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, 509 insertions, 0 deletions

diff --git a/drivers/remoteproc/qcom_common.c b/drivers/remoteproc/qcom_common.c
new file mode 100644
index 000000000..020349f89
--- /dev/null
+++ b/drivers/remoteproc/qcom_common.c
@@ -0,0 +1,509 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Qualcomm Peripheral Image Loader helpers
+ *
+ * Copyright (C) 2016 Linaro Ltd
+ * Copyright (C) 2015 Sony Mobile Communications Inc
+ * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/firmware.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/remoteproc.h>
+#include <linux/remoteproc/qcom_rproc.h>
+#include <linux/rpmsg/qcom_glink.h>
+#include <linux/rpmsg/qcom_smd.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/mdt_loader.h>
+#include <linux/soc/qcom/smem.h>
+
+#include "remoteproc_internal.h"
+#include "qcom_common.h"
+
+#define to_glink_subdev(d) container_of(d, struct qcom_rproc_glink, subdev)
+#define to_smd_subdev(d) container_of(d, struct qcom_rproc_subdev, subdev)
+#define to_ssr_subdev(d) container_of(d, struct qcom_rproc_ssr, subdev)
+
+#define MAX_NUM_OF_SS           10
+#define MAX_REGION_NAME_LENGTH  16
+#define SBL_MINIDUMP_SMEM_ID	602
+#define MD_REGION_VALID		('V' << 24 | 'A' << 16 | 'L' << 8 | 'I' << 0)
+#define MD_SS_ENCR_DONE		('D' << 24 | 'O' << 16 | 'N' << 8 | 'E' << 0)
+#define MD_SS_ENABLED		('E' << 24 | 'N' << 16 | 'B' << 8 | 'L' << 0)
+
+/**
+ * struct minidump_region - Minidump region
+ * @name		: Name of the region to be dumped
+ * @seq_num:		: Use to differentiate regions with same name.
+ * @valid		: This entry to be dumped (if set to 1)
+ * @address		: Physical address of region to be dumped
+ * @size		: Size of the region
+ */
+struct minidump_region {
+	char	name[MAX_REGION_NAME_LENGTH];
+	__le32	seq_num;
+	__le32	valid;
+	__le64	address;
+	__le64	size;
+};
+
+/**
+ * struct minidump_subsystem - Subsystem's SMEM Table of content
+ * @status : Subsystem toc init status
+ * @enabled : if set to 1, this region would be copied during coredump
+ * @encryption_status: Encryption status for this subsystem
+ * @encryption_required : Decides to encrypt the subsystem regions or not
+ * @region_count : Number of regions added in this subsystem toc
+ * @regions_baseptr : regions base pointer of the subsystem
+ */
+struct minidump_subsystem {
+	__le32	status;
+	__le32	enabled;
+	__le32	encryption_status;
+	__le32	encryption_required;
+	__le32	region_count;
+	__le64	regions_baseptr;
+};
+
+/**
+ * struct minidump_global_toc - Global Table of Content
+ * @status : Global Minidump init status
+ * @md_revision : Minidump revision
+ * @enabled : Minidump enable status
+ * @subsystems : Array of subsystems toc
+ */
+struct minidump_global_toc {
+	__le32				status;
+	__le32				md_revision;
+	__le32				enabled;
+	struct minidump_subsystem	subsystems[MAX_NUM_OF_SS];
+};
+
+struct qcom_ssr_subsystem {
+	const char *name;
+	struct srcu_notifier_head notifier_list;
+	struct list_head list;
+};
+
+static LIST_HEAD(qcom_ssr_subsystem_list);
+static DEFINE_MUTEX(qcom_ssr_subsys_lock);
+
+static void qcom_minidump_cleanup(struct rproc *rproc)
+{
+	struct rproc_dump_segment *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
+		list_del(&entry->node);
+		kfree(entry->priv);
+		kfree(entry);
+	}
+}
+
+static int qcom_add_minidump_segments(struct rproc *rproc, struct minidump_subsystem *subsystem)
+{
+	struct minidump_region __iomem *ptr;
+	struct minidump_region region;
+	int seg_cnt, i;
+	dma_addr_t da;
+	size_t size;
+	char *name;
+
+	if (WARN_ON(!list_empty(&rproc->dump_segments))) {
+		dev_err(&rproc->dev, "dump segment list already populated\n");
+		return -EUCLEAN;
+	}
+
+	seg_cnt = le32_to_cpu(subsystem->region_count);
+	ptr = ioremap((unsigned long)le64_to_cpu(subsystem->regions_baseptr),
+		      seg_cnt * sizeof(struct minidump_region));
+	if (!ptr)
+		return -EFAULT;
+
+	for (i = 0; i < seg_cnt; i++) {
+		memcpy_fromio(&region, ptr + i, sizeof(region));
+		if (region.valid == MD_REGION_VALID) {
+			name = kstrdup(region.name, GFP_KERNEL);
+			if (!name) {
+				iounmap(ptr);
+				return -ENOMEM;
+			}
+			da = le64_to_cpu(region.address);
+			size = le32_to_cpu(region.size);
+			rproc_coredump_add_custom_segment(rproc, da, size, NULL, name);
+		}
+	}
+
+	iounmap(ptr);
+	return 0;
+}
+
+void qcom_minidump(struct rproc *rproc, unsigned int minidump_id)
+{
+	int ret;
+	struct minidump_subsystem *subsystem;
+	struct minidump_global_toc *toc;
+
+	/* Get Global minidump ToC*/
+	toc = qcom_smem_get(QCOM_SMEM_HOST_ANY, SBL_MINIDUMP_SMEM_ID, NULL);
+
+	/* check if global table pointer exists and init is set */
+	if (IS_ERR(toc) || !toc->status) {
+		dev_err(&rproc->dev, "Minidump TOC not found in SMEM\n");
+		return;
+	}
+
+	/* Get subsystem table of contents using the minidump id */
+	subsystem = &toc->subsystems[minidump_id];
+
+	/**
+	 * Collect minidump if SS ToC is valid and segment table
+	 * is initialized in memory and encryption status is set.
+	 */
+	if (subsystem->regions_baseptr == 0 ||
+	    le32_to_cpu(subsystem->status) != 1 ||
+	    le32_to_cpu(subsystem->enabled) != MD_SS_ENABLED ||
+	    le32_to_cpu(subsystem->encryption_status) != MD_SS_ENCR_DONE) {
+		dev_err(&rproc->dev, "Minidump not ready, skipping\n");
+		return;
+	}
+
+	ret = qcom_add_minidump_segments(rproc, subsystem);
+	if (ret) {
+		dev_err(&rproc->dev, "Failed with error: %d while adding minidump entries\n", ret);
+		goto clean_minidump;
+	}
+	rproc_coredump_using_sections(rproc);
+clean_minidump:
+	qcom_minidump_cleanup(rproc);
+}
+EXPORT_SYMBOL_GPL(qcom_minidump);
+
+static int glink_subdev_start(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_glink *glink = to_glink_subdev(subdev);
+
+	glink->edge = qcom_glink_smem_register(glink->dev, glink->node);
+
+	return PTR_ERR_OR_ZERO(glink->edge);
+}
+
+static void glink_subdev_stop(struct rproc_subdev *subdev, bool crashed)
+{
+	struct qcom_rproc_glink *glink = to_glink_subdev(subdev);
+
+	qcom_glink_smem_unregister(glink->edge);
+	glink->edge = NULL;
+}
+
+static void glink_subdev_unprepare(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_glink *glink = to_glink_subdev(subdev);
+
+	qcom_glink_ssr_notify(glink->ssr_name);
+}
+
+/**
+ * qcom_add_glink_subdev() - try to add a GLINK subdevice to rproc
+ * @rproc:	rproc handle to parent the subdevice
+ * @glink:	reference to a GLINK subdev context
+ * @ssr_name:	identifier of the associated remoteproc for ssr notifications
+ */
+void qcom_add_glink_subdev(struct rproc *rproc, struct qcom_rproc_glink *glink,
+			   const char *ssr_name)
+{
+	struct device *dev = &rproc->dev;
+
+	glink->node = of_get_child_by_name(dev->parent->of_node, "glink-edge");
+	if (!glink->node)
+		return;
+
+	glink->ssr_name = kstrdup_const(ssr_name, GFP_KERNEL);
+	if (!glink->ssr_name)
+		return;
+
+	glink->dev = dev;
+	glink->subdev.start = glink_subdev_start;
+	glink->subdev.stop = glink_subdev_stop;
+	glink->subdev.unprepare = glink_subdev_unprepare;
+
+	rproc_add_subdev(rproc, &glink->subdev);
+}
+EXPORT_SYMBOL_GPL(qcom_add_glink_subdev);
+
+/**
+ * qcom_remove_glink_subdev() - remove a GLINK subdevice from rproc
+ * @rproc:	rproc handle
+ * @glink:	reference to a GLINK subdev context
+ */
+void qcom_remove_glink_subdev(struct rproc *rproc, struct qcom_rproc_glink *glink)
+{
+	if (!glink->node)
+		return;
+
+	rproc_remove_subdev(rproc, &glink->subdev);
+	kfree_const(glink->ssr_name);
+	of_node_put(glink->node);
+}
+EXPORT_SYMBOL_GPL(qcom_remove_glink_subdev);
+
+/**
+ * qcom_register_dump_segments() - register segments for coredump
+ * @rproc:	remoteproc handle
+ * @fw:		firmware header
+ *
+ * Register all segments of the ELF in the remoteproc coredump segment list
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int qcom_register_dump_segments(struct rproc *rproc,
+				const struct firmware *fw)
+{
+	const struct elf32_phdr *phdrs;
+	const struct elf32_phdr *phdr;
+	const struct elf32_hdr *ehdr;
+	int ret;
+	int i;
+
+	ehdr = (struct elf32_hdr *)fw->data;
+	phdrs = (struct elf32_phdr *)(ehdr + 1);
+
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		phdr = &phdrs[i];
+
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		if ((phdr->p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
+			continue;
+
+		if (!phdr->p_memsz)
+			continue;
+
+		ret = rproc_coredump_add_segment(rproc, phdr->p_paddr,
+						 phdr->p_memsz);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_register_dump_segments);
+
+static int smd_subdev_start(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_subdev *smd = to_smd_subdev(subdev);
+
+	smd->edge = qcom_smd_register_edge(smd->dev, smd->node);
+
+	return PTR_ERR_OR_ZERO(smd->edge);
+}
+
+static void smd_subdev_stop(struct rproc_subdev *subdev, bool crashed)
+{
+	struct qcom_rproc_subdev *smd = to_smd_subdev(subdev);
+
+	qcom_smd_unregister_edge(smd->edge);
+	smd->edge = NULL;
+}
+
+/**
+ * qcom_add_smd_subdev() - try to add a SMD subdevice to rproc
+ * @rproc:	rproc handle to parent the subdevice
+ * @smd:	reference to a Qualcomm subdev context
+ */
+void qcom_add_smd_subdev(struct rproc *rproc, struct qcom_rproc_subdev *smd)
+{
+	struct device *dev = &rproc->dev;
+
+	smd->node = of_get_child_by_name(dev->parent->of_node, "smd-edge");
+	if (!smd->node)
+		return;
+
+	smd->dev = dev;
+	smd->subdev.start = smd_subdev_start;
+	smd->subdev.stop = smd_subdev_stop;
+
+	rproc_add_subdev(rproc, &smd->subdev);
+}
+EXPORT_SYMBOL_GPL(qcom_add_smd_subdev);
+
+/**
+ * qcom_remove_smd_subdev() - remove the smd subdevice from rproc
+ * @rproc:	rproc handle
+ * @smd:	the SMD subdevice to remove
+ */
+void qcom_remove_smd_subdev(struct rproc *rproc, struct qcom_rproc_subdev *smd)
+{
+	if (!smd->node)
+		return;
+
+	rproc_remove_subdev(rproc, &smd->subdev);
+	of_node_put(smd->node);
+}
+EXPORT_SYMBOL_GPL(qcom_remove_smd_subdev);
+
+static struct qcom_ssr_subsystem *qcom_ssr_get_subsys(const char *name)
+{
+	struct qcom_ssr_subsystem *info;
+
+	mutex_lock(&qcom_ssr_subsys_lock);
+	/* Match in the global qcom_ssr_subsystem_list with name */
+	list_for_each_entry(info, &qcom_ssr_subsystem_list, list)
+		if (!strcmp(info->name, name))
+			goto out;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		info = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+	info->name = kstrdup_const(name, GFP_KERNEL);
+	srcu_init_notifier_head(&info->notifier_list);
+
+	/* Add to global notification list */
+	list_add_tail(&info->list, &qcom_ssr_subsystem_list);
+
+out:
+	mutex_unlock(&qcom_ssr_subsys_lock);
+	return info;
+}
+
+/**
+ * qcom_register_ssr_notifier() - register SSR notification handler
+ * @name:	Subsystem's SSR name
+ * @nb:		notifier_block to be invoked upon subsystem's state change
+ *
+ * This registers the @nb notifier block as part the notifier chain for a
+ * remoteproc associated with @name. The notifier block's callback
+ * will be invoked when the remote processor's SSR events occur
+ * (pre/post startup and pre/post shutdown).
+ *
+ * Return: a subsystem cookie on success, ERR_PTR on failure.
+ */
+void *qcom_register_ssr_notifier(const char *name, struct notifier_block *nb)
+{
+	struct qcom_ssr_subsystem *info;
+
+	info = qcom_ssr_get_subsys(name);
+	if (IS_ERR(info))
+		return info;
+
+	srcu_notifier_chain_register(&info->notifier_list, nb);
+
+	return &info->notifier_list;
+}
+EXPORT_SYMBOL_GPL(qcom_register_ssr_notifier);
+
+/**
+ * qcom_unregister_ssr_notifier() - unregister SSR notification handler
+ * @notify:	subsystem cookie returned from qcom_register_ssr_notifier
+ * @nb:		notifier_block to unregister
+ *
+ * This function will unregister the notifier from the particular notifier
+ * chain.
+ *
+ * Return: 0 on success, %ENOENT otherwise.
+ */
+int qcom_unregister_ssr_notifier(void *notify, struct notifier_block *nb)
+{
+	return srcu_notifier_chain_unregister(notify, nb);
+}
+EXPORT_SYMBOL_GPL(qcom_unregister_ssr_notifier);
+
+static int ssr_notify_prepare(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
+	struct qcom_ssr_notify_data data = {
+		.name = ssr->info->name,
+		.crashed = false,
+	};
+
+	srcu_notifier_call_chain(&ssr->info->notifier_list,
+				 QCOM_SSR_BEFORE_POWERUP, &data);
+	return 0;
+}
+
+static int ssr_notify_start(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
+	struct qcom_ssr_notify_data data = {
+		.name = ssr->info->name,
+		.crashed = false,
+	};
+
+	srcu_notifier_call_chain(&ssr->info->notifier_list,
+				 QCOM_SSR_AFTER_POWERUP, &data);
+	return 0;
+}
+
+static void ssr_notify_stop(struct rproc_subdev *subdev, bool crashed)
+{
+	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
+	struct qcom_ssr_notify_data data = {
+		.name = ssr->info->name,
+		.crashed = crashed,
+	};
+
+	srcu_notifier_call_chain(&ssr->info->notifier_list,
+				 QCOM_SSR_BEFORE_SHUTDOWN, &data);
+}
+
+static void ssr_notify_unprepare(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
+	struct qcom_ssr_notify_data data = {
+		.name = ssr->info->name,
+		.crashed = false,
+	};
+
+	srcu_notifier_call_chain(&ssr->info->notifier_list,
+				 QCOM_SSR_AFTER_SHUTDOWN, &data);
+}
+
+/**
+ * qcom_add_ssr_subdev() - register subdevice as restart notification source
+ * @rproc:	rproc handle
+ * @ssr:	SSR subdevice handle
+ * @ssr_name:	identifier to use for notifications originating from @rproc
+ *
+ * As the @ssr is registered with the @rproc SSR events will be sent to all
+ * registered listeners for the remoteproc when it's SSR events occur
+ * (pre/post startup and pre/post shutdown).
+ */
+void qcom_add_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr,
+			 const char *ssr_name)
+{
+	struct qcom_ssr_subsystem *info;
+
+	info = qcom_ssr_get_subsys(ssr_name);
+	if (IS_ERR(info)) {
+		dev_err(&rproc->dev, "Failed to add ssr subdevice\n");
+		return;
+	}
+
+	ssr->info = info;
+	ssr->subdev.prepare = ssr_notify_prepare;
+	ssr->subdev.start = ssr_notify_start;
+	ssr->subdev.stop = ssr_notify_stop;
+	ssr->subdev.unprepare = ssr_notify_unprepare;
+
+	rproc_add_subdev(rproc, &ssr->subdev);
+}
+EXPORT_SYMBOL_GPL(qcom_add_ssr_subdev);
+
+/**
+ * qcom_remove_ssr_subdev() - remove subdevice as restart notification source
+ * @rproc:	rproc handle
+ * @ssr:	SSR subdevice handle
+ */
+void qcom_remove_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr)
+{
+	rproc_remove_subdev(rproc, &ssr->subdev);
+	ssr->info = NULL;
+}
+EXPORT_SYMBOL_GPL(qcom_remove_ssr_subdev);
+
+MODULE_DESCRIPTION("Qualcomm Remoteproc helper driver");
+MODULE_LICENSE("GPL v2");