id: user-supplied decimal integer
+ * @lun: user-supplied decimal integer
+ *
+ * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
+ *
+ * does scsi_host_lookup() and either user_scan() if that transport
+ * type supports it, or else scsi_scan_host_selected()
+ *
+ * Note: this seems to be aimed exclusively at SCSI parallel busses.
+ */
+
+static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
+{
+	struct Scsi_Host *shost;
+	int error = -ENXIO;
+
+	shost = scsi_host_lookup(host);
+	if (!shost)
+		return error;
+
+	if (shost->transportt->user_scan)
+		error = shost->transportt->user_scan(shost, channel, id, lun);
+	else
+		error = scsi_scan_host_selected(shost, channel, id, lun,
+						SCSI_SCAN_MANUAL);
+	scsi_host_put(shost);
+	return error;
+}
+
+/**
+ * scsi_remove_single_device - Respond to user request to remove a device
+ * @host: user-supplied decimal integer
+ * @channel: user-supplied decimal integer
+ * @id: user-supplied decimal integer
+ * @lun: user-supplied decimal integer
+ *
+ * Description: called by writing "scsi remove-single-device" to
+ * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
+ */
+static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
+{
+	struct scsi_device *sdev;
+	struct Scsi_Host *shost;
+	int error = -ENXIO;
+
+	shost = scsi_host_lookup(host);
+	if (!shost)
+		return error;
+	sdev = scsi_device_lookup(shost, channel, id, lun);
+	if (sdev) {
+		scsi_remove_device(sdev);
+		scsi_device_put(sdev);
+		error = 0;
+	}
+
+	scsi_host_put(shost);
+	return error;
+}
+
+/**
+ * proc_scsi_write - handle writes to /proc/scsi/scsi
+ * @file: not used
+ * @buf: buffer to write
+ * @length: length of buf, at most PAGE_SIZE
+ * @ppos: not used
+ *
+ * Description: this provides a legacy mechanism to add or remove devices by
+ * Host, Channel, ID, and Lun.  To use,
+ * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
+ * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
+ * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
+ *
+ * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
+ * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
+ * provide a unique identifier and nothing more.
+ */
+
+
+static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
+			       size_t length, loff_t *ppos)
+{
+	int host, channel, id, lun;
+	char *buffer, *p;
+	int err;
+
+	if (!buf || length > PAGE_SIZE)
+		return -EINVAL;
+
+	buffer = (char *)__get_free_page(GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	err = -EFAULT;
+	if (copy_from_user(buffer, buf, length))
+		goto out;
+
+	err = -EINVAL;
+	if (length < PAGE_SIZE)
+		buffer[length] = '\0';
+	else if (buffer[PAGE_SIZE-1])
+		goto out;
+
+	/*
+	 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
+	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
+	 */
+	if (!strncmp("scsi add-single-device", buffer, 22)) {
+		p = buffer + 23;
+
+		host = simple_strtoul(p, &p, 0);
+		channel = simple_strtoul(p + 1, &p, 0);
+		id = simple_strtoul(p + 1, &p, 0);
+		lun = simple_strtoul(p + 1, &p, 0);
+
+		err = scsi_add_single_device(host, channel, id, lun);
+
+	/*
+	 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
+	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
+	 */
+	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
+		p = buffer + 26;
+
+		host = simple_strtoul(p, &p, 0);
+		channel = simple_strtoul(p + 1, &p, 0);
+		id = simple_strtoul(p + 1, &p, 0);
+		lun = simple_strtoul(p + 1, &p, 0);
+
+		err = scsi_remove_single_device(host, channel, id, lun);
+	}
+
+	/*
+	 * convert success returns so that we return the 
+	 * number of bytes consumed.
+	 */
+	if (!err)
+		err = length;
+
+ out:
+	free_page((unsigned long)buffer);
+	return err;
+}
+
+static inline struct device *next_scsi_device(struct device *start)
+{
+	struct device *next = bus_find_next_device(&scsi_bus_type, start);
+
+	put_device(start);
+	return next;
+}
+
+static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
+{
+	struct device *dev = NULL;
+	loff_t n = *pos;
+
+	while ((dev = next_scsi_device(dev))) {
+		if (!n--)
+			break;
+		sfile->private++;
+	}
+	return dev;
+}
+
+static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
+{
+	(*pos)++;
+	sfile->private++;
+	return next_scsi_device(v);
+}
+
+static void scsi_seq_stop(struct seq_file *sfile, void *v)
+{
+	put_device(v);
+}
+
+static int scsi_seq_show(struct seq_file *sfile, void *dev)
+{
+	if (!sfile->private)
+		seq_puts(sfile, "Attached devices:\n");
+
+	return proc_print_scsidevice(dev, sfile);
+}
+
+static const struct seq_operations scsi_seq_ops = {
+	.start	= scsi_seq_start,
+	.next	= scsi_seq_next,
+	.stop	= scsi_seq_stop,
+	.show	= scsi_seq_show
+};
+
+/**
+ * proc_scsi_open - glue function
+ * @inode: not used
+ * @file: passed to single_open()
+ *
+ * Associates proc_scsi_show with this file
+ */
+static int proc_scsi_open(struct inode *inode, struct file *file)
+{
+	/*
+	 * We don't really need this for the write case but it doesn't
+	 * harm either.
+	 */
+	return seq_open(file, &scsi_seq_ops);
+}
+
+static const struct proc_ops scsi_scsi_proc_ops = {
+	.proc_open	= proc_scsi_open,
+	.proc_read	= seq_read,
+	.proc_write	= proc_scsi_write,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
+};
+
+/**
+ * scsi_init_procfs - create scsi and scsi/scsi in procfs
+ */
+int __init scsi_init_procfs(void)
+{
+	struct proc_dir_entry *pde;
+
+	proc_scsi = proc_mkdir("scsi", NULL);
+	if (!proc_scsi)
+		goto err1;
+
+	pde = proc_create("scsi/scsi", 0, NULL, &scsi_scsi_proc_ops);
+	if (!pde)
+		goto err2;
+
+	return 0;
+
+err2:
+	remove_proc_entry("scsi", NULL);
+err1:
+	return -ENOMEM;
+}
+
+/**
+ * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
+ */
+void scsi_exit_procfs(void)
+{
+	remove_proc_entry("scsi/scsi", NULL);
+	remove_proc_entry("scsi", NULL);
+}