[PATCH net-next 02/11] net: dsa: tag_ocelot: convert to tagger-owned data

Vladimir Oltean
2021-12-08T20:06:02Z

The felix driver makes very light use of dp->priv, and the tagger is
effectively stateless. dp->priv is practically only needed to set up a
callback to perform deferred xmit of PTP and STP packets using the
ocelot-8021q tagging protocol (the main ocelot tagging protocol makes no
use of dp->priv, although this driver sets up dp->priv irrespective of
actual tagging protocol in use).

struct felix_port (what used to be pointed to by dp->priv) is removed
and replaced with a two-sided structure. The public side of this
structure, visible to the switch driver, is ocelot_8021q_tagger_data.
The private side is ocelot_8021q_tagger_private, and the latter
structure physically encapsulates the former. The public half of the
tagger data structure can be accessed through a helper of the same name
(ocelot_8021q_tagger_data) which also sanity-checks the protocol
currently in use by the switch. The public/private split was requested
by Andrew Lunn.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
drivers/net/dsa/ocelot/felix.c | 64 +++++++----------------------
include/linux/dsa/ocelot.h | 12 +++++-
net/dsa/tag_ocelot_8021q.c | 73 ++++++++++++++++++++++++++++++++--
3 files changed, 94 insertions(+), 55 deletions(-)

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index f76dcf0d369f..a52d0809619e 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -1152,38 +1152,22 @@ static void felix_port_deferred_xmit(struct kthread_work *work)
kfree(xmit_work);
}

-static int felix_port_setup_tagger_data(struct dsa_switch *ds, int port)
+static int felix_connect_tag_protocol(struct dsa_switch *ds,
+ enum dsa_tag_protocol proto)
{
- struct dsa_port *dp = dsa_to_port(ds, port);
- struct ocelot *ocelot = ds->priv;
- struct felix *felix = ocelot_to_felix(ocelot);
- struct felix_port *felix_port;
+ struct ocelot_8021q_tagger_data *tagger_data;

- if (!dsa_port_is_user(dp))
+ switch (proto) {
+ case DSA_TAG_PROTO_OCELOT_8021Q:
+ tagger_data = ocelot_8021q_tagger_data(ds);
+ tagger_data->xmit_work_fn = felix_port_deferred_xmit;
return 0;
-
- felix_port = kzalloc(sizeof(*felix_port), GFP_KERNEL);
- if (!felix_port)
- return -ENOMEM;
-
- felix_port->xmit_worker = felix->xmit_worker;
- felix_port->xmit_work_fn = felix_port_deferred_xmit;
-
- dp->priv = felix_port;
-
- return 0;
-}
-
-static void felix_port_teardown_tagger_data(struct dsa_switch *ds, int port)
-{
- struct dsa_port *dp = dsa_to_port(ds, port);
- struct felix_port *felix_port = dp->priv;
-
- if (!felix_port)
- return;
-
- dp->priv = NULL;
- kfree(felix_port);
+ case DSA_TAG_PROTO_OCELOT:
+ case DSA_TAG_PROTO_SEVILLE:
+ return 0;
+ default:
+ return -EPROTONOSUPPORT;
+ }
}

/* Hardware initialization done here so that we can allocate structures with
@@ -1214,12 +1198,6 @@ static int felix_setup(struct dsa_switch *ds)
}
}

- felix->xmit_worker = kthread_create_worker(0, "felix_xmit");
- if (IS_ERR(felix->xmit_worker)) {
- err = PTR_ERR(felix->xmit_worker);
- goto out_deinit_timestamp;
- }
-
for (port = 0; port < ds->num_ports; port++) {
if (dsa_is_unused_port(ds, port))
continue;
@@ -1230,14 +1208,6 @@ static int felix_setup(struct dsa_switch *ds)
* bits of vlan tag.
*/
felix_port_qos_map_init(ocelot, port);
-
- err = felix_port_setup_tagger_data(ds, port);
- if (err) {
- dev_err(ds->dev,
- "port %d failed to set up tagger data: %pe\n",
- port, ERR_PTR(err));
- goto out_deinit_ports;
- }
}

err = ocelot_devlink_sb_register(ocelot);
@@ -1265,13 +1235,9 @@ static int felix_setup(struct dsa_switch *ds)
if (dsa_is_unused_port(ds, port))
continue;

- felix_port_teardown_tagger_data(ds, port);
ocelot_deinit_port(ocelot, port);
}

- kthread_destroy_worker(felix->xmit_worker);
-
-out_deinit_timestamp:
ocelot_deinit_timestamp(ocelot);
ocelot_deinit(ocelot);

@@ -1300,12 +1266,9 @@ static void felix_teardown(struct dsa_switch *ds)
if (dsa_is_unused_port(ds, port))
continue;

- felix_port_teardown_tagger_data(ds, port);
ocelot_deinit_port(ocelot, port);
}

- kthread_destroy_worker(felix->xmit_worker);
-
ocelot_devlink_sb_unregister(ocelot);
ocelot_deinit_timestamp(ocelot);
ocelot_deinit(ocelot);
@@ -1645,6 +1608,7 @@ felix_mrp_del_ring_role(struct dsa_switch *ds, int port,
const struct dsa_switch_ops felix_switch_ops = {
.get_tag_protocol = felix_get_tag_protocol,
.change_tag_protocol = felix_change_tag_protocol,
+ .connect_tag_protocol = felix_connect_tag_protocol,
.setup = felix_setup,
.teardown = felix_teardown,
.set_ageing_time = felix_set_ageing_time,
diff --git a/include/linux/dsa/ocelot.h b/include/linux/dsa/ocelot.h
index 7ee708ad7df2..dca2969015d8 100644
--- a/include/linux/dsa/ocelot.h
+++ b/include/linux/dsa/ocelot.h
@@ -8,6 +8,7 @@
#include <linux/kthread.h>
#include <linux/packing.h>
#include <linux/skbuff.h>
+#include <net/dsa.h>

struct ocelot_skb_cb {
struct sk_buff *clone;
@@ -168,11 +169,18 @@ struct felix_deferred_xmit_work {
struct kthread_work work;
};

-struct felix_port {
+struct ocelot_8021q_tagger_data {
void (*xmit_work_fn)(struct kthread_work *work);
- struct kthread_worker *xmit_worker;
};

+static inline struct ocelot_8021q_tagger_data *
+ocelot_8021q_tagger_data(struct dsa_switch *ds)
+{
+ BUG_ON(ds->dst->tag_ops->proto != DSA_TAG_PROTO_OCELOT_8021Q);
+
+ return ds->tagger_data;
+}
+
static inline void ocelot_xfh_get_rew_val(void *extraction, u64 *rew_val)
{
packing(extraction, rew_val, 116, 85, OCELOT_TAG_LEN, UNPACK, 0);
diff --git a/net/dsa/tag_ocelot_8021q.c b/net/dsa/tag_ocelot_8021q.c
index a1919ea5e828..fe451f4de7ba 100644
--- a/net/dsa/tag_ocelot_8021q.c
+++ b/net/dsa/tag_ocelot_8021q.c
@@ -12,25 +12,39 @@
#include <linux/dsa/ocelot.h>
#include "dsa_priv.h"

+struct ocelot_8021q_tagger_private {
+ struct ocelot_8021q_tagger_data data; /* Must be first */
+ struct kthread_worker *xmit_worker;
+};
+
static struct sk_buff *ocelot_defer_xmit(struct dsa_port *dp,
struct sk_buff *skb)
{
+ struct ocelot_8021q_tagger_private *priv = dp->ds->tagger_data;
+ struct ocelot_8021q_tagger_data *data = &priv->data;
+ void (*xmit_work_fn)(struct kthread_work *work);
struct felix_deferred_xmit_work *xmit_work;
- struct felix_port *felix_port = dp->priv;
+ struct kthread_worker *xmit_worker;
+
+ xmit_work_fn = data->xmit_work_fn;
+ xmit_worker = priv->xmit_worker;
+
+ if (!xmit_work_fn || !xmit_worker)
+ return NULL;

xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
if (!xmit_work)
return NULL;

/* Calls felix_port_deferred_xmit in felix.c */
- kthread_init_work(&xmit_work->work, felix_port->xmit_work_fn);
+ kthread_init_work(&xmit_work->work, xmit_work_fn);
/* Increase refcount so the kfree_skb in dsa_slave_xmit
* won't really free the packet.
*/
xmit_work->dp = dp;
xmit_work->skb = skb_get(skb);

- kthread_queue_work(felix_port->xmit_worker, &xmit_work->work);
+ kthread_queue_work(xmit_worker, &xmit_work->work);

return NULL;
}
@@ -67,11 +81,64 @@ static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
return skb;
}

+static void ocelot_disconnect(struct dsa_switch_tree *dst)
+{
+ struct ocelot_8021q_tagger_private *priv;
+ struct dsa_port *dp;
+
+ list_for_each_entry(dp, &dst->ports, list) {
+ priv = dp->ds->tagger_data;
+
+ if (!priv)
+ continue;
+
+ if (priv->xmit_worker)
+ kthread_destroy_worker(priv->xmit_worker);
+
+ kfree(priv);
+ dp->ds->tagger_data = NULL;
+ }
+}
+
+static int ocelot_connect(struct dsa_switch_tree *dst)
+{
+ struct ocelot_8021q_tagger_private *priv;
+ struct dsa_port *dp;
+ int err;
+
+ list_for_each_entry(dp, &dst->ports, list) {
+ if (dp->ds->tagger_data)
+ continue;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ priv->xmit_worker = kthread_create_worker(0, "felix_xmit");
+ if (IS_ERR(priv->xmit_worker)) {
+ err = PTR_ERR(priv->xmit_worker);
+ goto out;
+ }
+
+ dp->ds->tagger_data = priv;
+ }
+
+ return 0;
+
+out:
+ ocelot_disconnect(dst);
+ return err;
+}
+
static const struct dsa_device_ops ocelot_8021q_netdev_ops = {
.name = "ocelot-8021q",
.proto = DSA_TAG_PROTO_OCELOT_8021Q,
.xmit = ocelot_xmit,
.rcv = ocelot_rcv,
+ .connect = ocelot_connect,
+ .disconnect = ocelot_disconnect,
.needed_headroom = VLAN_HLEN,
.promisc_on_master = true,
};
--
2.25.1