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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright(C) 2015 Linaro Limited. All rights reserved.4 * Author: Mathieu Poirier <mathieu.poirier@linaro.org>5 */6 7#include <linux/bitfield.h>8#include <linux/coresight.h>9#include <linux/coresight-pmu.h>10#include <linux/cpumask.h>11#include <linux/device.h>12#include <linux/list.h>13#include <linux/mm.h>14#include <linux/init.h>15#include <linux/perf_event.h>16#include <linux/percpu-defs.h>17#include <linux/slab.h>18#include <linux/stringhash.h>19#include <linux/types.h>20#include <linux/workqueue.h>21 22#include "coresight-config.h"23#include "coresight-etm-perf.h"24#include "coresight-priv.h"25#include "coresight-syscfg.h"26#include "coresight-trace-id.h"27 28static struct pmu etm_pmu;29static bool etm_perf_up;30 31/*32 * An ETM context for a running event includes the perf aux handle33 * and aux_data. For ETM, the aux_data (etm_event_data), consists of34 * the trace path and the sink configuration. The event data is accessible35 * via perf_get_aux(handle). However, a sink could "end" a perf output36 * handle via the IRQ handler. And if the "sink" encounters a failure37 * to "begin" another session (e.g due to lack of space in the buffer),38 * the handle will be cleared. Thus, the event_data may not be accessible39 * from the handle when we get to the etm_event_stop(), which is required40 * for stopping the trace path. The event_data is guaranteed to stay alive41 * until "free_aux()", which cannot happen as long as the event is active on42 * the ETM. Thus the event_data for the session must be part of the ETM context43 * to make sure we can disable the trace path.44 */45struct etm_ctxt {46	struct perf_output_handle handle;47	struct etm_event_data *event_data;48};49 50static DEFINE_PER_CPU(struct etm_ctxt, etm_ctxt);51static DEFINE_PER_CPU(struct coresight_device *, csdev_src);52 53/*54 * The PMU formats were orignally for ETMv3.5/PTM's ETMCR 'config';55 * now take them as general formats and apply on all ETMs.56 */57PMU_FORMAT_ATTR(branch_broadcast, "config:"__stringify(ETM_OPT_BRANCH_BROADCAST));58PMU_FORMAT_ATTR(cycacc,		"config:" __stringify(ETM_OPT_CYCACC));59/* contextid1 enables tracing CONTEXTIDR_EL1 for ETMv4 */60PMU_FORMAT_ATTR(contextid1,	"config:" __stringify(ETM_OPT_CTXTID));61/* contextid2 enables tracing CONTEXTIDR_EL2 for ETMv4 */62PMU_FORMAT_ATTR(contextid2,	"config:" __stringify(ETM_OPT_CTXTID2));63PMU_FORMAT_ATTR(timestamp,	"config:" __stringify(ETM_OPT_TS));64PMU_FORMAT_ATTR(retstack,	"config:" __stringify(ETM_OPT_RETSTK));65/* preset - if sink ID is used as a configuration selector */66PMU_FORMAT_ATTR(preset,		"config:0-3");67/* Sink ID - same for all ETMs */68PMU_FORMAT_ATTR(sinkid,		"config2:0-31");69/* config ID - set if a system configuration is selected */70PMU_FORMAT_ATTR(configid,	"config2:32-63");71PMU_FORMAT_ATTR(cc_threshold,	"config3:0-11");72 73 74/*75 * contextid always traces the "PID".  The PID is in CONTEXTIDR_EL176 * when the kernel is running at EL1; when the kernel is at EL2,77 * the PID is in CONTEXTIDR_EL2.78 */79static ssize_t format_attr_contextid_show(struct device *dev,80					  struct device_attribute *attr,81					  char *page)82{83	int pid_fmt = ETM_OPT_CTXTID;84 85#if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X)86	pid_fmt = is_kernel_in_hyp_mode() ? ETM_OPT_CTXTID2 : ETM_OPT_CTXTID;87#endif88	return sprintf(page, "config:%d\n", pid_fmt);89}90 91static struct device_attribute format_attr_contextid =92	__ATTR(contextid, 0444, format_attr_contextid_show, NULL);93 94static struct attribute *etm_config_formats_attr[] = {95	&format_attr_cycacc.attr,96	&format_attr_contextid.attr,97	&format_attr_contextid1.attr,98	&format_attr_contextid2.attr,99	&format_attr_timestamp.attr,100	&format_attr_retstack.attr,101	&format_attr_sinkid.attr,102	&format_attr_preset.attr,103	&format_attr_configid.attr,104	&format_attr_branch_broadcast.attr,105	&format_attr_cc_threshold.attr,106	NULL,107};108 109static const struct attribute_group etm_pmu_format_group = {110	.name   = "format",111	.attrs  = etm_config_formats_attr,112};113 114static struct attribute *etm_config_sinks_attr[] = {115	NULL,116};117 118static const struct attribute_group etm_pmu_sinks_group = {119	.name   = "sinks",120	.attrs  = etm_config_sinks_attr,121};122 123static struct attribute *etm_config_events_attr[] = {124	NULL,125};126 127static const struct attribute_group etm_pmu_events_group = {128	.name   = "events",129	.attrs  = etm_config_events_attr,130};131 132static const struct attribute_group *etm_pmu_attr_groups[] = {133	&etm_pmu_format_group,134	&etm_pmu_sinks_group,135	&etm_pmu_events_group,136	NULL,137};138 139static inline struct list_head **140etm_event_cpu_path_ptr(struct etm_event_data *data, int cpu)141{142	return per_cpu_ptr(data->path, cpu);143}144 145static inline struct list_head *146etm_event_cpu_path(struct etm_event_data *data, int cpu)147{148	return *etm_event_cpu_path_ptr(data, cpu);149}150 151static void etm_event_read(struct perf_event *event) {}152 153static int etm_addr_filters_alloc(struct perf_event *event)154{155	struct etm_filters *filters;156	int node = event->cpu == -1 ? -1 : cpu_to_node(event->cpu);157 158	filters = kzalloc_node(sizeof(struct etm_filters), GFP_KERNEL, node);159	if (!filters)160		return -ENOMEM;161 162	if (event->parent)163		memcpy(filters, event->parent->hw.addr_filters,164		       sizeof(*filters));165 166	event->hw.addr_filters = filters;167 168	return 0;169}170 171static void etm_event_destroy(struct perf_event *event)172{173	kfree(event->hw.addr_filters);174	event->hw.addr_filters = NULL;175}176 177static int etm_event_init(struct perf_event *event)178{179	int ret = 0;180 181	if (event->attr.type != etm_pmu.type) {182		ret = -ENOENT;183		goto out;184	}185 186	ret = etm_addr_filters_alloc(event);187	if (ret)188		goto out;189 190	event->destroy = etm_event_destroy;191out:192	return ret;193}194 195static void free_sink_buffer(struct etm_event_data *event_data)196{197	int cpu;198	cpumask_t *mask = &event_data->mask;199	struct coresight_device *sink;200 201	if (!event_data->snk_config)202		return;203 204	if (WARN_ON(cpumask_empty(mask)))205		return;206 207	cpu = cpumask_first(mask);208	sink = coresight_get_sink(etm_event_cpu_path(event_data, cpu));209	sink_ops(sink)->free_buffer(event_data->snk_config);210}211 212static void free_event_data(struct work_struct *work)213{214	int cpu;215	cpumask_t *mask;216	struct etm_event_data *event_data;217 218	event_data = container_of(work, struct etm_event_data, work);219	mask = &event_data->mask;220 221	/* Free the sink buffers, if there are any */222	free_sink_buffer(event_data);223 224	/* clear any configuration we were using */225	if (event_data->cfg_hash)226		cscfg_deactivate_config(event_data->cfg_hash);227 228	for_each_cpu(cpu, mask) {229		struct list_head **ppath;230 231		ppath = etm_event_cpu_path_ptr(event_data, cpu);232		if (!(IS_ERR_OR_NULL(*ppath))) {233			struct coresight_device *sink = coresight_get_sink(*ppath);234 235			/*236			 * Mark perf event as done for trace id allocator, but don't call237			 * coresight_trace_id_put_cpu_id_map() on individual IDs. Perf sessions238			 * never free trace IDs to ensure that the ID associated with a CPU239			 * cannot change during their and other's concurrent sessions. Instead,240			 * a refcount is used so that the last event to call241			 * coresight_trace_id_perf_stop() frees all IDs.242			 */243			coresight_trace_id_perf_stop(&sink->perf_sink_id_map);244 245			coresight_release_path(*ppath);246		}247		*ppath = NULL;248	}249 250	free_percpu(event_data->path);251	kfree(event_data);252}253 254static void *alloc_event_data(int cpu)255{256	cpumask_t *mask;257	struct etm_event_data *event_data;258 259	/* First get memory for the session's data */260	event_data = kzalloc(sizeof(struct etm_event_data), GFP_KERNEL);261	if (!event_data)262		return NULL;263 264 265	mask = &event_data->mask;266	if (cpu != -1)267		cpumask_set_cpu(cpu, mask);268	else269		cpumask_copy(mask, cpu_present_mask);270 271	/*272	 * Each CPU has a single path between source and destination.  As such273	 * allocate an array using CPU numbers as indexes.  That way a path274	 * for any CPU can easily be accessed at any given time.  We proceed275	 * the same way for sessions involving a single CPU.  The cost of276	 * unused memory when dealing with single CPU trace scenarios is small277	 * compared to the cost of searching through an optimized array.278	 */279	event_data->path = alloc_percpu(struct list_head *);280 281	if (!event_data->path) {282		kfree(event_data);283		return NULL;284	}285 286	return event_data;287}288 289static void etm_free_aux(void *data)290{291	struct etm_event_data *event_data = data;292 293	schedule_work(&event_data->work);294}295 296/*297 * Check if two given sinks are compatible with each other,298 * so that they can use the same sink buffers, when an event299 * moves around.300 */301static bool sinks_compatible(struct coresight_device *a,302			     struct coresight_device *b)303{304	if (!a || !b)305		return false;306	/*307	 * If the sinks are of the same subtype and driven308	 * by the same driver, we can use the same buffer309	 * on these sinks.310	 */311	return (a->subtype.sink_subtype == b->subtype.sink_subtype) &&312	       (sink_ops(a) == sink_ops(b));313}314 315static void *etm_setup_aux(struct perf_event *event, void **pages,316			   int nr_pages, bool overwrite)317{318	u32 id, cfg_hash;319	int cpu = event->cpu;320	int trace_id;321	cpumask_t *mask;322	struct coresight_device *sink = NULL;323	struct coresight_device *user_sink = NULL, *last_sink = NULL;324	struct etm_event_data *event_data = NULL;325 326	event_data = alloc_event_data(cpu);327	if (!event_data)328		return NULL;329	INIT_WORK(&event_data->work, free_event_data);330 331	/* First get the selected sink from user space. */332	if (event->attr.config2 & GENMASK_ULL(31, 0)) {333		id = (u32)event->attr.config2;334		sink = user_sink = coresight_get_sink_by_id(id);335	}336 337	/* check if user wants a coresight configuration selected */338	cfg_hash = (u32)((event->attr.config2 & GENMASK_ULL(63, 32)) >> 32);339	if (cfg_hash) {340		if (cscfg_activate_config(cfg_hash))341			goto err;342		event_data->cfg_hash = cfg_hash;343	}344 345	mask = &event_data->mask;346 347	/*348	 * Setup the path for each CPU in a trace session. We try to build349	 * trace path for each CPU in the mask. If we don't find an ETM350	 * for the CPU or fail to build a path, we clear the CPU from the351	 * mask and continue with the rest. If ever we try to trace on those352	 * CPUs, we can handle it and fail the session.353	 */354	for_each_cpu(cpu, mask) {355		struct list_head *path;356		struct coresight_device *csdev;357 358		csdev = per_cpu(csdev_src, cpu);359		/*360		 * If there is no ETM associated with this CPU clear it from361		 * the mask and continue with the rest. If ever we try to trace362		 * on this CPU, we handle it accordingly.363		 */364		if (!csdev) {365			cpumask_clear_cpu(cpu, mask);366			continue;367		}368 369		/*370		 * No sink provided - look for a default sink for all the ETMs,371		 * where this event can be scheduled.372		 * We allocate the sink specific buffers only once for this373		 * event. If the ETMs have different default sink devices, we374		 * can only use a single "type" of sink as the event can carry375		 * only one sink specific buffer. Thus we have to make sure376		 * that the sinks are of the same type and driven by the same377		 * driver, as the one we allocate the buffer for. As such378		 * we choose the first sink and check if the remaining ETMs379		 * have a compatible default sink. We don't trace on a CPU380		 * if the sink is not compatible.381		 */382		if (!user_sink) {383			/* Find the default sink for this ETM */384			sink = coresight_find_default_sink(csdev);385			if (!sink) {386				cpumask_clear_cpu(cpu, mask);387				continue;388			}389 390			/* Check if this sink compatible with the last sink */391			if (last_sink && !sinks_compatible(last_sink, sink)) {392				cpumask_clear_cpu(cpu, mask);393				continue;394			}395			last_sink = sink;396		}397 398		/*399		 * Building a path doesn't enable it, it simply builds a400		 * list of devices from source to sink that can be401		 * referenced later when the path is actually needed.402		 */403		path = coresight_build_path(csdev, sink);404		if (IS_ERR(path)) {405			cpumask_clear_cpu(cpu, mask);406			continue;407		}408 409		/* ensure we can allocate a trace ID for this CPU */410		trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink->perf_sink_id_map);411		if (!IS_VALID_CS_TRACE_ID(trace_id)) {412			cpumask_clear_cpu(cpu, mask);413			coresight_release_path(path);414			continue;415		}416 417		coresight_trace_id_perf_start(&sink->perf_sink_id_map);418		*etm_event_cpu_path_ptr(event_data, cpu) = path;419	}420 421	/* no sink found for any CPU - cannot trace */422	if (!sink)423		goto err;424 425	/* If we don't have any CPUs ready for tracing, abort */426	cpu = cpumask_first(mask);427	if (cpu >= nr_cpu_ids)428		goto err;429 430	if (!sink_ops(sink)->alloc_buffer || !sink_ops(sink)->free_buffer)431		goto err;432 433	/*434	 * Allocate the sink buffer for this session. All the sinks435	 * where this event can be scheduled are ensured to be of the436	 * same type. Thus the same sink configuration is used by the437	 * sinks.438	 */439	event_data->snk_config =440			sink_ops(sink)->alloc_buffer(sink, event, pages,441						     nr_pages, overwrite);442	if (!event_data->snk_config)443		goto err;444 445out:446	return event_data;447 448err:449	etm_free_aux(event_data);450	event_data = NULL;451	goto out;452}453 454static void etm_event_start(struct perf_event *event, int flags)455{456	int cpu = smp_processor_id();457	struct etm_event_data *event_data;458	struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt);459	struct perf_output_handle *handle = &ctxt->handle;460	struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);461	struct list_head *path;462	u64 hw_id;463	u8 trace_id;464 465	if (!csdev)466		goto fail;467 468	/* Have we messed up our tracking ? */469	if (WARN_ON(ctxt->event_data))470		goto fail;471 472	/*473	 * Deal with the ring buffer API and get a handle on the474	 * session's information.475	 */476	event_data = perf_aux_output_begin(handle, event);477	if (!event_data)478		goto fail;479 480	/*481	 * Check if this ETM is allowed to trace, as decided482	 * at etm_setup_aux(). This could be due to an unreachable483	 * sink from this ETM. We can't do much in this case if484	 * the sink was specified or hinted to the driver. For485	 * now, simply don't record anything on this ETM.486	 *487	 * As such we pretend that everything is fine, and let488	 * it continue without actually tracing. The event could489	 * continue tracing when it moves to a CPU where it is490	 * reachable to a sink.491	 */492	if (!cpumask_test_cpu(cpu, &event_data->mask))493		goto out;494 495	path = etm_event_cpu_path(event_data, cpu);496	/* We need a sink, no need to continue without one */497	sink = coresight_get_sink(path);498	if (WARN_ON_ONCE(!sink))499		goto fail_end_stop;500 501	/* Nothing will happen without a path */502	if (coresight_enable_path(path, CS_MODE_PERF, handle))503		goto fail_end_stop;504 505	/* Finally enable the tracer */506	if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF,507				      &sink->perf_sink_id_map))508		goto fail_disable_path;509 510	/*511	 * output cpu / trace ID in perf record, once for the lifetime512	 * of the event.513	 */514	if (!cpumask_test_cpu(cpu, &event_data->aux_hwid_done)) {515		cpumask_set_cpu(cpu, &event_data->aux_hwid_done);516 517		trace_id = coresight_trace_id_read_cpu_id_map(cpu, &sink->perf_sink_id_map);518 519		hw_id = FIELD_PREP(CS_AUX_HW_ID_MAJOR_VERSION_MASK,520				CS_AUX_HW_ID_MAJOR_VERSION);521		hw_id |= FIELD_PREP(CS_AUX_HW_ID_MINOR_VERSION_MASK,522				CS_AUX_HW_ID_MINOR_VERSION);523		hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK, trace_id);524		hw_id |= FIELD_PREP(CS_AUX_HW_ID_SINK_ID_MASK, coresight_get_sink_id(sink));525 526		perf_report_aux_output_id(event, hw_id);527	}528 529out:530	/* Tell the perf core the event is alive */531	event->hw.state = 0;532	/* Save the event_data for this ETM */533	ctxt->event_data = event_data;534	return;535 536fail_disable_path:537	coresight_disable_path(path);538fail_end_stop:539	/*540	 * Check if the handle is still associated with the event,541	 * to handle cases where if the sink failed to start the542	 * trace and TRUNCATED the handle already.543	 */544	if (READ_ONCE(handle->event)) {545		perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);546		perf_aux_output_end(handle, 0);547	}548fail:549	event->hw.state = PERF_HES_STOPPED;550	return;551}552 553static void etm_event_stop(struct perf_event *event, int mode)554{555	int cpu = smp_processor_id();556	unsigned long size;557	struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);558	struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt);559	struct perf_output_handle *handle = &ctxt->handle;560	struct etm_event_data *event_data;561	struct list_head *path;562 563	/*564	 * If we still have access to the event_data via handle,565	 * confirm that we haven't messed up the tracking.566	 */567	if (handle->event &&568	    WARN_ON(perf_get_aux(handle) != ctxt->event_data))569		return;570 571	event_data = ctxt->event_data;572	/* Clear the event_data as this ETM is stopping the trace. */573	ctxt->event_data = NULL;574 575	if (event->hw.state == PERF_HES_STOPPED)576		return;577 578	/* We must have a valid event_data for a running event */579	if (WARN_ON(!event_data))580		return;581 582	/*583	 * Check if this ETM was allowed to trace, as decided at584	 * etm_setup_aux(). If it wasn't allowed to trace, then585	 * nothing needs to be torn down other than outputting a586	 * zero sized record.587	 */588	if (handle->event && (mode & PERF_EF_UPDATE) &&589	    !cpumask_test_cpu(cpu, &event_data->mask)) {590		event->hw.state = PERF_HES_STOPPED;591		perf_aux_output_end(handle, 0);592		return;593	}594 595	if (!csdev)596		return;597 598	path = etm_event_cpu_path(event_data, cpu);599	if (!path)600		return;601 602	sink = coresight_get_sink(path);603	if (!sink)604		return;605 606	/* stop tracer */607	coresight_disable_source(csdev, event);608 609	/* tell the core */610	event->hw.state = PERF_HES_STOPPED;611 612	/*613	 * If the handle is not bound to an event anymore614	 * (e.g, the sink driver was unable to restart the615	 * handle due to lack of buffer space), we don't616	 * have to do anything here.617	 */618	if (handle->event && (mode & PERF_EF_UPDATE)) {619		if (WARN_ON_ONCE(handle->event != event))620			return;621 622		/* update trace information */623		if (!sink_ops(sink)->update_buffer)624			return;625 626		size = sink_ops(sink)->update_buffer(sink, handle,627					      event_data->snk_config);628		/*629		 * Make sure the handle is still valid as the630		 * sink could have closed it from an IRQ.631		 * The sink driver must handle the race with632		 * update_buffer() and IRQ. Thus either we633		 * should get a valid handle and valid size634		 * (which may be 0).635		 *636		 * But we should never get a non-zero size with637		 * an invalid handle.638		 */639		if (READ_ONCE(handle->event))640			perf_aux_output_end(handle, size);641		else642			WARN_ON(size);643	}644 645	/* Disabling the path make its elements available to other sessions */646	coresight_disable_path(path);647}648 649static int etm_event_add(struct perf_event *event, int mode)650{651	int ret = 0;652	struct hw_perf_event *hwc = &event->hw;653 654	if (mode & PERF_EF_START) {655		etm_event_start(event, 0);656		if (hwc->state & PERF_HES_STOPPED)657			ret = -EINVAL;658	} else {659		hwc->state = PERF_HES_STOPPED;660	}661 662	return ret;663}664 665static void etm_event_del(struct perf_event *event, int mode)666{667	etm_event_stop(event, PERF_EF_UPDATE);668}669 670static int etm_addr_filters_validate(struct list_head *filters)671{672	bool range = false, address = false;673	int index = 0;674	struct perf_addr_filter *filter;675 676	list_for_each_entry(filter, filters, entry) {677		/*678		 * No need to go further if there's no more679		 * room for filters.680		 */681		if (++index > ETM_ADDR_CMP_MAX)682			return -EOPNOTSUPP;683 684		/* filter::size==0 means single address trigger */685		if (filter->size) {686			/*687			 * The existing code relies on START/STOP filters688			 * being address filters.689			 */690			if (filter->action == PERF_ADDR_FILTER_ACTION_START ||691			    filter->action == PERF_ADDR_FILTER_ACTION_STOP)692				return -EOPNOTSUPP;693 694			range = true;695		} else696			address = true;697 698		/*699		 * At this time we don't allow range and start/stop filtering700		 * to cohabitate, they have to be mutually exclusive.701		 */702		if (range && address)703			return -EOPNOTSUPP;704	}705 706	return 0;707}708 709static void etm_addr_filters_sync(struct perf_event *event)710{711	struct perf_addr_filters_head *head = perf_event_addr_filters(event);712	unsigned long start, stop;713	struct perf_addr_filter_range *fr = event->addr_filter_ranges;714	struct etm_filters *filters = event->hw.addr_filters;715	struct etm_filter *etm_filter;716	struct perf_addr_filter *filter;717	int i = 0;718 719	list_for_each_entry(filter, &head->list, entry) {720		start = fr[i].start;721		stop = start + fr[i].size;722		etm_filter = &filters->etm_filter[i];723 724		switch (filter->action) {725		case PERF_ADDR_FILTER_ACTION_FILTER:726			etm_filter->start_addr = start;727			etm_filter->stop_addr = stop;728			etm_filter->type = ETM_ADDR_TYPE_RANGE;729			break;730		case PERF_ADDR_FILTER_ACTION_START:731			etm_filter->start_addr = start;732			etm_filter->type = ETM_ADDR_TYPE_START;733			break;734		case PERF_ADDR_FILTER_ACTION_STOP:735			etm_filter->stop_addr = stop;736			etm_filter->type = ETM_ADDR_TYPE_STOP;737			break;738		}739		i++;740	}741 742	filters->nr_filters = i;743}744 745int etm_perf_symlink(struct coresight_device *csdev, bool link)746{747	char entry[sizeof("cpu9999999")];748	int ret = 0, cpu = source_ops(csdev)->cpu_id(csdev);749	struct device *pmu_dev = etm_pmu.dev;750	struct device *cs_dev = &csdev->dev;751 752	sprintf(entry, "cpu%d", cpu);753 754	if (!etm_perf_up)755		return -EPROBE_DEFER;756 757	if (link) {758		ret = sysfs_create_link(&pmu_dev->kobj, &cs_dev->kobj, entry);759		if (ret)760			return ret;761		per_cpu(csdev_src, cpu) = csdev;762	} else {763		sysfs_remove_link(&pmu_dev->kobj, entry);764		per_cpu(csdev_src, cpu) = NULL;765	}766 767	return 0;768}769EXPORT_SYMBOL_GPL(etm_perf_symlink);770 771static ssize_t etm_perf_sink_name_show(struct device *dev,772				       struct device_attribute *dattr,773				       char *buf)774{775	struct dev_ext_attribute *ea;776 777	ea = container_of(dattr, struct dev_ext_attribute, attr);778	return scnprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)(ea->var));779}780 781static struct dev_ext_attribute *782etm_perf_add_symlink_group(struct device *dev, const char *name, const char *group_name)783{784	struct dev_ext_attribute *ea;785	unsigned long hash;786	int ret;787	struct device *pmu_dev = etm_pmu.dev;788 789	if (!etm_perf_up)790		return ERR_PTR(-EPROBE_DEFER);791 792	ea = devm_kzalloc(dev, sizeof(*ea), GFP_KERNEL);793	if (!ea)794		return ERR_PTR(-ENOMEM);795 796	/*797	 * If this function is called adding a sink then the hash is used for798	 * sink selection - see function coresight_get_sink_by_id().799	 * If adding a configuration then the hash is used for selection in800	 * cscfg_activate_config()801	 */802	hash = hashlen_hash(hashlen_string(NULL, name));803 804	sysfs_attr_init(&ea->attr.attr);805	ea->attr.attr.name = devm_kstrdup(dev, name, GFP_KERNEL);806	if (!ea->attr.attr.name)807		return ERR_PTR(-ENOMEM);808 809	ea->attr.attr.mode = 0444;810	ea->var = (unsigned long *)hash;811 812	ret = sysfs_add_file_to_group(&pmu_dev->kobj,813				      &ea->attr.attr, group_name);814 815	return ret ? ERR_PTR(ret) : ea;816}817 818int etm_perf_add_symlink_sink(struct coresight_device *csdev)819{820	const char *name;821	struct device *dev = &csdev->dev;822	int err = 0;823 824	if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&825	    csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)826		return -EINVAL;827 828	if (csdev->ea != NULL)829		return -EINVAL;830 831	name = dev_name(dev);832	csdev->ea = etm_perf_add_symlink_group(dev, name, "sinks");833	if (IS_ERR(csdev->ea)) {834		err = PTR_ERR(csdev->ea);835		csdev->ea = NULL;836	} else837		csdev->ea->attr.show = etm_perf_sink_name_show;838 839	return err;840}841 842static void etm_perf_del_symlink_group(struct dev_ext_attribute *ea, const char *group_name)843{844	struct device *pmu_dev = etm_pmu.dev;845 846	sysfs_remove_file_from_group(&pmu_dev->kobj,847				     &ea->attr.attr, group_name);848}849 850void etm_perf_del_symlink_sink(struct coresight_device *csdev)851{852	if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&853	    csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)854		return;855 856	if (!csdev->ea)857		return;858 859	etm_perf_del_symlink_group(csdev->ea, "sinks");860	csdev->ea = NULL;861}862 863static ssize_t etm_perf_cscfg_event_show(struct device *dev,864					 struct device_attribute *dattr,865					 char *buf)866{867	struct dev_ext_attribute *ea;868 869	ea = container_of(dattr, struct dev_ext_attribute, attr);870	return scnprintf(buf, PAGE_SIZE, "configid=0x%lx\n", (unsigned long)(ea->var));871}872 873int etm_perf_add_symlink_cscfg(struct device *dev, struct cscfg_config_desc *config_desc)874{875	int err = 0;876 877	if (config_desc->event_ea != NULL)878		return 0;879 880	config_desc->event_ea = etm_perf_add_symlink_group(dev, config_desc->name, "events");881 882	/* set the show function to the custom cscfg event */883	if (!IS_ERR(config_desc->event_ea))884		config_desc->event_ea->attr.show = etm_perf_cscfg_event_show;885	else {886		err = PTR_ERR(config_desc->event_ea);887		config_desc->event_ea = NULL;888	}889 890	return err;891}892 893void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *config_desc)894{895	if (!config_desc->event_ea)896		return;897 898	etm_perf_del_symlink_group(config_desc->event_ea, "events");899	config_desc->event_ea = NULL;900}901 902int __init etm_perf_init(void)903{904	int ret;905 906	etm_pmu.capabilities		= (PERF_PMU_CAP_EXCLUSIVE |907					   PERF_PMU_CAP_ITRACE);908 909	etm_pmu.attr_groups		= etm_pmu_attr_groups;910	etm_pmu.task_ctx_nr		= perf_sw_context;911	etm_pmu.read			= etm_event_read;912	etm_pmu.event_init		= etm_event_init;913	etm_pmu.setup_aux		= etm_setup_aux;914	etm_pmu.free_aux		= etm_free_aux;915	etm_pmu.start			= etm_event_start;916	etm_pmu.stop			= etm_event_stop;917	etm_pmu.add			= etm_event_add;918	etm_pmu.del			= etm_event_del;919	etm_pmu.addr_filters_sync	= etm_addr_filters_sync;920	etm_pmu.addr_filters_validate	= etm_addr_filters_validate;921	etm_pmu.nr_addr_filters		= ETM_ADDR_CMP_MAX;922	etm_pmu.module			= THIS_MODULE;923 924	ret = perf_pmu_register(&etm_pmu, CORESIGHT_ETM_PMU_NAME, -1);925	if (ret == 0)926		etm_perf_up = true;927 928	return ret;929}930 931void etm_perf_exit(void)932{933	perf_pmu_unregister(&etm_pmu);934}935