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, 981 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
new file mode 100644
index 000000000..c9740ae88
--- /dev/null
+++ b/drivers/s390/block/dasd_alias.c
@@ -0,0 +1,981 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PAV alias management for the DASD ECKD discipline
+ *
+ * Copyright IBM Corp. 2007
+ * Author(s): Stefan Weinhuber <wein@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "dasd-eckd"
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <asm/ebcdic.h>
+#include "dasd_int.h"
+#include "dasd_eckd.h"
+
+#ifdef PRINTK_HEADER
+#undef PRINTK_HEADER
+#endif				/* PRINTK_HEADER */
+#define PRINTK_HEADER "dasd(eckd):"
+
+
+/*
+ * General concept of alias management:
+ * - PAV and DASD alias management is specific to the eckd discipline.
+ * - A device is connected to an lcu as long as the device exists.
+ *   dasd_alias_make_device_known_to_lcu will be called wenn the
+ *   device is checked by the eckd discipline and
+ *   dasd_alias_disconnect_device_from_lcu will be called
+ *   before the device is deleted.
+ * - The dasd_alias_add_device / dasd_alias_remove_device
+ *   functions mark the point when a device is 'ready for service'.
+ * - A summary unit check is a rare occasion, but it is mandatory to
+ *   support it. It requires some complex recovery actions before the
+ *   devices can be used again (see dasd_alias_handle_summary_unit_check).
+ * - dasd_alias_get_start_dev will find an alias device that can be used
+ *   instead of the base device and does some (very simple) load balancing.
+ *   This is the function that gets called for each I/O, so when improving
+ *   something, this function should get faster or better, the rest has just
+ *   to be correct.
+ */
+
+
+static void summary_unit_check_handling_work(struct work_struct *);
+static void lcu_update_work(struct work_struct *);
+static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *);
+
+static struct alias_root aliastree = {
+	.serverlist = LIST_HEAD_INIT(aliastree.serverlist),
+	.lock = __SPIN_LOCK_UNLOCKED(aliastree.lock),
+};
+
+static struct alias_server *_find_server(struct dasd_uid *uid)
+{
+	struct alias_server *pos;
+	list_for_each_entry(pos, &aliastree.serverlist, server) {
+		if (!strncmp(pos->uid.vendor, uid->vendor,
+			     sizeof(uid->vendor))
+		    && !strncmp(pos->uid.serial, uid->serial,
+				sizeof(uid->serial)))
+			return pos;
+	}
+	return NULL;
+}
+
+static struct alias_lcu *_find_lcu(struct alias_server *server,
+				   struct dasd_uid *uid)
+{
+	struct alias_lcu *pos;
+	list_for_each_entry(pos, &server->lculist, lcu) {
+		if (pos->uid.ssid == uid->ssid)
+			return pos;
+	}
+	return NULL;
+}
+
+static struct alias_pav_group *_find_group(struct alias_lcu *lcu,
+					   struct dasd_uid *uid)
+{
+	struct alias_pav_group *pos;
+	__u8 search_unit_addr;
+
+	/* for hyper pav there is only one group */
+	if (lcu->pav == HYPER_PAV) {
+		if (list_empty(&lcu->grouplist))
+			return NULL;
+		else
+			return list_first_entry(&lcu->grouplist,
+						struct alias_pav_group, group);
+	}
+
+	/* for base pav we have to find the group that matches the base */
+	if (uid->type == UA_BASE_DEVICE)
+		search_unit_addr = uid->real_unit_addr;
+	else
+		search_unit_addr = uid->base_unit_addr;
+	list_for_each_entry(pos, &lcu->grouplist, group) {
+		if (pos->uid.base_unit_addr == search_unit_addr &&
+		    !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit)))
+			return pos;
+	}
+	return NULL;
+}
+
+static struct alias_server *_allocate_server(struct dasd_uid *uid)
+{
+	struct alias_server *server;
+
+	server = kzalloc(sizeof(*server), GFP_KERNEL);
+	if (!server)
+		return ERR_PTR(-ENOMEM);
+	memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor));
+	memcpy(server->uid.serial, uid->serial, sizeof(uid->serial));
+	INIT_LIST_HEAD(&server->server);
+	INIT_LIST_HEAD(&server->lculist);
+	return server;
+}
+
+static void _free_server(struct alias_server *server)
+{
+	kfree(server);
+}
+
+static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid)
+{
+	struct alias_lcu *lcu;
+
+	lcu = kzalloc(sizeof(*lcu), GFP_KERNEL);
+	if (!lcu)
+		return ERR_PTR(-ENOMEM);
+	lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA);
+	if (!lcu->uac)
+		goto out_err1;
+	lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA);
+	if (!lcu->rsu_cqr)
+		goto out_err2;
+	lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1),
+				       GFP_KERNEL | GFP_DMA);
+	if (!lcu->rsu_cqr->cpaddr)
+		goto out_err3;
+	lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA);
+	if (!lcu->rsu_cqr->data)
+		goto out_err4;
+
+	memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor));
+	memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial));
+	lcu->uid.ssid = uid->ssid;
+	lcu->pav = NO_PAV;
+	lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING;
+	INIT_LIST_HEAD(&lcu->lcu);
+	INIT_LIST_HEAD(&lcu->inactive_devices);
+	INIT_LIST_HEAD(&lcu->active_devices);
+	INIT_LIST_HEAD(&lcu->grouplist);
+	INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work);
+	INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work);
+	spin_lock_init(&lcu->lock);
+	init_completion(&lcu->lcu_setup);
+	return lcu;
+
+out_err4:
+	kfree(lcu->rsu_cqr->cpaddr);
+out_err3:
+	kfree(lcu->rsu_cqr);
+out_err2:
+	kfree(lcu->uac);
+out_err1:
+	kfree(lcu);
+	return ERR_PTR(-ENOMEM);
+}
+
+static void _free_lcu(struct alias_lcu *lcu)
+{
+	kfree(lcu->rsu_cqr->data);
+	kfree(lcu->rsu_cqr->cpaddr);
+	kfree(lcu->rsu_cqr);
+	kfree(lcu->uac);
+	kfree(lcu);
+}
+
+/*
+ * This is the function that will allocate all the server and lcu data,
+ * so this function must be called first for a new device.
+ * If the return value is 1, the lcu was already known before, if it
+ * is 0, this is a new lcu.
+ * Negative return code indicates that something went wrong (e.g. -ENOMEM)
+ */
+int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	unsigned long flags;
+	struct alias_server *server, *newserver;
+	struct alias_lcu *lcu, *newlcu;
+	struct dasd_uid uid;
+
+	device->discipline->get_uid(device, &uid);
+	spin_lock_irqsave(&aliastree.lock, flags);
+	server = _find_server(&uid);
+	if (!server) {
+		spin_unlock_irqrestore(&aliastree.lock, flags);
+		newserver = _allocate_server(&uid);
+		if (IS_ERR(newserver))
+			return PTR_ERR(newserver);
+		spin_lock_irqsave(&aliastree.lock, flags);
+		server = _find_server(&uid);
+		if (!server) {
+			list_add(&newserver->server, &aliastree.serverlist);
+			server = newserver;
+		} else {
+			/* someone was faster */
+			_free_server(newserver);
+		}
+	}
+
+	lcu = _find_lcu(server, &uid);
+	if (!lcu) {
+		spin_unlock_irqrestore(&aliastree.lock, flags);
+		newlcu = _allocate_lcu(&uid);
+		if (IS_ERR(newlcu))
+			return PTR_ERR(newlcu);
+		spin_lock_irqsave(&aliastree.lock, flags);
+		lcu = _find_lcu(server, &uid);
+		if (!lcu) {
+			list_add(&newlcu->lcu, &server->lculist);
+			lcu = newlcu;
+		} else {
+			/* someone was faster */
+			_free_lcu(newlcu);
+		}
+	}
+	spin_lock(&lcu->lock);
+	list_add(&device->alias_list, &lcu->inactive_devices);
+	private->lcu = lcu;
+	spin_unlock(&lcu->lock);
+	spin_unlock_irqrestore(&aliastree.lock, flags);
+
+	return 0;
+}
+
+/*
+ * This function removes a device from the scope of alias management.
+ * The complicated part is to make sure that it is not in use by
+ * any of the workers. If necessary cancel the work.
+ */
+void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	unsigned long flags;
+	struct alias_lcu *lcu;
+	struct alias_server *server;
+	int was_pending;
+	struct dasd_uid uid;
+
+	lcu = private->lcu;
+	/* nothing to do if already disconnected */
+	if (!lcu)
+		return;
+	device->discipline->get_uid(device, &uid);
+	spin_lock_irqsave(&lcu->lock, flags);
+	/* make sure that the workers don't use this device */
+	if (device == lcu->suc_data.device) {
+		spin_unlock_irqrestore(&lcu->lock, flags);
+		cancel_work_sync(&lcu->suc_data.worker);
+		spin_lock_irqsave(&lcu->lock, flags);
+		if (device == lcu->suc_data.device) {
+			dasd_put_device(device);
+			lcu->suc_data.device = NULL;
+		}
+	}
+	was_pending = 0;
+	if (device == lcu->ruac_data.device) {
+		spin_unlock_irqrestore(&lcu->lock, flags);
+		was_pending = 1;
+		cancel_delayed_work_sync(&lcu->ruac_data.dwork);
+		spin_lock_irqsave(&lcu->lock, flags);
+		if (device == lcu->ruac_data.device) {
+			dasd_put_device(device);
+			lcu->ruac_data.device = NULL;
+		}
+	}
+	private->lcu = NULL;
+	spin_unlock_irqrestore(&lcu->lock, flags);
+
+	spin_lock_irqsave(&aliastree.lock, flags);
+	spin_lock(&lcu->lock);
+	list_del_init(&device->alias_list);
+	if (list_empty(&lcu->grouplist) &&
+	    list_empty(&lcu->active_devices) &&
+	    list_empty(&lcu->inactive_devices)) {
+		list_del(&lcu->lcu);
+		spin_unlock(&lcu->lock);
+		_free_lcu(lcu);
+		lcu = NULL;
+	} else {
+		if (was_pending)
+			_schedule_lcu_update(lcu, NULL);
+		spin_unlock(&lcu->lock);
+	}
+	server = _find_server(&uid);
+	if (server && list_empty(&server->lculist)) {
+		list_del(&server->server);
+		_free_server(server);
+	}
+	spin_unlock_irqrestore(&aliastree.lock, flags);
+}
+
+/*
+ * This function assumes that the unit address configuration stored
+ * in the lcu is up to date and will update the device uid before
+ * adding it to a pav group.
+ */
+
+static int _add_device_to_lcu(struct alias_lcu *lcu,
+			      struct dasd_device *device,
+			      struct dasd_device *pos)
+{
+
+	struct dasd_eckd_private *private = device->private;
+	struct alias_pav_group *group;
+	struct dasd_uid uid;
+
+	spin_lock(get_ccwdev_lock(device->cdev));
+	private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type;
+	private->uid.base_unit_addr =
+		lcu->uac->unit[private->uid.real_unit_addr].base_ua;
+	uid = private->uid;
+	spin_unlock(get_ccwdev_lock(device->cdev));
+	/* if we have no PAV anyway, we don't need to bother with PAV groups */
+	if (lcu->pav == NO_PAV) {
+		list_move(&device->alias_list, &lcu->active_devices);
+		return 0;
+	}
+	group = _find_group(lcu, &uid);
+	if (!group) {
+		group = kzalloc(sizeof(*group), GFP_ATOMIC);
+		if (!group)
+			return -ENOMEM;
+		memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor));
+		memcpy(group->uid.serial, uid.serial, sizeof(uid.serial));
+		group->uid.ssid = uid.ssid;
+		if (uid.type == UA_BASE_DEVICE)
+			group->uid.base_unit_addr = uid.real_unit_addr;
+		else
+			group->uid.base_unit_addr = uid.base_unit_addr;
+		memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit));
+		INIT_LIST_HEAD(&group->group);
+		INIT_LIST_HEAD(&group->baselist);
+		INIT_LIST_HEAD(&group->aliaslist);
+		list_add(&group->group, &lcu->grouplist);
+	}
+	if (uid.type == UA_BASE_DEVICE)
+		list_move(&device->alias_list, &group->baselist);
+	else
+		list_move(&device->alias_list, &group->aliaslist);
+	private->pavgroup = group;
+	return 0;
+};
+
+static void _remove_device_from_lcu(struct alias_lcu *lcu,
+				    struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct alias_pav_group *group;
+
+	list_move(&device->alias_list, &lcu->inactive_devices);
+	group = private->pavgroup;
+	if (!group)
+		return;
+	private->pavgroup = NULL;
+	if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) {
+		list_del(&group->group);
+		kfree(group);
+		return;
+	}
+	if (group->next == device)
+		group->next = NULL;
+};
+
+static int
+suborder_not_supported(struct dasd_ccw_req *cqr)
+{
+	char *sense;
+	char reason;
+	char msg_format;
+	char msg_no;
+
+	/*
+	 * intrc values ENODEV, ENOLINK and EPERM
+	 * will be optained from sleep_on to indicate that no
+	 * IO operation can be started
+	 */
+	if (cqr->intrc == -ENODEV)
+		return 1;
+
+	if (cqr->intrc == -ENOLINK)
+		return 1;
+
+	if (cqr->intrc == -EPERM)
+		return 1;
+
+	sense = dasd_get_sense(&cqr->irb);
+	if (!sense)
+		return 0;
+
+	reason = sense[0];
+	msg_format = (sense[7] & 0xF0);
+	msg_no = (sense[7] & 0x0F);
+
+	/* command reject, Format 0 MSG 4 - invalid parameter */
+	if ((reason == 0x80) && (msg_format == 0x00) && (msg_no == 0x04))
+		return 1;
+
+	return 0;
+}
+
+static int read_unit_address_configuration(struct dasd_device *device,
+					   struct alias_lcu *lcu)
+{
+	struct dasd_psf_prssd_data *prssdp;
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+	int rc;
+	unsigned long flags;
+
+	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
+				   (sizeof(struct dasd_psf_prssd_data)),
+				   device, NULL);
+	if (IS_ERR(cqr))
+		return PTR_ERR(cqr);
+	cqr->startdev = device;
+	cqr->memdev = device;
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	cqr->retries = 10;
+	cqr->expires = 20 * HZ;
+
+	/* Prepare for Read Subsystem Data */
+	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
+	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
+	prssdp->order = PSF_ORDER_PRSSD;
+	prssdp->suborder = 0x0e;	/* Read unit address configuration */
+	/* all other bytes of prssdp must be zero */
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_PSF;
+	ccw->count = sizeof(struct dasd_psf_prssd_data);
+	ccw->flags |= CCW_FLAG_CC;
+	ccw->cda = (__u32)virt_to_phys(prssdp);
+
+	/* Read Subsystem Data - feature codes */
+	memset(lcu->uac, 0, sizeof(*(lcu->uac)));
+
+	ccw++;
+	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+	ccw->count = sizeof(*(lcu->uac));
+	ccw->cda = (__u32)virt_to_phys(lcu->uac);
+
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	/* need to unset flag here to detect race with summary unit check */
+	spin_lock_irqsave(&lcu->lock, flags);
+	lcu->flags &= ~NEED_UAC_UPDATE;
+	spin_unlock_irqrestore(&lcu->lock, flags);
+
+	rc = dasd_sleep_on(cqr);
+	if (!rc)
+		goto out;
+
+	if (suborder_not_supported(cqr)) {
+		/* suborder not supported or device unusable for IO */
+		rc = -EOPNOTSUPP;
+	} else {
+		/* IO failed but should be retried */
+		spin_lock_irqsave(&lcu->lock, flags);
+		lcu->flags |= NEED_UAC_UPDATE;
+		spin_unlock_irqrestore(&lcu->lock, flags);
+	}
+out:
+	dasd_sfree_request(cqr, cqr->memdev);
+	return rc;
+}
+
+static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu)
+{
+	unsigned long flags;
+	struct alias_pav_group *pavgroup, *tempgroup;
+	struct dasd_device *device, *tempdev;
+	int i, rc;
+	struct dasd_eckd_private *private;
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) {
+		list_for_each_entry_safe(device, tempdev, &pavgroup->baselist,
+					 alias_list) {
+			list_move(&device->alias_list, &lcu->active_devices);
+			private = device->private;
+			private->pavgroup = NULL;
+		}
+		list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist,
+					 alias_list) {
+			list_move(&device->alias_list, &lcu->active_devices);
+			private = device->private;
+			private->pavgroup = NULL;
+		}
+		list_del(&pavgroup->group);
+		kfree(pavgroup);
+	}
+	spin_unlock_irqrestore(&lcu->lock, flags);
+
+	rc = read_unit_address_configuration(refdev, lcu);
+	if (rc)
+		return rc;
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	/*
+	 * there is another update needed skip the remaining handling
+	 * the data might already be outdated
+	 * but especially do not add the device to an LCU with pending
+	 * update
+	 */
+	if (lcu->flags & NEED_UAC_UPDATE)
+		goto out;
+	lcu->pav = NO_PAV;
+	for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) {
+		switch (lcu->uac->unit[i].ua_type) {
+		case UA_BASE_PAV_ALIAS:
+			lcu->pav = BASE_PAV;
+			break;
+		case UA_HYPER_PAV_ALIAS:
+			lcu->pav = HYPER_PAV;
+			break;
+		}
+		if (lcu->pav != NO_PAV)
+			break;
+	}
+
+	list_for_each_entry_safe(device, tempdev, &lcu->active_devices,
+				 alias_list) {
+		_add_device_to_lcu(lcu, device, refdev);
+	}
+out:
+	spin_unlock_irqrestore(&lcu->lock, flags);
+	return 0;
+}
+
+static void lcu_update_work(struct work_struct *work)
+{
+	struct alias_lcu *lcu;
+	struct read_uac_work_data *ruac_data;
+	struct dasd_device *device;
+	unsigned long flags;
+	int rc;
+
+	ruac_data = container_of(work, struct read_uac_work_data, dwork.work);
+	lcu = container_of(ruac_data, struct alias_lcu, ruac_data);
+	device = ruac_data->device;
+	rc = _lcu_update(device, lcu);
+	/*
+	 * Need to check flags again, as there could have been another
+	 * prepare_update or a new device a new device while we were still
+	 * processing the data
+	 */
+	spin_lock_irqsave(&lcu->lock, flags);
+	if ((rc && (rc != -EOPNOTSUPP)) || (lcu->flags & NEED_UAC_UPDATE)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "could not update"
+			    " alias data in lcu (rc = %d), retry later", rc);
+		if (!schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ))
+			dasd_put_device(device);
+	} else {
+		dasd_put_device(device);
+		lcu->ruac_data.device = NULL;
+		lcu->flags &= ~UPDATE_PENDING;
+	}
+	spin_unlock_irqrestore(&lcu->lock, flags);
+}
+
+static int _schedule_lcu_update(struct alias_lcu *lcu,
+				struct dasd_device *device)
+{
+	struct dasd_device *usedev = NULL;
+	struct alias_pav_group *group;
+
+	lcu->flags |= NEED_UAC_UPDATE;
+	if (lcu->ruac_data.device) {
+		/* already scheduled or running */
+		return 0;
+	}
+	if (device && !list_empty(&device->alias_list))
+		usedev = device;
+
+	if (!usedev && !list_empty(&lcu->grouplist)) {
+		group = list_first_entry(&lcu->grouplist,
+					 struct alias_pav_group, group);
+		if (!list_empty(&group->baselist))
+			usedev = list_first_entry(&group->baselist,
+						  struct dasd_device,
+						  alias_list);
+		else if (!list_empty(&group->aliaslist))
+			usedev = list_first_entry(&group->aliaslist,
+						  struct dasd_device,
+						  alias_list);
+	}
+	if (!usedev && !list_empty(&lcu->active_devices)) {
+		usedev = list_first_entry(&lcu->active_devices,
+					  struct dasd_device, alias_list);
+	}
+	/*
+	 * if we haven't found a proper device yet, give up for now, the next
+	 * device that will be set active will trigger an lcu update
+	 */
+	if (!usedev)
+		return -EINVAL;
+	dasd_get_device(usedev);
+	lcu->ruac_data.device = usedev;
+	if (!schedule_delayed_work(&lcu->ruac_data.dwork, 0))
+		dasd_put_device(usedev);
+	return 0;
+}
+
+int dasd_alias_add_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	__u8 uaddr = private->uid.real_unit_addr;
+	struct alias_lcu *lcu = private->lcu;
+	unsigned long flags;
+	int rc;
+
+	rc = 0;
+	spin_lock_irqsave(&lcu->lock, flags);
+	/*
+	 * Check if device and lcu type differ. If so, the uac data may be
+	 * outdated and needs to be updated.
+	 */
+	if (private->uid.type !=  lcu->uac->unit[uaddr].ua_type) {
+		lcu->flags |= UPDATE_PENDING;
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "uid type mismatch - trigger rescan");
+	}
+	if (!(lcu->flags & UPDATE_PENDING)) {
+		rc = _add_device_to_lcu(lcu, device, device);
+		if (rc)
+			lcu->flags |= UPDATE_PENDING;
+	}
+	if (lcu->flags & UPDATE_PENDING) {
+		list_move(&device->alias_list, &lcu->active_devices);
+		private->pavgroup = NULL;
+		_schedule_lcu_update(lcu, device);
+	}
+	spin_unlock_irqrestore(&lcu->lock, flags);
+	return rc;
+}
+
+int dasd_alias_update_add_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+
+	private->lcu->flags |= UPDATE_PENDING;
+	return dasd_alias_add_device(device);
+}
+
+int dasd_alias_remove_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private = device->private;
+	struct alias_lcu *lcu = private->lcu;
+	unsigned long flags;
+
+	/* nothing to do if already removed */
+	if (!lcu)
+		return 0;
+	spin_lock_irqsave(&lcu->lock, flags);
+	_remove_device_from_lcu(lcu, device);
+	spin_unlock_irqrestore(&lcu->lock, flags);
+	return 0;
+}
+
+struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device)
+{
+	struct dasd_eckd_private *alias_priv, *private = base_device->private;
+	struct alias_lcu *lcu = private->lcu;
+	struct dasd_device *alias_device;
+	struct alias_pav_group *group;
+	unsigned long flags;
+
+	if (!lcu)
+		return NULL;
+	if (lcu->pav == NO_PAV ||
+	    lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING))
+		return NULL;
+	if (unlikely(!(private->features.feature[8] & 0x01))) {
+		/*
+		 * PAV enabled but prefix not, very unlikely
+		 * seems to be a lost pathgroup
+		 * use base device to do IO
+		 */
+		DBF_DEV_EVENT(DBF_ERR, base_device, "%s",
+			      "Prefix not enabled with PAV enabled\n");
+		return NULL;
+	}
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	group = private->pavgroup;
+	if (!group) {
+		spin_unlock_irqrestore(&lcu->lock, flags);
+		return NULL;
+	}
+	alias_device = group->next;
+	if (!alias_device) {
+		if (list_empty(&group->aliaslist)) {
+			spin_unlock_irqrestore(&lcu->lock, flags);
+			return NULL;
+		} else {
+			alias_device = list_first_entry(&group->aliaslist,
+							struct dasd_device,
+							alias_list);
+		}
+	}
+	if (list_is_last(&alias_device->alias_list, &group->aliaslist))
+		group->next = list_first_entry(&group->aliaslist,
+					       struct dasd_device, alias_list);
+	else
+		group->next = list_first_entry(&alias_device->alias_list,
+					       struct dasd_device, alias_list);
+	spin_unlock_irqrestore(&lcu->lock, flags);
+	alias_priv = alias_device->private;
+	if ((alias_priv->count < private->count) && !alias_device->stopped &&
+	    !test_bit(DASD_FLAG_OFFLINE, &alias_device->flags))
+		return alias_device;
+	else
+		return NULL;
+}
+
+/*
+ * Summary unit check handling depends on the way alias devices
+ * are handled so it is done here rather then in dasd_eckd.c
+ */
+static int reset_summary_unit_check(struct alias_lcu *lcu,
+				    struct dasd_device *device,
+				    char reason)
+{
+	struct dasd_ccw_req *cqr;
+	int rc = 0;
+	struct ccw1 *ccw;
+
+	cqr = lcu->rsu_cqr;
+	memcpy((char *) &cqr->magic, "ECKD", 4);
+	ASCEBC((char *) &cqr->magic, 4);
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = DASD_ECKD_CCW_RSCK;
+	ccw->flags = CCW_FLAG_SLI;
+	ccw->count = 16;
+	ccw->cda = (__u32)virt_to_phys(cqr->data);
+	((char *)cqr->data)[0] = reason;
+
+	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	cqr->retries = 255;	/* set retry counter to enable basic ERP */
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->block = NULL;
+	cqr->expires = 5 * HZ;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+
+	rc = dasd_sleep_on_immediatly(cqr);
+	return rc;
+}
+
+static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu)
+{
+	struct alias_pav_group *pavgroup;
+	struct dasd_device *device;
+	struct dasd_eckd_private *private;
+
+	/* active and inactive list can contain alias as well as base devices */
+	list_for_each_entry(device, &lcu->active_devices, alias_list) {
+		private = device->private;
+		if (private->uid.type != UA_BASE_DEVICE)
+			continue;
+		dasd_schedule_block_bh(device->block);
+		dasd_schedule_device_bh(device);
+	}
+	list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
+		private = device->private;
+		if (private->uid.type != UA_BASE_DEVICE)
+			continue;
+		dasd_schedule_block_bh(device->block);
+		dasd_schedule_device_bh(device);
+	}
+	list_for_each_entry(pavgroup, &lcu->grouplist, group) {
+		list_for_each_entry(device, &pavgroup->baselist, alias_list) {
+			dasd_schedule_block_bh(device->block);
+			dasd_schedule_device_bh(device);
+		}
+	}
+}
+
+static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu)
+{
+	struct alias_pav_group *pavgroup;
+	struct dasd_device *device, *temp;
+	struct dasd_eckd_private *private;
+	unsigned long flags;
+	LIST_HEAD(active);
+
+	/*
+	 * Problem here ist that dasd_flush_device_queue may wait
+	 * for termination of a request to complete. We can't keep
+	 * the lcu lock during that time, so we must assume that
+	 * the lists may have changed.
+	 * Idea: first gather all active alias devices in a separate list,
+	 * then flush the first element of this list unlocked, and afterwards
+	 * check if it is still on the list before moving it to the
+	 * active_devices list.
+	 */
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	list_for_each_entry_safe(device, temp, &lcu->active_devices,
+				 alias_list) {
+		private = device->private;
+		if (private->uid.type == UA_BASE_DEVICE)
+			continue;
+		list_move(&device->alias_list, &active);
+	}
+
+	list_for_each_entry(pavgroup, &lcu->grouplist, group) {
+		list_splice_init(&pavgroup->aliaslist, &active);
+	}
+	while (!list_empty(&active)) {
+		device = list_first_entry(&active, struct dasd_device,
+					  alias_list);
+		spin_unlock_irqrestore(&lcu->lock, flags);
+		dasd_flush_device_queue(device);
+		spin_lock_irqsave(&lcu->lock, flags);
+		/*
+		 * only move device around if it wasn't moved away while we
+		 * were waiting for the flush
+		 */
+		if (device == list_first_entry(&active,
+					       struct dasd_device, alias_list)) {
+			list_move(&device->alias_list, &lcu->active_devices);
+			private = device->private;
+			private->pavgroup = NULL;
+		}
+	}
+	spin_unlock_irqrestore(&lcu->lock, flags);
+}
+
+static void _stop_all_devices_on_lcu(struct alias_lcu *lcu)
+{
+	struct alias_pav_group *pavgroup;
+	struct dasd_device *device;
+
+	list_for_each_entry(device, &lcu->active_devices, alias_list) {
+		spin_lock(get_ccwdev_lock(device->cdev));
+		dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
+		spin_unlock(get_ccwdev_lock(device->cdev));
+	}
+	list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
+		spin_lock(get_ccwdev_lock(device->cdev));
+		dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
+		spin_unlock(get_ccwdev_lock(device->cdev));
+	}
+	list_for_each_entry(pavgroup, &lcu->grouplist, group) {
+		list_for_each_entry(device, &pavgroup->baselist, alias_list) {
+			spin_lock(get_ccwdev_lock(device->cdev));
+			dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
+			spin_unlock(get_ccwdev_lock(device->cdev));
+		}
+		list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
+			spin_lock(get_ccwdev_lock(device->cdev));
+			dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
+			spin_unlock(get_ccwdev_lock(device->cdev));
+		}
+	}
+}
+
+static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu)
+{
+	struct alias_pav_group *pavgroup;
+	struct dasd_device *device;
+
+	list_for_each_entry(device, &lcu->active_devices, alias_list) {
+		spin_lock(get_ccwdev_lock(device->cdev));
+		dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
+		spin_unlock(get_ccwdev_lock(device->cdev));
+	}
+	list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
+		spin_lock(get_ccwdev_lock(device->cdev));
+		dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
+		spin_unlock(get_ccwdev_lock(device->cdev));
+	}
+	list_for_each_entry(pavgroup, &lcu->grouplist, group) {
+		list_for_each_entry(device, &pavgroup->baselist, alias_list) {
+			spin_lock(get_ccwdev_lock(device->cdev));
+			dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
+			spin_unlock(get_ccwdev_lock(device->cdev));
+		}
+		list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
+			spin_lock(get_ccwdev_lock(device->cdev));
+			dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
+			spin_unlock(get_ccwdev_lock(device->cdev));
+		}
+	}
+}
+
+static void summary_unit_check_handling_work(struct work_struct *work)
+{
+	struct alias_lcu *lcu;
+	struct summary_unit_check_work_data *suc_data;
+	unsigned long flags;
+	struct dasd_device *device;
+
+	suc_data = container_of(work, struct summary_unit_check_work_data,
+				worker);
+	lcu = container_of(suc_data, struct alias_lcu, suc_data);
+	device = suc_data->device;
+
+	/* 1. flush alias devices */
+	flush_all_alias_devices_on_lcu(lcu);
+
+	/* 2. reset summary unit check */
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	dasd_device_remove_stop_bits(device,
+				     (DASD_STOPPED_SU | DASD_STOPPED_PENDING));
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	reset_summary_unit_check(lcu, device, suc_data->reason);
+
+	spin_lock_irqsave(&lcu->lock, flags);
+	_unstop_all_devices_on_lcu(lcu);
+	_restart_all_base_devices_on_lcu(lcu);
+	/* 3. read new alias configuration */
+	_schedule_lcu_update(lcu, device);
+	lcu->suc_data.device = NULL;
+	dasd_put_device(device);
+	spin_unlock_irqrestore(&lcu->lock, flags);
+}
+
+void dasd_alias_handle_summary_unit_check(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  suc_work);
+	struct dasd_eckd_private *private = device->private;
+	struct alias_lcu *lcu;
+	unsigned long flags;
+
+	lcu = private->lcu;
+	if (!lcu) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "device not ready to handle summary"
+			    " unit check (no lcu structure)");
+		goto out;
+	}
+	spin_lock_irqsave(&lcu->lock, flags);
+	/* If this device is about to be removed just return and wait for
+	 * the next interrupt on a different device
+	 */
+	if (list_empty(&device->alias_list)) {
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "device is in offline processing,"
+			    " don't do summary unit check handling");
+		goto out_unlock;
+	}
+	if (lcu->suc_data.device) {
+		/* already scheduled or running */
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			    "previous instance of summary unit check worker"
+			    " still pending");
+		goto out_unlock;
+	}
+	_stop_all_devices_on_lcu(lcu);
+	/* prepare for lcu_update */
+	lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING;
+	lcu->suc_data.reason = private->suc_reason;
+	lcu->suc_data.device = device;
+	dasd_get_device(device);
+	if (!schedule_work(&lcu->suc_data.worker))
+		dasd_put_device(device);
+out_unlock:
+	spin_unlock_irqrestore(&lcu->lock, flags);
+out:
+	clear_bit(DASD_FLAG_SUC, &device->flags);
+	dasd_put_device(device);
+};