coresight: etm3x: implementing perf_enable/disable() API

That way traces can be enabled and disabled automatically
from the Perf subystem using the PMU abstraction.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index c85935f3525a8543dd5e2f350f6c7785772219ad..db0541031c72c502a416d563e1318584365023aa 100644 (file)
--- 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 c82d545e68ef0fc8daae5884a6ddfea886ad7c2a..a9b820ec16aab4b45d4160d8f97d8ba56b80c54e 100644 (file)
--- 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 0026092fec7f0c50272b8add086c0809faa9266f..d0169ba7fbf21d17597a19c793ecc9cecdf82661 100644 (file)
--- 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 b20afb7091413b9f6655256ab56d22d20e9b9ae4..95cccb179763cfa0585db25b1e5e688049a3b8a2 100644 (file)
--- 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 61dfb8d511eaf0ec1bc2f4cbf56c666c2710d0e8..6801dd64ee5d23320d06eecd847deddccbd21258 100644 (file)
--- 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);
 };