diff options
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-etm-perf.c | 119 |
1 files changed, 118 insertions, 1 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index f8c7a8733b23..8fbb1dd9e243 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -22,6 +22,7 @@ #include <linux/list.h> #include <linux/mm.h> #include <linux/init.h> +#include <linux/parser.h> #include <linux/perf_event.h> #include <linux/slab.h> #include <linux/types.h> @@ -46,6 +47,17 @@ struct etm_event_data { struct list_head **path; }; +/** + * struct perf_pmu_drv_config - Driver specific configuration needed + * before a session can start. + * @sink: The name of the sink this session should use. + * @entry: Hook to the event->drv_configs list. + */ +struct perf_pmu_drv_config { + char *sink; + struct list_head entry; +}; + static DEFINE_PER_CPU(struct perf_output_handle, ctx_handle); static DEFINE_PER_CPU(struct coresight_device *, csdev_src); @@ -159,9 +171,22 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, int nr_pages, bool overwrite) { int cpu; + char *sink_def = NULL; cpumask_t *mask; struct coresight_device *sink; struct etm_event_data *event_data = NULL; + struct perf_pmu_drv_config *drv_config; + + /* + * Search the driver configurables looking for a sink. If more than + * one sink was specified the last one is taken. + */ + list_for_each_entry(drv_config, &event->drv_configs, entry) { + if (drv_config && drv_config->sink) { + sink_def = drv_config->sink; + break; + } + } event_data = alloc_event_data(event->cpu); if (!event_data) @@ -184,7 +209,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, * list of devices from source to sink that can be * referenced later when the path is actually needed. */ - event_data->path[cpu] = coresight_build_path(csdev, NULL); + event_data->path[cpu] = coresight_build_path(csdev, sink_def); if (!event_data->path[cpu]) goto err; } @@ -342,6 +367,95 @@ static void etm_event_del(struct perf_event *event, int mode) etm_event_stop(event, PERF_EF_UPDATE); } +enum { + ETM_TOKEN_SINK_CPU, + ETM_TOKEN_SINK, + ETM_TOKEN_ERR, +}; + +static const match_table_t drv_cfg_tokens = { + {ETM_TOKEN_SINK_CPU, "sink=cpu%d:%s"}, + {ETM_TOKEN_SINK, "sink=%s"}, + {ETM_TOKEN_ERR, NULL}, +}; + +static int etm_get_drv_configs(struct perf_event *event, void __user *arg) +{ + char *config, *sink = NULL; + int cpu = -1, token, ret = 0; + substring_t args[MAX_OPT_ARGS]; + struct perf_pmu_drv_config *drv_config = NULL; + + /* Make user supplied input usable */ + config = strndup_user(arg, PAGE_SIZE); + if (IS_ERR(config)) + return PTR_ERR(config); + + /* See above declared @drv_cfg_tokens for the usable formats */ + token = match_token(config, drv_cfg_tokens, args); + switch (token) { + case ETM_TOKEN_SINK: + /* Just a sink has been specified */ + sink = match_strdup(&args[0]); + if (IS_ERR(sink)) { + ret = PTR_ERR(sink); + goto err; + } + break; + case ETM_TOKEN_SINK_CPU: + /* We have a sink and a CPU */ + if (match_int(&args[0], &cpu)) { + ret = -EINVAL; + goto err; + } + sink = match_strdup(&args[1]); + if (IS_ERR(sink)) { + ret = PTR_ERR(sink); + goto err; + } + break; + default: + ret = -EINVAL; + goto err; + } + + /* If the CPUs don't match the sink is destined to another path */ + if (event->cpu != cpu) + goto err; + + /* + * We have a valid configuration, allocate memory and add to the list + * of driver configurables. + */ + drv_config = kzalloc(sizeof(*drv_config), GFP_KERNEL); + if (IS_ERR(drv_config)) { + ret = PTR_ERR(drv_config); + goto err; + } + + drv_config->sink = sink; + list_add(&drv_config->entry, &event->drv_configs); + +out: + kfree(config); + return ret; + +err: + kfree(sink); + goto out; +} + +static void etm_free_drv_configs(struct perf_event *event) +{ + struct perf_pmu_drv_config *config, *itr; + + list_for_each_entry_safe(config, itr, &event->drv_configs, entry) { + list_del(&config->entry); + kfree(config->sink); + kfree(config); + } +} + int etm_perf_symlink(struct coresight_device *csdev, bool link) { char entry[sizeof("cpu9999999")]; @@ -383,6 +497,9 @@ static int __init etm_perf_init(void) etm_pmu.stop = etm_event_stop; etm_pmu.add = etm_event_add; etm_pmu.del = etm_event_del; + etm_pmu.get_drv_configs = etm_get_drv_configs; + etm_pmu.free_drv_configs + = etm_free_drv_configs; ret = perf_pmu_register(&etm_pmu, CORESIGHT_ETM_PMU_NAME, -1); if (ret == 0) |