[PATCH 02/28] thunderbolt: Do not allocate switch if depth is greater than 6

[Mika Westerberg]

Maximum depth in Thunderbolt topology is 6 so make sure it is not
possible to allocate switches that exceed the depth limit.

While at it update tb_switch_alloc() to use upper/lower_32_bits()
following tb_switch_alloc_safe_mode().

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
 drivers/thunderbolt/icm.c    |  5 ++---
 drivers/thunderbolt/switch.c | 18 ++++++++++++------
 drivers/thunderbolt/tb.h     |  1 +
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
index e3fc920af682..041e7ab0efd3 100644
--- a/drivers/thunderbolt/icm.c
+++ b/drivers/thunderbolt/icm.c
@@ -42,7 +42,6 @@
 #define ICM_TIMEOUT			5000	/* ms */
 #define ICM_APPROVE_TIMEOUT		10000	/* ms */
 #define ICM_MAX_LINK			4
-#define ICM_MAX_DEPTH			6
 
 /**
  * struct icm - Internal connection manager private data
@@ -709,7 +708,7 @@ icm_fr_device_disconnected(struct tb *tb, const struct icm_pkg_header *hdr)
 	depth = (pkg->link_info & ICM_LINK_INFO_DEPTH_MASK) >>
 		ICM_LINK_INFO_DEPTH_SHIFT;
 
-	if (link > ICM_MAX_LINK || depth > ICM_MAX_DEPTH) {
+	if (link > ICM_MAX_LINK || depth > TB_SWITCH_MAX_DEPTH) {
 		tb_warn(tb, "invalid topology %u.%u, ignoring\n", link, depth);
 		return;
 	}
@@ -739,7 +738,7 @@ icm_fr_xdomain_connected(struct tb *tb, const struct icm_pkg_header *hdr)
 	depth = (pkg->link_info & ICM_LINK_INFO_DEPTH_MASK) >>
 		ICM_LINK_INFO_DEPTH_SHIFT;
 
-	if (link > ICM_MAX_LINK || depth > ICM_MAX_DEPTH) {
+	if (link > ICM_MAX_LINK || depth > TB_SWITCH_MAX_DEPTH) {
 		tb_warn(tb, "invalid topology %u.%u, ignoring\n", link, depth);
 		return;
 	}
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index cd96994dc094..a90d21abed88 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1155,10 +1155,16 @@ static int tb_switch_get_generation(struct tb_switch *sw)
 struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 				  u64 route)
 {
-	int i;
-	int cap;
 	struct tb_switch *sw;
-	int upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
+	int upstream_port;
+	int i, cap, depth;
+
+	/* Make sure we do not exceed maximum topology limit */
+	depth = tb_route_length(route);
+	if (depth > TB_SWITCH_MAX_DEPTH)
+		return NULL;
+
+	upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
 	if (upstream_port < 0)
 		return NULL;
 
@@ -1175,9 +1181,9 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 
 	/* configure switch */
 	sw->config.upstream_port_number = upstream_port;
-	sw->config.depth = tb_route_length(route);
-	sw->config.route_lo = route;
-	sw->config.route_hi = route >> 32;
+	sw->config.depth = depth;
+	sw->config.route_hi = upper_32_bits(route);
+	sw->config.route_lo = lower_32_bits(route);
 	sw->config.enabled = 0;
 
 	/* initialize ports */
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 52584c4003e3..5faec5a8eb98 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -43,6 +43,7 @@ struct tb_switch_nvm {
 };
 
 #define TB_SWITCH_KEY_SIZE		32
+#define TB_SWITCH_MAX_DEPTH		6
 
 /**
  * struct tb_switch - a thunderbolt switch
-- 
2.20.1