Merge tag 'x86_mm_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

[linux-2.6-microblaze.git] / net / dsa / master.c

diff --git a/net/dsa/master.c b/net/dsa/master.c
index cb3a5cf..052a977 100644 (file)
--- a/net/dsa/master.c
+++ b/net/dsa/master.c
@@ -280,7 +280,44 @@ static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
        return sprintf(buf, "%s\n",
                       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
 }
-static DEVICE_ATTR_RO(tagging);
+
+static ssize_t tagging_store(struct device *d, struct device_attribute *attr,
+                            const char *buf, size_t count)
+{
+       const struct dsa_device_ops *new_tag_ops, *old_tag_ops;
+       struct net_device *dev = to_net_dev(d);
+       struct dsa_port *cpu_dp = dev->dsa_ptr;
+       int err;
+
+       old_tag_ops = cpu_dp->tag_ops;
+       new_tag_ops = dsa_find_tagger_by_name(buf);
+       /* Bad tagger name, or module is not loaded? */
+       if (IS_ERR(new_tag_ops))
+               return PTR_ERR(new_tag_ops);
+
+       if (new_tag_ops == old_tag_ops)
+               /* Drop the temporarily held duplicate reference, since
+                * the DSA switch tree uses this tagger.
+                */
+               goto out;
+
+       err = dsa_tree_change_tag_proto(cpu_dp->ds->dst, dev, new_tag_ops,
+                                       old_tag_ops);
+       if (err) {
+               /* On failure the old tagger is restored, so we don't need the
+                * driver for the new one.
+                */
+               dsa_tag_driver_put(new_tag_ops);
+               return err;
+       }
+
+       /* On success we no longer need the module for the old tagging protocol
+        */
+out:
+       dsa_tag_driver_put(old_tag_ops);
+       return count;
+}
+static DEVICE_ATTR_RW(tagging);
 
 static struct attribute *dsa_slave_attrs[] = {
        &dev_attr_tagging.attr,