[PATCH 14/28] thunderbolt: Extend tunnel creation to more than 2 adjacent switches

Mika Westerberg
2019-01-29T15:05:19Z

Now that we can allocate hop IDs per port on a path, we can take
advantage of this and create tunnels covering longer paths than just
between two adjacent switches. PCIe actually does not need this as it is
always a daisy chain between two adjacent switches but this way we do
not need to hard-code creation of the tunnel.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/thunderbolt/path.c | 94 ++++++++++++++++++++++++++++++++++--
drivers/thunderbolt/tb.h | 4 +-
drivers/thunderbolt/tunnel.c | 54 +++++----------------
3 files changed, 106 insertions(+), 46 deletions(-)

diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c
index 48cb15ff4446..122e6a1daf34 100644
--- a/drivers/thunderbolt/path.c
+++ b/drivers/thunderbolt/path.c
@@ -31,23 +31,97 @@ static void tb_dump_hop(struct tb_port *port, struct tb_regs_hop *hop)
}

/**
- * tb_path_alloc() - allocate a thunderbolt path
+ * tb_path_alloc() - allocate a thunderbolt path between two ports
+ * @tb: Domain pointer
+ * @src: Source port of the path
+ * @dst: Destination port of the path
+ * @start_hopid: Hop ID used for the first ingress port in the path
+ * @end_hopid: Hop ID used for the last egress port in the path (%-1 for
+ * automatic allocation)
+ * @link_nr: Preferred link if there are dual links on the path
+ *
+ * Creates path between two ports starting with given @start_hopid. Reserves
+ * hop IDs for each port (they can be different from @start_hopid depending on
+ * how many hop IDs each port already have reserved). If there are dual
+ * links on the path, prioritizes using @link_nr.
*
* Return: Returns a tb_path on success or NULL on failure.
*/
-struct tb_path *tb_path_alloc(struct tb *tb, int num_hops)
+struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src,
+ struct tb_port *dst, int start_hopid,
+ int end_hopid, int link_nr)
{
- struct tb_path *path = kzalloc(sizeof(*path), GFP_KERNEL);
+ struct tb_port *in_port, *out_port;
+ int in_hopid, out_hopid;
+ struct tb_path *path;
+ size_t num_hops;
+ int i, ret;
+
+ path = kzalloc(sizeof(*path), GFP_KERNEL);
if (!path)
return NULL;
+
+ i = 0;
+ tb_for_each_port(in_port, src, dst)
+ i++;
+
+ /* Each hop takes two ports */
+ num_hops = i / 2;
+
path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);
if (!path->hops) {
kfree(path);
return NULL;
}
+
+ in_hopid = start_hopid;
+ out_port = NULL;
+ out_hopid = -1;
+
+ for (i = 0; i < num_hops; i++) {
+ in_port = tb_port_get_next(src, dst, out_port);
+
+ if (in_port->dual_link_port && in_port->link_nr != link_nr)
+ in_port = in_port->dual_link_port;
+
+ ret = tb_port_alloc_in_hopid(in_port, in_hopid, -1);
+ if (ret < 0)
+ goto err;
+ in_hopid = ret;
+
+ out_port = tb_port_get_next(src, dst, in_port);
+ if (!out_port)
+ goto err;
+
+ if (out_port->dual_link_port && out_port->link_nr != link_nr)
+ out_port = out_port->dual_link_port;
+
+ if (end_hopid && i == num_hops - 1)
+ ret = tb_port_alloc_out_hopid(out_port, end_hopid,
+ end_hopid);
+ else
+ ret = tb_port_alloc_out_hopid(out_port, -1, -1);
+
+ if (ret < 0)
+ goto err;
+ out_hopid = ret;
+
+ path->hops[i].in_hop_index = in_hopid;
+ path->hops[i].in_port = in_port;
+ path->hops[i].in_counter_index = -1;
+ path->hops[i].out_port = out_port;
+ path->hops[i].next_hop_index = out_hopid;
+
+ in_hopid = out_hopid;
+ }
+
path->tb = tb;
path->path_length = num_hops;
return path;
+
+err:
+ tb_path_free(path);
+ return NULL;
}

/**
@@ -55,10 +129,24 @@ struct tb_path *tb_path_alloc(struct tb *tb, int num_hops)
*/
void tb_path_free(struct tb_path *path)
{
+ int i;
+
if (path->activated) {
tb_WARN(path->tb, "trying to free an activated path\n")
return;
}
+
+ for (i = 0; i < path->path_length; i++) {
+ const struct tb_path_hop *hop = &path->hops[i];
+
+ if (hop->in_port)
+ tb_port_release_in_hopid(hop->in_port,
+ hop->in_hop_index);
+ if (hop->out_port)
+ tb_port_release_out_hopid(hop->out_port,
+ hop->next_hop_index);
+ }
+
kfree(path->hops);
kfree(path);
}
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 360333caa3c4..ceed33895105 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -460,7 +460,9 @@ int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap);

int tb_pci_port_enable(struct tb_port *port, bool enable);

-struct tb_path *tb_path_alloc(struct tb *tb, int num_hops);
+struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src,
+ struct tb_port *dst, int start_hopid,
+ int end_hopid, int link_nr);
void tb_path_free(struct tb_path *path);
int tb_path_activate(struct tb_path *path);
void tb_path_deactivate(struct tb_path *path);
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index 20ce28276f7a..cdf9ca1c043e 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -12,6 +12,9 @@
#include "tunnel.h"
#include "tb.h"

+/* PCIe adapters use always hop ID of 8 for both directions */
+#define TB_PCI_HOPID 8
+
#define TB_PCI_PATH_DOWN 0
#define TB_PCI_PATH_UP 1

@@ -86,21 +89,13 @@ static void tb_pci_init_path(struct tb_path *path)
* Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
* TB_TYPE_PCIE_DOWN.
*
- * Currently only paths consisting of two hops are supported (that is the
- * ports must be on "adjacent" switches).
- *
- * The paths are hard-coded to use hop 8 (the only working hop id available on
- * my thunderbolt devices). Therefore at most ONE path per device may be
- * activated.
- *
* Return: Returns a tb_tunnel on success or NULL on failure.
*/
struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
struct tb_port *down)
{
- struct tb_path *path_to_up;
- struct tb_path *path_to_down;
struct tb_tunnel *tunnel;
+ struct tb_path *path;

tunnel = tb_tunnel_alloc(tb, 2);
if (!tunnel)
@@ -110,46 +105,21 @@ struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
tunnel->src_port = down;
tunnel->dst_port = up;

- path_to_up = tb_path_alloc(tb, 2);
- if (!path_to_up) {
+ path = tb_path_alloc(tb, down, up, TB_PCI_HOPID, -1, 0);
+ if (!path) {
tb_tunnel_free(tunnel);
return NULL;
}
- tunnel->paths[TB_PCI_PATH_UP] = path_to_up;
+ tb_pci_init_path(path);
+ tunnel->paths[TB_PCI_PATH_UP] = path;

- path_to_down = tb_path_alloc(tb, 2);
- if (!path_to_down) {
+ path = tb_path_alloc(tb, up, down, TB_PCI_HOPID, -1, 0);
+ if (!path) {
tb_tunnel_free(tunnel);
return NULL;
}
- tunnel->paths[TB_PCI_PATH_DOWN] = path_to_down;
-
- tb_pci_init_path(path_to_up);
- tb_pci_init_path(path_to_down);
-
- path_to_up->hops[0].in_port = down;
- path_to_up->hops[0].in_hop_index = 8;
- path_to_up->hops[0].in_counter_index = -1;
- path_to_up->hops[0].out_port = tb_upstream_port(up->sw)->remote;
- path_to_up->hops[0].next_hop_index = 8;
-
- path_to_up->hops[1].in_port = tb_upstream_port(up->sw);
- path_to_up->hops[1].in_hop_index = 8;
- path_to_up->hops[1].in_counter_index = -1;
- path_to_up->hops[1].out_port = up;
- path_to_up->hops[1].next_hop_index = 8;
-
- path_to_down->hops[0].in_port = up;
- path_to_down->hops[0].in_hop_index = 8;
- path_to_down->hops[0].in_counter_index = -1;
- path_to_down->hops[0].out_port = tb_upstream_port(up->sw);
- path_to_down->hops[0].next_hop_index = 8;
-
- path_to_down->hops[1].in_port = tb_upstream_port(up->sw)->remote;
- path_to_down->hops[1].in_hop_index = 8;
- path_to_down->hops[1].in_counter_index = -1;
- path_to_down->hops[1].out_port = down;
- path_to_down->hops[1].next_hop_index = 8;
+ tb_pci_init_path(path);
+ tunnel->paths[TB_PCI_PATH_DOWN] = path;

return tunnel;
}
--
2.20.1