[PATCH v1 19/21] coresight: disable trace path with device being removed
Tingwei Zhang
tingwei at codeaurora.org
Wed Jul 1 03:14:25 EDT 2020
Coresight trace path holds the reference to devices on the path.
Disable trace path before really remove coresight device.
Signed-off-by: Tingwei Zhang <tingwei at codeaurora.org>
---
drivers/hwtracing/coresight/coresight.c | 137 ++++++++++++++++++++++++
1 file changed, 137 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index cf7079f4b99c..0870316ec4c4 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -490,6 +490,138 @@ void coresight_disable_path(struct list_head *path)
}
EXPORT_SYMBOL_GPL(coresight_disable_path);
+/*
+ * coresight_dev_on_path - Check if device is on trace path.
+ *
+ * @path - The trace path to check with.
+ * @csdev - The coresight device to check
+ *
+ * Returns true if the device is on trace path.
+ */
+bool coresight_dev_on_path(struct list_head *path,
+ struct coresight_device *csdev)
+{
+ struct coresight_node *nd;
+
+ list_for_each_entry(nd, path, link) {
+ if (csdev == nd->csdev)
+ return true;
+ }
+ return false;
+}
+
+/*
+ * coresight_disable_path_with - Disable trace path
+ * if trace path has concerned device on it.
+ *
+ * @path - The trace path to check.
+ * @csdev - Concerned coresight device
+ *
+ * Returns true if the device is on trace path.
+ */
+static bool coresight_disable_path_with(struct list_head *path,
+ struct coresight_device *csdev)
+{
+ struct coresight_node *src_nd;
+ struct coresight_device *srcdev;
+ bool ret;
+
+ ret = coresight_dev_on_path(path, csdev);
+ if (ret) {
+ src_nd = list_first_entry(path, struct coresight_node, link);
+ srcdev = src_nd->csdev;
+ if (source_ops(srcdev)->disable)
+ source_ops(srcdev)->disable(srcdev, NULL);
+ srcdev->enable = false;
+ coresight_disable_path(path);
+ coresight_release_path(path);
+ }
+
+ return ret;
+}
+
+/*
+ * __coresight_disable_with - Check cpu trace path and
+ * stm trace path. Disable any path with conerned device.
+ *
+ * @csdev - Concerned coresight device
+ *
+ */
+static void __coresight_disable_with(struct coresight_device *csdev)
+{
+ int cpu;
+ struct list_head *path = NULL;
+
+ for_each_possible_cpu(cpu) {
+ path = per_cpu(tracer_path, cpu);
+ if (path) {
+ if (coresight_disable_path_with(path, csdev))
+ per_cpu(tracer_path, cpu) = NULL;
+ }
+ }
+ if (stm_path) {
+ path = stm_path;
+ if (coresight_disable_path_with(path, csdev))
+ stm_path = NULL;
+ }
+}
+
+static int coresight_disable_match(struct device *dev, void *data)
+{
+ int i;
+ struct coresight_device *csdev, *iterator;
+ struct coresight_connection *conn;
+
+ csdev = data;
+ iterator = to_coresight_device(dev);
+
+ /* No need to check oneself */
+ if (csdev == iterator)
+ return 0;
+
+ /*
+ * Circle throuch all the connection of that component. If we find
+ * a connection whose name matches @csdev, disable path with it.
+ */
+ for (i = 0; i < iterator->pdata->nr_outport; i++) {
+ conn = &iterator->pdata->conns[i];
+
+ if (conn->child_dev == NULL)
+ continue;
+
+ if (csdev->dev.fwnode == conn->child_fwnode) {
+ __coresight_disable_with(iterator);
+
+ /* No need to continue */
+ break;
+ }
+ }
+
+ /*
+ * Returning '0' ensures that all known components on the
+ * bus will be checked.
+ */
+ return 0;
+}
+
+/**
+ * coresight_disable_with - disable any path with @csdev.
+ * @csdev: The device to check.
+ *
+ * Search for all the active paths. If @csdev is part of that path,
+ * disable the whole path. Device with CORESIGHT_DEV_TYPE_HELPER type
+ * is not part of path. Search for its parent device and disable any
+ * path with that device.
+ */
+void coresight_disable_with(struct coresight_device *csdev)
+{
+ if (csdev->type != CORESIGHT_DEV_TYPE_HELPER)
+ return __coresight_disable_with(csdev);
+ if (csdev->pdata->nr_inport)
+ bus_for_each_dev(&coresight_bustype, NULL,
+ csdev, coresight_disable_match);
+}
+
int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data)
{
@@ -1243,6 +1375,7 @@ void coresight_release_platform_data(struct coresight_platform_data *pdata)
for (i = 0; i < pdata->nr_outport; i++) {
if (pdata->conns[i].child_fwnode) {
+ pdata->conns[i].child_dev = NULL;
fwnode_handle_put(pdata->conns[i].child_fwnode);
pdata->conns[i].child_fwnode = NULL;
}
@@ -1349,9 +1482,13 @@ EXPORT_SYMBOL_GPL(coresight_register);
void coresight_unregister(struct coresight_device *csdev)
{
etm_perf_del_symlink_sink(csdev);
+
+ mutex_lock(&coresight_mutex);
+ coresight_disable_with(csdev);
/* Remove references of that device in the topology */
coresight_remove_conns(csdev);
coresight_release_platform_data(csdev->pdata);
+ mutex_unlock(&coresight_mutex);
device_unregister(&csdev->dev);
}
EXPORT_SYMBOL_GPL(coresight_unregister);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
More information about the linux-arm-kernel
mailing list