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, 436 insertions, 0 deletions

diff --git a/drivers/regulator/irq_helpers.c b/drivers/regulator/irq_helpers.c
new file mode 100644
index 000000000..fe7ae0f3f
--- /dev/null
+++ b/drivers/regulator/irq_helpers.c
@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2021 ROHM Semiconductors
+// regulator IRQ based event notification helpers
+//
+// Logic has been partially adapted from qcom-labibb driver.
+//
+// Author: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/regulator/driver.h>
+
+#include "internal.h"
+
+#define REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS 10000
+
+struct regulator_irq {
+	struct regulator_irq_data rdata;
+	struct regulator_irq_desc desc;
+	int irq;
+	int retry_cnt;
+	struct delayed_work isr_work;
+};
+
+/*
+ * Should only be called from threaded handler to prevent potential deadlock
+ */
+static void rdev_flag_err(struct regulator_dev *rdev, int err)
+{
+	spin_lock(&rdev->err_lock);
+	rdev->cached_err |= err;
+	spin_unlock(&rdev->err_lock);
+}
+
+static void rdev_clear_err(struct regulator_dev *rdev, int err)
+{
+	spin_lock(&rdev->err_lock);
+	rdev->cached_err &= ~err;
+	spin_unlock(&rdev->err_lock);
+}
+
+static void regulator_notifier_isr_work(struct work_struct *work)
+{
+	struct regulator_irq *h;
+	struct regulator_irq_desc *d;
+	struct regulator_irq_data *rid;
+	int ret = 0;
+	int tmo, i;
+	int num_rdevs;
+
+	h = container_of(work, struct regulator_irq,
+			    isr_work.work);
+	d = &h->desc;
+	rid = &h->rdata;
+	num_rdevs = rid->num_states;
+
+reread:
+	if (d->fatal_cnt && h->retry_cnt > d->fatal_cnt) {
+		if (!d->die)
+			return hw_protection_shutdown("Regulator HW failure? - no IC recovery",
+						      REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS);
+		ret = d->die(rid);
+		/*
+		 * If the 'last resort' IC recovery failed we will have
+		 * nothing else left to do...
+		 */
+		if (ret)
+			return hw_protection_shutdown("Regulator HW failure. IC recovery failed",
+						      REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS);
+
+		/*
+		 * If h->die() was implemented we assume recovery has been
+		 * attempted (probably regulator was shut down) and we
+		 * just enable IRQ and bail-out.
+		 */
+		goto enable_out;
+	}
+	if (d->renable) {
+		ret = d->renable(rid);
+
+		if (ret == REGULATOR_FAILED_RETRY) {
+			/* Driver could not get current status */
+			h->retry_cnt++;
+			if (!d->reread_ms)
+				goto reread;
+
+			tmo = d->reread_ms;
+			goto reschedule;
+		}
+
+		if (ret) {
+			/*
+			 * IC status reading succeeded. update error info
+			 * just in case the renable changed it.
+			 */
+			for (i = 0; i < num_rdevs; i++) {
+				struct regulator_err_state *stat;
+				struct regulator_dev *rdev;
+
+				stat = &rid->states[i];
+				rdev = stat->rdev;
+				rdev_clear_err(rdev, (~stat->errors) &
+						      stat->possible_errs);
+			}
+			h->retry_cnt++;
+			/*
+			 * The IC indicated problem is still ON - no point in
+			 * re-enabling the IRQ. Retry later.
+			 */
+			tmo = d->irq_off_ms;
+			goto reschedule;
+		}
+	}
+
+	/*
+	 * Either IC reported problem cleared or no status checker was provided.
+	 * If problems are gone - good. If not - then the IRQ will fire again
+	 * and we'll have a new nice loop. In any case we should clear error
+	 * flags here and re-enable IRQs.
+	 */
+	for (i = 0; i < num_rdevs; i++) {
+		struct regulator_err_state *stat;
+		struct regulator_dev *rdev;
+
+		stat = &rid->states[i];
+		rdev = stat->rdev;
+		rdev_clear_err(rdev, stat->possible_errs);
+	}
+
+	/*
+	 * Things have been seemingly successful => zero retry-counter.
+	 */
+	h->retry_cnt = 0;
+
+enable_out:
+	enable_irq(h->irq);
+
+	return;
+
+reschedule:
+	if (!d->high_prio)
+		mod_delayed_work(system_wq, &h->isr_work,
+				 msecs_to_jiffies(tmo));
+	else
+		mod_delayed_work(system_highpri_wq, &h->isr_work,
+				 msecs_to_jiffies(tmo));
+}
+
+static irqreturn_t regulator_notifier_isr(int irq, void *data)
+{
+	struct regulator_irq *h = data;
+	struct regulator_irq_desc *d;
+	struct regulator_irq_data *rid;
+	unsigned long rdev_map = 0;
+	int num_rdevs;
+	int ret, i;
+
+	d = &h->desc;
+	rid = &h->rdata;
+	num_rdevs = rid->num_states;
+
+	if (d->fatal_cnt)
+		h->retry_cnt++;
+
+	/*
+	 * we spare a few cycles by not clearing statuses prior to this call.
+	 * The IC driver must initialize the status buffers for rdevs
+	 * which it indicates having active events via rdev_map.
+	 *
+	 * Maybe we should just to be on a safer side(?)
+	 */
+	ret = d->map_event(irq, rid, &rdev_map);
+
+	/*
+	 * If status reading fails (which is unlikely) we don't ack/disable
+	 * IRQ but just increase fail count and retry when IRQ fires again.
+	 * If retry_count exceeds the given safety limit we call IC specific die
+	 * handler which can try disabling regulator(s).
+	 *
+	 * If no die handler is given we will just power-off as a last resort.
+	 *
+	 * We could try disabling all associated rdevs - but we might shoot
+	 * ourselves in the head and leave the problematic regulator enabled. So
+	 * if IC has no die-handler populated we just assume the regulator
+	 * can't be disabled.
+	 */
+	if (unlikely(ret == REGULATOR_FAILED_RETRY))
+		goto fail_out;
+
+	h->retry_cnt = 0;
+	/*
+	 * Let's not disable IRQ if there were no status bits for us. We'd
+	 * better leave spurious IRQ handling to genirq
+	 */
+	if (ret || !rdev_map)
+		return IRQ_NONE;
+
+	/*
+	 * Some events are bogus if the regulator is disabled. Skip such events
+	 * if all relevant regulators are disabled
+	 */
+	if (d->skip_off) {
+		for_each_set_bit(i, &rdev_map, num_rdevs) {
+			struct regulator_dev *rdev;
+			const struct regulator_ops *ops;
+
+			rdev = rid->states[i].rdev;
+			ops = rdev->desc->ops;
+
+			/*
+			 * If any of the flagged regulators is enabled we do
+			 * handle this
+			 */
+			if (ops->is_enabled(rdev))
+				break;
+		}
+		if (i == num_rdevs)
+			return IRQ_NONE;
+	}
+
+	/* Disable IRQ if HW keeps line asserted */
+	if (d->irq_off_ms)
+		disable_irq_nosync(irq);
+
+	/*
+	 * IRQ seems to be for us. Let's fire correct notifiers / store error
+	 * flags
+	 */
+	for_each_set_bit(i, &rdev_map, num_rdevs) {
+		struct regulator_err_state *stat;
+		struct regulator_dev *rdev;
+
+		stat = &rid->states[i];
+		rdev = stat->rdev;
+
+		rdev_dbg(rdev, "Sending regulator notification EVT 0x%lx\n",
+			 stat->notifs);
+
+		regulator_notifier_call_chain(rdev, stat->notifs, NULL);
+		rdev_flag_err(rdev, stat->errors);
+	}
+
+	if (d->irq_off_ms) {
+		if (!d->high_prio)
+			schedule_delayed_work(&h->isr_work,
+					      msecs_to_jiffies(d->irq_off_ms));
+		else
+			mod_delayed_work(system_highpri_wq,
+					 &h->isr_work,
+					 msecs_to_jiffies(d->irq_off_ms));
+	}
+
+	return IRQ_HANDLED;
+
+fail_out:
+	if (d->fatal_cnt && h->retry_cnt > d->fatal_cnt) {
+		/* If we have no recovery, just try shut down straight away */
+		if (!d->die) {
+			hw_protection_shutdown("Regulator failure. Retry count exceeded",
+					       REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS);
+		} else {
+			ret = d->die(rid);
+			/* If die() failed shut down as a last attempt to save the HW */
+			if (ret)
+				hw_protection_shutdown("Regulator failure. Recovery failed",
+						       REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS);
+		}
+	}
+
+	return IRQ_NONE;
+}
+
+static int init_rdev_state(struct device *dev, struct regulator_irq *h,
+			   struct regulator_dev **rdev, int common_err,
+			   int *rdev_err, int rdev_amount)
+{
+	int i;
+
+	h->rdata.states = devm_kzalloc(dev, sizeof(*h->rdata.states) *
+				       rdev_amount, GFP_KERNEL);
+	if (!h->rdata.states)
+		return -ENOMEM;
+
+	h->rdata.num_states = rdev_amount;
+	h->rdata.data = h->desc.data;
+
+	for (i = 0; i < rdev_amount; i++) {
+		h->rdata.states[i].possible_errs = common_err;
+		if (rdev_err)
+			h->rdata.states[i].possible_errs |= *rdev_err++;
+		h->rdata.states[i].rdev = *rdev++;
+	}
+
+	return 0;
+}
+
+static void init_rdev_errors(struct regulator_irq *h)
+{
+	int i;
+
+	for (i = 0; i < h->rdata.num_states; i++)
+		if (h->rdata.states[i].possible_errs)
+			h->rdata.states[i].rdev->use_cached_err = true;
+}
+
+/**
+ * regulator_irq_helper - register IRQ based regulator event/error notifier
+ *
+ * @dev:		device providing the IRQs
+ * @d:			IRQ helper descriptor.
+ * @irq:		IRQ used to inform events/errors to be notified.
+ * @irq_flags:		Extra IRQ flags to be OR'ed with the default
+ *			IRQF_ONESHOT when requesting the (threaded) irq.
+ * @common_errs:	Errors which can be flagged by this IRQ for all rdevs.
+ *			When IRQ is re-enabled these errors will be cleared
+ *			from all associated regulators. Use this instead of the
+ *			per_rdev_errs if you use
+ *			regulator_irq_map_event_simple() for event mapping.
+ * @per_rdev_errs:	Optional error flag array describing errors specific
+ *			for only some of the regulators. These errors will be
+ *			or'ed with common errors. If this is given the array
+ *			should contain rdev_amount flags. Can be set to NULL
+ *			if there is no regulator specific error flags for this
+ *			IRQ.
+ * @rdev:		Array of pointers to regulators associated with this
+ *			IRQ.
+ * @rdev_amount:	Amount of regulators associated with this IRQ.
+ *
+ * Return: handle to irq_helper or an ERR_PTR() encoded error code.
+ */
+void *regulator_irq_helper(struct device *dev,
+			   const struct regulator_irq_desc *d, int irq,
+			   int irq_flags, int common_errs, int *per_rdev_errs,
+			   struct regulator_dev **rdev, int rdev_amount)
+{
+	struct regulator_irq *h;
+	int ret;
+
+	if (!rdev_amount || !d || !d->map_event || !d->name)
+		return ERR_PTR(-EINVAL);
+
+	h = devm_kzalloc(dev, sizeof(*h), GFP_KERNEL);
+	if (!h)
+		return ERR_PTR(-ENOMEM);
+
+	h->irq = irq;
+	h->desc = *d;
+
+	ret = init_rdev_state(dev, h, rdev, common_errs, per_rdev_errs,
+			      rdev_amount);
+	if (ret)
+		return ERR_PTR(ret);
+
+	init_rdev_errors(h);
+
+	if (h->desc.irq_off_ms)
+		INIT_DELAYED_WORK(&h->isr_work, regulator_notifier_isr_work);
+
+	ret = request_threaded_irq(h->irq, NULL, regulator_notifier_isr,
+				   IRQF_ONESHOT | irq_flags, h->desc.name, h);
+	if (ret) {
+		dev_err(dev, "Failed to request IRQ %d\n", irq);
+
+		return ERR_PTR(ret);
+	}
+
+	return h;
+}
+EXPORT_SYMBOL_GPL(regulator_irq_helper);
+
+/**
+ * regulator_irq_helper_cancel - drop IRQ based regulator event/error notifier
+ *
+ * @handle:		Pointer to handle returned by a successful call to
+ *			regulator_irq_helper(). Will be NULLed upon return.
+ *
+ * The associated IRQ is released and work is cancelled when the function
+ * returns.
+ */
+void regulator_irq_helper_cancel(void **handle)
+{
+	if (handle && *handle) {
+		struct regulator_irq *h = *handle;
+
+		free_irq(h->irq, h);
+		if (h->desc.irq_off_ms)
+			cancel_delayed_work_sync(&h->isr_work);
+
+		h = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(regulator_irq_helper_cancel);
+
+/**
+ * regulator_irq_map_event_simple - regulator IRQ notification for trivial IRQs
+ *
+ * @irq:	Number of IRQ that occurred
+ * @rid:	Information about the event IRQ indicates
+ * @dev_mask:	mask indicating the regulator originating the IRQ
+ *
+ * Regulators whose IRQ has single, well defined purpose (always indicate
+ * exactly one event, and are relevant to exactly one regulator device) can
+ * use this function as their map_event callbac for their regulator IRQ
+ * notification helperk. Exactly one rdev and exactly one error (in
+ * "common_errs"-field) can be given at IRQ helper registration for
+ * regulator_irq_map_event_simple() to be viable.
+ */
+int regulator_irq_map_event_simple(int irq, struct regulator_irq_data *rid,
+			    unsigned long *dev_mask)
+{
+	int err = rid->states[0].possible_errs;
+
+	*dev_mask = 1;
+	/*
+	 * This helper should only be used in a situation where the IRQ
+	 * can indicate only one type of problem for one specific rdev.
+	 * Something fishy is going on if we are having multiple rdevs or ERROR
+	 * flags here.
+	 */
+	if (WARN_ON(rid->num_states != 1 || hweight32(err) != 1))
+		return 0;
+
+	rid->states[0].errors = err;
+	rid->states[0].notifs = regulator_err2notif(err);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(regulator_irq_map_event_simple);
+