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Message-Id: <1468871491-10997-9-git-send-email-mathieu.poirier@linaro.org>
Date: Mon, 18 Jul 2016 13:51:29 -0600
From: Mathieu Poirier <mathieu.poirier@...aro.org>
To: linux-arm-kernel@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org, alexander.shishkin@...ux.intel.com,
Mathieu Poirier <mathieu.poirier@...aro.org>
Subject: [PATCH 08/10] 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 <mathieu.poirier@...aro.org>
---
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 9eba6d8f4633..b807333ce6a1 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -46,7 +46,9 @@ 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 void etm4_os_unlock(struct etmv4_drvdata *drvdata)
{
@@ -195,11 +197,14 @@ 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));
@@ -211,7 +216,12 @@ 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))
@@ -219,23 +229,30 @@ 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)
@@ -685,6 +702,99 @@ 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->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;
--
2.7.4
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