[PATCH V9 13/18] coresight: etm3x: implementing perf_enable/disable() API
Mathieu Poirier
mathieu.poirier at linaro.org
Wed Feb 3 10:39:11 PST 2016
That way traces can be enabled and disabled automatically
from the Perf subystem using the PMU abstraction.
Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
---
drivers/hwtracing/coresight/Kconfig | 1 +
drivers/hwtracing/coresight/coresight-etm3x.c | 95 +++++++++++++++++++++++++--
drivers/hwtracing/coresight/coresight-etm4x.c | 4 +-
drivers/hwtracing/coresight/coresight.c | 2 +-
include/linux/coresight.h | 6 +-
5 files changed, 99 insertions(+), 9 deletions(-)
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index c85935f3525a..db0541031c72 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -4,6 +4,7 @@
menuconfig CORESIGHT
bool "CoreSight Tracing Support"
select ARM_AMBA
+ select PERF_EVENTS
help
This framework provides a kernel interface for the CoreSight debug
and trace drivers to register themselves with. It's intended to build
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index c82d545e68ef..a9b820ec16aa 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -31,6 +31,7 @@
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/clk.h>
+#include <linux/perf_event.h>
#include <asm/sections.h>
#include "coresight-etm.h"
@@ -297,6 +298,47 @@ void etm_config_trace_mode(struct etm_config *config)
config->addr_type[1] = ETM_ADDR_TYPE_RANGE;
}
+#define ETM3X_SUPPORTED_OPTIONS (ETMCR_CYC_ACC | ETMCR_TIMESTAMP_EN)
+
+static int etm_parse_event_config(struct etm_drvdata *drvdata,
+ struct perf_event_attr *attr)
+{
+ struct etm_config *config = &drvdata->config;
+
+ if (!attr)
+ return -EINVAL;
+
+ /* Clear configuration from previous run */
+ memset(config, 0, sizeof(struct etm_config));
+
+ if (attr->exclude_kernel)
+ config->mode = ETM_MODE_EXCL_KERN;
+
+ if (attr->exclude_user)
+ config->mode = ETM_MODE_EXCL_USER;
+
+ /* Always start from the default config */
+ etm_set_default(config);
+
+ /*
+ * By default the tracers are configured to trace the whole address
+ * range. Narrow the field only if requested by user space.
+ */
+ if (config->mode)
+ etm_config_trace_mode(config);
+
+ /*
+ * At this time only cycle accurate and timestamp options are
+ * available.
+ */
+ if (attr->config & ~ETM3X_SUPPORTED_OPTIONS)
+ return -EINVAL;
+
+ config->ctrl = attr->config;
+
+ return 0;
+}
+
static void etm_enable_hw(void *info)
{
int i;
@@ -316,8 +358,10 @@ 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);
@@ -357,9 +401,6 @@ 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);
@@ -407,6 +448,22 @@ static int etm_trace_id(struct coresight_device *csdev)
return etm_get_trace_id(drvdata);
}
+static int etm_enable_perf(struct coresight_device *csdev,
+ struct perf_event_attr *attr)
+{
+ struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
+ return -EINVAL;
+
+ /* Configure the tracer based on the session's specifics */
+ etm_parse_event_config(drvdata, attr);
+ /* And enable it */
+ etm_enable_hw(drvdata);
+
+ return 0;
+}
+
static int etm_enable_sysfs(struct coresight_device *csdev)
{
struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -437,7 +494,8 @@ err:
return ret;
}
-static int etm_enable(struct coresight_device *csdev, u32 mode)
+static int etm_enable(struct coresight_device *csdev,
+ struct perf_event_attr *attr, u32 mode)
{
int ret;
u32 val;
@@ -453,6 +511,9 @@ static int etm_enable(struct coresight_device *csdev, u32 mode)
case CS_MODE_SYSFS:
ret = etm_enable_sysfs(csdev);
break;
+ case CS_MODE_PERF:
+ ret = etm_enable_perf(csdev, attr);
+ break;
default:
ret = -EINVAL;
}
@@ -485,6 +546,27 @@ static void etm_disable_hw(void *info)
dev_dbg(drvdata->dev, "cpu: %d disable smp call done\n", drvdata->cpu);
}
+static void etm_disable_perf(struct coresight_device *csdev)
+{
+ struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
+ return;
+
+ CS_UNLOCK(drvdata->base);
+
+ /* Setting the prog bit disables tracing immediately */
+ etm_set_prog(drvdata);
+
+ /*
+ * There is no way to know when the tracer will be used again so
+ * power down the tracer.
+ */
+ etm_set_pwrdwn(drvdata);
+
+ CS_LOCK(drvdata->base);
+}
+
static void etm_disable_sysfs(struct coresight_device *csdev)
{
struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -528,6 +610,9 @@ static void etm_disable(struct coresight_device *csdev)
case CS_MODE_SYSFS:
etm_disable_sysfs(csdev);
break;
+ case CS_MODE_PERF:
+ etm_disable_perf(csdev);
+ break;
default:
WARN_ON_ONCE(mode);
return;
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
index 0026092fec7f..d0169ba7fbf2 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -32,6 +32,7 @@
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/pm_runtime.h>
+#include <linux/perf_event.h>
#include <asm/sections.h>
#include "coresight-etm4x.h"
@@ -187,7 +188,8 @@ static void etm4_enable_hw(void *info)
dev_dbg(drvdata->dev, "cpu: %d enable smp call done\n", drvdata->cpu);
}
-static int etm4_enable(struct coresight_device *csdev, u32 mode)
+static int etm4_enable(struct coresight_device *csdev,
+ struct perf_event_attr *attr, u32 mode)
{
struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
int ret;
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index b20afb709141..95cccb179763 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -234,7 +234,7 @@ static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
if (!csdev->enable) {
if (source_ops(csdev)->enable) {
- ret = source_ops(csdev)->enable(csdev, mode);
+ ret = source_ops(csdev)->enable(csdev, NULL, mode);
if (ret)
return ret;
}
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 61dfb8d511ea..6801dd64ee5d 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -14,6 +14,7 @@
#define _LINUX_CORESIGHT_H
#include <linux/device.h>
+#include <linux/perf_event.h>
#include <linux/sched.h>
/* Peripheral id registers (0xFD0-0xFEC) */
@@ -206,14 +207,15 @@ struct coresight_ops_link {
* @cpu_id: returns the value of the CPU number this component
* is associated to.
* @trace_id: returns the value of the component's trace ID as known
- to the HW.
+ * to the HW.
* @enable: enables tracing for a source.
* @disable: disables tracing for a source.
*/
struct coresight_ops_source {
int (*cpu_id)(struct coresight_device *csdev);
int (*trace_id)(struct coresight_device *csdev);
- int (*enable)(struct coresight_device *csdev, u32 mode);
+ int (*enable)(struct coresight_device *csdev,
+ struct perf_event_attr *attr, u32 mode);
void (*disable)(struct coresight_device *csdev);
};
--
2.1.4
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