@@ -676,6 +676,60 @@ void tb_port_release_out_hopid(struct tb_port *port, int hopid)
ida_simple_remove(&port->out_hopids, hopid);
}
+/**
+ * tb_next_port_on_path() - Return next port for given port on a path
+ * @start: Start port of the walk
+ * @end: End port of the walk
+ * @prev: Previous port (%NULL if this is the first)
+ *
+ * This function can be used to walk from one port to another if they
+ * are connected through zero or more switches. If the @prev is dual
+ * link port, the function follows that link and returns another end on
+ * that same link.
+ *
+ * If the @end port has been reached, return %NULL.
+ *
+ * Domain tb->lock must be held when this function is called.
+ */
+struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
+ struct tb_port *prev)
+{
+ struct tb_port *next;
+
+ if (!prev)
+ return start;
+
+ if (prev->sw == end->sw) {
+ if (prev == end)
+ return NULL;
+ return end;
+ }
+
+ if (start->sw->config.depth < end->sw->config.depth) {
+ if (prev->remote &&
+ prev->remote->sw->config.depth > prev->sw->config.depth)
+ next = prev->remote;
+ else
+ next = tb_port_at(tb_route(end->sw), prev->sw);
+ } else {
+ if (tb_is_upstream_port(prev)) {
+ next = prev->remote;
+ } else {
+ next = tb_upstream_port(prev->sw);
+ /*
+ * Keep the same link if prev and next are both
+ * dual link ports.
+ */
+ if (next->dual_link_port &&
+ next->link_nr != prev->link_nr) {
+ next = next->dual_link_port;
+ }
+ }
+ }
+
+ return next;
+}
+
/**
* tb_pci_port_enable() - Enable PCIe adapter port
* @port: PCIe port to enable
@@ -496,6 +496,8 @@ int tb_port_alloc_in_hopid(struct tb_port *port, int hopid, int max_hopid);
void tb_port_release_in_hopid(struct tb_port *port, int hopid);
int tb_port_alloc_out_hopid(struct tb_port *port, int hopid, int max_hopid);
void tb_port_release_out_hopid(struct tb_port *port, int hopid);
+struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
+ struct tb_port *prev);
int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec);
int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap);
We need to be able to walk from one port to another when we are creating paths where there are multiple switches between two ports. For this reason introduce a new function tb_next_port_on_path(). Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> --- drivers/thunderbolt/switch.c | 54 ++++++++++++++++++++++++++++++++++++ drivers/thunderbolt/tb.h | 2 ++ 2 files changed, 56 insertions(+)