Perf is a well known and used tool for performance monitoring and much more. A such it is an ideal candidate for integration with coresight based HW tracing.
This patch introduces a PMU that represent a coresight tracer to the Perf core. Signed-off-by: Mathieu Poirier <[email protected]> --- drivers/hwtracing/coresight/Makefile | 3 +- drivers/hwtracing/coresight/coresight-etm-perf.c | 465 +++++++++++++++++++++++ drivers/hwtracing/coresight/coresight-etm-perf.h | 32 ++ drivers/hwtracing/coresight/coresight-etm3x.c | 7 + include/linux/coresight-pmu.h | 27 ++ 5 files changed, 533 insertions(+), 1 deletion(-) create mode 100644 drivers/hwtracing/coresight/coresight-etm-perf.c create mode 100644 drivers/hwtracing/coresight/coresight-etm-perf.h create mode 100644 include/linux/coresight-pmu.h diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index 233d66cf22d3..cf8c6d689747 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_CORESIGHT_SINK_ETBV10) += coresight-etb10.o obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \ coresight-replicator.o obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o coresight-etm-cp14.o \ - coresight-etm3x-sysfs.o + coresight-etm3x-sysfs.o \ + coresight-etm-perf.o obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o obj-$(CONFIG_CORESIGHT_QCOM_REPLICATOR) += coresight-replicator-qcom.o diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c new file mode 100644 index 000000000000..cc033980f822 --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -0,0 +1,465 @@ +/* + * Copyright(C) 2015 Linaro Limited. All rights reserved. + * Author: Mathieu Poirier <[email protected]> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/coresight.h> +#include <linux/coresight-pmu.h> +#include <linux/cpumask.h> +#include <linux/device.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/perf_event.h> +#include <linux/slab.h> +#include <linux/types.h> + +#include "coresight-priv.h" + +static struct pmu etm_pmu; +static bool etm_perf_up; + +/** + * struct etm_cpu_data - Coresight specifics accociated to a single CPU + * @src_config: The tracer configuration. + * @snk_config: The sink configuration. + * @patch: The path from source to sink. + */ +struct etm_cpu_data { + void *src_config; + void *snk_config; + struct list_head *path; +}; + +/** + * struct etm_event_data - Coresight specifics associated to an event + * @mask: Hold the CPU(s) this event was set for. + * @cpu_data: An array of cpu data, each slot for one CPU. + */ +struct etm_event_data { + cpumask_t mask; + struct etm_cpu_data **cpu_data; +}; + +static DEFINE_PER_CPU(struct perf_output_handle, ctx_handle); +static DEFINE_PER_CPU(struct coresight_device *, csdev_src); + +/* ETMv3.5/PTM's ETMCR is 'config' */ +PMU_FORMAT_ATTR(cycacc, "config:" __stringify(ETM_OPT_CYCACC)); +PMU_FORMAT_ATTR(timestamp, "config:" __stringify(ETM_OPT_TS)); + +static struct attribute *etm_config_formats_attr[] = { + &format_attr_cycacc.attr, + &format_attr_timestamp.attr, + NULL, +}; + +static struct attribute_group etm_pmu_format_group = { + .name = "format", + .attrs = etm_config_formats_attr, +}; + +static const struct attribute_group *etm_pmu_attr_groups[] = { + &etm_pmu_format_group, + NULL, +}; + +static void etm_event_read(struct perf_event *event) {} +static void etm_event_destroy(struct perf_event *event) {} + +static int etm_event_init(struct perf_event *event) +{ + if (event->attr.type != etm_pmu.type) + return -ENOENT; + + if (event->cpu >= nr_cpu_ids) + return -EINVAL; + + event->destroy = etm_event_destroy; + + return 0; +} + +static void free_cpu_data(int cpu, struct etm_cpu_data *cpu_data) +{ + struct coresight_device *sink, *csdev; + + csdev = per_cpu(csdev_src, cpu); + if (!csdev) + return; + + if (source_ops(csdev)->put_config) + source_ops(csdev)->put_config(cpu_data->src_config); + + /* No need to continue if there isn't a path to work with */ + if (!cpu_data->path) + return; + + sink = coresight_get_sink(cpu_data->path); + if (sink_ops(sink)->put_config) + sink_ops(sink)->put_config(cpu_data->snk_config); + + coresight_release_path(cpu_data->path); +} + +static void free_event_data(struct etm_event_data *event_data) +{ + int cpu; + cpumask_t *mask = &event_data->mask; + + for_each_cpu(cpu, mask) { + if (event_data->cpu_data[cpu]) + free_cpu_data(cpu, event_data->cpu_data[cpu]); + kfree(event_data->cpu_data[cpu]); + } + + kfree(event_data->cpu_data); + kfree(event_data); +} + +static void *alloc_event_data(int cpu) +{ + int lcpu, size; + cpumask_t *mask; + struct etm_cpu_data *cpu_data; + 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; + + /* Make sure nothing disappears under us */ + get_online_cpus(); + size = num_online_cpus(); + + mask = &event_data->mask; + if (cpu != -1) + cpumask_set_cpu(cpu, mask); + else + cpumask_copy(mask, cpu_online_mask); + put_online_cpus(); + + /* Allocate an array of cpu_data to work with */ + event_data->cpu_data = kcalloc(size, + sizeof(struct etm_cpu_data *), + GFP_KERNEL); + if (!event_data->cpu_data) + goto free_event_data; + + /* Allocate a cpu_data for each CPU this event is dealing with */ + for_each_cpu(lcpu, mask) { + cpu_data = kzalloc(sizeof(struct etm_cpu_data), GFP_KERNEL); + if (!cpu_data) + goto free_event_data; + + event_data->cpu_data[lcpu] = cpu_data; + } + +out: + return event_data; + +free_event_data: + free_event_data(event_data); + event_data = NULL; + + goto out; +} + +static void *etm_setup_aux(struct perf_event *event, void **pages, + int nr_pages, bool overwrite) +{ + int cpu; + cpumask_t *mask; + struct etm_event_data *event_data = NULL; + struct coresight_device *csdev; + + event_data = alloc_event_data(event->cpu); + if (!event_data) + return NULL; + + mask = &event_data->mask; + + for_each_cpu(cpu, mask) { + struct etm_cpu_data *cpu_data; + struct coresight_device *sink; + + csdev = per_cpu(csdev_src, cpu); + if (!csdev) + goto err; + + cpu_data = event_data->cpu_data[cpu]; + + /* Get the tracer's config from perf */ + if (!source_ops(csdev)->get_config) + goto err; + + cpu_data->src_config = + source_ops(csdev)->get_config(csdev, event); + if (!cpu_data->src_config) + goto err; + + /* + * 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. + */ + cpu_data->path = coresight_build_path(csdev); + if (!cpu_data->path) + goto err; + + /* Grab the sink at the end of the path */ + sink = coresight_get_sink(cpu_data->path); + if (!sink) + goto err; + + if (!sink_ops(sink)->get_config) + goto err; + + /* Finally get the AUX specific data from the sink buffer */ + cpu_data->snk_config = + sink_ops(sink)->get_config(sink, cpu, pages, + nr_pages, overwrite); + if (!cpu_data->snk_config) + goto err; + + } + +out: + return event_data; + +err: + free_event_data(event_data); + event_data = NULL; + goto out; + + return NULL; +} + +static void etm_free_aux(void *data) +{ + free_event_data(data); +} + +static void etm_event_stop(struct perf_event *event, int mode) +{ + int cpu = smp_processor_id(); + struct coresight_device *csdev = per_cpu(csdev_src, cpu); + + if (event->hw.state == PERF_HES_STOPPED) + return; + + if (!csdev) + return; + + /* stop tracer */ + source_ops(csdev)->disable(csdev); + + /* tell the core */ + event->hw.state = PERF_HES_STOPPED; + + + if (mode & PERF_EF_UPDATE) { + struct coresight_device *sink; + struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle); + struct etm_event_data *event_data = perf_get_aux(handle); + struct etm_cpu_data *cpu_data = event_data->cpu_data[cpu]; + + if (WARN_ON_ONCE(handle->event != event)) + return; + + if (WARN_ON_ONCE(!cpu_data)) + return; + + sink = coresight_get_sink(cpu_data->path); + if (WARN_ON_ONCE(!sink)) + return; + + /* update trace information */ + if (!sink_ops(sink)->update_buffer) + return; + + sink_ops(sink)->update_buffer(sink, handle, + cpu_data->snk_config); + } +} + +static void etm_event_start(struct perf_event *event, int flags) +{ + int cpu = smp_processor_id(); + struct coresight_device *csdev = per_cpu(csdev_src, cpu); + + if (!csdev) + goto fail; + + /* tell the perf core the event is alive */ + event->hw.state = 0; + + if (source_ops(csdev)->enable(csdev, CS_MODE_PERF)) + goto fail; + + return; + +fail: + event->hw.state = PERF_HES_STOPPED; +} + +static void etm_event_del(struct perf_event *event, int mode) +{ + bool lost = true; + int cpu = smp_processor_id(); + unsigned long size; + struct coresight_device *sink; + struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle); + struct etm_event_data *event_data = perf_get_aux(handle); + struct etm_cpu_data *cpu_data = event_data->cpu_data[cpu]; + + if (WARN_ON_ONCE(!cpu_data)) + return; + + etm_event_stop(event, PERF_EF_UPDATE); + + sink = coresight_get_sink(cpu_data->path); + if (!sink) + return; + + if (!sink_ops(sink)->reset_buffer) + return; + + size = sink_ops(sink)->reset_buffer(sink, handle, + cpu_data->snk_config, + &lost); + + perf_aux_output_end(handle, size, lost); + + coresight_disable_path(cpu_data->path); +} + +static int etm_event_add(struct perf_event *event, int mode) +{ + int ret = -EBUSY, cpu = smp_processor_id(); + struct etm_event_data *event_data; + struct etm_cpu_data *cpu_data; + struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle); + struct hw_perf_event *hwc = &event->hw; + struct coresight_device *csdev = per_cpu(csdev_src, cpu); + struct coresight_device *sink; + + if (handle->event) + goto out; + + event_data = perf_aux_output_begin(handle, event); + ret = -EINVAL; + if (WARN_ON_ONCE(!event_data)) + goto fail_stop; + + cpu_data = event_data->cpu_data[cpu]; + + sink = coresight_get_sink(cpu_data->path); + if (!sink) + goto fail_end_stop; + + if (!sink_ops(sink)->set_buffer) + goto fail_end_stop; + + ret = sink_ops(sink)->set_buffer(sink, handle, + cpu_data->snk_config); + + if (ret) + goto fail_end_stop; + + if (!source_ops(csdev)->set_config) { + ret = -EINVAL; + goto fail_end_stop; + } + + source_ops(csdev)->set_config(csdev, cpu_data->src_config); + + ret = coresight_enable_path(cpu_data->path, CS_MODE_PERF); + if (ret) + goto fail_end_stop; + + if (mode & PERF_EF_START) { + etm_event_start(event, 0); + if (hwc->state & PERF_HES_STOPPED) { + etm_event_del(event, 0); + ret = -EBUSY; + goto fail_path_end_stop; + } + } + +out: + return ret; + +fail_path_end_stop: + coresight_disable_path(cpu_data->path); +fail_end_stop: + perf_aux_output_end(handle, 0, true); +fail_stop: + hwc->state = PERF_HES_STOPPED; + goto out; + + return 0; +} + +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; +} + +static int __init etm_perf_init(void) +{ + int ret; + + etm_pmu.capabilities = PERF_PMU_CAP_EXCLUSIVE; + + 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.stop = etm_event_stop; + etm_pmu.start = etm_event_start; + etm_pmu.del = etm_event_del; + etm_pmu.add = etm_event_add; + + ret = perf_pmu_register(&etm_pmu, CORESIGHT_ETM_PMU_NAME, -1); + if (ret == 0) + etm_perf_up = true; + + return ret; +} +module_init(etm_perf_init); diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h new file mode 100644 index 000000000000..87f5a134eb6f --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-etm-perf.h @@ -0,0 +1,32 @@ +/* + * Copyright(C) 2015 Linaro Limited. All rights reserved. + * Author: Mathieu Poirier <[email protected]> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef _CORESIGHT_ETM_PERF_H +#define _CORESIGHT_ETM_PERF_H + +struct coresight_device; + +#ifdef CONFIG_CORESIGHT +int etm_perf_symlink(struct coresight_device *csdev, bool link); + +#else +static inline int etm_perf_symlink(struct coresight_device *csdev, bool link) +{ return -EINVAL; } + +#endif /* CONFIG_CORESIGHT */ + +#endif diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c index fbd04979e21c..6170df1b9e59 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x.c @@ -35,6 +35,7 @@ #include <asm/sections.h> #include "coresight-etm.h" +#include "coresight-etm-perf.h" static int boot_enable; module_param_named(boot_enable, boot_enable, int, S_IRUGO); @@ -879,6 +880,12 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) goto err_arch_supported; } + ret = etm_perf_symlink(drvdata->csdev, true); + if (ret) { + coresight_unregister(drvdata->csdev); + goto err_arch_supported; + } + pm_runtime_put(&adev->dev); dev_info(dev, "%s initialized\n", (char *)id->data); diff --git a/include/linux/coresight-pmu.h b/include/linux/coresight-pmu.h new file mode 100644 index 000000000000..6c5386b23b10 --- /dev/null +++ b/include/linux/coresight-pmu.h @@ -0,0 +1,27 @@ +/* + * Copyright(C) 2015 Linaro Limited. All rights reserved. + * Author: Mathieu Poirier <[email protected]> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef _LINUX_CORESIGHT_PMU_H +#define _LINUX_CORESIGHT_PMU_H + +#define CORESIGHT_ETM_PMU_NAME "cs_etm" + +/* ETMv3.5/PTM's ETMCR config bit */ +#define ETM_OPT_CYCACC 12 +#define ETM_OPT_TS 28 + +#endif -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
