Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 629 insertions, 0 deletions

diff --git a/drivers/remoteproc/qcom_common.c b/drivers/remoteproc/qcom_common.c
new file mode 100644
index 000000000..5294e327f
--- /dev/null
+++ b/drivers/remoteproc/qcom_common.c
@@ -0,0 +1,629 @@
+// 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/auxiliary_bus.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 to_pdm_subdev(d) container_of(d, struct qcom_rproc_pdm, subdev)
+
+#define MAX_REGION_NAME_LENGTH  16
+#define SBL_MINIDUMP_SMEM_ID	602
+#define MINIDUMP_REGION_VALID		('V' << 24 | 'A' << 16 | 'L' << 8 | 'I' << 0)
+#define MINIDUMP_SS_ENCR_DONE		('D' << 24 | 'O' << 16 | 'N' << 8 | 'E' << 0)
+#define MINIDUMP_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[];
+};
+
+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,
+			void (*rproc_dumpfn_t)(struct rproc *rproc, struct rproc_dump_segment *segment,
+				void *dest, size_t offset, size_t size))
+{
+	struct minidump_region __iomem *ptr;
+	struct minidump_region region;
+	int seg_cnt, i;
+	int ret = 0;
+	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 (le32_to_cpu(region.valid) == MINIDUMP_REGION_VALID) {
+			name = kstrndup(region.name, MAX_REGION_NAME_LENGTH - 1, GFP_KERNEL);
+			if (!name) {
+				ret = -ENOMEM;
+				break;
+			}
+			da = le64_to_cpu(region.address);
+			size = le64_to_cpu(region.size);
+			ret = rproc_coredump_add_custom_segment(rproc, da, size, rproc_dumpfn_t,
+								name);
+			if (ret) {
+				kfree(name);
+				break;
+			}
+		}
+	}
+
+	iounmap(ptr);
+	return ret;
+}
+
+void qcom_minidump(struct rproc *rproc, unsigned int minidump_id,
+		void (*rproc_dumpfn_t)(struct rproc *rproc,
+		struct rproc_dump_segment *segment, void *dest, size_t offset,
+		size_t size))
+{
+	int ret;
+	struct minidump_subsystem *subsystem;
+	struct minidump_global_toc *toc;
+	unsigned int num_ss;
+	size_t toc_size;
+
+	/* Get Global minidump ToC*/
+	toc = qcom_smem_get(QCOM_SMEM_HOST_ANY, SBL_MINIDUMP_SMEM_ID, &toc_size);
+
+	/* 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;
+	}
+
+	/* Derive the number of subsystems from the actual SMEM item size */
+	num_ss = (toc_size - offsetof(struct minidump_global_toc, subsystems)) /
+		 sizeof(struct minidump_subsystem);
+
+	if (minidump_id >= num_ss) {
+		dev_err(&rproc->dev, "Minidump id %d is out of range: %d\n",
+			minidump_id, num_ss);
+		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) != MINIDUMP_SS_ENABLED) {
+		return rproc_coredump(rproc);
+	}
+
+	if (le32_to_cpu(subsystem->encryption_status) != MINIDUMP_SS_ENCR_DONE) {
+		dev_err(&rproc->dev, "Minidump not ready, skipping\n");
+		return;
+	}
+
+	/**
+	 * Clear out the dump segments populated by parse_fw before
+	 * re-populating them with minidump segments.
+	 */
+	rproc_coredump_cleanup(rproc);
+
+	ret = qcom_add_minidump_segments(rproc, subsystem, rproc_dumpfn_t);
+	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) {
+		of_node_put(glink->node);
+		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_obj(*info);
+	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);
+
+static void pdm_dev_release(struct device *dev)
+{
+	struct auxiliary_device *adev = to_auxiliary_dev(dev);
+
+	kfree(adev);
+}
+
+static int pdm_notify_prepare(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_pdm *pdm = to_pdm_subdev(subdev);
+	struct auxiliary_device *adev;
+	int ret;
+
+	adev = kzalloc_obj(*adev);
+	if (!adev)
+		return -ENOMEM;
+
+	adev->dev.parent = pdm->dev;
+	adev->dev.release = pdm_dev_release;
+	adev->name = "pd-mapper";
+	adev->id = pdm->index;
+
+	ret = auxiliary_device_init(adev);
+	if (ret) {
+		kfree(adev);
+		return ret;
+	}
+
+	ret = auxiliary_device_add(adev);
+	if (ret) {
+		auxiliary_device_uninit(adev);
+		return ret;
+	}
+
+	pdm->adev = adev;
+
+	return 0;
+}
+
+
+static void pdm_notify_unprepare(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_pdm *pdm = to_pdm_subdev(subdev);
+
+	if (!pdm->adev)
+		return;
+
+	auxiliary_device_delete(pdm->adev);
+	auxiliary_device_uninit(pdm->adev);
+	pdm->adev = NULL;
+}
+
+/**
+ * qcom_add_pdm_subdev() - register PD Mapper subdevice
+ * @rproc:	rproc handle
+ * @pdm:	PDM subdevice handle
+ *
+ * Register @pdm so that Protection Device mapper service is started when the
+ * DSP is started too.
+ */
+void qcom_add_pdm_subdev(struct rproc *rproc, struct qcom_rproc_pdm *pdm)
+{
+	pdm->dev = &rproc->dev;
+	pdm->index = rproc->index;
+
+	pdm->subdev.prepare = pdm_notify_prepare;
+	pdm->subdev.unprepare = pdm_notify_unprepare;
+
+	rproc_add_subdev(rproc, &pdm->subdev);
+}
+EXPORT_SYMBOL_GPL(qcom_add_pdm_subdev);
+
+/**
+ * qcom_remove_pdm_subdev() - remove PD Mapper subdevice
+ * @rproc:	rproc handle
+ * @pdm:	PDM subdevice handle
+ *
+ * Remove the PD Mapper subdevice.
+ */
+void qcom_remove_pdm_subdev(struct rproc *rproc, struct qcom_rproc_pdm *pdm)
+{
+	rproc_remove_subdev(rproc, &pdm->subdev);
+}
+EXPORT_SYMBOL_GPL(qcom_remove_pdm_subdev);
+
+MODULE_DESCRIPTION("Qualcomm Remoteproc helper driver");
+MODULE_LICENSE("GPL v2");