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authorFlorian Fainelli <f.fainelli@gmail.com>2020-01-08 08:06:05 +0300
committerDavid S. Miller <davem@davemloft.net>2020-01-09 03:01:13 +0300
commit4d776482ecc689bdd68627985ac4cb5a6f325953 (patch)
tree799ed8d4daa1e725790048d6b994f3e28647bc6f /net/dsa
parent8d2ff126536320f7243bd05a69703c9b4cd7e46e (diff)
downloadlinux-4d776482ecc689bdd68627985ac4cb5a6f325953.tar.xz
net: dsa: Get information about stacked DSA protocol
It is possible to stack multiple DSA switches in a way that they are not part of the tree (disjoint) but the DSA master of a switch is a DSA slave of another. When that happens switch drivers may have to know this is the case so as to determine whether their tagging protocol has a remove chance of working. This is useful for specific switch drivers such as b53 where devices have been known to be stacked in the wild without the Broadcom tag protocol supporting that feature. This allows b53 to continue supporting those devices by forcing the disabling of Broadcom tags on the outermost switches if necessary. The get_tag_protocol() function is therefore updated to gain an additional enum dsa_tag_protocol argument which denotes the current tagging protocol used by the DSA master we are attached to, else DSA_TAG_PROTO_NONE for the top of the dsa_switch_tree. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dsa')
-rw-r--r--net/dsa/dsa2.c31
-rw-r--r--net/dsa/dsa_priv.h1
-rw-r--r--net/dsa/slave.c4
3 files changed, 31 insertions, 5 deletions
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index c66abbed4daf..c6d81f2baf4e 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -614,6 +614,32 @@ static int dsa_port_parse_dsa(struct dsa_port *dp)
return 0;
}
+static enum dsa_tag_protocol dsa_get_tag_protocol(struct dsa_port *dp,
+ struct net_device *master)
+{
+ enum dsa_tag_protocol tag_protocol = DSA_TAG_PROTO_NONE;
+ struct dsa_switch *mds, *ds = dp->ds;
+ unsigned int mdp_upstream;
+ struct dsa_port *mdp;
+
+ /* It is possible to stack DSA switches onto one another when that
+ * happens the switch driver may want to know if its tagging protocol
+ * is going to work in such a configuration.
+ */
+ if (dsa_slave_dev_check(master)) {
+ mdp = dsa_slave_to_port(master);
+ mds = mdp->ds;
+ mdp_upstream = dsa_upstream_port(mds, mdp->index);
+ tag_protocol = mds->ops->get_tag_protocol(mds, mdp_upstream,
+ DSA_TAG_PROTO_NONE);
+ }
+
+ /* If the master device is not itself a DSA slave in a disjoint DSA
+ * tree, then return immediately.
+ */
+ return ds->ops->get_tag_protocol(ds, dp->index, tag_protocol);
+}
+
static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
{
struct dsa_switch *ds = dp->ds;
@@ -621,20 +647,21 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
const struct dsa_device_ops *tag_ops;
enum dsa_tag_protocol tag_protocol;
- tag_protocol = ds->ops->get_tag_protocol(ds, dp->index);
+ tag_protocol = dsa_get_tag_protocol(dp, master);
tag_ops = dsa_tag_driver_get(tag_protocol);
if (IS_ERR(tag_ops)) {
if (PTR_ERR(tag_ops) == -ENOPROTOOPT)
return -EPROBE_DEFER;
dev_warn(ds->dev, "No tagger for this switch\n");
+ dp->master = NULL;
return PTR_ERR(tag_ops);
}
+ dp->master = master;
dp->type = DSA_PORT_TYPE_CPU;
dp->filter = tag_ops->filter;
dp->rcv = tag_ops->rcv;
dp->tag_ops = tag_ops;
- dp->master = master;
dp->dst = dst;
return 0;
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 8a162605b861..a7662e7a691d 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -157,6 +157,7 @@ extern const struct dsa_device_ops notag_netdev_ops;
void dsa_slave_mii_bus_init(struct dsa_switch *ds);
int dsa_slave_create(struct dsa_port *dp);
void dsa_slave_destroy(struct net_device *slave_dev);
+bool dsa_slave_dev_check(const struct net_device *dev);
int dsa_slave_suspend(struct net_device *slave_dev);
int dsa_slave_resume(struct net_device *slave_dev);
int dsa_slave_register_notifier(void);
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index c1828bdc79dc..088c886e609e 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -22,8 +22,6 @@
#include "dsa_priv.h"
-static bool dsa_slave_dev_check(const struct net_device *dev);
-
/* slave mii_bus handling ***************************************************/
static int dsa_slave_phy_read(struct mii_bus *bus, int addr, int reg)
{
@@ -1473,7 +1471,7 @@ void dsa_slave_destroy(struct net_device *slave_dev)
free_netdev(slave_dev);
}
-static bool dsa_slave_dev_check(const struct net_device *dev)
+bool dsa_slave_dev_check(const struct net_device *dev)
{
return dev->netdev_ops == &dsa_slave_netdev_ops;
}