[PATCH v5 08/14] coresight: cti: Enable CTI associated with devices.

Mike Leach
2019-11-19T23:22:34Z

The CoreSight subsystem enables a path of devices from source to sink.
Any CTI devices associated with the path devices must be enabled at the
same time.

This patch adds an associated coresight_device element to the main
coresight device structure, and uses this to create associations between
the CTI and other devices based on the device tree data. The associated
device element is used to enable CTI in conjunction with the path elements.

CTI devices are reference counted so where a single CTI is associated with
multiple elements on the path, it will be enabled on the first associated
device enable, and disabled with the last associated device disable.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
---
drivers/hwtracing/coresight/coresight-cti.c | 87 +++++++++++++++++++
.../hwtracing/coresight/coresight-platform.c | 23 +++++
drivers/hwtracing/coresight/coresight-priv.h | 6 ++
drivers/hwtracing/coresight/coresight.c | 58 +++++++++++--
include/linux/coresight.h | 5 ++
5 files changed, 173 insertions(+), 6 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
index 369488dd7b8e..cf116463149a 100644
--- a/drivers/hwtracing/coresight/coresight-cti.c
+++ b/drivers/hwtracing/coresight/coresight-cti.c
@@ -440,6 +440,90 @@ int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
return err;
}

+/*
+ * Look for a matching connection device name in the list of
+ * connections. If found then swap in the csdev name and return
+ * found.
+ */
+static bool
+cti_match_con_name(struct cti_device *ctidev, const char *node_name,
+ const char *csdev_name)
+{
+ struct cti_trig_con *trig_con;
+
+ list_for_each_entry(trig_con, &ctidev->trig_cons, node) {
+ if (trig_con->con_dev_name) {
+ if (!strcmp(node_name, trig_con->con_dev_name)) {
+ /* match: so swap in csdev name */
+ kfree(trig_con->con_dev_name);
+ trig_con->con_dev_name =
+ kstrdup(csdev_name, GFP_KERNEL);
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+/*
+ * Search the cti list to add an associated CTI into the supplied CS device
+ * This will set the association if CTI declared before the CS device
+ */
+void cti_add_assoc_to_csdev(struct coresight_device *csdev)
+{
+ struct cti_drvdata *ect_item;
+ struct cti_device *ctidev;
+ const char *node_name = NULL, *csdev_name;
+
+ /* protect the list */
+ mutex_lock(&ect_mutex);
+
+ /* exit if current is an ECT device.*/
+ if ((csdev->type == CORESIGHT_DEV_TYPE_ECT) || list_empty(&ect_net))
+ goto cti_add_done;
+
+ /* if we didn't find the csdev previously we used the fwnode name */
+ node_name = coresight_get_fwnode_name(csdev->dev.parent);
+
+ if (!node_name)
+ goto cti_add_done;
+
+ /* this is the name we want to use for the association */
+ csdev_name = dev_name(&csdev->dev);
+
+ /* for each CTI in list... */
+ list_for_each_entry(ect_item, &ect_net, node) {
+ ctidev = &ect_item->ctidev;
+ if (cti_match_con_name(ctidev, node_name, csdev_name)) {
+ /*
+ * if we found a matching name then update the
+ * association pointers.
+ */
+ csdev->ect_dev = ect_item->csdev;
+ goto cti_add_done;
+ }
+ }
+cti_add_done:
+ mutex_unlock(&ect_mutex);
+}
+EXPORT_SYMBOL_GPL(cti_add_assoc_to_csdev);
+
+/*
+ * Update the cross references where the associated device was found
+ * while we were building the connection info. This will occur if the
+ * assoc device was registered before the CTI.
+ */
+static void cti_update_conn_xrefs(struct cti_drvdata *drvdata)
+{
+ struct cti_trig_con *tc;
+ struct cti_device *ctidev = &drvdata->ctidev;
+
+ list_for_each_entry(tc, &ctidev->trig_cons, node) {
+ if (tc->con_dev)
+ tc->con_dev->ect_dev = drvdata->csdev;
+ }
+}
+
/** cti ect operations **/
int cti_enable(struct coresight_device *csdev)
{
@@ -574,6 +658,9 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
drvdata->csdev_release = drvdata->csdev->dev.release;
drvdata->csdev->dev.release = cti_device_release;

+ /* set any cross references */
+ cti_update_conn_xrefs(drvdata);
+
/* all done - dec pm refcount */
pm_runtime_put(&adev->dev);
dev_info(&drvdata->csdev->dev, "CTI initialized\n");
diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index 3c5bee429105..6721cb1af5fe 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -293,6 +293,12 @@ static int of_get_coresight_platform_data(struct device *dev,

return 0;
}
+
+static inline const char *of_coresight_get_node_name(struct device *dev)
+{
+ return dev->of_node->full_name;
+}
+
#else
static inline int
of_get_coresight_platform_data(struct device *dev,
@@ -305,6 +311,11 @@ static inline int of_coresight_get_cpu(struct device *dev)
{
return -ENODEV;
}
+
+static inline const char *of_coresight_get_node_name(struct device *dev)
+{
+ return NULL;
+}
#endif

#ifdef CONFIG_ACPI
@@ -766,6 +777,18 @@ static inline int acpi_coresight_get_cpu(struct device *dev)
}
#endif

+const char *coresight_get_fwnode_name(struct device *dev)
+{
+ const char *node_name = NULL;
+ struct fwnode_handle *fwnode = dev_fwnode(dev);
+
+ if (is_of_node(fwnode))
+ node_name = of_coresight_get_node_name(dev);
+
+ return node_name;
+}
+EXPORT_SYMBOL_GPL(coresight_get_fwnode_name);
+
int coresight_get_cpu(struct device *dev)
{
if (is_of_node(dev->fwnode))
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index aba6b789c969..484e5ec593bb 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -162,6 +162,12 @@ static inline int etm_readl_cp14(u32 off, unsigned int *val) { return 0; }
static inline int etm_writel_cp14(u32 off, u32 val) { return 0; }
#endif

+#ifdef CONFIG_CORESIGHT_CTI
+extern void cti_add_assoc_to_csdev(struct coresight_device *csdev);
+#else
+static inline void cti_add_assoc_to_csdev(struct coresight_device *csdev) {}
+#endif
+
/*
* Macros and inline functions to handle CoreSight UCI data and driver
* private data in AMBA ID table entries, and extract data values.
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 1a5fdf2710ff..7657be009246 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -216,6 +216,31 @@ void coresight_disclaim_device(void __iomem *base)
CS_LOCK(base);
}

+/* enable or disable an associated CTI device of the supplied CS device */
+static int
+coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable)
+{
+ int ect_ret = 0;
+ struct coresight_device *ect_csdev = csdev->ect_dev;
+
+ if (!ect_csdev)
+ return 0;
+
+ if (enable) {
+ if (ect_ops(ect_csdev)->enable)
+ ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
+ } else {
+ if (ect_ops(ect_csdev)->disable)
+ ect_ret = ect_ops(ect_csdev)->disable(ect_csdev);
+ }
+
+ /* output warning if ECT enable is preventing trace operation */
+ if (ect_ret)
+ dev_info(&csdev->dev, "Associated ECT device (%s) %s failed\n",
+ dev_name(&ect_csdev->dev), enable ? "enable" : "disable");
+ return ect_ret;
+}
+
static int coresight_enable_sink(struct coresight_device *csdev,
u32 mode, void *data)
{
@@ -228,11 +253,15 @@ static int coresight_enable_sink(struct coresight_device *csdev,
if (!sink_ops(csdev)->enable)
return -EINVAL;

- ret = sink_ops(csdev)->enable(csdev, mode, data);
+ ret = coresight_control_assoc_ectdev(csdev, true);
if (ret)
return ret;
+ ret = sink_ops(csdev)->enable(csdev, mode, data);
+ if (ret) {
+ coresight_control_assoc_ectdev(csdev, false);
+ return ret;
+ }
csdev->enable = true;
-
return 0;
}

@@ -246,6 +275,7 @@ static void coresight_disable_sink(struct coresight_device *csdev)
ret = sink_ops(csdev)->disable(csdev);
if (ret)
return;
+ coresight_control_assoc_ectdev(csdev, false);
csdev->enable = false;
}

@@ -269,8 +299,15 @@ static int coresight_enable_link(struct coresight_device *csdev,
if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && outport < 0)
return outport;

- if (link_ops(csdev)->enable)
- ret = link_ops(csdev)->enable(csdev, inport, outport);
+ if (link_ops(csdev)->enable) {
+ ret = coresight_control_assoc_ectdev(csdev, true);
+ if (!ret) {
+ ret = link_ops(csdev)->enable(csdev, inport, outport);
+ if (ret)
+ coresight_control_assoc_ectdev(csdev, false);
+ }
+ }
+
if (!ret)
csdev->enable = true;

@@ -300,8 +337,10 @@ static void coresight_disable_link(struct coresight_device *csdev,
nr_conns = 1;
}

- if (link_ops(csdev)->disable)
+ if (link_ops(csdev)->disable) {
link_ops(csdev)->disable(csdev, inport, outport);
+ coresight_control_assoc_ectdev(csdev, false);
+ }

for (i = 0; i < nr_conns; i++)
if (atomic_read(&csdev->refcnt[i]) != 0)
@@ -322,9 +361,14 @@ 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, NULL, mode);
+ ret = coresight_control_assoc_ectdev(csdev, true);
if (ret)
return ret;
+ ret = source_ops(csdev)->enable(csdev, NULL, mode);
+ if (ret) {
+ coresight_control_assoc_ectdev(csdev, false);
+ return ret;
+ };
}
csdev->enable = true;
}
@@ -347,6 +391,7 @@ static bool coresight_disable_source(struct coresight_device *csdev)
if (atomic_dec_return(csdev->refcnt) == 0) {
if (source_ops(csdev)->disable)
source_ops(csdev)->disable(csdev, NULL);
+ coresight_control_assoc_ectdev(csdev, false);
csdev->enable = false;
}
return !csdev->enable;
@@ -1252,6 +1297,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)

coresight_fixup_device_conns(csdev);
coresight_fixup_orphan_conns(csdev);
+ cti_add_assoc_to_csdev(csdev);

mutex_unlock(&coresight_mutex);

diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index b3e582d96a34..b5dc9baf0c58 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -163,6 +163,8 @@ struct coresight_connection {
* activated but not yet enabled. Enabling for a _sink_
* appens when a source has been selected for that it.
* @ea: Device attribute for sink representation under PMU directory.
+ * @ect_dev: Associated cross trigger device. Not part of the trace data
+ * path or connections.
*/
struct coresight_device {
struct coresight_platform_data *pdata;
@@ -176,6 +178,8 @@ struct coresight_device {
/* sink specific fields */
bool activated; /* true only if a sink is part of a path */
struct dev_ext_attribute *ea;
+ /* cross trigger handling */
+ struct coresight_device *ect_dev;
};

/*
@@ -341,5 +345,6 @@ static inline bool coresight_loses_context_with_cpu(struct device *dev)
extern int coresight_get_cpu(struct device *dev);

struct coresight_platform_data *coresight_get_platform_data(struct device *dev);
+extern const char *coresight_get_fwnode_name(struct device *dev);

#endif
--
2.17.1