That way traces can be enable and disabled automatically
from the Perf subystem using the PMU abstraction.
Signed-off-by: Mathieu Poirier <mathieu.poir...@linaro.org>
---
drivers/hwtracing/coresight/coresight-etm3x.c | 50 ++++++++++++++++++++++++---
include/linux/coresight.h | 4 +++
2 files changed, 50 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c
b/drivers/hwtracing/coresight/coresight-etm3x.c
index 0994bf0a8334..f565554744fe 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -369,8 +369,10 @@ static void etm_enable_hw(void *info)
etm_set_prog(drvdata);
etmcr = etm_readl(drvdata, ETMCR);
- etmcr &= (ETMCR_PWD_DWN | ETMCR_ETM_PRG);
+ /* Clear setting from a previous run if need be */
+ etmcr &= ~ETM3X_SUPPORTED_OPTIONS;
etmcr |= drvdata->port_size;
+ etmcr |= ETMCR_ETM_EN;
etm_writel(drvdata, config->ctrl | etmcr, ETMCR);
etm_writel(drvdata, config->trigger_event, ETMTRIGGER);
etm_writel(drvdata, config->startstop_ctrl, ETMTSSCR);
@@ -410,9 +412,6 @@ static void etm_enable_hw(void *info)
/* No VMID comparator value selected */
etm_writel(drvdata, 0x0, ETMVMIDCVR);
- /* Ensures trace output is enabled from this ETM */
- etm_writel(drvdata, config->ctrl | ETMCR_ETM_EN | etmcr, ETMCR);
-
etm_clr_prog(drvdata);
CS_LOCK(drvdata->base);
@@ -485,6 +484,47 @@ static void perf_etm_set_config(struct coresight_device
*csdev, void *config)
drvdata->config = config;
}
+static int perf_etm_enable(struct coresight_device *csdev)
+{
+ struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
+ return -EINVAL;
+
+ if (local_cmpxchg(&drvdata->state,
+ ETM_STATE_DISABLED, ETM_STATE_PERF))
+ return -EBUSY;
+
+ etm_enable_hw(drvdata);
+
+ return 0;
+}
+
+static int perf_etm_disable(struct coresight_device *csdev)
+{
+ struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
+ return -EINVAL;
+
+ CS_UNLOCK(drvdata->base);
+
+ /* setting the prog bit disables tracing immediately */
+ etm_set_prog(drvdata);
+ /* Get ready for another session */
+ drvdata->config = NULL;
+ /*
+ * There is no way to know when the tracer will be used again so
+ * power down the tracer.
+ */
+ etm_set_pwrdwn(drvdata);
+ local_set(&drvdata->state, ETM_STATE_DISABLED);
+
+ CS_LOCK(drvdata->base);
+
+ return 0;
+}
+
static int sysfs_etm_enable(struct coresight_device *csdev)
{
struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -587,6 +627,8 @@ static const struct coresight_ops_source etm_source_ops = {
.trace_id = etm_trace_id,
.perf_get_config = perf_etm_get_config,
.perf_set_config = perf_etm_set_config,
+ .perf_enable = perf_etm_enable,
+ .perf_disable = perf_etm_disable,
.sysfs_enable = sysfs_etm_enable,
.sysfs_disable = sysfs_etm_disable,
};
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 32463da877eb..b853d722346b 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -211,6 +211,8 @@ struct coresight_ops_link {
to the HW.
* @perf_get_config: builds the ETM configuration after event' specifics.
* @perf_set_config: associate a tracer with a configuration..
+ * @perf_enable: enables tracing for a source, from Perf.
+ * @perf_disable: disables tracing for a source, from Perf.
* @sysfs_enable: enables tracing for a source, from sysFS.
* @sysfs_disable: disables tracing for a source, from sysFS.
*/
@@ -220,6 +222,8 @@ struct coresight_ops_source {
void *(*perf_get_config)(struct coresight_device *csdev,
struct perf_event *event);
void (*perf_set_config)(struct coresight_device *csdev, void *config);
+ int (*perf_enable)(struct coresight_device *csdev);
+ int (*perf_disable)(struct coresight_device *csdev);
int (*sysfs_enable)(struct coresight_device *csdev);
void (*sysfs_disable)(struct coresight_device *csdev);
};
--
1.9.1
--
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