diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 3c0ac421e211..c7e8a183af14 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for CoreSight drivers.
 #
-obj-$(CONFIG_CORESIGHT) += coresight.o coresight-etm-perf.o coresight-platform.o
+obj-$(CONFIG_CORESIGHT) += coresight-bus.o coresight-etm-perf.o coresight-platform.o
 obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o \
 					     coresight-tmc-etf.o \
 					     coresight-tmc-etr.o
diff --git a/drivers/hwtracing/coresight/coresight-bus.c b/drivers/hwtracing/coresight/coresight-bus.c
new file mode 100644
index 000000000000..ef20f74c85fa
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-bus.c
@@ -0,0 +1,1338 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/stringhash.h>
+#include <linux/mutex.h>
+#include <linux/clk.h>
+#include <linux/coresight.h>
+#include <linux/of_platform.h>
+#include <linux/delay.h>
+#include <linux/pm_runtime.h>
+
+#include "coresight-etm-perf.h"
+#include "coresight-priv.h"
+
+static DEFINE_MUTEX(coresight_mutex);
+
+/**
+ * struct coresight_node - elements of a path, from source to sink
+ * @csdev:	Address of an element.
+ * @link:	hook to the list.
+ */
+struct coresight_node {
+	struct coresight_device *csdev;
+	struct list_head link;
+};
+
+/*
+ * When operating Coresight drivers from the sysFS interface, only a single
+ * path can exist from a tracer (associated to a CPU) to a sink.
+ */
+static DEFINE_PER_CPU(struct list_head *, tracer_path);
+
+/*
+ * As of this writing only a single STM can be found in CS topologies.  Since
+ * there is no way to know if we'll ever see more and what kind of
+ * configuration they will enact, for the time being only define a single path
+ * for STM.
+ */
+static struct list_head *stm_path;
+
+/*
+ * When losing synchronisation a new barrier packet needs to be inserted at the
+ * beginning of the data collected in a buffer.  That way the decoder knows that
+ * it needs to look for another sync sequence.
+ */
+const u32 barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};
+
+static int coresight_id_match(struct device *dev, void *data)
+{
+	int trace_id, i_trace_id;
+	struct coresight_device *csdev, *i_csdev;
+
+	csdev = data;
+	i_csdev = to_coresight_device(dev);
+
+	/*
+	 * No need to care about oneself and components that are not
+	 * sources or not enabled
+	 */
+	if (i_csdev == csdev || !i_csdev->enable ||
+	    i_csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
+		return 0;
+
+	/* Get the source ID for both compoment */
+	trace_id = source_ops(csdev)->trace_id(csdev);
+	i_trace_id = source_ops(i_csdev)->trace_id(i_csdev);
+
+	/* All you need is one */
+	if (trace_id == i_trace_id)
+		return 1;
+
+	return 0;
+}
+
+static int coresight_source_is_unique(struct coresight_device *csdev)
+{
+	int trace_id = source_ops(csdev)->trace_id(csdev);
+
+	/* this shouldn't happen */
+	if (trace_id < 0)
+		return 0;
+
+	return !bus_for_each_dev(&coresight_bustype, NULL,
+				 csdev, coresight_id_match);
+}
+
+static int coresight_find_link_inport(struct coresight_device *csdev,
+				      struct coresight_device *parent)
+{
+	int i;
+	struct coresight_connection *conn;
+
+	for (i = 0; i < parent->pdata->nr_outport; i++) {
+		conn = &parent->pdata->conns[i];
+		if (conn->child_dev == csdev)
+			return conn->child_port;
+	}
+
+	dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n",
+		dev_name(&parent->dev), dev_name(&csdev->dev));
+
+	return -ENODEV;
+}
+
+static int coresight_find_link_outport(struct coresight_device *csdev,
+				       struct coresight_device *child)
+{
+	int i;
+	struct coresight_connection *conn;
+
+	for (i = 0; i < csdev->pdata->nr_outport; i++) {
+		conn = &csdev->pdata->conns[i];
+		if (conn->child_dev == child)
+			return conn->outport;
+	}
+
+	dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n",
+		dev_name(&csdev->dev), dev_name(&child->dev));
+
+	return -ENODEV;
+}
+
+static inline u32 coresight_read_claim_tags(void __iomem *base)
+{
+	return readl_relaxed(base + CORESIGHT_CLAIMCLR);
+}
+
+static inline bool coresight_is_claimed_self_hosted(void __iomem *base)
+{
+	return coresight_read_claim_tags(base) == CORESIGHT_CLAIM_SELF_HOSTED;
+}
+
+static inline bool coresight_is_claimed_any(void __iomem *base)
+{
+	return coresight_read_claim_tags(base) != 0;
+}
+
+static inline void coresight_set_claim_tags(void __iomem *base)
+{
+	writel_relaxed(CORESIGHT_CLAIM_SELF_HOSTED, base + CORESIGHT_CLAIMSET);
+	isb();
+}
+
+static inline void coresight_clear_claim_tags(void __iomem *base)
+{
+	writel_relaxed(CORESIGHT_CLAIM_SELF_HOSTED, base + CORESIGHT_CLAIMCLR);
+	isb();
+}
+
+/*
+ * coresight_claim_device_unlocked : Claim the device for self-hosted usage
+ * to prevent an external tool from touching this device. As per PSCI
+ * standards, section "Preserving the execution context" => "Debug and Trace
+ * save and Restore", DBGCLAIM[1] is reserved for Self-hosted debug/trace and
+ * DBGCLAIM[0] is reserved for external tools.
+ *
+ * Called with CS_UNLOCKed for the component.
+ * Returns : 0 on success
+ */
+int coresight_claim_device_unlocked(void __iomem *base)
+{
+	if (coresight_is_claimed_any(base))
+		return -EBUSY;
+
+	coresight_set_claim_tags(base);
+	if (coresight_is_claimed_self_hosted(base))
+		return 0;
+	/* There was a race setting the tags, clean up and fail */
+	coresight_clear_claim_tags(base);
+	return -EBUSY;
+}
+
+int coresight_claim_device(void __iomem *base)
+{
+	int rc;
+
+	CS_UNLOCK(base);
+	rc = coresight_claim_device_unlocked(base);
+	CS_LOCK(base);
+
+	return rc;
+}
+
+/*
+ * coresight_disclaim_device_unlocked : Clear the claim tags for the device.
+ * Called with CS_UNLOCKed for the component.
+ */
+void coresight_disclaim_device_unlocked(void __iomem *base)
+{
+
+	if (coresight_is_claimed_self_hosted(base))
+		coresight_clear_claim_tags(base);
+	else
+		/*
+		 * The external agent may have not honoured our claim
+		 * and has manipulated it. Or something else has seriously
+		 * gone wrong in our driver.
+		 */
+		WARN_ON_ONCE(1);
+}
+
+void coresight_disclaim_device(void __iomem *base)
+{
+	CS_UNLOCK(base);
+	coresight_disclaim_device_unlocked(base);
+	CS_LOCK(base);
+}
+
+static int coresight_enable_sink(struct coresight_device *csdev,
+				 u32 mode, void *data)
+{
+	int ret;
+
+	/*
+	 * We need to make sure the "new" session is compatible with the
+	 * existing "mode" of operation.
+	 */
+	if (!sink_ops(csdev)->enable)
+		return -EINVAL;
+
+	ret = sink_ops(csdev)->enable(csdev, mode, data);
+	if (ret)
+		return ret;
+	csdev->enable = true;
+
+	return 0;
+}
+
+static void coresight_disable_sink(struct coresight_device *csdev)
+{
+	int ret;
+
+	if (!sink_ops(csdev)->disable)
+		return;
+
+	ret = sink_ops(csdev)->disable(csdev);
+	if (ret)
+		return;
+	csdev->enable = false;
+}
+
+static int coresight_enable_link(struct coresight_device *csdev,
+				 struct coresight_device *parent,
+				 struct coresight_device *child)
+{
+	int ret = 0;
+	int link_subtype;
+	int inport, outport;
+
+	if (!parent || !child)
+		return -EINVAL;
+
+	inport = coresight_find_link_inport(csdev, parent);
+	outport = coresight_find_link_outport(csdev, child);
+	link_subtype = csdev->subtype.link_subtype;
+
+	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG && inport < 0)
+		return inport;
+	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && outport < 0)
+		return outport;
+
+	if (link_ops(csdev)->enable)
+		ret = link_ops(csdev)->enable(csdev, inport, outport);
+	if (!ret)
+		csdev->enable = true;
+
+	return ret;
+}
+
+static void coresight_disable_link(struct coresight_device *csdev,
+				   struct coresight_device *parent,
+				   struct coresight_device *child)
+{
+	int i, nr_conns;
+	int link_subtype;
+	int inport, outport;
+
+	if (!parent || !child)
+		return;
+
+	inport = coresight_find_link_inport(csdev, parent);
+	outport = coresight_find_link_outport(csdev, child);
+	link_subtype = csdev->subtype.link_subtype;
+
+	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
+		nr_conns = csdev->pdata->nr_inport;
+	} else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
+		nr_conns = csdev->pdata->nr_outport;
+	} else {
+		nr_conns = 1;
+	}
+
+	if (link_ops(csdev)->disable)
+		link_ops(csdev)->disable(csdev, inport, outport);
+
+	for (i = 0; i < nr_conns; i++)
+		if (atomic_read(&csdev->refcnt[i]) != 0)
+			return;
+
+	csdev->enable = false;
+}
+
+static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
+{
+	int ret;
+
+	if (!coresight_source_is_unique(csdev)) {
+		dev_warn(&csdev->dev, "traceID %d not unique\n",
+			 source_ops(csdev)->trace_id(csdev));
+		return -EINVAL;
+	}
+
+	if (!csdev->enable) {
+		if (source_ops(csdev)->enable) {
+			ret = source_ops(csdev)->enable(csdev, NULL, mode);
+			if (ret)
+				return ret;
+		}
+		csdev->enable = true;
+	}
+
+	atomic_inc(csdev->refcnt);
+
+	return 0;
+}
+
+/**
+ *  coresight_disable_source - Drop the reference count by 1 and disable
+ *  the device if there are no users left.
+ *
+ *  @csdev - The coresight device to disable
+ *
+ *  Returns true if the device has been disabled.
+ */
+static bool coresight_disable_source(struct coresight_device *csdev)
+{
+	if (atomic_dec_return(csdev->refcnt) == 0) {
+		if (source_ops(csdev)->disable)
+			source_ops(csdev)->disable(csdev, NULL);
+		csdev->enable = false;
+	}
+	return !csdev->enable;
+}
+
+/*
+ * coresight_disable_path_from : Disable components in the given path beyond
+ * @nd in the list. If @nd is NULL, all the components, except the SOURCE are
+ * disabled.
+ */
+static void coresight_disable_path_from(struct list_head *path,
+					struct coresight_node *nd)
+{
+	u32 type;
+	struct coresight_device *csdev, *parent, *child;
+
+	if (!nd)
+		nd = list_first_entry(path, struct coresight_node, link);
+
+	list_for_each_entry_continue(nd, path, link) {
+		csdev = nd->csdev;
+		type = csdev->type;
+
+		/*
+		 * ETF devices are tricky... They can be a link or a sink,
+		 * depending on how they are configured.  If an ETF has been
+		 * "activated" it will be configured as a sink, otherwise
+		 * go ahead with the link configuration.
+		 */
+		if (type == CORESIGHT_DEV_TYPE_LINKSINK)
+			type = (csdev == coresight_get_sink(path)) ?
+						CORESIGHT_DEV_TYPE_SINK :
+						CORESIGHT_DEV_TYPE_LINK;
+
+		switch (type) {
+		case CORESIGHT_DEV_TYPE_SINK:
+			coresight_disable_sink(csdev);
+			break;
+		case CORESIGHT_DEV_TYPE_SOURCE:
+			/*
+			 * We skip the first node in the path assuming that it
+			 * is the source. So we don't expect a source device in
+			 * the middle of a path.
+			 */
+			WARN_ON(1);
+			break;
+		case CORESIGHT_DEV_TYPE_LINK:
+			parent = list_prev_entry(nd, link)->csdev;
+			child = list_next_entry(nd, link)->csdev;
+			coresight_disable_link(csdev, parent, child);
+			break;
+		default:
+			break;
+		}
+	}
+}
+
+void coresight_disable_path(struct list_head *path)
+{
+	coresight_disable_path_from(path, NULL);
+}
+
+int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data)
+{
+
+	int ret = 0;
+	u32 type;
+	struct coresight_node *nd;
+	struct coresight_device *csdev, *parent, *child;
+
+	list_for_each_entry_reverse(nd, path, link) {
+		csdev = nd->csdev;
+		type = csdev->type;
+
+		/*
+		 * ETF devices are tricky... They can be a link or a sink,
+		 * depending on how they are configured.  If an ETF has been
+		 * "activated" it will be configured as a sink, otherwise
+		 * go ahead with the link configuration.
+		 */
+		if (type == CORESIGHT_DEV_TYPE_LINKSINK)
+			type = (csdev == coresight_get_sink(path)) ?
+						CORESIGHT_DEV_TYPE_SINK :
+						CORESIGHT_DEV_TYPE_LINK;
+
+		switch (type) {
+		case CORESIGHT_DEV_TYPE_SINK:
+			ret = coresight_enable_sink(csdev, mode, sink_data);
+			/*
+			 * Sink is the first component turned on. If we
+			 * failed to enable the sink, there are no components
+			 * that need disabling. Disabling the path here
+			 * would mean we could disrupt an existing session.
+			 */
+			if (ret)
+				goto out;
+			break;
+		case CORESIGHT_DEV_TYPE_SOURCE:
+			/* sources are enabled from either sysFS or Perf */
+			break;
+		case CORESIGHT_DEV_TYPE_LINK:
+			parent = list_prev_entry(nd, link)->csdev;
+			child = list_next_entry(nd, link)->csdev;
+			ret = coresight_enable_link(csdev, parent, child);
+			if (ret)
+				goto err;
+			break;
+		default:
+			goto err;
+		}
+	}
+
+out:
+	return ret;
+err:
+	coresight_disable_path_from(path, nd);
+	goto out;
+}
+
+struct coresight_device *coresight_get_sink(struct list_head *path)
+{
+	struct coresight_device *csdev;
+
+	if (!path)
+		return NULL;
+
+	csdev = list_last_entry(path, struct coresight_node, link)->csdev;
+	if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
+	    csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
+		return NULL;
+
+	return csdev;
+}
+
+static int coresight_enabled_sink(struct device *dev, const void *data)
+{
+	const bool *reset = data;
+	struct coresight_device *csdev = to_coresight_device(dev);
+
+	if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
+	     csdev->activated) {
+		/*
+		 * Now that we have a handle on the sink for this session,
+		 * disable the sysFS "enable_sink" flag so that possible
+		 * concurrent perf session that wish to use another sink don't
+		 * trip on it.  Doing so has no ramification for the current
+		 * session.
+		 */
+		if (*reset)
+			csdev->activated = false;
+
+		return 1;
+	}
+
+	return 0;
+}
+
+/**
+ * coresight_get_enabled_sink - returns the first enabled sink found on the bus
+ * @deactivate:	Whether the 'enable_sink' flag should be reset
+ *
+ * When operated from perf the deactivate parameter should be set to 'true'.
+ * That way the "enabled_sink" flag of the sink that was selected can be reset,
+ * allowing for other concurrent perf sessions to choose a different sink.
+ *
+ * When operated from sysFS users have full control and as such the deactivate
+ * parameter should be set to 'false', hence mandating users to explicitly
+ * clear the flag.
+ */
+struct coresight_device *coresight_get_enabled_sink(bool deactivate)
+{
+	struct device *dev = NULL;
+
+	dev = bus_find_device(&coresight_bustype, NULL, &deactivate,
+			      coresight_enabled_sink);
+
+	return dev ? to_coresight_device(dev) : NULL;
+}
+
+static int coresight_sink_by_id(struct device *dev, const void *data)
+{
+	struct coresight_device *csdev = to_coresight_device(dev);
+	unsigned long hash;
+
+	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+
+		if (!csdev->ea)
+			return 0;
+		/*
+		 * See function etm_perf_add_symlink_sink() to know where
+		 * this comes from.
+		 */
+		hash = (unsigned long)csdev->ea->var;
+
+		if ((u32)hash == *(u32 *)data)
+			return 1;
+	}
+
+	return 0;
+}
+
+/**
+ * coresight_get_sink_by_id - returns the sink that matches the id
+ * @id: Id of the sink to match
+ *
+ * The name of a sink is unique, whether it is found on the AMBA bus or
+ * otherwise.  As such the hash of that name can easily be used to identify
+ * a sink.
+ */
+struct coresight_device *coresight_get_sink_by_id(u32 id)
+{
+	struct device *dev = NULL;
+
+	dev = bus_find_device(&coresight_bustype, NULL, &id,
+			      coresight_sink_by_id);
+
+	return dev ? to_coresight_device(dev) : NULL;
+}
+
+/*
+ * coresight_grab_device - Power up this device and any of the helper
+ * devices connected to it for trace operation. Since the helper devices
+ * don't appear on the trace path, they should be handled along with the
+ * the master device.
+ */
+static void coresight_grab_device(struct coresight_device *csdev)
+{
+	int i;
+
+	for (i = 0; i < csdev->pdata->nr_outport; i++) {
+		struct coresight_device *child;
+
+		child  = csdev->pdata->conns[i].child_dev;
+		if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
+			pm_runtime_get_sync(child->dev.parent);
+	}
+	pm_runtime_get_sync(csdev->dev.parent);
+}
+
+/*
+ * coresight_drop_device - Release this device and any of the helper
+ * devices connected to it.
+ */
+static void coresight_drop_device(struct coresight_device *csdev)
+{
+	int i;
+
+	pm_runtime_put(csdev->dev.parent);
+	for (i = 0; i < csdev->pdata->nr_outport; i++) {
+		struct coresight_device *child;
+
+		child  = csdev->pdata->conns[i].child_dev;
+		if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
+			pm_runtime_put(child->dev.parent);
+	}
+}
+
+/**
+ * _coresight_build_path - recursively build a path from a @csdev to a sink.
+ * @csdev:	The device to start from.
+ * @path:	The list to add devices to.
+ *
+ * The tree of Coresight device is traversed until an activated sink is
+ * found.  From there the sink is added to the list along with all the
+ * devices that led to that point - the end result is a list from source
+ * to sink. In that list the source is the first device and the sink the
+ * last one.
+ */
+static int _coresight_build_path(struct coresight_device *csdev,
+				 struct coresight_device *sink,
+				 struct list_head *path)
+{
+	int i;
+	bool found = false;
+	struct coresight_node *node;
+
+	/* An activated sink has been found.  Enqueue the element */
+	if (csdev == sink)
+		goto out;
+
+	/* Not a sink - recursively explore each port found on this element */
+	for (i = 0; i < csdev->pdata->nr_outport; i++) {
+		struct coresight_device *child_dev;
+
+		child_dev = csdev->pdata->conns[i].child_dev;
+		if (child_dev &&
+		    _coresight_build_path(child_dev, sink, path) == 0) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		return -ENODEV;
+
+out:
+	/*
+	 * A path from this element to a sink has been found.  The elements
+	 * leading to the sink are already enqueued, all that is left to do
+	 * is tell the PM runtime core we need this element and add a node
+	 * for it.
+	 */
+	node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);
+	if (!node)
+		return -ENOMEM;
+
+	coresight_grab_device(csdev);
+	node->csdev = csdev;
+	list_add(&node->link, path);
+
+	return 0;
+}
+
+struct list_head *coresight_build_path(struct coresight_device *source,
+				       struct coresight_device *sink)
+{
+	struct list_head *path;
+	int rc;
+
+	if (!sink)
+		return ERR_PTR(-EINVAL);
+
+	path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
+	if (!path)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(path);
+
+	rc = _coresight_build_path(source, sink, path);
+	if (rc) {
+		kfree(path);
+		return ERR_PTR(rc);
+	}
+
+	return path;
+}
+
+/**
+ * coresight_release_path - release a previously built path.
+ * @path:	the path to release.
+ *
+ * Go through all the elements of a path and 1) removed it from the list and
+ * 2) free the memory allocated for each node.
+ */
+void coresight_release_path(struct list_head *path)
+{
+	struct coresight_device *csdev;
+	struct coresight_node *nd, *next;
+
+	list_for_each_entry_safe(nd, next, path, link) {
+		csdev = nd->csdev;
+
+		coresight_drop_device(csdev);
+		list_del(&nd->link);
+		kfree(nd);
+	}
+
+	kfree(path);
+	path = NULL;
+}
+
+/** coresight_validate_source - make sure a source has the right credentials
+ *  @csdev:	the device structure for a source.
+ *  @function:	the function this was called from.
+ *
+ * Assumes the coresight_mutex is held.
+ */
+static int coresight_validate_source(struct coresight_device *csdev,
+				     const char *function)
+{
+	u32 type, subtype;
+
+	type = csdev->type;
+	subtype = csdev->subtype.source_subtype;
+
+	if (type != CORESIGHT_DEV_TYPE_SOURCE) {
+		dev_err(&csdev->dev, "wrong device type in %s\n", function);
+		return -EINVAL;
+	}
+
+	if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&
+	    subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) {
+		dev_err(&csdev->dev, "wrong device subtype in %s\n", function);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int coresight_enable(struct coresight_device *csdev)
+{
+	int cpu, ret = 0;
+	struct coresight_device *sink;
+	struct list_head *path;
+	enum coresight_dev_subtype_source subtype;
+
+	subtype = csdev->subtype.source_subtype;
+
+	mutex_lock(&coresight_mutex);
+
+	ret = coresight_validate_source(csdev, __func__);
+	if (ret)
+		goto out;
+
+	if (csdev->enable) {
+		/*
+		 * There could be multiple applications driving the software
+		 * source. So keep the refcount for each such user when the
+		 * source is already enabled.
+		 */
+		if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
+			atomic_inc(csdev->refcnt);
+		goto out;
+	}
+
+	/*
+	 * Search for a valid sink for this session but don't reset the
+	 * "enable_sink" flag in sysFS.  Users get to do that explicitly.
+	 */
+	sink = coresight_get_enabled_sink(false);
+	if (!sink) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	path = coresight_build_path(csdev, sink);
+	if (IS_ERR(path)) {
+		pr_err("building path(s) failed\n");
+		ret = PTR_ERR(path);
+		goto out;
+	}
+
+	ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
+	if (ret)
+		goto err_path;
+
+	ret = coresight_enable_source(csdev, CS_MODE_SYSFS);
+	if (ret)
+		goto err_source;
+
+	switch (subtype) {
+	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
+		/*
+		 * When working from sysFS it is important to keep track
+		 * of the paths that were created so that they can be
+		 * undone in 'coresight_disable()'.  Since there can only
+		 * be a single session per tracer (when working from sysFS)
+		 * a per-cpu variable will do just fine.
+		 */
+		cpu = source_ops(csdev)->cpu_id(csdev);
+		per_cpu(tracer_path, cpu) = path;
+		break;
+	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
+		stm_path = path;
+		break;
+	default:
+		/* We can't be here */
+		break;
+	}
+
+out:
+	mutex_unlock(&coresight_mutex);
+	return ret;
+
+err_source:
+	coresight_disable_path(path);
+
+err_path:
+	coresight_release_path(path);
+	goto out;
+}
+EXPORT_SYMBOL_GPL(coresight_enable);
+
+void coresight_disable(struct coresight_device *csdev)
+{
+	int cpu, ret;
+	struct list_head *path = NULL;
+
+	mutex_lock(&coresight_mutex);
+
+	ret = coresight_validate_source(csdev, __func__);
+	if (ret)
+		goto out;
+
+	if (!csdev->enable || !coresight_disable_source(csdev))
+		goto out;
+
+	switch (csdev->subtype.source_subtype) {
+	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
+		cpu = source_ops(csdev)->cpu_id(csdev);
+		path = per_cpu(tracer_path, cpu);
+		per_cpu(tracer_path, cpu) = NULL;
+		break;
+	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
+		path = stm_path;
+		stm_path = NULL;
+		break;
+	default:
+		/* We can't be here */
+		break;
+	}
+
+	coresight_disable_path(path);
+	coresight_release_path(path);
+
+out:
+	mutex_unlock(&coresight_mutex);
+}
+EXPORT_SYMBOL_GPL(coresight_disable);
+
+static ssize_t enable_sink_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct coresight_device *csdev = to_coresight_device(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->activated);
+}
+
+static ssize_t enable_sink_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t size)
+{
+	int ret;
+	unsigned long val;
+	struct coresight_device *csdev = to_coresight_device(dev);
+
+	ret = kstrtoul(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	if (val)
+		csdev->activated = true;
+	else
+		csdev->activated = false;
+
+	return size;
+
+}
+static DEVICE_ATTR_RW(enable_sink);
+
+static ssize_t enable_source_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct coresight_device *csdev = to_coresight_device(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->enable);
+}
+
+static ssize_t enable_source_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t size)
+{
+	int ret = 0;
+	unsigned long val;
+	struct coresight_device *csdev = to_coresight_device(dev);
+
+	ret = kstrtoul(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	if (val) {
+		ret = coresight_enable(csdev);
+		if (ret)
+			return ret;
+	} else {
+		coresight_disable(csdev);
+	}
+
+	return size;
+}
+static DEVICE_ATTR_RW(enable_source);
+
+static struct attribute *coresight_sink_attrs[] = {
+	&dev_attr_enable_sink.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(coresight_sink);
+
+static struct attribute *coresight_source_attrs[] = {
+	&dev_attr_enable_source.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(coresight_source);
+
+static struct device_type coresight_dev_type[] = {
+	{
+		.name = "none",
+	},
+	{
+		.name = "sink",
+		.groups = coresight_sink_groups,
+	},
+	{
+		.name = "link",
+	},
+	{
+		.name = "linksink",
+		.groups = coresight_sink_groups,
+	},
+	{
+		.name = "source",
+		.groups = coresight_source_groups,
+	},
+	{
+		.name = "helper",
+	},
+};
+
+static void coresight_device_release(struct device *dev)
+{
+	struct coresight_device *csdev = to_coresight_device(dev);
+
+	fwnode_handle_put(csdev->dev.fwnode);
+	kfree(csdev->refcnt);
+	kfree(csdev);
+}
+
+static int coresight_orphan_match(struct device *dev, void *data)
+{
+	int i;
+	bool still_orphan = false;
+	struct coresight_device *csdev, *i_csdev;
+	struct coresight_connection *conn;
+
+	csdev = data;
+	i_csdev = to_coresight_device(dev);
+
+	/* No need to check oneself */
+	if (csdev == i_csdev)
+		return 0;
+
+	/* Move on to another component if no connection is orphan */
+	if (!i_csdev->orphan)
+		return 0;
+	/*
+	 * Circle throuch all the connection of that component.  If we find
+	 * an orphan connection whose name matches @csdev, link it.
+	 */
+	for (i = 0; i < i_csdev->pdata->nr_outport; i++) {
+		conn = &i_csdev->pdata->conns[i];
+
+		/* We have found at least one orphan connection */
+		if (conn->child_dev == NULL) {
+			/* Does it match this newly added device? */
+			if (conn->child_fwnode == csdev->dev.fwnode)
+				conn->child_dev = csdev;
+			else
+				/* This component still has an orphan */
+				still_orphan = true;
+		}
+	}
+
+	i_csdev->orphan = still_orphan;
+
+	/*
+	 * Returning '0' ensures that all known component on the
+	 * bus will be checked.
+	 */
+	return 0;
+}
+
+static void coresight_fixup_orphan_conns(struct coresight_device *csdev)
+{
+	/*
+	 * No need to check for a return value as orphan connection(s)
+	 * are hooked-up with each newly added component.
+	 */
+	bus_for_each_dev(&coresight_bustype, NULL,
+			 csdev, coresight_orphan_match);
+}
+
+
+static void coresight_fixup_device_conns(struct coresight_device *csdev)
+{
+	int i;
+
+	for (i = 0; i < csdev->pdata->nr_outport; i++) {
+		struct coresight_connection *conn = &csdev->pdata->conns[i];
+		struct device *dev = NULL;
+
+		dev = bus_find_device_by_fwnode(&coresight_bustype, conn->child_fwnode);
+		if (dev) {
+			conn->child_dev = to_coresight_device(dev);
+			/* and put reference from 'bus_find_device()' */
+			put_device(dev);
+		} else {
+			csdev->orphan = true;
+			conn->child_dev = NULL;
+		}
+	}
+}
+
+static int coresight_remove_match(struct device *dev, void *data)
+{
+	int i;
+	struct coresight_device *csdev, *iterator;
+	struct coresight_connection *conn;
+
+	csdev = data;
+	iterator = to_coresight_device(dev);
+
+	/* No need to check oneself */
+	if (csdev == iterator)
+		return 0;
+
+	/*
+	 * Circle throuch all the connection of that component.  If we find
+	 * a connection whose name matches @csdev, remove it.
+	 */
+	for (i = 0; i < iterator->pdata->nr_outport; i++) {
+		conn = &iterator->pdata->conns[i];
+
+		if (conn->child_dev == NULL)
+			continue;
+
+		if (csdev->dev.fwnode == conn->child_fwnode) {
+			iterator->orphan = true;
+			conn->child_dev = NULL;
+			/*
+			 * Drop the reference to the handle for the remote
+			 * device acquired in parsing the connections from
+			 * platform data.
+			 */
+			fwnode_handle_put(conn->child_fwnode);
+			/* No need to continue */
+			break;
+		}
+	}
+
+	/*
+	 * Returning '0' ensures that all known component on the
+	 * bus will be checked.
+	 */
+	return 0;
+}
+
+/*
+ * coresight_remove_conns - Remove references to this given devices
+ * from the connections of other devices.
+ */
+static void coresight_remove_conns(struct coresight_device *csdev)
+{
+	/*
+	 * Another device will point to this device only if there is
+	 * an output port connected to this one. i.e, if the device
+	 * doesn't have at least one input port, there is no point
+	 * in searching all the devices.
+	 */
+	if (csdev->pdata->nr_inport)
+		bus_for_each_dev(&coresight_bustype, NULL,
+				 csdev, coresight_remove_match);
+}
+
+/**
+ * coresight_timeout - loop until a bit has changed to a specific state.
+ * @addr: base address of the area of interest.
+ * @offset: address of a register, starting from @addr.
+ * @position: the position of the bit of interest.
+ * @value: the value the bit should have.
+ *
+ * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
+ * TIMEOUT_US has elapsed, which ever happens first.
+ */
+
+int coresight_timeout(void __iomem *addr, u32 offset, int position, int value)
+{
+	int i;
+	u32 val;
+
+	for (i = TIMEOUT_US; i > 0; i--) {
+		val = __raw_readl(addr + offset);
+		/* waiting on the bit to go from 0 to 1 */
+		if (value) {
+			if (val & BIT(position))
+				return 0;
+		/* waiting on the bit to go from 1 to 0 */
+		} else {
+			if (!(val & BIT(position)))
+				return 0;
+		}
+
+		/*
+		 * Delay is arbitrary - the specification doesn't say how long
+		 * we are expected to wait.  Extra check required to make sure
+		 * we don't wait needlessly on the last iteration.
+		 */
+		if (i - 1)
+			udelay(1);
+	}
+
+	return -EAGAIN;
+}
+
+struct bus_type coresight_bustype = {
+	.name	= "coresight",
+};
+
+static int __init coresight_init(void)
+{
+	return bus_register(&coresight_bustype);
+}
+postcore_initcall(coresight_init);
+
+/*
+ * coresight_release_platform_data: Release references to the devices connected
+ * to the output port of this device.
+ */
+void coresight_release_platform_data(struct coresight_platform_data *pdata)
+{
+	int i;
+
+	for (i = 0; i < pdata->nr_outport; i++) {
+		if (pdata->conns[i].child_fwnode) {
+			fwnode_handle_put(pdata->conns[i].child_fwnode);
+			pdata->conns[i].child_fwnode = NULL;
+		}
+	}
+}
+
+struct coresight_device *coresight_register(struct coresight_desc *desc)
+{
+	int ret;
+	int link_subtype;
+	int nr_refcnts = 1;
+	atomic_t *refcnts = NULL;
+	struct coresight_device *csdev;
+
+	csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
+	if (!csdev) {
+		ret = -ENOMEM;
+		goto err_out;
+	}
+
+	if (desc->type == CORESIGHT_DEV_TYPE_LINK ||
+	    desc->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+		link_subtype = desc->subtype.link_subtype;
+
+		if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
+			nr_refcnts = desc->pdata->nr_inport;
+		else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
+			nr_refcnts = desc->pdata->nr_outport;
+	}
+
+	refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
+	if (!refcnts) {
+		ret = -ENOMEM;
+		goto err_free_csdev;
+	}
+
+	csdev->refcnt = refcnts;
+
+	csdev->pdata = desc->pdata;
+
+	csdev->type = desc->type;
+	csdev->subtype = desc->subtype;
+	csdev->ops = desc->ops;
+	csdev->orphan = false;
+
+	csdev->dev.type = &coresight_dev_type[desc->type];
+	csdev->dev.groups = desc->groups;
+	csdev->dev.parent = desc->dev;
+	csdev->dev.release = coresight_device_release;
+	csdev->dev.bus = &coresight_bustype;
+	/*
+	 * Hold the reference to our parent device. This will be
+	 * dropped only in coresight_device_release().
+	 */
+	csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));
+	dev_set_name(&csdev->dev, "%s", desc->name);
+
+	ret = device_register(&csdev->dev);
+	if (ret) {
+		put_device(&csdev->dev);
+		/*
+		 * All resources are free'd explicitly via
+		 * coresight_device_release(), triggered from put_device().
+		 */
+		goto err_out;
+	}
+
+	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+		ret = etm_perf_add_symlink_sink(csdev);
+
+		if (ret) {
+			device_unregister(&csdev->dev);
+			/*
+			 * As with the above, all resources are free'd
+			 * explicitly via coresight_device_release() triggered
+			 * from put_device(), which is in turn called from
+			 * function device_unregister().
+			 */
+			goto err_out;
+		}
+	}
+
+	mutex_lock(&coresight_mutex);
+
+	coresight_fixup_device_conns(csdev);
+	coresight_fixup_orphan_conns(csdev);
+
+	mutex_unlock(&coresight_mutex);
+
+	return csdev;
+
+err_free_csdev:
+	kfree(csdev);
+err_out:
+	/* Cleanup the connection information */
+	coresight_release_platform_data(desc->pdata);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(coresight_register);
+
+void coresight_unregister(struct coresight_device *csdev)
+{
+	etm_perf_del_symlink_sink(csdev);
+	/* Remove references of that device in the topology */
+	coresight_remove_conns(csdev);
+	coresight_release_platform_data(csdev->pdata);
+	device_unregister(&csdev->dev);
+}
+EXPORT_SYMBOL_GPL(coresight_unregister);
+
+
+/*
+ * coresight_search_device_idx - Search the fwnode handle of a device
+ * in the given dev_idx list. Must be called with the coresight_mutex held.
+ *
+ * Returns the index of the entry, when found. Otherwise, -ENOENT.
+ */
+static inline int coresight_search_device_idx(struct coresight_dev_list *dict,
+					      struct fwnode_handle *fwnode)
+{
+	int i;
+
+	for (i = 0; i < dict->nr_idx; i++)
+		if (dict->fwnode_list[i] == fwnode)
+			return i;
+	return -ENOENT;
+}
+
+bool coresight_loses_context_with_cpu(struct device *dev)
+{
+	return fwnode_property_present(dev_fwnode(dev),
+				       "arm,coresight-loses-context-with-cpu");
+}
+
+/*
+ * coresight_alloc_device_name - Get an index for a given device in the
+ * device index list specific to a driver. An index is allocated for a
+ * device and is tracked with the fwnode_handle to prevent allocating
+ * duplicate indices for the same device (e.g, if we defer probing of
+ * a device due to dependencies), in case the index is requested again.
+ */
+char *coresight_alloc_device_name(struct coresight_dev_list *dict,
+				  struct device *dev)
+{
+	int idx;
+	char *name = NULL;
+	struct fwnode_handle **list;
+
+	mutex_lock(&coresight_mutex);
+
+	idx = coresight_search_device_idx(dict, dev_fwnode(dev));
+	if (idx < 0) {
+		/* Make space for the new entry */
+		idx = dict->nr_idx;
+		list = krealloc(dict->fwnode_list,
+				(idx + 1) * sizeof(*dict->fwnode_list),
+				GFP_KERNEL);
+		if (ZERO_OR_NULL_PTR(list)) {
+			idx = -ENOMEM;
+			goto done;
+		}
+
+		list[idx] = dev_fwnode(dev);
+		dict->fwnode_list = list;
+		dict->nr_idx = idx + 1;
+	}
+
+	name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
+done:
+	mutex_unlock(&coresight_mutex);
+	return name;
+}
+EXPORT_SYMBOL_GPL(coresight_alloc_device_name);
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
deleted file mode 100644
index ef20f74c85fa..000000000000
--- a/drivers/hwtracing/coresight/coresight.c
+++ /dev/null
@@ -1,1338 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2012, The Linux Foundation. All rights reserved.
- */
-
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/types.h>
-#include <linux/device.h>
-#include <linux/io.h>
-#include <linux/err.h>
-#include <linux/export.h>
-#include <linux/slab.h>
-#include <linux/stringhash.h>
-#include <linux/mutex.h>
-#include <linux/clk.h>
-#include <linux/coresight.h>
-#include <linux/of_platform.h>
-#include <linux/delay.h>
-#include <linux/pm_runtime.h>
-
-#include "coresight-etm-perf.h"
-#include "coresight-priv.h"
-
-static DEFINE_MUTEX(coresight_mutex);
-
-/**
- * struct coresight_node - elements of a path, from source to sink
- * @csdev:	Address of an element.
- * @link:	hook to the list.
- */
-struct coresight_node {
-	struct coresight_device *csdev;
-	struct list_head link;
-};
-
-/*
- * When operating Coresight drivers from the sysFS interface, only a single
- * path can exist from a tracer (associated to a CPU) to a sink.
- */
-static DEFINE_PER_CPU(struct list_head *, tracer_path);
-
-/*
- * As of this writing only a single STM can be found in CS topologies.  Since
- * there is no way to know if we'll ever see more and what kind of
- * configuration they will enact, for the time being only define a single path
- * for STM.
- */
-static struct list_head *stm_path;
-
-/*
- * When losing synchronisation a new barrier packet needs to be inserted at the
- * beginning of the data collected in a buffer.  That way the decoder knows that
- * it needs to look for another sync sequence.
- */
-const u32 barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};
-
-static int coresight_id_match(struct device *dev, void *data)
-{
-	int trace_id, i_trace_id;
-	struct coresight_device *csdev, *i_csdev;
-
-	csdev = data;
-	i_csdev = to_coresight_device(dev);
-
-	/*
-	 * No need to care about oneself and components that are not
-	 * sources or not enabled
-	 */
-	if (i_csdev == csdev || !i_csdev->enable ||
-	    i_csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
-		return 0;
-
-	/* Get the source ID for both compoment */
-	trace_id = source_ops(csdev)->trace_id(csdev);
-	i_trace_id = source_ops(i_csdev)->trace_id(i_csdev);
-
-	/* All you need is one */
-	if (trace_id == i_trace_id)
-		return 1;
-
-	return 0;
-}
-
-static int coresight_source_is_unique(struct coresight_device *csdev)
-{
-	int trace_id = source_ops(csdev)->trace_id(csdev);
-
-	/* this shouldn't happen */
-	if (trace_id < 0)
-		return 0;
-
-	return !bus_for_each_dev(&coresight_bustype, NULL,
-				 csdev, coresight_id_match);
-}
-
-static int coresight_find_link_inport(struct coresight_device *csdev,
-				      struct coresight_device *parent)
-{
-	int i;
-	struct coresight_connection *conn;
-
-	for (i = 0; i < parent->pdata->nr_outport; i++) {
-		conn = &parent->pdata->conns[i];
-		if (conn->child_dev == csdev)
-			return conn->child_port;
-	}
-
-	dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n",
-		dev_name(&parent->dev), dev_name(&csdev->dev));
-
-	return -ENODEV;
-}
-
-static int coresight_find_link_outport(struct coresight_device *csdev,
-				       struct coresight_device *child)
-{
-	int i;
-	struct coresight_connection *conn;
-
-	for (i = 0; i < csdev->pdata->nr_outport; i++) {
-		conn = &csdev->pdata->conns[i];
-		if (conn->child_dev == child)
-			return conn->outport;
-	}
-
-	dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n",
-		dev_name(&csdev->dev), dev_name(&child->dev));
-
-	return -ENODEV;
-}
-
-static inline u32 coresight_read_claim_tags(void __iomem *base)
-{
-	return readl_relaxed(base + CORESIGHT_CLAIMCLR);
-}
-
-static inline bool coresight_is_claimed_self_hosted(void __iomem *base)
-{
-	return coresight_read_claim_tags(base) == CORESIGHT_CLAIM_SELF_HOSTED;
-}
-
-static inline bool coresight_is_claimed_any(void __iomem *base)
-{
-	return coresight_read_claim_tags(base) != 0;
-}
-
-static inline void coresight_set_claim_tags(void __iomem *base)
-{
-	writel_relaxed(CORESIGHT_CLAIM_SELF_HOSTED, base + CORESIGHT_CLAIMSET);
-	isb();
-}
-
-static inline void coresight_clear_claim_tags(void __iomem *base)
-{
-	writel_relaxed(CORESIGHT_CLAIM_SELF_HOSTED, base + CORESIGHT_CLAIMCLR);
-	isb();
-}
-
-/*
- * coresight_claim_device_unlocked : Claim the device for self-hosted usage
- * to prevent an external tool from touching this device. As per PSCI
- * standards, section "Preserving the execution context" => "Debug and Trace
- * save and Restore", DBGCLAIM[1] is reserved for Self-hosted debug/trace and
- * DBGCLAIM[0] is reserved for external tools.
- *
- * Called with CS_UNLOCKed for the component.
- * Returns : 0 on success
- */
-int coresight_claim_device_unlocked(void __iomem *base)
-{
-	if (coresight_is_claimed_any(base))
-		return -EBUSY;
-
-	coresight_set_claim_tags(base);
-	if (coresight_is_claimed_self_hosted(base))
-		return 0;
-	/* There was a race setting the tags, clean up and fail */
-	coresight_clear_claim_tags(base);
-	return -EBUSY;
-}
-
-int coresight_claim_device(void __iomem *base)
-{
-	int rc;
-
-	CS_UNLOCK(base);
-	rc = coresight_claim_device_unlocked(base);
-	CS_LOCK(base);
-
-	return rc;
-}
-
-/*
- * coresight_disclaim_device_unlocked : Clear the claim tags for the device.
- * Called with CS_UNLOCKed for the component.
- */
-void coresight_disclaim_device_unlocked(void __iomem *base)
-{
-
-	if (coresight_is_claimed_self_hosted(base))
-		coresight_clear_claim_tags(base);
-	else
-		/*
-		 * The external agent may have not honoured our claim
-		 * and has manipulated it. Or something else has seriously
-		 * gone wrong in our driver.
-		 */
-		WARN_ON_ONCE(1);
-}
-
-void coresight_disclaim_device(void __iomem *base)
-{
-	CS_UNLOCK(base);
-	coresight_disclaim_device_unlocked(base);
-	CS_LOCK(base);
-}
-
-static int coresight_enable_sink(struct coresight_device *csdev,
-				 u32 mode, void *data)
-{
-	int ret;
-
-	/*
-	 * We need to make sure the "new" session is compatible with the
-	 * existing "mode" of operation.
-	 */
-	if (!sink_ops(csdev)->enable)
-		return -EINVAL;
-
-	ret = sink_ops(csdev)->enable(csdev, mode, data);
-	if (ret)
-		return ret;
-	csdev->enable = true;
-
-	return 0;
-}
-
-static void coresight_disable_sink(struct coresight_device *csdev)
-{
-	int ret;
-
-	if (!sink_ops(csdev)->disable)
-		return;
-
-	ret = sink_ops(csdev)->disable(csdev);
-	if (ret)
-		return;
-	csdev->enable = false;
-}
-
-static int coresight_enable_link(struct coresight_device *csdev,
-				 struct coresight_device *parent,
-				 struct coresight_device *child)
-{
-	int ret = 0;
-	int link_subtype;
-	int inport, outport;
-
-	if (!parent || !child)
-		return -EINVAL;
-
-	inport = coresight_find_link_inport(csdev, parent);
-	outport = coresight_find_link_outport(csdev, child);
-	link_subtype = csdev->subtype.link_subtype;
-
-	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG && inport < 0)
-		return inport;
-	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && outport < 0)
-		return outport;
-
-	if (link_ops(csdev)->enable)
-		ret = link_ops(csdev)->enable(csdev, inport, outport);
-	if (!ret)
-		csdev->enable = true;
-
-	return ret;
-}
-
-static void coresight_disable_link(struct coresight_device *csdev,
-				   struct coresight_device *parent,
-				   struct coresight_device *child)
-{
-	int i, nr_conns;
-	int link_subtype;
-	int inport, outport;
-
-	if (!parent || !child)
-		return;
-
-	inport = coresight_find_link_inport(csdev, parent);
-	outport = coresight_find_link_outport(csdev, child);
-	link_subtype = csdev->subtype.link_subtype;
-
-	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
-		nr_conns = csdev->pdata->nr_inport;
-	} else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
-		nr_conns = csdev->pdata->nr_outport;
-	} else {
-		nr_conns = 1;
-	}
-
-	if (link_ops(csdev)->disable)
-		link_ops(csdev)->disable(csdev, inport, outport);
-
-	for (i = 0; i < nr_conns; i++)
-		if (atomic_read(&csdev->refcnt[i]) != 0)
-			return;
-
-	csdev->enable = false;
-}
-
-static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
-{
-	int ret;
-
-	if (!coresight_source_is_unique(csdev)) {
-		dev_warn(&csdev->dev, "traceID %d not unique\n",
-			 source_ops(csdev)->trace_id(csdev));
-		return -EINVAL;
-	}
-
-	if (!csdev->enable) {
-		if (source_ops(csdev)->enable) {
-			ret = source_ops(csdev)->enable(csdev, NULL, mode);
-			if (ret)
-				return ret;
-		}
-		csdev->enable = true;
-	}
-
-	atomic_inc(csdev->refcnt);
-
-	return 0;
-}
-
-/**
- *  coresight_disable_source - Drop the reference count by 1 and disable
- *  the device if there are no users left.
- *
- *  @csdev - The coresight device to disable
- *
- *  Returns true if the device has been disabled.
- */
-static bool coresight_disable_source(struct coresight_device *csdev)
-{
-	if (atomic_dec_return(csdev->refcnt) == 0) {
-		if (source_ops(csdev)->disable)
-			source_ops(csdev)->disable(csdev, NULL);
-		csdev->enable = false;
-	}
-	return !csdev->enable;
-}
-
-/*
- * coresight_disable_path_from : Disable components in the given path beyond
- * @nd in the list. If @nd is NULL, all the components, except the SOURCE are
- * disabled.
- */
-static void coresight_disable_path_from(struct list_head *path,
-					struct coresight_node *nd)
-{
-	u32 type;
-	struct coresight_device *csdev, *parent, *child;
-
-	if (!nd)
-		nd = list_first_entry(path, struct coresight_node, link);
-
-	list_for_each_entry_continue(nd, path, link) {
-		csdev = nd->csdev;
-		type = csdev->type;
-
-		/*
-		 * ETF devices are tricky... They can be a link or a sink,
-		 * depending on how they are configured.  If an ETF has been
-		 * "activated" it will be configured as a sink, otherwise
-		 * go ahead with the link configuration.
-		 */
-		if (type == CORESIGHT_DEV_TYPE_LINKSINK)
-			type = (csdev == coresight_get_sink(path)) ?
-						CORESIGHT_DEV_TYPE_SINK :
-						CORESIGHT_DEV_TYPE_LINK;
-
-		switch (type) {
-		case CORESIGHT_DEV_TYPE_SINK:
-			coresight_disable_sink(csdev);
-			break;
-		case CORESIGHT_DEV_TYPE_SOURCE:
-			/*
-			 * We skip the first node in the path assuming that it
-			 * is the source. So we don't expect a source device in
-			 * the middle of a path.
-			 */
-			WARN_ON(1);
-			break;
-		case CORESIGHT_DEV_TYPE_LINK:
-			parent = list_prev_entry(nd, link)->csdev;
-			child = list_next_entry(nd, link)->csdev;
-			coresight_disable_link(csdev, parent, child);
-			break;
-		default:
-			break;
-		}
-	}
-}
-
-void coresight_disable_path(struct list_head *path)
-{
-	coresight_disable_path_from(path, NULL);
-}
-
-int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data)
-{
-
-	int ret = 0;
-	u32 type;
-	struct coresight_node *nd;
-	struct coresight_device *csdev, *parent, *child;
-
-	list_for_each_entry_reverse(nd, path, link) {
-		csdev = nd->csdev;
-		type = csdev->type;
-
-		/*
-		 * ETF devices are tricky... They can be a link or a sink,
-		 * depending on how they are configured.  If an ETF has been
-		 * "activated" it will be configured as a sink, otherwise
-		 * go ahead with the link configuration.
-		 */
-		if (type == CORESIGHT_DEV_TYPE_LINKSINK)
-			type = (csdev == coresight_get_sink(path)) ?
-						CORESIGHT_DEV_TYPE_SINK :
-						CORESIGHT_DEV_TYPE_LINK;
-
-		switch (type) {
-		case CORESIGHT_DEV_TYPE_SINK:
-			ret = coresight_enable_sink(csdev, mode, sink_data);
-			/*
-			 * Sink is the first component turned on. If we
-			 * failed to enable the sink, there are no components
-			 * that need disabling. Disabling the path here
-			 * would mean we could disrupt an existing session.
-			 */
-			if (ret)
-				goto out;
-			break;
-		case CORESIGHT_DEV_TYPE_SOURCE:
-			/* sources are enabled from either sysFS or Perf */
-			break;
-		case CORESIGHT_DEV_TYPE_LINK:
-			parent = list_prev_entry(nd, link)->csdev;
-			child = list_next_entry(nd, link)->csdev;
-			ret = coresight_enable_link(csdev, parent, child);
-			if (ret)
-				goto err;
-			break;
-		default:
-			goto err;
-		}
-	}
-
-out:
-	return ret;
-err:
-	coresight_disable_path_from(path, nd);
-	goto out;
-}
-
-struct coresight_device *coresight_get_sink(struct list_head *path)
-{
-	struct coresight_device *csdev;
-
-	if (!path)
-		return NULL;
-
-	csdev = list_last_entry(path, struct coresight_node, link)->csdev;
-	if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
-	    csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
-		return NULL;
-
-	return csdev;
-}
-
-static int coresight_enabled_sink(struct device *dev, const void *data)
-{
-	const bool *reset = data;
-	struct coresight_device *csdev = to_coresight_device(dev);
-
-	if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
-	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
-	     csdev->activated) {
-		/*
-		 * Now that we have a handle on the sink for this session,
-		 * disable the sysFS "enable_sink" flag so that possible
-		 * concurrent perf session that wish to use another sink don't
-		 * trip on it.  Doing so has no ramification for the current
-		 * session.
-		 */
-		if (*reset)
-			csdev->activated = false;
-
-		return 1;
-	}
-
-	return 0;
-}
-
-/**
- * coresight_get_enabled_sink - returns the first enabled sink found on the bus
- * @deactivate:	Whether the 'enable_sink' flag should be reset
- *
- * When operated from perf the deactivate parameter should be set to 'true'.
- * That way the "enabled_sink" flag of the sink that was selected can be reset,
- * allowing for other concurrent perf sessions to choose a different sink.
- *
- * When operated from sysFS users have full control and as such the deactivate
- * parameter should be set to 'false', hence mandating users to explicitly
- * clear the flag.
- */
-struct coresight_device *coresight_get_enabled_sink(bool deactivate)
-{
-	struct device *dev = NULL;
-
-	dev = bus_find_device(&coresight_bustype, NULL, &deactivate,
-			      coresight_enabled_sink);
-
-	return dev ? to_coresight_device(dev) : NULL;
-}
-
-static int coresight_sink_by_id(struct device *dev, const void *data)
-{
-	struct coresight_device *csdev = to_coresight_device(dev);
-	unsigned long hash;
-
-	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
-	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
-
-		if (!csdev->ea)
-			return 0;
-		/*
-		 * See function etm_perf_add_symlink_sink() to know where
-		 * this comes from.
-		 */
-		hash = (unsigned long)csdev->ea->var;
-
-		if ((u32)hash == *(u32 *)data)
-			return 1;
-	}
-
-	return 0;
-}
-
-/**
- * coresight_get_sink_by_id - returns the sink that matches the id
- * @id: Id of the sink to match
- *
- * The name of a sink is unique, whether it is found on the AMBA bus or
- * otherwise.  As such the hash of that name can easily be used to identify
- * a sink.
- */
-struct coresight_device *coresight_get_sink_by_id(u32 id)
-{
-	struct device *dev = NULL;
-
-	dev = bus_find_device(&coresight_bustype, NULL, &id,
-			      coresight_sink_by_id);
-
-	return dev ? to_coresight_device(dev) : NULL;
-}
-
-/*
- * coresight_grab_device - Power up this device and any of the helper
- * devices connected to it for trace operation. Since the helper devices
- * don't appear on the trace path, they should be handled along with the
- * the master device.
- */
-static void coresight_grab_device(struct coresight_device *csdev)
-{
-	int i;
-
-	for (i = 0; i < csdev->pdata->nr_outport; i++) {
-		struct coresight_device *child;
-
-		child  = csdev->pdata->conns[i].child_dev;
-		if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
-			pm_runtime_get_sync(child->dev.parent);
-	}
-	pm_runtime_get_sync(csdev->dev.parent);
-}
-
-/*
- * coresight_drop_device - Release this device and any of the helper
- * devices connected to it.
- */
-static void coresight_drop_device(struct coresight_device *csdev)
-{
-	int i;
-
-	pm_runtime_put(csdev->dev.parent);
-	for (i = 0; i < csdev->pdata->nr_outport; i++) {
-		struct coresight_device *child;
-
-		child  = csdev->pdata->conns[i].child_dev;
-		if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
-			pm_runtime_put(child->dev.parent);
-	}
-}
-
-/**
- * _coresight_build_path - recursively build a path from a @csdev to a sink.
- * @csdev:	The device to start from.
- * @path:	The list to add devices to.
- *
- * The tree of Coresight device is traversed until an activated sink is
- * found.  From there the sink is added to the list along with all the
- * devices that led to that point - the end result is a list from source
- * to sink. In that list the source is the first device and the sink the
- * last one.
- */
-static int _coresight_build_path(struct coresight_device *csdev,
-				 struct coresight_device *sink,
-				 struct list_head *path)
-{
-	int i;
-	bool found = false;
-	struct coresight_node *node;
-
-	/* An activated sink has been found.  Enqueue the element */
-	if (csdev == sink)
-		goto out;
-
-	/* Not a sink - recursively explore each port found on this element */
-	for (i = 0; i < csdev->pdata->nr_outport; i++) {
-		struct coresight_device *child_dev;
-
-		child_dev = csdev->pdata->conns[i].child_dev;
-		if (child_dev &&
-		    _coresight_build_path(child_dev, sink, path) == 0) {
-			found = true;
-			break;
-		}
-	}
-
-	if (!found)
-		return -ENODEV;
-
-out:
-	/*
-	 * A path from this element to a sink has been found.  The elements
-	 * leading to the sink are already enqueued, all that is left to do
-	 * is tell the PM runtime core we need this element and add a node
-	 * for it.
-	 */
-	node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);
-	if (!node)
-		return -ENOMEM;
-
-	coresight_grab_device(csdev);
-	node->csdev = csdev;
-	list_add(&node->link, path);
-
-	return 0;
-}
-
-struct list_head *coresight_build_path(struct coresight_device *source,
-				       struct coresight_device *sink)
-{
-	struct list_head *path;
-	int rc;
-
-	if (!sink)
-		return ERR_PTR(-EINVAL);
-
-	path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
-	if (!path)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(path);
-
-	rc = _coresight_build_path(source, sink, path);
-	if (rc) {
-		kfree(path);
-		return ERR_PTR(rc);
-	}
-
-	return path;
-}
-
-/**
- * coresight_release_path - release a previously built path.
- * @path:	the path to release.
- *
- * Go through all the elements of a path and 1) removed it from the list and
- * 2) free the memory allocated for each node.
- */
-void coresight_release_path(struct list_head *path)
-{
-	struct coresight_device *csdev;
-	struct coresight_node *nd, *next;
-
-	list_for_each_entry_safe(nd, next, path, link) {
-		csdev = nd->csdev;
-
-		coresight_drop_device(csdev);
-		list_del(&nd->link);
-		kfree(nd);
-	}
-
-	kfree(path);
-	path = NULL;
-}
-
-/** coresight_validate_source - make sure a source has the right credentials
- *  @csdev:	the device structure for a source.
- *  @function:	the function this was called from.
- *
- * Assumes the coresight_mutex is held.
- */
-static int coresight_validate_source(struct coresight_device *csdev,
-				     const char *function)
-{
-	u32 type, subtype;
-
-	type = csdev->type;
-	subtype = csdev->subtype.source_subtype;
-
-	if (type != CORESIGHT_DEV_TYPE_SOURCE) {
-		dev_err(&csdev->dev, "wrong device type in %s\n", function);
-		return -EINVAL;
-	}
-
-	if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&
-	    subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) {
-		dev_err(&csdev->dev, "wrong device subtype in %s\n", function);
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-int coresight_enable(struct coresight_device *csdev)
-{
-	int cpu, ret = 0;
-	struct coresight_device *sink;
-	struct list_head *path;
-	enum coresight_dev_subtype_source subtype;
-
-	subtype = csdev->subtype.source_subtype;
-
-	mutex_lock(&coresight_mutex);
-
-	ret = coresight_validate_source(csdev, __func__);
-	if (ret)
-		goto out;
-
-	if (csdev->enable) {
-		/*
-		 * There could be multiple applications driving the software
-		 * source. So keep the refcount for each such user when the
-		 * source is already enabled.
-		 */
-		if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
-			atomic_inc(csdev->refcnt);
-		goto out;
-	}
-
-	/*
-	 * Search for a valid sink for this session but don't reset the
-	 * "enable_sink" flag in sysFS.  Users get to do that explicitly.
-	 */
-	sink = coresight_get_enabled_sink(false);
-	if (!sink) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	path = coresight_build_path(csdev, sink);
-	if (IS_ERR(path)) {
-		pr_err("building path(s) failed\n");
-		ret = PTR_ERR(path);
-		goto out;
-	}
-
-	ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
-	if (ret)
-		goto err_path;
-
-	ret = coresight_enable_source(csdev, CS_MODE_SYSFS);
-	if (ret)
-		goto err_source;
-
-	switch (subtype) {
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
-		/*
-		 * When working from sysFS it is important to keep track
-		 * of the paths that were created so that they can be
-		 * undone in 'coresight_disable()'.  Since there can only
-		 * be a single session per tracer (when working from sysFS)
-		 * a per-cpu variable will do just fine.
-		 */
-		cpu = source_ops(csdev)->cpu_id(csdev);
-		per_cpu(tracer_path, cpu) = path;
-		break;
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
-		stm_path = path;
-		break;
-	default:
-		/* We can't be here */
-		break;
-	}
-
-out:
-	mutex_unlock(&coresight_mutex);
-	return ret;
-
-err_source:
-	coresight_disable_path(path);
-
-err_path:
-	coresight_release_path(path);
-	goto out;
-}
-EXPORT_SYMBOL_GPL(coresight_enable);
-
-void coresight_disable(struct coresight_device *csdev)
-{
-	int cpu, ret;
-	struct list_head *path = NULL;
-
-	mutex_lock(&coresight_mutex);
-
-	ret = coresight_validate_source(csdev, __func__);
-	if (ret)
-		goto out;
-
-	if (!csdev->enable || !coresight_disable_source(csdev))
-		goto out;
-
-	switch (csdev->subtype.source_subtype) {
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
-		cpu = source_ops(csdev)->cpu_id(csdev);
-		path = per_cpu(tracer_path, cpu);
-		per_cpu(tracer_path, cpu) = NULL;
-		break;
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
-		path = stm_path;
-		stm_path = NULL;
-		break;
-	default:
-		/* We can't be here */
-		break;
-	}
-
-	coresight_disable_path(path);
-	coresight_release_path(path);
-
-out:
-	mutex_unlock(&coresight_mutex);
-}
-EXPORT_SYMBOL_GPL(coresight_disable);
-
-static ssize_t enable_sink_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
-{
-	struct coresight_device *csdev = to_coresight_device(dev);
-
-	return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->activated);
-}
-
-static ssize_t enable_sink_store(struct device *dev,
-				 struct device_attribute *attr,
-				 const char *buf, size_t size)
-{
-	int ret;
-	unsigned long val;
-	struct coresight_device *csdev = to_coresight_device(dev);
-
-	ret = kstrtoul(buf, 10, &val);
-	if (ret)
-		return ret;
-
-	if (val)
-		csdev->activated = true;
-	else
-		csdev->activated = false;
-
-	return size;
-
-}
-static DEVICE_ATTR_RW(enable_sink);
-
-static ssize_t enable_source_show(struct device *dev,
-				  struct device_attribute *attr, char *buf)
-{
-	struct coresight_device *csdev = to_coresight_device(dev);
-
-	return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->enable);
-}
-
-static ssize_t enable_source_store(struct device *dev,
-				   struct device_attribute *attr,
-				   const char *buf, size_t size)
-{
-	int ret = 0;
-	unsigned long val;
-	struct coresight_device *csdev = to_coresight_device(dev);
-
-	ret = kstrtoul(buf, 10, &val);
-	if (ret)
-		return ret;
-
-	if (val) {
-		ret = coresight_enable(csdev);
-		if (ret)
-			return ret;
-	} else {
-		coresight_disable(csdev);
-	}
-
-	return size;
-}
-static DEVICE_ATTR_RW(enable_source);
-
-static struct attribute *coresight_sink_attrs[] = {
-	&dev_attr_enable_sink.attr,
-	NULL,
-};
-ATTRIBUTE_GROUPS(coresight_sink);
-
-static struct attribute *coresight_source_attrs[] = {
-	&dev_attr_enable_source.attr,
-	NULL,
-};
-ATTRIBUTE_GROUPS(coresight_source);
-
-static struct device_type coresight_dev_type[] = {
-	{
-		.name = "none",
-	},
-	{
-		.name = "sink",
-		.groups = coresight_sink_groups,
-	},
-	{
-		.name = "link",
-	},
-	{
-		.name = "linksink",
-		.groups = coresight_sink_groups,
-	},
-	{
-		.name = "source",
-		.groups = coresight_source_groups,
-	},
-	{
-		.name = "helper",
-	},
-};
-
-static void coresight_device_release(struct device *dev)
-{
-	struct coresight_device *csdev = to_coresight_device(dev);
-
-	fwnode_handle_put(csdev->dev.fwnode);
-	kfree(csdev->refcnt);
-	kfree(csdev);
-}
-
-static int coresight_orphan_match(struct device *dev, void *data)
-{
-	int i;
-	bool still_orphan = false;
-	struct coresight_device *csdev, *i_csdev;
-	struct coresight_connection *conn;
-
-	csdev = data;
-	i_csdev = to_coresight_device(dev);
-
-	/* No need to check oneself */
-	if (csdev == i_csdev)
-		return 0;
-
-	/* Move on to another component if no connection is orphan */
-	if (!i_csdev->orphan)
-		return 0;
-	/*
-	 * Circle throuch all the connection of that component.  If we find
-	 * an orphan connection whose name matches @csdev, link it.
-	 */
-	for (i = 0; i < i_csdev->pdata->nr_outport; i++) {
-		conn = &i_csdev->pdata->conns[i];
-
-		/* We have found at least one orphan connection */
-		if (conn->child_dev == NULL) {
-			/* Does it match this newly added device? */
-			if (conn->child_fwnode == csdev->dev.fwnode)
-				conn->child_dev = csdev;
-			else
-				/* This component still has an orphan */
-				still_orphan = true;
-		}
-	}
-
-	i_csdev->orphan = still_orphan;
-
-	/*
-	 * Returning '0' ensures that all known component on the
-	 * bus will be checked.
-	 */
-	return 0;
-}
-
-static void coresight_fixup_orphan_conns(struct coresight_device *csdev)
-{
-	/*
-	 * No need to check for a return value as orphan connection(s)
-	 * are hooked-up with each newly added component.
-	 */
-	bus_for_each_dev(&coresight_bustype, NULL,
-			 csdev, coresight_orphan_match);
-}
-
-
-static void coresight_fixup_device_conns(struct coresight_device *csdev)
-{
-	int i;
-
-	for (i = 0; i < csdev->pdata->nr_outport; i++) {
-		struct coresight_connection *conn = &csdev->pdata->conns[i];
-		struct device *dev = NULL;
-
-		dev = bus_find_device_by_fwnode(&coresight_bustype, conn->child_fwnode);
-		if (dev) {
-			conn->child_dev = to_coresight_device(dev);
-			/* and put reference from 'bus_find_device()' */
-			put_device(dev);
-		} else {
-			csdev->orphan = true;
-			conn->child_dev = NULL;
-		}
-	}
-}
-
-static int coresight_remove_match(struct device *dev, void *data)
-{
-	int i;
-	struct coresight_device *csdev, *iterator;
-	struct coresight_connection *conn;
-
-	csdev = data;
-	iterator = to_coresight_device(dev);
-
-	/* No need to check oneself */
-	if (csdev == iterator)
-		return 0;
-
-	/*
-	 * Circle throuch all the connection of that component.  If we find
-	 * a connection whose name matches @csdev, remove it.
-	 */
-	for (i = 0; i < iterator->pdata->nr_outport; i++) {
-		conn = &iterator->pdata->conns[i];
-
-		if (conn->child_dev == NULL)
-			continue;
-
-		if (csdev->dev.fwnode == conn->child_fwnode) {
-			iterator->orphan = true;
-			conn->child_dev = NULL;
-			/*
-			 * Drop the reference to the handle for the remote
-			 * device acquired in parsing the connections from
-			 * platform data.
-			 */
-			fwnode_handle_put(conn->child_fwnode);
-			/* No need to continue */
-			break;
-		}
-	}
-
-	/*
-	 * Returning '0' ensures that all known component on the
-	 * bus will be checked.
-	 */
-	return 0;
-}
-
-/*
- * coresight_remove_conns - Remove references to this given devices
- * from the connections of other devices.
- */
-static void coresight_remove_conns(struct coresight_device *csdev)
-{
-	/*
-	 * Another device will point to this device only if there is
-	 * an output port connected to this one. i.e, if the device
-	 * doesn't have at least one input port, there is no point
-	 * in searching all the devices.
-	 */
-	if (csdev->pdata->nr_inport)
-		bus_for_each_dev(&coresight_bustype, NULL,
-				 csdev, coresight_remove_match);
-}
-
-/**
- * coresight_timeout - loop until a bit has changed to a specific state.
- * @addr: base address of the area of interest.
- * @offset: address of a register, starting from @addr.
- * @position: the position of the bit of interest.
- * @value: the value the bit should have.
- *
- * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
- * TIMEOUT_US has elapsed, which ever happens first.
- */
-
-int coresight_timeout(void __iomem *addr, u32 offset, int position, int value)
-{
-	int i;
-	u32 val;
-
-	for (i = TIMEOUT_US; i > 0; i--) {
-		val = __raw_readl(addr + offset);
-		/* waiting on the bit to go from 0 to 1 */
-		if (value) {
-			if (val & BIT(position))
-				return 0;
-		/* waiting on the bit to go from 1 to 0 */
-		} else {
-			if (!(val & BIT(position)))
-				return 0;
-		}
-
-		/*
-		 * Delay is arbitrary - the specification doesn't say how long
-		 * we are expected to wait.  Extra check required to make sure
-		 * we don't wait needlessly on the last iteration.
-		 */
-		if (i - 1)
-			udelay(1);
-	}
-
-	return -EAGAIN;
-}
-
-struct bus_type coresight_bustype = {
-	.name	= "coresight",
-};
-
-static int __init coresight_init(void)
-{
-	return bus_register(&coresight_bustype);
-}
-postcore_initcall(coresight_init);
-
-/*
- * coresight_release_platform_data: Release references to the devices connected
- * to the output port of this device.
- */
-void coresight_release_platform_data(struct coresight_platform_data *pdata)
-{
-	int i;
-
-	for (i = 0; i < pdata->nr_outport; i++) {
-		if (pdata->conns[i].child_fwnode) {
-			fwnode_handle_put(pdata->conns[i].child_fwnode);
-			pdata->conns[i].child_fwnode = NULL;
-		}
-	}
-}
-
-struct coresight_device *coresight_register(struct coresight_desc *desc)
-{
-	int ret;
-	int link_subtype;
-	int nr_refcnts = 1;
-	atomic_t *refcnts = NULL;
-	struct coresight_device *csdev;
-
-	csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
-	if (!csdev) {
-		ret = -ENOMEM;
-		goto err_out;
-	}
-
-	if (desc->type == CORESIGHT_DEV_TYPE_LINK ||
-	    desc->type == CORESIGHT_DEV_TYPE_LINKSINK) {
-		link_subtype = desc->subtype.link_subtype;
-
-		if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
-			nr_refcnts = desc->pdata->nr_inport;
-		else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
-			nr_refcnts = desc->pdata->nr_outport;
-	}
-
-	refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
-	if (!refcnts) {
-		ret = -ENOMEM;
-		goto err_free_csdev;
-	}
-
-	csdev->refcnt = refcnts;
-
-	csdev->pdata = desc->pdata;
-
-	csdev->type = desc->type;
-	csdev->subtype = desc->subtype;
-	csdev->ops = desc->ops;
-	csdev->orphan = false;
-
-	csdev->dev.type = &coresight_dev_type[desc->type];
-	csdev->dev.groups = desc->groups;
-	csdev->dev.parent = desc->dev;
-	csdev->dev.release = coresight_device_release;
-	csdev->dev.bus = &coresight_bustype;
-	/*
-	 * Hold the reference to our parent device. This will be
-	 * dropped only in coresight_device_release().
-	 */
-	csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));
-	dev_set_name(&csdev->dev, "%s", desc->name);
-
-	ret = device_register(&csdev->dev);
-	if (ret) {
-		put_device(&csdev->dev);
-		/*
-		 * All resources are free'd explicitly via
-		 * coresight_device_release(), triggered from put_device().
-		 */
-		goto err_out;
-	}
-
-	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
-	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
-		ret = etm_perf_add_symlink_sink(csdev);
-
-		if (ret) {
-			device_unregister(&csdev->dev);
-			/*
-			 * As with the above, all resources are free'd
-			 * explicitly via coresight_device_release() triggered
-			 * from put_device(), which is in turn called from
-			 * function device_unregister().
-			 */
-			goto err_out;
-		}
-	}
-
-	mutex_lock(&coresight_mutex);
-
-	coresight_fixup_device_conns(csdev);
-	coresight_fixup_orphan_conns(csdev);
-
-	mutex_unlock(&coresight_mutex);
-
-	return csdev;
-
-err_free_csdev:
-	kfree(csdev);
-err_out:
-	/* Cleanup the connection information */
-	coresight_release_platform_data(desc->pdata);
-	return ERR_PTR(ret);
-}
-EXPORT_SYMBOL_GPL(coresight_register);
-
-void coresight_unregister(struct coresight_device *csdev)
-{
-	etm_perf_del_symlink_sink(csdev);
-	/* Remove references of that device in the topology */
-	coresight_remove_conns(csdev);
-	coresight_release_platform_data(csdev->pdata);
-	device_unregister(&csdev->dev);
-}
-EXPORT_SYMBOL_GPL(coresight_unregister);
-
-
-/*
- * coresight_search_device_idx - Search the fwnode handle of a device
- * in the given dev_idx list. Must be called with the coresight_mutex held.
- *
- * Returns the index of the entry, when found. Otherwise, -ENOENT.
- */
-static inline int coresight_search_device_idx(struct coresight_dev_list *dict,
-					      struct fwnode_handle *fwnode)
-{
-	int i;
-
-	for (i = 0; i < dict->nr_idx; i++)
-		if (dict->fwnode_list[i] == fwnode)
-			return i;
-	return -ENOENT;
-}
-
-bool coresight_loses_context_with_cpu(struct device *dev)
-{
-	return fwnode_property_present(dev_fwnode(dev),
-				       "arm,coresight-loses-context-with-cpu");
-}
-
-/*
- * coresight_alloc_device_name - Get an index for a given device in the
- * device index list specific to a driver. An index is allocated for a
- * device and is tracked with the fwnode_handle to prevent allocating
- * duplicate indices for the same device (e.g, if we defer probing of
- * a device due to dependencies), in case the index is requested again.
- */
-char *coresight_alloc_device_name(struct coresight_dev_list *dict,
-				  struct device *dev)
-{
-	int idx;
-	char *name = NULL;
-	struct fwnode_handle **list;
-
-	mutex_lock(&coresight_mutex);
-
-	idx = coresight_search_device_idx(dict, dev_fwnode(dev));
-	if (idx < 0) {
-		/* Make space for the new entry */
-		idx = dict->nr_idx;
-		list = krealloc(dict->fwnode_list,
-				(idx + 1) * sizeof(*dict->fwnode_list),
-				GFP_KERNEL);
-		if (ZERO_OR_NULL_PTR(list)) {
-			idx = -ENOMEM;
-			goto done;
-		}
-
-		list[idx] = dev_fwnode(dev);
-		dict->fwnode_list = list;
-		dict->nr_idx = idx + 1;
-	}
-
-	name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
-done:
-	mutex_unlock(&coresight_mutex);
-	return name;
-}
-EXPORT_SYMBOL_GPL(coresight_alloc_device_name);
