[PATCH v4 06/36] thunderbolt: Do not allocate switch if depth is greater than 6

Mika Westerberg
2019-04-10T13:42:26Z

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@linux.intel.com>
---
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 7c923e16a7d8..bec360eef6cf 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
@@ -714,7 +713,7 @@ 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;
}
@@ -744,7 +743,7 @@ 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 7fa4ab076404..1e29c06947af 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1130,10 +1130,16 @@ 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;

@@ -1150,9 +1156,9 @@ 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 f7b0c43c29a7..93c1ea21feeb 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