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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2012, The Linux Foundation. All rights reserved.4 */5 6#include <linux/build_bug.h>7#include <linux/kernel.h>8#include <linux/init.h>9#include <linux/types.h>10#include <linux/device.h>11#include <linux/io.h>12#include <linux/err.h>13#include <linux/export.h>14#include <linux/slab.h>15#include <linux/stringhash.h>16#include <linux/mutex.h>17#include <linux/clk.h>18#include <linux/coresight.h>19#include <linux/property.h>20#include <linux/delay.h>21#include <linux/pm_runtime.h>22 23#include "coresight-etm-perf.h"24#include "coresight-priv.h"25#include "coresight-syscfg.h"26 27/*28 * Mutex used to lock all sysfs enable and disable actions and loading and29 * unloading devices by the Coresight core.30 */31DEFINE_MUTEX(coresight_mutex);32static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);33 34/**35 * struct coresight_node - elements of a path, from source to sink36 * @csdev:	Address of an element.37 * @link:	hook to the list.38 */39struct coresight_node {40	struct coresight_device *csdev;41	struct list_head link;42};43 44/*45 * When losing synchronisation a new barrier packet needs to be inserted at the46 * beginning of the data collected in a buffer.  That way the decoder knows that47 * it needs to look for another sync sequence.48 */49const u32 coresight_barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};50EXPORT_SYMBOL_GPL(coresight_barrier_pkt);51 52static const struct cti_assoc_op *cti_assoc_ops;53 54void coresight_set_cti_ops(const struct cti_assoc_op *cti_op)55{56	cti_assoc_ops = cti_op;57}58EXPORT_SYMBOL_GPL(coresight_set_cti_ops);59 60void coresight_remove_cti_ops(void)61{62	cti_assoc_ops = NULL;63}64EXPORT_SYMBOL_GPL(coresight_remove_cti_ops);65 66void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev)67{68	per_cpu(csdev_sink, cpu) = csdev;69}70EXPORT_SYMBOL_GPL(coresight_set_percpu_sink);71 72struct coresight_device *coresight_get_percpu_sink(int cpu)73{74	return per_cpu(csdev_sink, cpu);75}76EXPORT_SYMBOL_GPL(coresight_get_percpu_sink);77 78static struct coresight_connection *79coresight_find_out_connection(struct coresight_device *src_dev,80			      struct coresight_device *dest_dev)81{82	int i;83	struct coresight_connection *conn;84 85	for (i = 0; i < src_dev->pdata->nr_outconns; i++) {86		conn = src_dev->pdata->out_conns[i];87		if (conn->dest_dev == dest_dev)88			return conn;89	}90 91	dev_err(&src_dev->dev,92		"couldn't find output connection, src_dev: %s, dest_dev: %s\n",93		dev_name(&src_dev->dev), dev_name(&dest_dev->dev));94 95	return ERR_PTR(-ENODEV);96}97 98static inline u32 coresight_read_claim_tags(struct coresight_device *csdev)99{100	return csdev_access_relaxed_read32(&csdev->access, CORESIGHT_CLAIMCLR);101}102 103static inline bool coresight_is_claimed_self_hosted(struct coresight_device *csdev)104{105	return coresight_read_claim_tags(csdev) == CORESIGHT_CLAIM_SELF_HOSTED;106}107 108static inline bool coresight_is_claimed_any(struct coresight_device *csdev)109{110	return coresight_read_claim_tags(csdev) != 0;111}112 113static inline void coresight_set_claim_tags(struct coresight_device *csdev)114{115	csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,116				     CORESIGHT_CLAIMSET);117	isb();118}119 120static inline void coresight_clear_claim_tags(struct coresight_device *csdev)121{122	csdev_access_relaxed_write32(&csdev->access, CORESIGHT_CLAIM_SELF_HOSTED,123				     CORESIGHT_CLAIMCLR);124	isb();125}126 127/*128 * coresight_claim_device_unlocked : Claim the device for self-hosted usage129 * to prevent an external tool from touching this device. As per PSCI130 * standards, section "Preserving the execution context" => "Debug and Trace131 * save and Restore", DBGCLAIM[1] is reserved for Self-hosted debug/trace and132 * DBGCLAIM[0] is reserved for external tools.133 *134 * Called with CS_UNLOCKed for the component.135 * Returns : 0 on success136 */137int coresight_claim_device_unlocked(struct coresight_device *csdev)138{139	if (WARN_ON(!csdev))140		return -EINVAL;141 142	if (coresight_is_claimed_any(csdev))143		return -EBUSY;144 145	coresight_set_claim_tags(csdev);146	if (coresight_is_claimed_self_hosted(csdev))147		return 0;148	/* There was a race setting the tags, clean up and fail */149	coresight_clear_claim_tags(csdev);150	return -EBUSY;151}152EXPORT_SYMBOL_GPL(coresight_claim_device_unlocked);153 154int coresight_claim_device(struct coresight_device *csdev)155{156	int rc;157 158	if (WARN_ON(!csdev))159		return -EINVAL;160 161	CS_UNLOCK(csdev->access.base);162	rc = coresight_claim_device_unlocked(csdev);163	CS_LOCK(csdev->access.base);164 165	return rc;166}167EXPORT_SYMBOL_GPL(coresight_claim_device);168 169/*170 * coresight_disclaim_device_unlocked : Clear the claim tags for the device.171 * Called with CS_UNLOCKed for the component.172 */173void coresight_disclaim_device_unlocked(struct coresight_device *csdev)174{175 176	if (WARN_ON(!csdev))177		return;178 179	if (coresight_is_claimed_self_hosted(csdev))180		coresight_clear_claim_tags(csdev);181	else182		/*183		 * The external agent may have not honoured our claim184		 * and has manipulated it. Or something else has seriously185		 * gone wrong in our driver.186		 */187		WARN_ON_ONCE(1);188}189EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);190 191void coresight_disclaim_device(struct coresight_device *csdev)192{193	if (WARN_ON(!csdev))194		return;195 196	CS_UNLOCK(csdev->access.base);197	coresight_disclaim_device_unlocked(csdev);198	CS_LOCK(csdev->access.base);199}200EXPORT_SYMBOL_GPL(coresight_disclaim_device);201 202/*203 * Add a helper as an output device. This function takes the @coresight_mutex204 * because it's assumed that it's called from the helper device, outside of the205 * core code where the mutex would already be held. Don't add new calls to this206 * from inside the core code, instead try to add the new helper to the DT and207 * ACPI where it will be picked up and linked automatically.208 */209void coresight_add_helper(struct coresight_device *csdev,210			  struct coresight_device *helper)211{212	int i;213	struct coresight_connection conn = {};214	struct coresight_connection *new_conn;215 216	mutex_lock(&coresight_mutex);217	conn.dest_fwnode = fwnode_handle_get(dev_fwnode(&helper->dev));218	conn.dest_dev = helper;219	conn.dest_port = conn.src_port = -1;220	conn.src_dev = csdev;221 222	/*223	 * Check for duplicates because this is called every time a helper224	 * device is re-loaded. Existing connections will get re-linked225	 * automatically.226	 */227	for (i = 0; i < csdev->pdata->nr_outconns; ++i)228		if (csdev->pdata->out_conns[i]->dest_fwnode == conn.dest_fwnode)229			goto unlock;230 231	new_conn = coresight_add_out_conn(csdev->dev.parent, csdev->pdata,232					  &conn);233	if (!IS_ERR(new_conn))234		coresight_add_in_conn(new_conn);235 236unlock:237	mutex_unlock(&coresight_mutex);238}239EXPORT_SYMBOL_GPL(coresight_add_helper);240 241static int coresight_enable_sink(struct coresight_device *csdev,242				 enum cs_mode mode, void *data)243{244	return sink_ops(csdev)->enable(csdev, mode, data);245}246 247static void coresight_disable_sink(struct coresight_device *csdev)248{249	sink_ops(csdev)->disable(csdev);250}251 252static int coresight_enable_link(struct coresight_device *csdev,253				 struct coresight_device *parent,254				 struct coresight_device *child)255{256	int link_subtype;257	struct coresight_connection *inconn, *outconn;258 259	if (!parent || !child)260		return -EINVAL;261 262	inconn = coresight_find_out_connection(parent, csdev);263	outconn = coresight_find_out_connection(csdev, child);264	link_subtype = csdev->subtype.link_subtype;265 266	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG && IS_ERR(inconn))267		return PTR_ERR(inconn);268	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && IS_ERR(outconn))269		return PTR_ERR(outconn);270 271	return link_ops(csdev)->enable(csdev, inconn, outconn);272}273 274static void coresight_disable_link(struct coresight_device *csdev,275				   struct coresight_device *parent,276				   struct coresight_device *child)277{278	struct coresight_connection *inconn, *outconn;279 280	if (!parent || !child)281		return;282 283	inconn = coresight_find_out_connection(parent, csdev);284	outconn = coresight_find_out_connection(csdev, child);285 286	link_ops(csdev)->disable(csdev, inconn, outconn);287}288 289static bool coresight_is_helper(struct coresight_device *csdev)290{291	return csdev->type == CORESIGHT_DEV_TYPE_HELPER;292}293 294static int coresight_enable_helper(struct coresight_device *csdev,295				   enum cs_mode mode, void *data)296{297	return helper_ops(csdev)->enable(csdev, mode, data);298}299 300static void coresight_disable_helper(struct coresight_device *csdev)301{302	helper_ops(csdev)->disable(csdev, NULL);303}304 305static void coresight_disable_helpers(struct coresight_device *csdev)306{307	int i;308	struct coresight_device *helper;309 310	for (i = 0; i < csdev->pdata->nr_outconns; ++i) {311		helper = csdev->pdata->out_conns[i]->dest_dev;312		if (helper && coresight_is_helper(helper))313			coresight_disable_helper(helper);314	}315}316 317/*318 * Helper function to call source_ops(csdev)->disable and also disable the319 * helpers.320 *321 * There is an imbalance between coresight_enable_path() and322 * coresight_disable_path(). Enabling also enables the source's helpers as part323 * of the path, but disabling always skips the first item in the path (which is324 * the source), so sources and their helpers don't get disabled as part of that325 * function and we need the extra step here.326 */327void coresight_disable_source(struct coresight_device *csdev, void *data)328{329	source_ops(csdev)->disable(csdev, data);330	coresight_disable_helpers(csdev);331}332EXPORT_SYMBOL_GPL(coresight_disable_source);333 334/*335 * coresight_disable_path_from : Disable components in the given path beyond336 * @nd in the list. If @nd is NULL, all the components, except the SOURCE are337 * disabled.338 */339static void coresight_disable_path_from(struct list_head *path,340					struct coresight_node *nd)341{342	u32 type;343	struct coresight_device *csdev, *parent, *child;344 345	if (!nd)346		nd = list_first_entry(path, struct coresight_node, link);347 348	list_for_each_entry_continue(nd, path, link) {349		csdev = nd->csdev;350		type = csdev->type;351 352		/*353		 * ETF devices are tricky... They can be a link or a sink,354		 * depending on how they are configured.  If an ETF has been355		 * selected as a sink it will be configured as a sink, otherwise356		 * go ahead with the link configuration.357		 */358		if (type == CORESIGHT_DEV_TYPE_LINKSINK)359			type = (csdev == coresight_get_sink(path)) ?360						CORESIGHT_DEV_TYPE_SINK :361						CORESIGHT_DEV_TYPE_LINK;362 363		switch (type) {364		case CORESIGHT_DEV_TYPE_SINK:365			coresight_disable_sink(csdev);366			break;367		case CORESIGHT_DEV_TYPE_SOURCE:368			/*369			 * We skip the first node in the path assuming that it370			 * is the source. So we don't expect a source device in371			 * the middle of a path.372			 */373			WARN_ON(1);374			break;375		case CORESIGHT_DEV_TYPE_LINK:376			parent = list_prev_entry(nd, link)->csdev;377			child = list_next_entry(nd, link)->csdev;378			coresight_disable_link(csdev, parent, child);379			break;380		default:381			break;382		}383 384		/* Disable all helpers adjacent along the path last */385		coresight_disable_helpers(csdev);386	}387}388 389void coresight_disable_path(struct list_head *path)390{391	coresight_disable_path_from(path, NULL);392}393EXPORT_SYMBOL_GPL(coresight_disable_path);394 395static int coresight_enable_helpers(struct coresight_device *csdev,396				    enum cs_mode mode, void *data)397{398	int i, ret = 0;399	struct coresight_device *helper;400 401	for (i = 0; i < csdev->pdata->nr_outconns; ++i) {402		helper = csdev->pdata->out_conns[i]->dest_dev;403		if (!helper || !coresight_is_helper(helper))404			continue;405 406		ret = coresight_enable_helper(helper, mode, data);407		if (ret)408			return ret;409	}410 411	return 0;412}413 414int coresight_enable_path(struct list_head *path, enum cs_mode mode,415			  void *sink_data)416{417	int ret = 0;418	u32 type;419	struct coresight_node *nd;420	struct coresight_device *csdev, *parent, *child;421 422	list_for_each_entry_reverse(nd, path, link) {423		csdev = nd->csdev;424		type = csdev->type;425 426		/* Enable all helpers adjacent to the path first */427		ret = coresight_enable_helpers(csdev, mode, sink_data);428		if (ret)429			goto err;430		/*431		 * ETF devices are tricky... They can be a link or a sink,432		 * depending on how they are configured.  If an ETF has been433		 * selected as a sink it will be configured as a sink, otherwise434		 * go ahead with the link configuration.435		 */436		if (type == CORESIGHT_DEV_TYPE_LINKSINK)437			type = (csdev == coresight_get_sink(path)) ?438						CORESIGHT_DEV_TYPE_SINK :439						CORESIGHT_DEV_TYPE_LINK;440 441		switch (type) {442		case CORESIGHT_DEV_TYPE_SINK:443			ret = coresight_enable_sink(csdev, mode, sink_data);444			/*445			 * Sink is the first component turned on. If we446			 * failed to enable the sink, there are no components447			 * that need disabling. Disabling the path here448			 * would mean we could disrupt an existing session.449			 */450			if (ret)451				goto out;452			break;453		case CORESIGHT_DEV_TYPE_SOURCE:454			/* sources are enabled from either sysFS or Perf */455			break;456		case CORESIGHT_DEV_TYPE_LINK:457			parent = list_prev_entry(nd, link)->csdev;458			child = list_next_entry(nd, link)->csdev;459			ret = coresight_enable_link(csdev, parent, child);460			if (ret)461				goto err;462			break;463		default:464			goto err;465		}466	}467 468out:469	return ret;470err:471	coresight_disable_path_from(path, nd);472	goto out;473}474 475struct coresight_device *coresight_get_sink(struct list_head *path)476{477	struct coresight_device *csdev;478 479	if (!path)480		return NULL;481 482	csdev = list_last_entry(path, struct coresight_node, link)->csdev;483	if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&484	    csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)485		return NULL;486 487	return csdev;488}489 490u32 coresight_get_sink_id(struct coresight_device *csdev)491{492	if (!csdev->ea)493		return 0;494 495	/*496	 * See function etm_perf_add_symlink_sink() to know where497	 * this comes from.498	 */499	return (u32) (unsigned long) csdev->ea->var;500}501 502static int coresight_sink_by_id(struct device *dev, const void *data)503{504	struct coresight_device *csdev = to_coresight_device(dev);505 506	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||507	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {508		if (coresight_get_sink_id(csdev) == *(u32 *)data)509			return 1;510	}511 512	return 0;513}514 515/**516 * coresight_get_sink_by_id - returns the sink that matches the id517 * @id: Id of the sink to match518 *519 * The name of a sink is unique, whether it is found on the AMBA bus or520 * otherwise.  As such the hash of that name can easily be used to identify521 * a sink.522 */523struct coresight_device *coresight_get_sink_by_id(u32 id)524{525	struct device *dev = NULL;526 527	dev = bus_find_device(&coresight_bustype, NULL, &id,528			      coresight_sink_by_id);529 530	return dev ? to_coresight_device(dev) : NULL;531}532 533/**534 * coresight_get_ref- Helper function to increase reference count to module535 * and device.536 *537 * @csdev: The coresight device to get a reference on.538 *539 * Return true in successful case and power up the device.540 * Return false when failed to get reference of module.541 */542static inline bool coresight_get_ref(struct coresight_device *csdev)543{544	struct device *dev = csdev->dev.parent;545 546	/* Make sure the driver can't be removed */547	if (!try_module_get(dev->driver->owner))548		return false;549	/* Make sure the device can't go away */550	get_device(dev);551	pm_runtime_get_sync(dev);552	return true;553}554 555/**556 * coresight_put_ref- Helper function to decrease reference count to module557 * and device. Power off the device.558 *559 * @csdev: The coresight device to decrement a reference from.560 */561static inline void coresight_put_ref(struct coresight_device *csdev)562{563	struct device *dev = csdev->dev.parent;564 565	pm_runtime_put(dev);566	put_device(dev);567	module_put(dev->driver->owner);568}569 570/*571 * coresight_grab_device - Power up this device and any of the helper572 * devices connected to it for trace operation. Since the helper devices573 * don't appear on the trace path, they should be handled along with the574 * master device.575 */576static int coresight_grab_device(struct coresight_device *csdev)577{578	int i;579 580	for (i = 0; i < csdev->pdata->nr_outconns; i++) {581		struct coresight_device *child;582 583		child = csdev->pdata->out_conns[i]->dest_dev;584		if (child && coresight_is_helper(child))585			if (!coresight_get_ref(child))586				goto err;587	}588	if (coresight_get_ref(csdev))589		return 0;590err:591	for (i--; i >= 0; i--) {592		struct coresight_device *child;593 594		child = csdev->pdata->out_conns[i]->dest_dev;595		if (child && coresight_is_helper(child))596			coresight_put_ref(child);597	}598	return -ENODEV;599}600 601/*602 * coresight_drop_device - Release this device and any of the helper603 * devices connected to it.604 */605static void coresight_drop_device(struct coresight_device *csdev)606{607	int i;608 609	coresight_put_ref(csdev);610	for (i = 0; i < csdev->pdata->nr_outconns; i++) {611		struct coresight_device *child;612 613		child = csdev->pdata->out_conns[i]->dest_dev;614		if (child && coresight_is_helper(child))615			coresight_put_ref(child);616	}617}618 619/**620 * _coresight_build_path - recursively build a path from a @csdev to a sink.621 * @csdev:	The device to start from.622 * @sink:	The final sink we want in this path.623 * @path:	The list to add devices to.624 *625 * The tree of Coresight device is traversed until @sink is found.626 * From there the sink is added to the list along with all the devices that led627 * to that point - the end result is a list from source to sink. In that list628 * the source is the first device and the sink the last one.629 */630static int _coresight_build_path(struct coresight_device *csdev,631				 struct coresight_device *sink,632				 struct list_head *path)633{634	int i, ret;635	bool found = false;636	struct coresight_node *node;637 638	/* The sink has been found.  Enqueue the element */639	if (csdev == sink)640		goto out;641 642	if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) &&643	    sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) {644		if (_coresight_build_path(sink, sink, path) == 0) {645			found = true;646			goto out;647		}648	}649 650	/* Not a sink - recursively explore each port found on this element */651	for (i = 0; i < csdev->pdata->nr_outconns; i++) {652		struct coresight_device *child_dev;653 654		child_dev = csdev->pdata->out_conns[i]->dest_dev;655		if (child_dev &&656		    _coresight_build_path(child_dev, sink, path) == 0) {657			found = true;658			break;659		}660	}661 662	if (!found)663		return -ENODEV;664 665out:666	/*667	 * A path from this element to a sink has been found.  The elements668	 * leading to the sink are already enqueued, all that is left to do669	 * is tell the PM runtime core we need this element and add a node670	 * for it.671	 */672	ret = coresight_grab_device(csdev);673	if (ret)674		return ret;675 676	node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);677	if (!node)678		return -ENOMEM;679 680	node->csdev = csdev;681	list_add(&node->link, path);682 683	return 0;684}685 686struct list_head *coresight_build_path(struct coresight_device *source,687				       struct coresight_device *sink)688{689	struct list_head *path;690	int rc;691 692	if (!sink)693		return ERR_PTR(-EINVAL);694 695	path = kzalloc(sizeof(struct list_head), GFP_KERNEL);696	if (!path)697		return ERR_PTR(-ENOMEM);698 699	INIT_LIST_HEAD(path);700 701	rc = _coresight_build_path(source, sink, path);702	if (rc) {703		kfree(path);704		return ERR_PTR(rc);705	}706 707	return path;708}709 710/**711 * coresight_release_path - release a previously built path.712 * @path:	the path to release.713 *714 * Go through all the elements of a path and 1) removed it from the list and715 * 2) free the memory allocated for each node.716 */717void coresight_release_path(struct list_head *path)718{719	struct coresight_device *csdev;720	struct coresight_node *nd, *next;721 722	list_for_each_entry_safe(nd, next, path, link) {723		csdev = nd->csdev;724 725		coresight_drop_device(csdev);726		list_del(&nd->link);727		kfree(nd);728	}729 730	kfree(path);731}732 733/* return true if the device is a suitable type for a default sink */734static inline bool coresight_is_def_sink_type(struct coresight_device *csdev)735{736	/* sink & correct subtype */737	if (((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||738	     (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) &&739	    (csdev->subtype.sink_subtype >= CORESIGHT_DEV_SUBTYPE_SINK_BUFFER))740		return true;741	return false;742}743 744/**745 * coresight_select_best_sink - return the best sink for use as default from746 * the two provided.747 *748 * @sink:	current best sink.749 * @depth:      search depth where current sink was found.750 * @new_sink:	new sink for comparison with current sink.751 * @new_depth:  search depth where new sink was found.752 *753 * Sinks prioritised according to coresight_dev_subtype_sink, with only754 * subtypes CORESIGHT_DEV_SUBTYPE_SINK_BUFFER or higher being used.755 *756 * Where two sinks of equal priority are found, the sink closest to the757 * source is used (smallest search depth).758 *759 * return @new_sink & update @depth if better than @sink, else return @sink.760 */761static struct coresight_device *762coresight_select_best_sink(struct coresight_device *sink, int *depth,763			   struct coresight_device *new_sink, int new_depth)764{765	bool update = false;766 767	if (!sink) {768		/* first found at this level */769		update = true;770	} else if (new_sink->subtype.sink_subtype >771		   sink->subtype.sink_subtype) {772		/* found better sink */773		update = true;774	} else if ((new_sink->subtype.sink_subtype ==775		    sink->subtype.sink_subtype) &&776		   (*depth > new_depth)) {777		/* found same but closer sink */778		update = true;779	}780 781	if (update)782		*depth = new_depth;783	return update ? new_sink : sink;784}785 786/**787 * coresight_find_sink - recursive function to walk trace connections from788 * source to find a suitable default sink.789 *790 * @csdev: source / current device to check.791 * @depth: [in] search depth of calling dev, [out] depth of found sink.792 *793 * This will walk the connection path from a source (ETM) till a suitable794 * sink is encountered and return that sink to the original caller.795 *796 * If current device is a plain sink return that & depth, otherwise recursively797 * call child connections looking for a sink. Select best possible using798 * coresight_select_best_sink.799 *800 * return best sink found, or NULL if not found at this node or child nodes.801 */802static struct coresight_device *803coresight_find_sink(struct coresight_device *csdev, int *depth)804{805	int i, curr_depth = *depth + 1, found_depth = 0;806	struct coresight_device *found_sink = NULL;807 808	if (coresight_is_def_sink_type(csdev)) {809		found_depth = curr_depth;810		found_sink = csdev;811		if (csdev->type == CORESIGHT_DEV_TYPE_SINK)812			goto return_def_sink;813		/* look past LINKSINK for something better */814	}815 816	/*817	 * Not a sink we want - or possible child sink may be better.818	 * recursively explore each port found on this element.819	 */820	for (i = 0; i < csdev->pdata->nr_outconns; i++) {821		struct coresight_device *child_dev, *sink = NULL;822		int child_depth = curr_depth;823 824		child_dev = csdev->pdata->out_conns[i]->dest_dev;825		if (child_dev)826			sink = coresight_find_sink(child_dev, &child_depth);827 828		if (sink)829			found_sink = coresight_select_best_sink(found_sink,830								&found_depth,831								sink,832								child_depth);833	}834 835return_def_sink:836	/* return found sink and depth */837	if (found_sink)838		*depth = found_depth;839	return found_sink;840}841 842/**843 * coresight_find_default_sink: Find a sink suitable for use as a844 * default sink.845 *846 * @csdev: starting source to find a connected sink.847 *848 * Walks connections graph looking for a suitable sink to enable for the849 * supplied source. Uses CoreSight device subtypes and distance from source850 * to select the best sink.851 *852 * If a sink is found, then the default sink for this device is set and853 * will be automatically used in future.854 *855 * Used in cases where the CoreSight user (perf / sysfs) has not selected a856 * sink.857 */858struct coresight_device *859coresight_find_default_sink(struct coresight_device *csdev)860{861	int depth = 0;862 863	/* look for a default sink if we have not found for this device */864	if (!csdev->def_sink) {865		if (coresight_is_percpu_source(csdev))866			csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev));867		if (!csdev->def_sink)868			csdev->def_sink = coresight_find_sink(csdev, &depth);869	}870	return csdev->def_sink;871}872 873static int coresight_remove_sink_ref(struct device *dev, void *data)874{875	struct coresight_device *sink = data;876	struct coresight_device *source = to_coresight_device(dev);877 878	if (source->def_sink == sink)879		source->def_sink = NULL;880	return 0;881}882 883/**884 * coresight_clear_default_sink: Remove all default sink references to the885 * supplied sink.886 *887 * If supplied device is a sink, then check all the bus devices and clear888 * out all the references to this sink from the coresight_device def_sink889 * parameter.890 *891 * @csdev: coresight sink - remove references to this from all sources.892 */893static void coresight_clear_default_sink(struct coresight_device *csdev)894{895	if ((csdev->type == CORESIGHT_DEV_TYPE_SINK) ||896	    (csdev->type == CORESIGHT_DEV_TYPE_LINKSINK)) {897		bus_for_each_dev(&coresight_bustype, NULL, csdev,898				 coresight_remove_sink_ref);899	}900}901 902static void coresight_device_release(struct device *dev)903{904	struct coresight_device *csdev = to_coresight_device(dev);905 906	fwnode_handle_put(csdev->dev.fwnode);907	free_percpu(csdev->perf_sink_id_map.cpu_map);908	kfree(csdev);909}910 911static int coresight_orphan_match(struct device *dev, void *data)912{913	int i, ret = 0;914	bool still_orphan = false;915	struct coresight_device *dst_csdev = data;916	struct coresight_device *src_csdev = to_coresight_device(dev);917	struct coresight_connection *conn;918	bool fixup_self = (src_csdev == dst_csdev);919 920	/* Move on to another component if no connection is orphan */921	if (!src_csdev->orphan)922		return 0;923	/*924	 * Circle through all the connections of that component.  If we find925	 * an orphan connection whose name matches @dst_csdev, link it.926	 */927	for (i = 0; i < src_csdev->pdata->nr_outconns; i++) {928		conn = src_csdev->pdata->out_conns[i];929 930		/* Skip the port if it's already connected. */931		if (conn->dest_dev)932			continue;933 934		/*935		 * If we are at the "new" device, which triggered this search,936		 * we must find the remote device from the fwnode in the937		 * connection.938		 */939		if (fixup_self)940			dst_csdev = coresight_find_csdev_by_fwnode(941				conn->dest_fwnode);942 943		/* Does it match this newly added device? */944		if (dst_csdev && conn->dest_fwnode == dst_csdev->dev.fwnode) {945			ret = coresight_make_links(src_csdev, conn, dst_csdev);946			if (ret)947				return ret;948 949			/*950			 * Install the device connection. This also indicates that951			 * the links are operational on both ends.952			 */953			conn->dest_dev = dst_csdev;954			conn->src_dev = src_csdev;955 956			ret = coresight_add_in_conn(conn);957			if (ret)958				return ret;959		} else {960			/* This component still has an orphan */961			still_orphan = true;962		}963	}964 965	src_csdev->orphan = still_orphan;966 967	/*968	 * Returning '0' in case we didn't encounter any error,969	 * ensures that all known component on the bus will be checked.970	 */971	return 0;972}973 974static int coresight_fixup_orphan_conns(struct coresight_device *csdev)975{976	return bus_for_each_dev(&coresight_bustype, NULL,977			 csdev, coresight_orphan_match);978}979 980/* coresight_remove_conns - Remove other device's references to this device */981static void coresight_remove_conns(struct coresight_device *csdev)982{983	int i, j;984	struct coresight_connection *conn;985 986	/*987	 * Remove the input connection references from the destination device988	 * for each output connection.989	 */990	for (i = 0; i < csdev->pdata->nr_outconns; i++) {991		conn = csdev->pdata->out_conns[i];992		if (!conn->dest_dev)993			continue;994 995		for (j = 0; j < conn->dest_dev->pdata->nr_inconns; ++j)996			if (conn->dest_dev->pdata->in_conns[j] == conn) {997				conn->dest_dev->pdata->in_conns[j] = NULL;998				break;999			}1000	}1001 1002	/*1003	 * For all input connections, remove references to this device.1004	 * Connection objects are shared so modifying this device's input1005	 * connections affects the other device's output connection.1006	 */1007	for (i = 0; i < csdev->pdata->nr_inconns; ++i) {1008		conn = csdev->pdata->in_conns[i];1009		/* Input conns array is sparse */1010		if (!conn)1011			continue;1012 1013		conn->src_dev->orphan = true;1014		coresight_remove_links(conn->src_dev, conn);1015		conn->dest_dev = NULL;1016	}1017}1018 1019/**1020 * coresight_timeout - loop until a bit has changed to a specific register1021 *			state.1022 * @csa: coresight device access for the device1023 * @offset: Offset of the register from the base of the device.1024 * @position: the position of the bit of interest.1025 * @value: the value the bit should have.1026 *1027 * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if1028 * TIMEOUT_US has elapsed, which ever happens first.1029 */1030int coresight_timeout(struct csdev_access *csa, u32 offset,1031		      int position, int value)1032{1033	int i;1034	u32 val;1035 1036	for (i = TIMEOUT_US; i > 0; i--) {1037		val = csdev_access_read32(csa, offset);1038		/* waiting on the bit to go from 0 to 1 */1039		if (value) {1040			if (val & BIT(position))1041				return 0;1042		/* waiting on the bit to go from 1 to 0 */1043		} else {1044			if (!(val & BIT(position)))1045				return 0;1046		}1047 1048		/*1049		 * Delay is arbitrary - the specification doesn't say how long1050		 * we are expected to wait.  Extra check required to make sure1051		 * we don't wait needlessly on the last iteration.1052		 */1053		if (i - 1)1054			udelay(1);1055	}1056 1057	return -EAGAIN;1058}1059EXPORT_SYMBOL_GPL(coresight_timeout);1060 1061u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset)1062{1063	return csdev_access_relaxed_read32(&csdev->access, offset);1064}1065 1066u32 coresight_read32(struct coresight_device *csdev, u32 offset)1067{1068	return csdev_access_read32(&csdev->access, offset);1069}1070 1071void coresight_relaxed_write32(struct coresight_device *csdev,1072			       u32 val, u32 offset)1073{1074	csdev_access_relaxed_write32(&csdev->access, val, offset);1075}1076 1077void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset)1078{1079	csdev_access_write32(&csdev->access, val, offset);1080}1081 1082u64 coresight_relaxed_read64(struct coresight_device *csdev, u32 offset)1083{1084	return csdev_access_relaxed_read64(&csdev->access, offset);1085}1086 1087u64 coresight_read64(struct coresight_device *csdev, u32 offset)1088{1089	return csdev_access_read64(&csdev->access, offset);1090}1091 1092void coresight_relaxed_write64(struct coresight_device *csdev,1093			       u64 val, u32 offset)1094{1095	csdev_access_relaxed_write64(&csdev->access, val, offset);1096}1097 1098void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset)1099{1100	csdev_access_write64(&csdev->access, val, offset);1101}1102 1103/*1104 * coresight_release_platform_data: Release references to the devices connected1105 * to the output port of this device.1106 */1107void coresight_release_platform_data(struct coresight_device *csdev,1108				     struct device *dev,1109				     struct coresight_platform_data *pdata)1110{1111	int i;1112	struct coresight_connection **conns = pdata->out_conns;1113 1114	for (i = 0; i < pdata->nr_outconns; i++) {1115		/* If we have made the links, remove them now */1116		if (csdev && conns[i]->dest_dev)1117			coresight_remove_links(csdev, conns[i]);1118		/*1119		 * Drop the refcount and clear the handle as this device1120		 * is going away1121		 */1122		fwnode_handle_put(conns[i]->dest_fwnode);1123		conns[i]->dest_fwnode = NULL;1124		devm_kfree(dev, conns[i]);1125	}1126	devm_kfree(dev, pdata->out_conns);1127	devm_kfree(dev, pdata->in_conns);1128	devm_kfree(dev, pdata);1129	if (csdev)1130		coresight_remove_conns_sysfs_group(csdev);1131}1132 1133struct coresight_device *coresight_register(struct coresight_desc *desc)1134{1135	int ret;1136	struct coresight_device *csdev;1137	bool registered = false;1138 1139	csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);1140	if (!csdev) {1141		ret = -ENOMEM;1142		goto err_out;1143	}1144 1145	csdev->pdata = desc->pdata;1146 1147	csdev->type = desc->type;1148	csdev->subtype = desc->subtype;1149	csdev->ops = desc->ops;1150	csdev->access = desc->access;1151	csdev->orphan = true;1152 1153	csdev->dev.type = &coresight_dev_type[desc->type];1154	csdev->dev.groups = desc->groups;1155	csdev->dev.parent = desc->dev;1156	csdev->dev.release = coresight_device_release;1157	csdev->dev.bus = &coresight_bustype;1158	/*1159	 * Hold the reference to our parent device. This will be1160	 * dropped only in coresight_device_release().1161	 */1162	csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));1163	dev_set_name(&csdev->dev, "%s", desc->name);1164 1165	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||1166	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {1167		spin_lock_init(&csdev->perf_sink_id_map.lock);1168		csdev->perf_sink_id_map.cpu_map = alloc_percpu(atomic_t);1169		if (!csdev->perf_sink_id_map.cpu_map) {1170			kfree(csdev);1171			ret = -ENOMEM;1172			goto err_out;1173		}1174	}1175	/*1176	 * Make sure the device registration and the connection fixup1177	 * are synchronised, so that we don't see uninitialised devices1178	 * on the coresight bus while trying to resolve the connections.1179	 */1180	mutex_lock(&coresight_mutex);1181 1182	ret = device_register(&csdev->dev);1183	if (ret) {1184		put_device(&csdev->dev);1185		/*1186		 * All resources are free'd explicitly via1187		 * coresight_device_release(), triggered from put_device().1188		 */1189		goto out_unlock;1190	}1191 1192	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||1193	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {1194		ret = etm_perf_add_symlink_sink(csdev);1195 1196		if (ret) {1197			device_unregister(&csdev->dev);1198			/*1199			 * As with the above, all resources are free'd1200			 * explicitly via coresight_device_release() triggered1201			 * from put_device(), which is in turn called from1202			 * function device_unregister().1203			 */1204			goto out_unlock;1205		}1206	}1207	/* Device is now registered */1208	registered = true;1209 1210	ret = coresight_create_conns_sysfs_group(csdev);1211	if (!ret)1212		ret = coresight_fixup_orphan_conns(csdev);1213 1214out_unlock:1215	mutex_unlock(&coresight_mutex);1216	/* Success */1217	if (!ret) {1218		if (cti_assoc_ops && cti_assoc_ops->add)1219			cti_assoc_ops->add(csdev);1220		return csdev;1221	}1222 1223	/* Unregister the device if needed */1224	if (registered) {1225		coresight_unregister(csdev);1226		return ERR_PTR(ret);1227	}1228 1229err_out:1230	/* Cleanup the connection information */1231	coresight_release_platform_data(NULL, desc->dev, desc->pdata);1232	return ERR_PTR(ret);1233}1234EXPORT_SYMBOL_GPL(coresight_register);1235 1236void coresight_unregister(struct coresight_device *csdev)1237{1238	etm_perf_del_symlink_sink(csdev);1239	/* Remove references of that device in the topology */1240	if (cti_assoc_ops && cti_assoc_ops->remove)1241		cti_assoc_ops->remove(csdev);1242	coresight_remove_conns(csdev);1243	coresight_clear_default_sink(csdev);1244	coresight_release_platform_data(csdev, csdev->dev.parent, csdev->pdata);1245	device_unregister(&csdev->dev);1246}1247EXPORT_SYMBOL_GPL(coresight_unregister);1248 1249 1250/*1251 * coresight_search_device_idx - Search the fwnode handle of a device1252 * in the given dev_idx list. Must be called with the coresight_mutex held.1253 *1254 * Returns the index of the entry, when found. Otherwise, -ENOENT.1255 */1256static inline int coresight_search_device_idx(struct coresight_dev_list *dict,1257					      struct fwnode_handle *fwnode)1258{1259	int i;1260 1261	for (i = 0; i < dict->nr_idx; i++)1262		if (dict->fwnode_list[i] == fwnode)1263			return i;1264	return -ENOENT;1265}1266 1267static bool coresight_compare_type(enum coresight_dev_type type_a,1268				   union coresight_dev_subtype subtype_a,1269				   enum coresight_dev_type type_b,1270				   union coresight_dev_subtype subtype_b)1271{1272	if (type_a != type_b)1273		return false;1274 1275	switch (type_a) {1276	case CORESIGHT_DEV_TYPE_SINK:1277		return subtype_a.sink_subtype == subtype_b.sink_subtype;1278	case CORESIGHT_DEV_TYPE_LINK:1279		return subtype_a.link_subtype == subtype_b.link_subtype;1280	case CORESIGHT_DEV_TYPE_LINKSINK:1281		return subtype_a.link_subtype == subtype_b.link_subtype &&1282		       subtype_a.sink_subtype == subtype_b.sink_subtype;1283	case CORESIGHT_DEV_TYPE_SOURCE:1284		return subtype_a.source_subtype == subtype_b.source_subtype;1285	case CORESIGHT_DEV_TYPE_HELPER:1286		return subtype_a.helper_subtype == subtype_b.helper_subtype;1287	default:1288		return false;1289	}1290}1291 1292struct coresight_device *1293coresight_find_input_type(struct coresight_platform_data *pdata,1294			  enum coresight_dev_type type,1295			  union coresight_dev_subtype subtype)1296{1297	int i;1298	struct coresight_connection *conn;1299 1300	for (i = 0; i < pdata->nr_inconns; ++i) {1301		conn = pdata->in_conns[i];1302		if (conn &&1303		    coresight_compare_type(type, subtype, conn->src_dev->type,1304					   conn->src_dev->subtype))1305			return conn->src_dev;1306	}1307	return NULL;1308}1309EXPORT_SYMBOL_GPL(coresight_find_input_type);1310 1311struct coresight_device *1312coresight_find_output_type(struct coresight_platform_data *pdata,1313			   enum coresight_dev_type type,1314			   union coresight_dev_subtype subtype)1315{1316	int i;1317	struct coresight_connection *conn;1318 1319	for (i = 0; i < pdata->nr_outconns; ++i) {1320		conn = pdata->out_conns[i];1321		if (conn->dest_dev &&1322		    coresight_compare_type(type, subtype, conn->dest_dev->type,1323					   conn->dest_dev->subtype))1324			return conn->dest_dev;1325	}1326	return NULL;1327}1328EXPORT_SYMBOL_GPL(coresight_find_output_type);1329 1330bool coresight_loses_context_with_cpu(struct device *dev)1331{1332	return fwnode_property_present(dev_fwnode(dev),1333				       "arm,coresight-loses-context-with-cpu");1334}1335EXPORT_SYMBOL_GPL(coresight_loses_context_with_cpu);1336 1337/*1338 * coresight_alloc_device_name - Get an index for a given device in the1339 * device index list specific to a driver. An index is allocated for a1340 * device and is tracked with the fwnode_handle to prevent allocating1341 * duplicate indices for the same device (e.g, if we defer probing of1342 * a device due to dependencies), in case the index is requested again.1343 */1344char *coresight_alloc_device_name(struct coresight_dev_list *dict,1345				  struct device *dev)1346{1347	int idx;1348	char *name = NULL;1349	struct fwnode_handle **list;1350 1351	mutex_lock(&coresight_mutex);1352 1353	idx = coresight_search_device_idx(dict, dev_fwnode(dev));1354	if (idx < 0) {1355		/* Make space for the new entry */1356		idx = dict->nr_idx;1357		list = krealloc_array(dict->fwnode_list,1358				      idx + 1, sizeof(*dict->fwnode_list),1359				      GFP_KERNEL);1360		if (ZERO_OR_NULL_PTR(list)) {1361			idx = -ENOMEM;1362			goto done;1363		}1364 1365		list[idx] = dev_fwnode(dev);1366		dict->fwnode_list = list;1367		dict->nr_idx = idx + 1;1368	}1369 1370	name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);1371done:1372	mutex_unlock(&coresight_mutex);1373	return name;1374}1375EXPORT_SYMBOL_GPL(coresight_alloc_device_name);1376 1377const struct bus_type coresight_bustype = {1378	.name	= "coresight",1379};1380 1381static int __init coresight_init(void)1382{1383	int ret;1384 1385	ret = bus_register(&coresight_bustype);1386	if (ret)1387		return ret;1388 1389	ret = etm_perf_init();1390	if (ret)1391		goto exit_bus_unregister;1392 1393	/* initialise the coresight syscfg API */1394	ret = cscfg_init();1395	if (!ret)1396		return 0;1397 1398	etm_perf_exit();1399exit_bus_unregister:1400	bus_unregister(&coresight_bustype);1401	return ret;1402}1403 1404static void __exit coresight_exit(void)1405{1406	cscfg_exit();1407	etm_perf_exit();1408	bus_unregister(&coresight_bustype);1409}1410 1411module_init(coresight_init);1412module_exit(coresight_exit);1413 1414int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,1415			  struct platform_driver *pdev_drv)1416{1417	int ret;1418 1419	ret = amba_driver_register(amba_drv);1420	if (ret) {1421		pr_err("%s: error registering AMBA driver\n", drv);1422		return ret;1423	}1424 1425	ret = platform_driver_register(pdev_drv);1426	if (!ret)1427		return 0;1428 1429	pr_err("%s: error registering platform driver\n", drv);1430	amba_driver_unregister(amba_drv);1431	return ret;1432}1433EXPORT_SYMBOL_GPL(coresight_init_driver);1434 1435void coresight_remove_driver(struct amba_driver *amba_drv,1436			     struct platform_driver *pdev_drv)1437{1438	amba_driver_unregister(amba_drv);1439	platform_driver_unregister(pdev_drv);1440}1441EXPORT_SYMBOL_GPL(coresight_remove_driver);1442 1443MODULE_LICENSE("GPL v2");1444MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");1445MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");1446MODULE_DESCRIPTION("Arm CoreSight tracer driver");1447