From 2703d74c1313271ba78439b0796444add6a9328f Mon Sep 17 00:00:00 2001 From: Mathieu Poirier Date: Thu, 25 Aug 2016 15:19:17 -0600 Subject: [PATCH] coresight: etm4x: adding configurable address range filtering This patch adds the capability to specify address ranges from the perf cmd line using the --filter option. If the IP falls within the range(s) program flow traces are generated. Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-etm4x.c | 128 ++++++++++++++++-- 1 file changed, 119 insertions(+), 9 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 1044ed609d81..ebaefb45130f 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -45,7 +45,9 @@ module_param_named(boot_enable, boot_enable, int, S_IRUGO); /* The number of ETMv4 currently registered */ static int etm4_count; static struct etmv4_drvdata *etmdrvdata[NR_CPUS]; -static void etm4_set_default(struct etmv4_config *config); +static void etm4_set_default_config(struct etmv4_config *config); +static int etm4_set_event_filters(struct etmv4_drvdata *drvdata, + struct perf_event *event); static enum cpuhp_state hp_online; @@ -187,11 +189,14 @@ static void etm4_enable_hw(void *info) static int etm4_parse_event_config(struct etmv4_drvdata *drvdata, struct perf_event *event) { + int ret = 0; struct etmv4_config *config = &drvdata->config; struct perf_event_attr *attr = &event->attr; - if (!attr) - return -EINVAL; + if (!attr) { + ret = -EINVAL; + goto out; + } /* Clear configuration from previous run */ memset(config, 0, sizeof(struct etmv4_config)); @@ -203,7 +208,12 @@ static int etm4_parse_event_config(struct etmv4_drvdata *drvdata, config->mode = ETM_MODE_EXCL_USER; /* Always start from the default config */ - etm4_set_default(config); + etm4_set_default_config(config); + + /* Configure filters specified on the perf cmd line, if any. */ + ret = etm4_set_event_filters(drvdata, event); + if (ret) + goto out; /* Go from generic option to ETMv4 specifics */ if (attr->config & BIT(ETM_OPT_CYCACC)) @@ -211,23 +221,30 @@ static int etm4_parse_event_config(struct etmv4_drvdata *drvdata, if (attr->config & BIT(ETM_OPT_TS)) config->cfg |= ETMv4_MODE_TIMESTAMP; - return 0; +out: + return ret; } static int etm4_enable_perf(struct coresight_device *csdev, struct perf_event *event) { + int ret = 0; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); - if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) - return -EINVAL; + if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) { + ret = -EINVAL; + goto out; + } /* Configure the tracer based on the session's specifics */ - etm4_parse_event_config(drvdata, event); + ret = etm4_parse_event_config(drvdata, event); + if (ret) + goto out; /* And enable it */ etm4_enable_hw(drvdata); - return 0; +out: + return ret; } static int etm4_enable_sysfs(struct coresight_device *csdev) @@ -682,6 +699,99 @@ static void etm4_set_default(struct etmv4_config *config) etm4_set_default_filter(config); } +static int etm4_get_next_comparator(struct etmv4_drvdata *drvdata, u32 type) +{ + int nr_comparator, index = 0; + struct etmv4_config *config = &drvdata->config; + + /* + * nr_addr_cmp holds the number of comparator _pair_, so time 2 + * for the total number of comparators. + */ + nr_comparator = drvdata->nr_addr_cmp * 2; + + /* Go through the tally of comparators looking for a free one. */ + while (index < nr_comparator) { + switch (type) { + case ETM_ADDR_TYPE_RANGE: + if (config->addr_type[index] == ETM_ADDR_TYPE_NONE && + config->addr_type[index + 1] == ETM_ADDR_TYPE_NONE) + return index; + + /* Address range comparators go in pairs */ + index += 2; + break; + default: + return -EINVAL; + } + } + + /* If we are here all the comparators have been used. */ + return -ENOSPC; +} + +static int etm4_set_event_filters(struct etmv4_drvdata *drvdata, + struct perf_event *event) +{ + int i, comparator, ret = 0; + struct etmv4_config *config = &drvdata->config; + struct etm_filters *filters = event->hw.addr_filters; + + if (!filters) + goto default_filter; + + /* Sync events with what Perf got */ + perf_event_addr_filters_sync(event); + + /* + * If there are no filters to deal with simply go ahead with + * the default filter, i.e the entire address range. + */ + if (!filters->nr_filters) + goto default_filter; + + for (i = 0; i < filters->nr_filters; i++) { + struct etm_filter *filter = &filters->etm_filter[i]; + enum etm_addr_type type = filter->type; + + /* See if a comparator is free. */ + comparator = etm4_get_next_comparator(drvdata, type); + if (comparator < 0) { + ret = comparator; + goto out; + } + + switch (type) { + case ETM_ADDR_TYPE_RANGE: + etm4_set_comparator_filter(config, + filter->start_addr, + filter->stop_addr, + comparator); + /* + * TRCVICTLR::SSSTATUS == 1, the start-stop logic is + * in the started state + */ + config->vinst_ctrl |= BIT(9); + + /* No start-stop filtering for ViewInst */ + config->vissctlr = 0x0; + break; + default: + ret = -EINVAL; + goto out; + } + } + + goto out; + + +default_filter: + etm4_set_default_filter(config); + +out: + return ret; +} + void etm4_config_trace_mode(struct etmv4_config *config) { u32 addr_acc, mode; -- 2.20.1