// SPDX-License-Identifier: GPL-2.0 /* * Copyright(C) 2015 Linaro Limited. All rights reserved. * Author: Mathieu Poirier */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "coresight-config.h" #include "coresight-etm-perf.h" #include "coresight-priv.h" #include "coresight-syscfg.h" #include "coresight-trace-id.h" static struct pmu etm_pmu; static bool etm_perf_up; /* * An ETM context for a running event includes the perf aux handle * and aux_data. For ETM, the aux_data (etm_event_data), consists of * the trace path and the sink configuration. The event data is accessible * via perf_get_aux(handle). However, a sink could "end" a perf output * handle via the IRQ handler. And if the "sink" encounters a failure * to "begin" another session (e.g due to lack of space in the buffer), * the handle will be cleared. Thus, the event_data may not be accessible * from the handle when we get to the etm_event_stop(), which is required * for stopping the trace path. The event_data is guaranteed to stay alive * until "free_aux()", which cannot happen as long as the event is active on * the ETM. Thus the event_data for the session must be part of the ETM context * to make sure we can disable the trace path. */ struct etm_ctxt { struct perf_output_handle handle; struct etm_event_data *event_data; }; static DEFINE_PER_CPU(struct etm_ctxt, etm_ctxt); static DEFINE_PER_CPU(struct coresight_device *, csdev_src); /* * The PMU formats were orignally for ETMv3.5/PTM's ETMCR 'config'; * now take them as general formats and apply on all ETMs. */ PMU_FORMAT_ATTR(branch_broadcast, "config:"__stringify(ETM_OPT_BRANCH_BROADCAST)); PMU_FORMAT_ATTR(cycacc, "config:" __stringify(ETM_OPT_CYCACC)); /* contextid1 enables tracing CONTEXTIDR_EL1 for ETMv4 */ PMU_FORMAT_ATTR(contextid1, "config:" __stringify(ETM_OPT_CTXTID)); /* contextid2 enables tracing CONTEXTIDR_EL2 for ETMv4 */ PMU_FORMAT_ATTR(contextid2, "config:" __stringify(ETM_OPT_CTXTID2)); PMU_FORMAT_ATTR(timestamp, "config:" __stringify(ETM_OPT_TS)); PMU_FORMAT_ATTR(retstack, "config:" __stringify(ETM_OPT_RETSTK)); /* preset - if sink ID is used as a configuration selector */ PMU_FORMAT_ATTR(preset, "config:0-3"); /* Sink ID - same for all ETMs */ PMU_FORMAT_ATTR(sinkid, "config2:0-31"); /* config ID - set if a system configuration is selected */ PMU_FORMAT_ATTR(configid, "config2:32-63"); /* * contextid always traces the "PID". The PID is in CONTEXTIDR_EL1 * when the kernel is running at EL1; when the kernel is at EL2, * the PID is in CONTEXTIDR_EL2. */ static ssize_t format_attr_contextid_show(struct device *dev, struct device_attribute *attr, char *page) { int pid_fmt = ETM_OPT_CTXTID; #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) pid_fmt = is_kernel_in_hyp_mode() ? ETM_OPT_CTXTID2 : ETM_OPT_CTXTID; #endif return sprintf(page, "config:%d\n", pid_fmt); } static struct device_attribute format_attr_contextid = __ATTR(contextid, 0444, format_attr_contextid_show, NULL); static struct attribute *etm_config_formats_attr[] = { &format_attr_cycacc.attr, &format_attr_contextid.attr, &format_attr_contextid1.attr, &format_attr_contextid2.attr, &format_attr_timestamp.attr, &format_attr_retstack.attr, &format_attr_sinkid.attr, &format_attr_preset.attr, &format_attr_configid.attr, &format_attr_branch_broadcast.attr, NULL, }; static const struct attribute_group etm_pmu_format_group = { .name = "format", .attrs = etm_config_formats_attr, }; static struct attribute *etm_config_sinks_attr[] = { NULL, }; static const struct attribute_group etm_pmu_sinks_group = { .name = "sinks", .attrs = etm_config_sinks_attr, }; static struct attribute *etm_config_events_attr[] = { NULL, }; static const struct attribute_group etm_pmu_events_group = { .name = "events", .attrs = etm_config_events_attr, }; static const struct attribute_group *etm_pmu_attr_groups[] = { &etm_pmu_format_group, &etm_pmu_sinks_group, &etm_pmu_events_group, NULL, }; static inline struct list_head ** etm_event_cpu_path_ptr(struct etm_event_data *data, int cpu) { return per_cpu_ptr(data->path, cpu); } static inline struct list_head * etm_event_cpu_path(struct etm_event_data *data, int cpu) { return *etm_event_cpu_path_ptr(data, cpu); } static void etm_event_read(struct perf_event *event) {} static int etm_addr_filters_alloc(struct perf_event *event) { struct etm_filters *filters; int node = event->cpu == -1 ? -1 : cpu_to_node(event->cpu); filters = kzalloc_node(sizeof(struct etm_filters), GFP_KERNEL, node); if (!filters) return -ENOMEM; if (event->parent) memcpy(filters, event->parent->hw.addr_filters, sizeof(*filters)); event->hw.addr_filters = filters; return 0; } static void etm_event_destroy(struct perf_event *event) { kfree(event->hw.addr_filters); event->hw.addr_filters = NULL; } static int etm_event_init(struct perf_event *event) { int ret = 0; if (event->attr.type != etm_pmu.type) { ret = -ENOENT; goto out; } ret = etm_addr_filters_alloc(event); if (ret) goto out; event->destroy = etm_event_destroy; out: return ret; } static void free_sink_buffer(struct etm_event_data *event_data) { int cpu; cpumask_t *mask = &event_data->mask; struct coresight_device *sink; if (!event_data->snk_config) return; if (WARN_ON(cpumask_empty(mask))) return; cpu = cpumask_first(mask); sink = coresight_get_sink(etm_event_cpu_path(event_data, cpu)); sink_ops(sink)->free_buffer(event_data->snk_config); } static void free_event_data(struct work_struct *work) { int cpu; cpumask_t *mask; struct etm_event_data *event_data; event_data = container_of(work, struct etm_event_data, work); mask = &event_data->mask; /* Free the sink buffers, if there are any */ free_sink_buffer(event_data); /* clear any configuration we were using */ if (event_data->cfg_hash) cscfg_deactivate_config(event_data->cfg_hash); for_each_cpu(cpu, mask) { struct list_head **ppath; ppath = etm_event_cpu_path_ptr(event_data, cpu); if (!(IS_ERR_OR_NULL(*ppath))) coresight_release_path(*ppath); *ppath = NULL; coresight_trace_id_put_cpu_id(cpu); } /* mark perf event as done for trace id allocator */ coresight_trace_id_perf_stop(); free_percpu(event_data->path); kfree(event_data); } static void *alloc_event_data(int cpu) { cpumask_t *mask; struct etm_event_data *event_data; /* First get memory for the session's data */ event_data = kzalloc(sizeof(struct etm_event_data), GFP_KERNEL); if (!event_data) return NULL; mask = &event_data->mask; if (cpu != -1) cpumask_set_cpu(cpu, mask); else cpumask_copy(mask, cpu_present_mask); /* * Each CPU has a single path between source and destination. As such * allocate an array using CPU numbers as indexes. That way a path * for any CPU can easily be accessed at any given time. We proceed * the same way for sessions involving a single CPU. The cost of * unused memory when dealing with single CPU trace scenarios is small * compared to the cost of searching through an optimized array. */ event_data->path = alloc_percpu(struct list_head *); if (!event_data->path) { kfree(event_data); return NULL; } return event_data; } static void etm_free_aux(void *data) { struct etm_event_data *event_data = data; schedule_work(&event_data->work); } /* * Check if two given sinks are compatible with each other, * so that they can use the same sink buffers, when an event * moves around. */ static bool sinks_compatible(struct coresight_device *a, struct coresight_device *b) { if (!a || !b) return false; /* * If the sinks are of the same subtype and driven * by the same driver, we can use the same buffer * on these sinks. */ return (a->subtype.sink_subtype == b->subtype.sink_subtype) && (sink_ops(a) == sink_ops(b)); } static void *etm_setup_aux(struct perf_event *event, void **pages, int nr_pages, bool overwrite) { u32 id, cfg_hash; int cpu = event->cpu; int trace_id; cpumask_t *mask; struct coresight_device *sink = NULL; struct coresight_device *user_sink = NULL, *last_sink = NULL; struct etm_event_data *event_data = NULL; event_data = alloc_event_data(cpu); if (!event_data) return NULL; INIT_WORK(&event_data->work, free_event_data); /* First get the selected sink from user space. */ if (event->attr.config2 & GENMASK_ULL(31, 0)) { id = (u32)event->attr.config2; sink = user_sink = coresight_get_sink_by_id(id); } /* tell the trace ID allocator that a perf event is starting up */ coresight_trace_id_perf_start(); /* check if user wants a coresight configuration selected */ cfg_hash = (u32)((event->attr.config2 & GENMASK_ULL(63, 32)) >> 32); if (cfg_hash) { if (cscfg_activate_config(cfg_hash)) goto err; event_data->cfg_hash = cfg_hash; } mask = &event_data->mask; /* * Setup the path for each CPU in a trace session. We try to build * trace path for each CPU in the mask. If we don't find an ETM * for the CPU or fail to build a path, we clear the CPU from the * mask and continue with the rest. If ever we try to trace on those * CPUs, we can handle it and fail the session. */ for_each_cpu(cpu, mask) { struct list_head *path; struct coresight_device *csdev; csdev = per_cpu(csdev_src, cpu); /* * If there is no ETM associated with this CPU clear it from * the mask and continue with the rest. If ever we try to trace * on this CPU, we handle it accordingly. */ if (!csdev) { cpumask_clear_cpu(cpu, mask); continue; } /* * No sink provided - look for a default sink for all the ETMs, * where this event can be scheduled. * We allocate the sink specific buffers only once for this * event. If the ETMs have different default sink devices, we * can only use a single "type" of sink as the event can carry * only one sink specific buffer. Thus we have to make sure * that the sinks are of the same type and driven by the same * driver, as the one we allocate the buffer for. As such * we choose the first sink and check if the remaining ETMs * have a compatible default sink. We don't trace on a CPU * if the sink is not compatible. */ if (!user_sink) { /* Find the default sink for this ETM */ sink = coresight_find_default_sink(csdev); if (!sink) { cpumask_clear_cpu(cpu, mask); continue; } /* Check if this sink compatible with the last sink */ if (last_sink && !sinks_compatible(last_sink, sink)) { cpumask_clear_cpu(cpu, mask); continue; } last_sink = sink; } /* * Building a path doesn't enable it, it simply builds a * list of devices from source to sink that can be * referenced later when the path is actually needed. */ path = coresight_build_path(csdev, sink); if (IS_ERR(path)) { cpumask_clear_cpu(cpu, mask); continue; } /* ensure we can allocate a trace ID for this CPU */ trace_id = coresight_trace_id_get_cpu_id(cpu); if (!IS_VALID_CS_TRACE_ID(trace_id)) { cpumask_clear_cpu(cpu, mask); continue; } *etm_event_cpu_path_ptr(event_data, cpu) = path; } /* no sink found for any CPU - cannot trace */ if (!sink) goto err; /* If we don't have any CPUs ready for tracing, abort */ cpu = cpumask_first(mask); if (cpu >= nr_cpu_ids) goto err; if (!sink_ops(sink)->alloc_buffer || !sink_ops(sink)->free_buffer) goto err; /* * Allocate the sink buffer for this session. All the sinks * where this event can be scheduled are ensured to be of the * same type. Thus the same sink configuration is used by the * sinks. */ event_data->snk_config = sink_ops(sink)->alloc_buffer(sink, event, pages, nr_pages, overwrite); if (!event_data->snk_config) goto err; out: return event_data; err: etm_free_aux(event_data); event_data = NULL; goto out; } static void etm_event_start(struct perf_event *event, int flags) { int cpu = smp_processor_id(); struct etm_event_data *event_data; struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt); struct perf_output_handle *handle = &ctxt->handle; struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu); struct list_head *path; u64 hw_id; if (!csdev) goto fail; /* Have we messed up our tracking ? */ if (WARN_ON(ctxt->event_data)) goto fail; /* * Deal with the ring buffer API and get a handle on the * session's information. */ event_data = perf_aux_output_begin(handle, event); if (!event_data) goto fail; /* * Check if this ETM is allowed to trace, as decided * at etm_setup_aux(). This could be due to an unreachable * sink from this ETM. We can't do much in this case if * the sink was specified or hinted to the driver. For * now, simply don't record anything on this ETM. * * As such we pretend that everything is fine, and let * it continue without actually tracing. The event could * continue tracing when it moves to a CPU where it is * reachable to a sink. */ if (!cpumask_test_cpu(cpu, &event_data->mask)) goto out; path = etm_event_cpu_path(event_data, cpu); /* We need a sink, no need to continue without one */ sink = coresight_get_sink(path); if (WARN_ON_ONCE(!sink)) goto fail_end_stop; /* Nothing will happen without a path */ if (coresight_enable_path(path, CS_MODE_PERF, handle)) goto fail_end_stop; /* Finally enable the tracer */ if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF)) goto fail_disable_path; /* output cpu / trace ID in perf record */ hw_id = FIELD_PREP(CS_AUX_HW_ID_VERSION_MASK, CS_AUX_HW_ID_CURR_VERSION); hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK, coresight_trace_id_read_cpu_id(cpu)); perf_report_aux_output_id(event, hw_id); out: /* Tell the perf core the event is alive */ event->hw.state = 0; /* Save the event_data for this ETM */ ctxt->event_data = event_data; return; fail_disable_path: coresight_disable_path(path); fail_end_stop: /* * Check if the handle is still associated with the event, * to handle cases where if the sink failed to start the * trace and TRUNCATED the handle already. */ if (READ_ONCE(handle->event)) { perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); perf_aux_output_end(handle, 0); } fail: event->hw.state = PERF_HES_STOPPED; return; } static void etm_event_stop(struct perf_event *event, int mode) { int cpu = smp_processor_id(); unsigned long size; struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu); struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt); struct perf_output_handle *handle = &ctxt->handle; struct etm_event_data *event_data; struct list_head *path; /* * If we still have access to the event_data via handle, * confirm that we haven't messed up the tracking. */ if (handle->event && WARN_ON(perf_get_aux(handle) != ctxt->event_data)) return; event_data = ctxt->event_data; /* Clear the event_data as this ETM is stopping the trace. */ ctxt->event_data = NULL; if (event->hw.state == PERF_HES_STOPPED) return; /* We must have a valid event_data for a running event */ if (WARN_ON(!event_data)) return; /* * Check if this ETM was allowed to trace, as decided at * etm_setup_aux(). If it wasn't allowed to trace, then * nothing needs to be torn down other than outputting a * zero sized record. */ if (handle->event && (mode & PERF_EF_UPDATE) && !cpumask_test_cpu(cpu, &event_data->mask)) { event->hw.state = PERF_HES_STOPPED; perf_aux_output_end(handle, 0); return; } if (!csdev) return; path = etm_event_cpu_path(event_data, cpu); if (!path) return; sink = coresight_get_sink(path); if (!sink) return; /* stop tracer */ source_ops(csdev)->disable(csdev, event); /* tell the core */ event->hw.state = PERF_HES_STOPPED; /* * If the handle is not bound to an event anymore * (e.g, the sink driver was unable to restart the * handle due to lack of buffer space), we don't * have to do anything here. */ if (handle->event && (mode & PERF_EF_UPDATE)) { if (WARN_ON_ONCE(handle->event != event)) return; /* update trace information */ if (!sink_ops(sink)->update_buffer) return; size = sink_ops(sink)->update_buffer(sink, handle, event_data->snk_config); /* * Make sure the handle is still valid as the * sink could have closed it from an IRQ. * The sink driver must handle the race with * update_buffer() and IRQ. Thus either we * should get a valid handle and valid size * (which may be 0). * * But we should never get a non-zero size with * an invalid handle. */ if (READ_ONCE(handle->event)) perf_aux_output_end(handle, size); else WARN_ON(size); } /* Disabling the path make its elements available to other sessions */ coresight_disable_path(path); } static int etm_event_add(struct perf_event *event, int mode) { int ret = 0; struct hw_perf_event *hwc = &event->hw; if (mode & PERF_EF_START) { etm_event_start(event, 0); if (hwc->state & PERF_HES_STOPPED) ret = -EINVAL; } else { hwc->state = PERF_HES_STOPPED; } return ret; } static void etm_event_del(struct perf_event *event, int mode) { etm_event_stop(event, PERF_EF_UPDATE); } static int etm_addr_filters_validate(struct list_head *filters) { bool range = false, address = false; int index = 0; struct perf_addr_filter *filter; list_for_each_entry(filter, filters, entry) { /* * No need to go further if there's no more * room for filters. */ if (++index > ETM_ADDR_CMP_MAX) return -EOPNOTSUPP; /* filter::size==0 means single address trigger */ if (filter->size) { /* * The existing code relies on START/STOP filters * being address filters. */ if (filter->action == PERF_ADDR_FILTER_ACTION_START || filter->action == PERF_ADDR_FILTER_ACTION_STOP) return -EOPNOTSUPP; range = true; } else address = true; /* * At this time we don't allow range and start/stop filtering * to cohabitate, they have to be mutually exclusive. */ if (range && address) return -EOPNOTSUPP; } return 0; } static void etm_addr_filters_sync(struct perf_event *event) { struct perf_addr_filters_head *head = perf_event_addr_filters(event); unsigned long start, stop; struct perf_addr_filter_range *fr = event->addr_filter_ranges; struct etm_filters *filters = event->hw.addr_filters; struct etm_filter *etm_filter; struct perf_addr_filter *filter; int i = 0; list_for_each_entry(filter, &head->list, entry) { start = fr[i].start; stop = start + fr[i].size; etm_filter = &filters->etm_filter[i]; switch (filter->action) { case PERF_ADDR_FILTER_ACTION_FILTER: etm_filter->start_addr = start; etm_filter->stop_addr = stop; etm_filter->type = ETM_ADDR_TYPE_RANGE; break; case PERF_ADDR_FILTER_ACTION_START: etm_filter->start_addr = start; etm_filter->type = ETM_ADDR_TYPE_START; break; case PERF_ADDR_FILTER_ACTION_STOP: etm_filter->stop_addr = stop; etm_filter->type = ETM_ADDR_TYPE_STOP; break; } i++; } filters->nr_filters = i; } int etm_perf_symlink(struct coresight_device *csdev, bool link) { char entry[sizeof("cpu9999999")]; int ret = 0, cpu = source_ops(csdev)->cpu_id(csdev); struct device *pmu_dev = etm_pmu.dev; struct device *cs_dev = &csdev->dev; sprintf(entry, "cpu%d", cpu); if (!etm_perf_up) return -EPROBE_DEFER; if (link) { ret = sysfs_create_link(&pmu_dev->kobj, &cs_dev->kobj, entry); if (ret) return ret; per_cpu(csdev_src, cpu) = csdev; } else { sysfs_remove_link(&pmu_dev->kobj, entry); per_cpu(csdev_src, cpu) = NULL; } return 0; } EXPORT_SYMBOL_GPL(etm_perf_symlink); static ssize_t etm_perf_sink_name_show(struct device *dev, struct device_attribute *dattr, char *buf) { struct dev_ext_attribute *ea; ea = container_of(dattr, struct dev_ext_attribute, attr); return scnprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)(ea->var)); } static struct dev_ext_attribute * etm_perf_add_symlink_group(struct device *dev, const char *name, const char *group_name) { struct dev_ext_attribute *ea; unsigned long hash; int ret; struct device *pmu_dev = etm_pmu.dev; if (!etm_perf_up) return ERR_PTR(-EPROBE_DEFER); ea = devm_kzalloc(dev, sizeof(*ea), GFP_KERNEL); if (!ea) return ERR_PTR(-ENOMEM); /* * If this function is called adding a sink then the hash is used for * sink selection - see function coresight_get_sink_by_id(). * If adding a configuration then the hash is used for selection in * cscfg_activate_config() */ hash = hashlen_hash(hashlen_string(NULL, name)); sysfs_attr_init(&ea->attr.attr); ea->attr.attr.name = devm_kstrdup(dev, name, GFP_KERNEL); if (!ea->attr.attr.name) return ERR_PTR(-ENOMEM); ea->attr.attr.mode = 0444; ea->var = (unsigned long *)hash; ret = sysfs_add_file_to_group(&pmu_dev->kobj, &ea->attr.attr, group_name); return ret ? ERR_PTR(ret) : ea; } int etm_perf_add_symlink_sink(struct coresight_device *csdev) { const char *name; struct device *dev = &csdev->dev; int err = 0; if (csdev->type != CORESIGHT_DEV_TYPE_SINK && csdev->type != CORESIGHT_DEV_TYPE_LINKSINK) return -EINVAL; if (csdev->ea != NULL) return -EINVAL; name = dev_name(dev); csdev->ea = etm_perf_add_symlink_group(dev, name, "sinks"); if (IS_ERR(csdev->ea)) { err = PTR_ERR(csdev->ea); csdev->ea = NULL; } else csdev->ea->attr.show = etm_perf_sink_name_show; return err; } static void etm_perf_del_symlink_group(struct dev_ext_attribute *ea, const char *group_name) { struct device *pmu_dev = etm_pmu.dev; sysfs_remove_file_from_group(&pmu_dev->kobj, &ea->attr.attr, group_name); } void etm_perf_del_symlink_sink(struct coresight_device *csdev) { if (csdev->type != CORESIGHT_DEV_TYPE_SINK && csdev->type != CORESIGHT_DEV_TYPE_LINKSINK) return; if (!csdev->ea) return; etm_perf_del_symlink_group(csdev->ea, "sinks"); csdev->ea = NULL; } static ssize_t etm_perf_cscfg_event_show(struct device *dev, struct device_attribute *dattr, char *buf) { struct dev_ext_attribute *ea; ea = container_of(dattr, struct dev_ext_attribute, attr); return scnprintf(buf, PAGE_SIZE, "configid=0x%lx\n", (unsigned long)(ea->var)); } int etm_perf_add_symlink_cscfg(struct device *dev, struct cscfg_config_desc *config_desc) { int err = 0; if (config_desc->event_ea != NULL) return 0; config_desc->event_ea = etm_perf_add_symlink_group(dev, config_desc->name, "events"); /* set the show function to the custom cscfg event */ if (!IS_ERR(config_desc->event_ea)) config_desc->event_ea->attr.show = etm_perf_cscfg_event_show; else { err = PTR_ERR(config_desc->event_ea); config_desc->event_ea = NULL; } return err; } void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *config_desc) { if (!config_desc->event_ea) return; etm_perf_del_symlink_group(config_desc->event_ea, "events"); config_desc->event_ea = NULL; } int __init etm_perf_init(void) { int ret; etm_pmu.capabilities = (PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE); etm_pmu.attr_groups = etm_pmu_attr_groups; etm_pmu.task_ctx_nr = perf_sw_context; etm_pmu.read = etm_event_read; etm_pmu.event_init = etm_event_init; etm_pmu.setup_aux = etm_setup_aux; etm_pmu.free_aux = etm_free_aux; etm_pmu.start = etm_event_start; etm_pmu.stop = etm_event_stop; etm_pmu.add = etm_event_add; etm_pmu.del = etm_event_del; etm_pmu.addr_filters_sync = etm_addr_filters_sync; etm_pmu.addr_filters_validate = etm_addr_filters_validate; etm_pmu.nr_addr_filters = ETM_ADDR_CMP_MAX; ret = perf_pmu_register(&etm_pmu, CORESIGHT_ETM_PMU_NAME, -1); if (ret == 0) etm_perf_up = true; return ret; } void etm_perf_exit(void) { perf_pmu_unregister(&etm_pmu); }