static DEFINE_MUTEX(coresight_mutex);
+/**
+ * struct coresight_node - elements of a path, from source to sink
+ * @csdev: Address of an element.
+ * @link: hook to the list.
+ */
+struct coresight_node {
+ struct coresight_device *csdev;
+ struct list_head link;
+};
+
+/*
+ * When operating Coresight drivers from the sysFS interface, only a single
+ * path can exist from a tracer (associated to a CPU) to a sink.
+ */
+static DEFINE_PER_CPU(struct list_head *, sysfs_path);
+
static int coresight_id_match(struct device *dev, void *data)
{
int trace_id, i_trace_id;
csdev, coresight_id_match);
}
-static int coresight_find_link_inport(struct coresight_device *csdev)
+static int coresight_find_link_inport(struct coresight_device *csdev,
+ struct coresight_device *parent)
{
int i;
- struct coresight_device *parent;
struct coresight_connection *conn;
- parent = container_of(csdev->path_link.next,
- struct coresight_device, path_link);
-
for (i = 0; i < parent->nr_outport; i++) {
conn = &parent->conns[i];
if (conn->child_dev == csdev)
return 0;
}
-static int coresight_find_link_outport(struct coresight_device *csdev)
+static int coresight_find_link_outport(struct coresight_device *csdev,
+ struct coresight_device *child)
{
int i;
- struct coresight_device *child;
struct coresight_connection *conn;
- child = container_of(csdev->path_link.prev,
- struct coresight_device, path_link);
-
for (i = 0; i < csdev->nr_outport; i++) {
conn = &csdev->conns[i];
if (conn->child_dev == child)
}
}
-static int coresight_enable_link(struct coresight_device *csdev)
+static int coresight_enable_link(struct coresight_device *csdev,
+ struct coresight_device *parent,
+ struct coresight_device *child)
{
int ret;
int link_subtype;
int refport, inport, outport;
- inport = coresight_find_link_inport(csdev);
- outport = coresight_find_link_outport(csdev);
+ if (!parent || !child)
+ return -EINVAL;
+
+ inport = coresight_find_link_inport(csdev, parent);
+ outport = coresight_find_link_outport(csdev, child);
link_subtype = csdev->subtype.link_subtype;
if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
return 0;
}
-static void coresight_disable_link(struct coresight_device *csdev)
+static void coresight_disable_link(struct coresight_device *csdev,
+ struct coresight_device *parent,
+ struct coresight_device *child)
{
int i, nr_conns;
int link_subtype;
int refport, inport, outport;
- inport = coresight_find_link_inport(csdev);
- outport = coresight_find_link_outport(csdev);
+ if (!parent || !child)
+ return;
+
+ inport = coresight_find_link_inport(csdev, parent);
+ outport = coresight_find_link_outport(csdev, child);
link_subtype = csdev->subtype.link_subtype;
if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
}
}
-static int coresight_enable_path(struct list_head *path)
+void coresight_disable_path(struct list_head *path)
{
- int ret = 0;
- struct coresight_device *cd;
+ struct coresight_node *nd;
+ struct coresight_device *csdev, *parent, *child;
- /*
- * At this point we have a full @path, from source to sink. The
- * sink is the first entry and the source the last one. Go through
- * all the components and enable them one by one.
- */
- list_for_each_entry(cd, path, path_link) {
- if (cd == list_first_entry(path, struct coresight_device,
- path_link)) {
- ret = coresight_enable_sink(cd);
- } else if (list_is_last(&cd->path_link, path)) {
- /*
- * Don't enable the source just yet - this needs to
- * happen at the very end when all links and sink
- * along the path have been configured properly.
- */
- ;
- } else {
- ret = coresight_enable_link(cd);
+ list_for_each_entry(nd, path, link) {
+ csdev = nd->csdev;
+
+ switch (csdev->type) {
+ case CORESIGHT_DEV_TYPE_SINK:
+ case CORESIGHT_DEV_TYPE_LINKSINK:
+ coresight_disable_sink(csdev);
+ break;
+ case CORESIGHT_DEV_TYPE_SOURCE:
+ /* sources are disabled from either sysFS or Perf */
+ break;
+ case CORESIGHT_DEV_TYPE_LINK:
+ parent = list_prev_entry(nd, link)->csdev;
+ child = list_next_entry(nd, link)->csdev;
+ coresight_disable_link(csdev, parent, child);
+ break;
+ default:
+ break;
}
- if (ret)
- goto err;
}
+}
- return 0;
-err:
- list_for_each_entry_continue_reverse(cd, path, path_link) {
- if (cd == list_first_entry(path, struct coresight_device,
- path_link)) {
- coresight_disable_sink(cd);
- } else if (list_is_last(&cd->path_link, path)) {
- ;
- } else {
- coresight_disable_link(cd);
+int coresight_enable_path(struct list_head *path)
+{
+
+ int ret = 0;
+ struct coresight_node *nd;
+ struct coresight_device *csdev, *parent, *child;
+
+ list_for_each_entry_reverse(nd, path, link) {
+ csdev = nd->csdev;
+
+ switch (csdev->type) {
+ case CORESIGHT_DEV_TYPE_SINK:
+ case CORESIGHT_DEV_TYPE_LINKSINK:
+ ret = coresight_enable_sink(csdev);
+ if (ret)
+ goto err;
+ break;
+ case CORESIGHT_DEV_TYPE_SOURCE:
+ /* sources are enabled from either sysFS or Perf */
+ break;
+ case CORESIGHT_DEV_TYPE_LINK:
+ parent = list_prev_entry(nd, link)->csdev;
+ child = list_next_entry(nd, link)->csdev;
+ ret = coresight_enable_link(csdev, parent, child);
+ if (ret)
+ goto err;
+ break;
+ default:
+ goto err;
}
}
+out:
return ret;
+err:
+ coresight_disable_path(path);
+ goto out;
}
-static int coresight_disable_path(struct list_head *path)
+/**
+ * _coresight_build_path - recursively build a path from a @csdev to a sink.
+ * @csdev: The device to start from.
+ * @path: The list to add devices to.
+ *
+ * The tree of Coresight device is traversed until an activated sink is
+ * found. From there the sink is added to the list along with all the
+ * devices that led to that point - the end result is a list from source
+ * to sink. In that list the source is the first device and the sink the
+ * last one.
+ */
+static int _coresight_build_path(struct coresight_device *csdev,
+ struct list_head *path)
{
- struct coresight_device *cd;
+ int i;
+ bool found = false;
+ struct coresight_node *node;
+ struct coresight_connection *conn;
- list_for_each_entry_reverse(cd, path, path_link) {
- if (cd == list_first_entry(path, struct coresight_device,
- path_link)) {
- coresight_disable_sink(cd);
- } else if (list_is_last(&cd->path_link, path)) {
- /*
- * The source has already been stopped, no need
- * to do it again here.
- */
- ;
- } else {
- coresight_disable_link(cd);
+ /* An activated sink has been found. Enqueue the element */
+ if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+ csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) && csdev->activated)
+ goto out;
+
+ /* Not a sink - recursively explore each port found on this element */
+ for (i = 0; i < csdev->nr_outport; i++) {
+ conn = &csdev->conns[i];
+ if (_coresight_build_path(conn->child_dev, path) == 0) {
+ found = true;
+ break;
}
}
+ if (!found)
+ return -ENODEV;
+
+out:
+ /*
+ * A path from this element to a sink has been found. The elements
+ * leading to the sink are already enqueued, all that is left to do
+ * is add a node for this element.
+ */
+ node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);
+ if (!node)
+ return -ENOMEM;
+
+ node->csdev = csdev;
+ list_add(&node->link, path);
+
return 0;
}
-static int coresight_build_paths(struct coresight_device *csdev,
- struct list_head *path,
- bool enable)
+struct list_head *coresight_build_path(struct coresight_device *csdev)
{
- int i, ret = -EINVAL;
- struct coresight_connection *conn;
+ struct list_head *path;
- list_add(&csdev->path_link, path);
+ path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
+ if (!path)
+ return NULL;
- if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
- csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
- csdev->activated) {
- if (enable)
- ret = coresight_enable_path(path);
- else
- ret = coresight_disable_path(path);
- } else {
- for (i = 0; i < csdev->nr_outport; i++) {
- conn = &csdev->conns[i];
- if (coresight_build_paths(conn->child_dev,
- path, enable) == 0)
- ret = 0;
- }
+ INIT_LIST_HEAD(path);
+
+ if (_coresight_build_path(csdev, path)) {
+ kfree(path);
+ path = NULL;
}
- if (list_first_entry(path, struct coresight_device, path_link) != csdev)
- dev_err(&csdev->dev, "wrong device in %s\n", __func__);
+ return path;
+}
- list_del(&csdev->path_link);
+/**
+ * coresight_release_path - release a previously built path.
+ * @path: the path to release.
+ *
+ * Go through all the elements of a path and 1) removed it from the list and
+ * 2) free the memory allocated for each node.
+ */
+void coresight_release_path(struct list_head *path)
+{
+ struct coresight_node *nd, *next;
- return ret;
+ list_for_each_entry_safe(nd, next, path, link) {
+ list_del(&nd->link);
+ kfree(nd);
+ }
+
+ kfree(path);
+ path = NULL;
}
int coresight_enable(struct coresight_device *csdev)
{
int ret = 0;
- LIST_HEAD(path);
+ int cpu;
+ struct list_head *path;
mutex_lock(&coresight_mutex);
if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
if (csdev->enable)
goto out;
- if (coresight_build_paths(csdev, &path, true)) {
- dev_err(&csdev->dev, "building path(s) failed\n");
+ path = coresight_build_path(csdev);
+ if (!path) {
+ pr_err("building path(s) failed\n");
goto out;
}
- if (coresight_enable_source(csdev))
- dev_err(&csdev->dev, "source enable failed\n");
+ ret = coresight_enable_path(path);
+ if (ret)
+ goto err_path;
+
+ ret = coresight_enable_source(csdev);
+ if (ret)
+ goto err_source;
+
+ /*
+ * When working from sysFS it is important to keep track
+ * of the paths that were created so that they can be
+ * undone in 'coresight_disable()'. Since there can only
+ * be a single session per tracer (when working from sysFS)
+ * a per-cpu variable will do just fine.
+ */
+ cpu = source_ops(csdev)->cpu_id(csdev);
+ per_cpu(sysfs_path, cpu) = path;
+
out:
mutex_unlock(&coresight_mutex);
return ret;
+
+err_source:
+ coresight_disable_path(path);
+
+err_path:
+ coresight_release_path(path);
+ goto out;
}
EXPORT_SYMBOL_GPL(coresight_enable);
void coresight_disable(struct coresight_device *csdev)
{
- LIST_HEAD(path);
+ int cpu;
+ struct list_head *path;
mutex_lock(&coresight_mutex);
if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
if (!csdev->enable)
goto out;
+ cpu = source_ops(csdev)->cpu_id(csdev);
+ path = per_cpu(sysfs_path, cpu);
coresight_disable_source(csdev);
- if (coresight_build_paths(csdev, &path, false))
- dev_err(&csdev->dev, "releasing path(s) failed\n");
+ coresight_disable_path(path);
+ coresight_release_path(path);
+ per_cpu(sysfs_path, cpu) = NULL;
out:
mutex_unlock(&coresight_mutex);
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff