Messages in this thread Patch in this message | | | From | Mika Westerberg <> | Subject | [PATCH v3 18/36] thunderbolt: Add helper function to iterate from one port to another | Date | Thu, 28 Mar 2019 15:36:15 +0300 |
| |
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(+)
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index 6f98b3d6eb2a..ecd41f7b7649 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -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 diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h index 5e317ca87786..c797512dfb05 100644 --- a/drivers/thunderbolt/tb.h +++ b/drivers/thunderbolt/tb.h @@ -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); -- 2.20.1
| |