[PATCH net-next v2 0/7] net: dsa: change dsa_ptr for a dsa_port

[PATCH net-next v2 0/7] net: dsa: change dsa_ptr for a dsa_port

[Vivien Didelot]

With DSA, a master net_device is physically wired to a dedicated CPU
switch port. For interaction with the DSA layer, the struct net_device
contains a dsa_ptr, which currently points to a dsa_switch_tree object.

This is only valid for a switch fabric with a single CPU port. In order
to support switch fabrics with multiple CPU ports, we first need to
change the type of dsa_ptr to what it really is: a dsa_port object.

This is what this patchset does. The first patches adds a
dsa_master_get_slave helper and cleans up portions of DSA core to make
the next patches more readable. These next patches prepare the xmit and
receive hot paths and finally change dsa_ptr.

Changes in v2:
  - introduce dsa_master_get_slave helper to simplify patch 6
  - keep hot path data at beginning of dsa_port for cacheline 1

Vivien Didelot (7):
  net: dsa: add master helper to look up slaves
  net: dsa: use cpu_dp in master code
  net: dsa: use temporary dsa_device_ops variable
  net: dsa: add tagging ops to port
  net: dsa: prepare master receive hot path
  net: dsa: change dsa_ptr for a dsa_port
  net: dsa: remove tag ops from the switch tree

 include/linux/netdevice.h |  4 ++--
 include/net/dsa.h         | 19 ++++++++-----------
 net/dsa/dsa.c             |  6 +++---
 net/dsa/dsa2.c            | 15 ++++++++++-----
 net/dsa/dsa_priv.h        | 27 +++++++++++++++++++++------
 net/dsa/legacy.c          | 15 ++++++++++-----
 net/dsa/master.c          | 47 ++++++++++++++++++++++-------------------------
 net/dsa/slave.c           |  3 +--
 net/dsa/tag_brcm.c        |  9 ++-------
 net/dsa/tag_dsa.c         | 18 ++----------------
 net/dsa/tag_edsa.c        | 18 ++----------------
 net/dsa/tag_ksz.c         |  9 +++------
 net/dsa/tag_lan9303.c     | 20 ++------------------
 net/dsa/tag_mtk.c         | 16 +++-------------
 net/dsa/tag_qca.c         | 17 +++--------------
 net/dsa/tag_trailer.c     |  9 +++------
 16 files changed, 97 insertions(+), 155 deletions(-)

-- 
2.14.1

[PATCH net-next v2 1/7] net: dsa: add master helper to look up slaves

[Vivien Didelot]

The DSA tagging code does not need to know about the DSA architecture,
it only needs to return the slave device corresponding to the source
port index (and eventually the source device index for cascade-capable
switches) parsed from the frame received on the master device.

For this purpose, provide an inline dsa_master_get_slave helper which
validates the device and port indexes and look up the slave device.

This makes the tagging rcv functions more concise and robust, and also
makes dsa_get_cpu_port obsolete.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
---
 net/dsa/dsa_priv.h    | 24 +++++++++++++++++++-----
 net/dsa/tag_brcm.c    |  9 ++-------
 net/dsa/tag_dsa.c     | 18 ++----------------
 net/dsa/tag_edsa.c    | 18 ++----------------
 net/dsa/tag_ksz.c     |  9 +++------
 net/dsa/tag_lan9303.c | 20 ++------------------
 net/dsa/tag_mtk.c     | 16 +++-------------
 net/dsa/tag_qca.c     | 17 +++--------------
 net/dsa/tag_trailer.c |  9 +++------
 9 files changed, 39 insertions(+), 101 deletions(-)

diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index eccc62776283..d429505dc4e7 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -113,6 +113,25 @@ int dsa_legacy_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
 int dsa_master_ethtool_setup(struct net_device *dev);
 void dsa_master_ethtool_restore(struct net_device *dev);
 
+static inline struct net_device *dsa_master_get_slave(struct net_device *dev,
+						      int device, int port)
+{
+	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_switch *ds;
+
+	if (device < 0 || device >= DSA_MAX_SWITCHES)
+		return NULL;
+
+	ds = dst->ds[device];
+	if (!ds)
+		return NULL;
+
+	if (port < 0 || port >= ds->num_ports)
+		return NULL;
+
+	return ds->ports[port].netdev;
+}
+
 /* port.c */
 int dsa_port_set_state(struct dsa_port *dp, u8 state,
 		       struct switchdev_trans *trans);
@@ -182,9 +201,4 @@ static inline struct net_device *dsa_master_netdev(struct dsa_slave_priv *p)
 	return p->dp->cpu_dp->netdev;
 }
 
-static inline struct dsa_port *dsa_get_cpu_port(struct dsa_switch_tree *dst)
-{
-	return dst->cpu_dp;
-}
-
 #endif
diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
index dbb016434ace..8e4bdb9d9ae3 100644
--- a/net/dsa/tag_brcm.c
+++ b/net/dsa/tag_brcm.c
@@ -92,9 +92,6 @@ static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev
 static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 				    struct packet_type *pt)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
-	struct dsa_switch *ds = cpu_dp->ds;
 	int source_port;
 	u8 *brcm_tag;
 
@@ -117,8 +114,8 @@ static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 	/* Locate which port this is coming from */
 	source_port = brcm_tag[3] & BRCM_EG_PID_MASK;
 
-	/* Validate port against switch setup, either the port is totally */
-	if (source_port >= ds->num_ports || !ds->ports[source_port].netdev)
+	skb->dev = dsa_master_get_slave(dev, 0, source_port);
+	if (!skb->dev)
 		return NULL;
 
 	/* Remove Broadcom tag and update checksum */
@@ -129,8 +126,6 @@ static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 		skb->data - ETH_HLEN - BRCM_TAG_LEN,
 		2 * ETH_ALEN);
 
-	skb->dev = ds->ports[source_port].netdev;
-
 	return skb;
 }
 
diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c
index fbf9ca954773..c77218f173d1 100644
--- a/net/dsa/tag_dsa.c
+++ b/net/dsa/tag_dsa.c
@@ -67,8 +67,6 @@ static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev)
 static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev,
 			       struct packet_type *pt)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds;
 	u8 *dsa_header;
 	int source_device;
 	int source_port;
@@ -93,18 +91,8 @@ static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev,
 	source_device = dsa_header[0] & 0x1f;
 	source_port = (dsa_header[1] >> 3) & 0x1f;
 
-	/*
-	 * Check that the source device exists and that the source
-	 * port is a registered DSA port.
-	 */
-	if (source_device >= DSA_MAX_SWITCHES)
-		return NULL;
-
-	ds = dst->ds[source_device];
-	if (!ds)
-		return NULL;
-
-	if (source_port >= ds->num_ports || !ds->ports[source_port].netdev)
+	skb->dev = dsa_master_get_slave(dev, source_device, source_port);
+	if (!skb->dev)
 		return NULL;
 
 	/*
@@ -153,8 +141,6 @@ static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev,
 			2 * ETH_ALEN);
 	}
 
-	skb->dev = ds->ports[source_port].netdev;
-
 	return skb;
 }
 
diff --git a/net/dsa/tag_edsa.c b/net/dsa/tag_edsa.c
index 76367ba1b2e2..0b83cbe0c9e8 100644
--- a/net/dsa/tag_edsa.c
+++ b/net/dsa/tag_edsa.c
@@ -80,8 +80,6 @@ static struct sk_buff *edsa_xmit(struct sk_buff *skb, struct net_device *dev)
 static struct sk_buff *edsa_rcv(struct sk_buff *skb, struct net_device *dev,
 				struct packet_type *pt)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds;
 	u8 *edsa_header;
 	int source_device;
 	int source_port;
@@ -106,18 +104,8 @@ static struct sk_buff *edsa_rcv(struct sk_buff *skb, struct net_device *dev,
 	source_device = edsa_header[0] & 0x1f;
 	source_port = (edsa_header[1] >> 3) & 0x1f;
 
-	/*
-	 * Check that the source device exists and that the source
-	 * port is a registered DSA port.
-	 */
-	if (source_device >= DSA_MAX_SWITCHES)
-		return NULL;
-
-	ds = dst->ds[source_device];
-	if (!ds)
-		return NULL;
-
-	if (source_port >= ds->num_ports || !ds->ports[source_port].netdev)
+	skb->dev = dsa_master_get_slave(dev, source_device, source_port);
+	if (!skb->dev)
 		return NULL;
 
 	/*
@@ -172,8 +160,6 @@ static struct sk_buff *edsa_rcv(struct sk_buff *skb, struct net_device *dev,
 			2 * ETH_ALEN);
 	}
 
-	skb->dev = ds->ports[source_port].netdev;
-
 	return skb;
 }
 
diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 010ca0a336c4..b241c990cde0 100644
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -80,22 +80,19 @@ static struct sk_buff *ksz_xmit(struct sk_buff *skb, struct net_device *dev)
 static struct sk_buff *ksz_rcv(struct sk_buff *skb, struct net_device *dev,
 			       struct packet_type *pt)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
-	struct dsa_switch *ds = cpu_dp->ds;
 	u8 *tag;
 	int source_port;
 
 	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
 
 	source_port = tag[0] & 7;
-	if (source_port >= ds->num_ports || !ds->ports[source_port].netdev)
+
+	skb->dev = dsa_master_get_slave(dev, 0, source_port);
+	if (!skb->dev)
 		return NULL;
 
 	pskb_trim_rcsum(skb, skb->len - KSZ_EGRESS_TAG_LEN);
 
-	skb->dev = ds->ports[source_port].netdev;
-
 	return skb;
 }
 
diff --git a/net/dsa/tag_lan9303.c b/net/dsa/tag_lan9303.c
index 0b9826105e42..4f211e56c81f 100644
--- a/net/dsa/tag_lan9303.c
+++ b/net/dsa/tag_lan9303.c
@@ -71,17 +71,8 @@ static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev,
 			struct packet_type *pt)
 {
 	u16 *lan9303_tag;
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds;
 	unsigned int source_port;
 
-	ds = dst->ds[0];
-
-	if (unlikely(!ds)) {
-		dev_warn_ratelimited(&dev->dev, "Dropping packet, due to missing DSA switch device\n");
-		return NULL;
-	}
-
 	if (unlikely(!pskb_may_pull(skb, LAN9303_TAG_LEN))) {
 		dev_warn_ratelimited(&dev->dev,
 				     "Dropping packet, cannot pull\n");
@@ -103,16 +94,12 @@ static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev,
 
 	source_port = ntohs(lan9303_tag[1]) & 0x3;
 
-	if (source_port >= ds->num_ports) {
+	skb->dev = dsa_master_get_slave(dev, 0, source_port);
+	if (!skb->dev) {
 		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid source port\n");
 		return NULL;
 	}
 
-	if (!ds->ports[source_port].netdev) {
-		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid netdev or device\n");
-		return NULL;
-	}
-
 	/* remove the special VLAN tag between the MAC addresses
 	 * and the current ethertype field.
 	 */
@@ -120,9 +107,6 @@ static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev,
 	memmove(skb->data - ETH_HLEN, skb->data - (ETH_HLEN + LAN9303_TAG_LEN),
 		2 * ETH_ALEN);
 
-	/* forward the packet to the dedicated interface */
-	skb->dev = ds->ports[source_port].netdev;
-
 	return skb;
 }
 
diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c
index ec8ee5f43255..968586c5d40e 100644
--- a/net/dsa/tag_mtk.c
+++ b/net/dsa/tag_mtk.c
@@ -46,8 +46,6 @@ static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb,
 static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 				   struct packet_type *pt)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds;
 	int port;
 	__be16 *phdr, hdr;
 
@@ -68,20 +66,12 @@ static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 		skb->data - ETH_HLEN - MTK_HDR_LEN,
 		2 * ETH_ALEN);
 
-	/* This protocol doesn't support cascading multiple
-	 * switches so it's safe to assume the switch is first
-	 * in the tree.
-	 */
-	ds = dst->ds[0];
-	if (!ds)
-		return NULL;
-
 	/* Get source port information */
 	port = (hdr & MTK_HDR_RECV_SOURCE_PORT_MASK);
-	if (!ds->ports[port].netdev)
-		return NULL;
 
-	skb->dev = ds->ports[port].netdev;
+	skb->dev = dsa_master_get_slave(dev, 0, port);
+	if (!skb->dev)
+		return NULL;
 
 	return skb;
 }
diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c
index 1d4c70711c0f..8d33d9ebf910 100644
--- a/net/dsa/tag_qca.c
+++ b/net/dsa/tag_qca.c
@@ -65,9 +65,6 @@ static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
 static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 				   struct packet_type *pt)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
-	struct dsa_switch *ds;
 	u8 ver;
 	int port;
 	__be16 *phdr, hdr;
@@ -92,20 +89,12 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 	memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN,
 		ETH_HLEN - QCA_HDR_LEN);
 
-	/* This protocol doesn't support cascading multiple switches so it's
-	 * safe to assume the switch is first in the tree
-	 */
-	ds = cpu_dp->ds;
-	if (!ds)
-		return NULL;
-
 	/* Get source port information */
 	port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
-	if (!ds->ports[port].netdev)
-		return NULL;
 
-	/* Update skb & forward the frame accordingly */
-	skb->dev = ds->ports[port].netdev;
+	skb->dev = dsa_master_get_slave(dev, 0, port);
+	if (!skb->dev)
+		return NULL;
 
 	return skb;
 }
diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c
index d2fd4923aa3e..61668be267f5 100644
--- a/net/dsa/tag_trailer.c
+++ b/net/dsa/tag_trailer.c
@@ -58,9 +58,6 @@ static struct sk_buff *trailer_xmit(struct sk_buff *skb, struct net_device *dev)
 static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev,
 				   struct packet_type *pt)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
-	struct dsa_switch *ds = cpu_dp->ds;
 	u8 *trailer;
 	int source_port;
 
@@ -73,13 +70,13 @@ static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev,
 		return NULL;
 
 	source_port = trailer[1] & 7;
-	if (source_port >= ds->num_ports || !ds->ports[source_port].netdev)
+
+	skb->dev = dsa_master_get_slave(dev, 0, source_port);
+	if (!skb->dev)
 		return NULL;
 
 	pskb_trim_rcsum(skb, skb->len - 4);
 
-	skb->dev = ds->ports[source_port].netdev;
-
 	return skb;
 }
 
-- 
2.14.1

[PATCH net-next v2 2/7] net: dsa: use cpu_dp in master code

[Vivien Didelot]

Make it clear that the master device is linked to a CPU port by using
"cpu_dp" for the dsa_port variable in master.c instead of "port", then
use a "port" variable to describe the port index, as usually seen in
other places of DSA core.

This will make the future patch touching dsa_ptr more readable. There is
no functional changes.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
 net/dsa/master.c | 42 ++++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/net/dsa/master.c b/net/dsa/master.c
index 5e5147ec5a44..ef15d35f1574 100644
--- a/net/dsa/master.c
+++ b/net/dsa/master.c
@@ -17,9 +17,10 @@ static void dsa_master_get_ethtool_stats(struct net_device *dev,
 					 uint64_t *data)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *port = dst->cpu_dp;
-	struct dsa_switch *ds = port->ds;
-	const struct ethtool_ops *ops = port->orig_ethtool_ops;
+	struct dsa_port *cpu_dp = dst->cpu_dp;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch *ds = cpu_dp->ds;
+	int port = cpu_dp->index;
 	int count = 0;
 
 	if (ops && ops->get_sset_count && ops->get_ethtool_stats) {
@@ -28,15 +29,15 @@ static void dsa_master_get_ethtool_stats(struct net_device *dev,
 	}
 
 	if (ds->ops->get_ethtool_stats)
-		ds->ops->get_ethtool_stats(ds, port->index, data + count);
+		ds->ops->get_ethtool_stats(ds, port, data + count);
 }
 
 static int dsa_master_get_sset_count(struct net_device *dev, int sset)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *port = dst->cpu_dp;
-	struct dsa_switch *ds = port->ds;
-	const struct ethtool_ops *ops = port->orig_ethtool_ops;
+	struct dsa_port *cpu_dp = dst->cpu_dp;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch *ds = cpu_dp->ds;
 	int count = 0;
 
 	if (ops && ops->get_sset_count)
@@ -52,16 +53,17 @@ static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
 				   uint8_t *data)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *port = dst->cpu_dp;
-	struct dsa_switch *ds = port->ds;
-	const struct ethtool_ops *ops = port->orig_ethtool_ops;
+	struct dsa_port *cpu_dp = dst->cpu_dp;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch *ds = cpu_dp->ds;
+	int port = cpu_dp->index;
 	int len = ETH_GSTRING_LEN;
 	int mcount = 0, count;
 	unsigned int i;
 	uint8_t pfx[4];
 	uint8_t *ndata;
 
-	snprintf(pfx, sizeof(pfx), "p%.2d", port->index);
+	snprintf(pfx, sizeof(pfx), "p%.2d", port);
 	/* We do not want to be NULL-terminated, since this is a prefix */
 	pfx[sizeof(pfx) - 1] = '_';
 
@@ -76,7 +78,7 @@ static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
 		 * the output after to prepend our CPU port prefix we
 		 * constructed earlier
 		 */
-		ds->ops->get_strings(ds, port->index, ndata);
+		ds->ops->get_strings(ds, port, ndata);
 		count = ds->ops->get_sset_count(ds);
 		for (i = 0; i < count; i++) {
 			memmove(ndata + (i * len + sizeof(pfx)),
@@ -89,17 +91,17 @@ static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
 int dsa_master_ethtool_setup(struct net_device *dev)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *port = dst->cpu_dp;
-	struct dsa_switch *ds = port->ds;
+	struct dsa_port *cpu_dp = dst->cpu_dp;
+	struct dsa_switch *ds = cpu_dp->ds;
 	struct ethtool_ops *ops;
 
 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
 	if (!ops)
 		return -ENOMEM;
 
-	port->orig_ethtool_ops = dev->ethtool_ops;
-	if (port->orig_ethtool_ops)
-		memcpy(ops, port->orig_ethtool_ops, sizeof(*ops));
+	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
+	if (cpu_dp->orig_ethtool_ops)
+		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
 
 	ops->get_sset_count = dsa_master_get_sset_count;
 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
@@ -113,8 +115,8 @@ int dsa_master_ethtool_setup(struct net_device *dev)
 void dsa_master_ethtool_restore(struct net_device *dev)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *port = dst->cpu_dp;
+	struct dsa_port *cpu_dp = dst->cpu_dp;
 
-	dev->ethtool_ops = port->orig_ethtool_ops;
-	port->orig_ethtool_ops = NULL;
+	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
+	cpu_dp->orig_ethtool_ops = NULL;
 }
-- 
2.14.1

[PATCH net-next v2 3/7] net: dsa: use temporary dsa_device_ops variable

[Vivien Didelot]

When resolving the DSA tagging protocol used by a CPU switch, use a
temporary "tag_ops" variable to store the dsa_device_ops instead of
using directly dst->tag_ops. This will make the future patches moving
this pointer around easier to read.

There is no functional changes.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
 net/dsa/dsa2.c   | 8 +++++---
 net/dsa/legacy.c | 8 +++++---
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index dcccaebde708..6a10c5c1639f 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -485,6 +485,7 @@ static int dsa_cpu_parse(struct dsa_port *port, u32 index,
 			 struct dsa_switch_tree *dst,
 			 struct dsa_switch *ds)
 {
+	const struct dsa_device_ops *tag_ops;
 	enum dsa_tag_protocol tag_protocol;
 	struct net_device *ethernet_dev;
 	struct device_node *ethernet;
@@ -514,13 +515,14 @@ static int dsa_cpu_parse(struct dsa_port *port, u32 index,
 	ds->cpu_port_mask |= BIT(index);
 
 	tag_protocol = ds->ops->get_tag_protocol(ds);
-	dst->tag_ops = dsa_resolve_tag_protocol(tag_protocol);
-	if (IS_ERR(dst->tag_ops)) {
+	tag_ops = dsa_resolve_tag_protocol(tag_protocol);
+	if (IS_ERR(tag_ops)) {
 		dev_warn(ds->dev, "No tagger for this switch\n");
 		ds->cpu_port_mask &= ~BIT(index);
-		return PTR_ERR(dst->tag_ops);
+		return PTR_ERR(tag_ops);
 	}
 
+	dst->tag_ops = tag_ops;
 	dst->rcv = dst->tag_ops->rcv;
 
 	return 0;
diff --git a/net/dsa/legacy.c b/net/dsa/legacy.c
index ae505d8e4417..8e849013f69d 100644
--- a/net/dsa/legacy.c
+++ b/net/dsa/legacy.c
@@ -144,13 +144,15 @@ static int dsa_switch_setup_one(struct dsa_switch *ds,
 	 * switch.
 	 */
 	if (dst->cpu_dp->ds == ds) {
+		const struct dsa_device_ops *tag_ops;
 		enum dsa_tag_protocol tag_protocol;
 
 		tag_protocol = ops->get_tag_protocol(ds);
-		dst->tag_ops = dsa_resolve_tag_protocol(tag_protocol);
-		if (IS_ERR(dst->tag_ops))
-			return PTR_ERR(dst->tag_ops);
+		tag_ops = dsa_resolve_tag_protocol(tag_protocol);
+		if (IS_ERR(tag_ops))
+			return PTR_ERR(tag_ops);
 
+		dst->tag_ops = tag_ops;
 		dst->rcv = dst->tag_ops->rcv;
 	}
 
-- 
2.14.1

[PATCH net-next v2 4/7] net: dsa: add tagging ops to port

[Vivien Didelot]

The DSA tagging protocol operations are specific to each CPU port,
thus the dsa_device_ops pointer belongs to the dsa_port structure.

>From now on assign a slave's xmit copy from its CPU port tagging
operations. This will ease the future support for multiple CPU ports.

Also keep the tag_ops at the beginning of the dsa_port structure so that
we ensure copies for hot path are in cacheline 1.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
---
 include/net/dsa.h  | 3 +++
 net/dsa/dsa2.c     | 1 +
 net/dsa/dsa_priv.h | 2 +-
 net/dsa/legacy.c   | 1 +
 net/dsa/slave.c    | 3 +--
 5 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 8dee216a5a9b..4d1df2f086e8 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -175,6 +175,9 @@ struct dsa_mall_tc_entry {
 
 
 struct dsa_port {
+	/* CPU port tagging operations used by master or slave devices */
+	const struct dsa_device_ops *tag_ops;
+
 	struct dsa_switch	*ds;
 	unsigned int		index;
 	const char		*name;
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 6a10c5c1639f..9eac4726dc0c 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -522,6 +522,7 @@ static int dsa_cpu_parse(struct dsa_port *port, u32 index,
 		return PTR_ERR(tag_ops);
 	}
 
+	dst->cpu_dp->tag_ops = tag_ops;
 	dst->tag_ops = tag_ops;
 	dst->rcv = dst->tag_ops->rcv;
 
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index d429505dc4e7..9397291bb3aa 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -66,7 +66,7 @@ struct dsa_notifier_vlan_info {
 };
 
 struct dsa_slave_priv {
-	/* Copy of dp->ds->dst->tag_ops->xmit for faster access in hot path */
+	/* Copy of CPU port xmit for faster access in slave transmit hot path */
 	struct sk_buff *	(*xmit)(struct sk_buff *skb,
 					struct net_device *dev);
 
diff --git a/net/dsa/legacy.c b/net/dsa/legacy.c
index 8e849013f69d..4d374541815a 100644
--- a/net/dsa/legacy.c
+++ b/net/dsa/legacy.c
@@ -152,6 +152,7 @@ static int dsa_switch_setup_one(struct dsa_switch *ds,
 		if (IS_ERR(tag_ops))
 			return PTR_ERR(tag_ops);
 
+		dst->cpu_dp->tag_ops = tag_ops;
 		dst->tag_ops = tag_ops;
 		dst->rcv = dst->tag_ops->rcv;
 	}
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index bf8800de13c1..4b634db05cee 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1117,7 +1117,6 @@ int dsa_slave_resume(struct net_device *slave_dev)
 int dsa_slave_create(struct dsa_port *port, const char *name)
 {
 	struct dsa_switch *ds = port->ds;
-	struct dsa_switch_tree *dst = ds->dst;
 	struct net_device *master;
 	struct net_device *slave_dev;
 	struct dsa_slave_priv *p;
@@ -1162,7 +1161,7 @@ int dsa_slave_create(struct dsa_port *port, const char *name)
 	}
 	p->dp = port;
 	INIT_LIST_HEAD(&p->mall_tc_list);
-	p->xmit = dst->tag_ops->xmit;
+	p->xmit = cpu_dp->tag_ops->xmit;
 
 	p->old_pause = -1;
 	p->old_link = -1;
-- 
2.14.1

[PATCH net-next v2 5/7] net: dsa: prepare master receive hot path

[Vivien Didelot]

In preparation to make DSA master devices point to their corresponding
CPU port instead of the whole tree, add copies of dst and rcv in the
dsa_port structure so that we keep fast access in the receive hot path.

Also keep the copies at the beginning of the dsa_port structure in order
to ensure they are available in cacheline 1.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
---
 include/net/dsa.h | 5 +++++
 net/dsa/dsa2.c    | 4 ++++
 net/dsa/legacy.c  | 4 ++++
 3 files changed, 13 insertions(+)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 4d1df2f086e8..6bda01fa5747 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -178,6 +178,11 @@ struct dsa_port {
 	/* CPU port tagging operations used by master or slave devices */
 	const struct dsa_device_ops *tag_ops;
 
+	/* Copies for faster access in master receive hot path */
+	struct dsa_switch_tree *dst;
+	struct sk_buff *(*rcv)(struct sk_buff *skb, struct net_device *dev,
+			       struct packet_type *pt);
+
 	struct dsa_switch	*ds;
 	unsigned int		index;
 	const char		*name;
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 9eac4726dc0c..b71e3bb478e4 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -524,7 +524,11 @@ static int dsa_cpu_parse(struct dsa_port *port, u32 index,
 
 	dst->cpu_dp->tag_ops = tag_ops;
 	dst->tag_ops = tag_ops;
+
+	/* Make a few copies for faster access in master receive hot path */
+	dst->cpu_dp->rcv = dst->cpu_dp->tag_ops->rcv;
 	dst->rcv = dst->tag_ops->rcv;
+	dst->cpu_dp->dst = dst;
 
 	return 0;
 }
diff --git a/net/dsa/legacy.c b/net/dsa/legacy.c
index 4d374541815a..96c7e3f8b8bb 100644
--- a/net/dsa/legacy.c
+++ b/net/dsa/legacy.c
@@ -154,7 +154,11 @@ static int dsa_switch_setup_one(struct dsa_switch *ds,
 
 		dst->cpu_dp->tag_ops = tag_ops;
 		dst->tag_ops = tag_ops;
+
+		/* Few copies for faster access in master receive hot path */
+		dst->cpu_dp->rcv = dst->cpu_dp->tag_ops->rcv;
 		dst->rcv = dst->tag_ops->rcv;
+		dst->cpu_dp->dst = dst;
 	}
 
 	memcpy(ds->rtable, cd->rtable, sizeof(ds->rtable));
-- 
2.14.1

[PATCH net-next v2 6/7] net: dsa: change dsa_ptr for a dsa_port

[Vivien Didelot]

With DSA, a master net device (CPU facing interface) has a dsa_ptr
pointer to which hangs a dsa_switch_tree. This is not correct because a
master interface is wired to a dedicated switch port, and because we can
theoretically have several master interfaces pointing to several CPU
ports of the same switch fabric.

Change the master interface's dsa_ptr for the CPU dsa_port pointer.
This is a step towards supporting multiple CPU ports.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
---
 include/linux/netdevice.h |  4 ++--
 net/dsa/dsa.c             |  6 +++---
 net/dsa/dsa2.c            |  2 +-
 net/dsa/dsa_priv.h        |  3 ++-
 net/dsa/legacy.c          |  2 +-
 net/dsa/master.c          | 15 +++++----------
 6 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f535779d9dc1..e1d6ef130611 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -55,7 +55,7 @@
 struct netpoll_info;
 struct device;
 struct phy_device;
-struct dsa_switch_tree;
+struct dsa_port;
 
 /* 802.11 specific */
 struct wireless_dev;
@@ -1752,7 +1752,7 @@ struct net_device {
 	struct vlan_info __rcu	*vlan_info;
 #endif
 #if IS_ENABLED(CONFIG_NET_DSA)
-	struct dsa_switch_tree	*dsa_ptr;
+	struct dsa_port		*dsa_ptr;
 #endif
 #if IS_ENABLED(CONFIG_TIPC)
 	struct tipc_bearer __rcu *tipc_ptr;
diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 81c852e32821..51ca2a524a27 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -160,12 +160,12 @@ EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 			  struct packet_type *pt, struct net_device *unused)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
 	struct sk_buff *nskb = NULL;
 	struct pcpu_sw_netstats *s;
 	struct dsa_slave_priv *p;
 
-	if (unlikely(dst == NULL)) {
+	if (unlikely(!cpu_dp)) {
 		kfree_skb(skb);
 		return 0;
 	}
@@ -174,7 +174,7 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 	if (!skb)
 		return 0;
 
-	nskb = dst->rcv(skb, dev, pt);
+	nskb = cpu_dp->rcv(skb, dev, pt);
 	if (!nskb) {
 		kfree_skb(skb);
 		return 0;
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index b71e3bb478e4..62302558f38c 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -438,7 +438,7 @@ static int dsa_dst_apply(struct dsa_switch_tree *dst)
 	 * sent to the tag format's receive function.
 	 */
 	wmb();
-	dst->cpu_dp->netdev->dsa_ptr = dst;
+	dst->cpu_dp->netdev->dsa_ptr = dst->cpu_dp;
 
 	err = dsa_master_ethtool_setup(dst->cpu_dp->netdev);
 	if (err)
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 9397291bb3aa..2850077cc9cc 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -116,7 +116,8 @@ void dsa_master_ethtool_restore(struct net_device *dev);
 static inline struct net_device *dsa_master_get_slave(struct net_device *dev,
 						      int device, int port)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
 	struct dsa_switch *ds;
 
 	if (device < 0 || device >= DSA_MAX_SWITCHES)
diff --git a/net/dsa/legacy.c b/net/dsa/legacy.c
index 96c7e3f8b8bb..71917505a5cc 100644
--- a/net/dsa/legacy.c
+++ b/net/dsa/legacy.c
@@ -607,7 +607,7 @@ static int dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
 	 * sent to the tag format's receive function.
 	 */
 	wmb();
-	dev->dsa_ptr = dst;
+	dev->dsa_ptr = dst->cpu_dp;
 
 	return dsa_master_ethtool_setup(dst->cpu_dp->netdev);
 }
diff --git a/net/dsa/master.c b/net/dsa/master.c
index ef15d35f1574..5f3f57e372e0 100644
--- a/net/dsa/master.c
+++ b/net/dsa/master.c
@@ -16,8 +16,7 @@ static void dsa_master_get_ethtool_stats(struct net_device *dev,
 					 struct ethtool_stats *stats,
 					 uint64_t *data)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dst->cpu_dp;
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 	struct dsa_switch *ds = cpu_dp->ds;
 	int port = cpu_dp->index;
@@ -34,8 +33,7 @@ static void dsa_master_get_ethtool_stats(struct net_device *dev,
 
 static int dsa_master_get_sset_count(struct net_device *dev, int sset)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dst->cpu_dp;
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 	struct dsa_switch *ds = cpu_dp->ds;
 	int count = 0;
@@ -52,8 +50,7 @@ static int dsa_master_get_sset_count(struct net_device *dev, int sset)
 static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
 				   uint8_t *data)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dst->cpu_dp;
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 	struct dsa_switch *ds = cpu_dp->ds;
 	int port = cpu_dp->index;
@@ -90,8 +87,7 @@ static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
 
 int dsa_master_ethtool_setup(struct net_device *dev)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dst->cpu_dp;
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
 	struct dsa_switch *ds = cpu_dp->ds;
 	struct ethtool_ops *ops;
 
@@ -114,8 +110,7 @@ int dsa_master_ethtool_setup(struct net_device *dev)
 
 void dsa_master_ethtool_restore(struct net_device *dev)
 {
-	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_port *cpu_dp = dst->cpu_dp;
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
 
 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
 	cpu_dp->orig_ethtool_ops = NULL;
-- 
2.14.1

[PATCH net-next v2 7/7] net: dsa: remove tag ops from the switch tree

[Vivien Didelot]

Now that the dsa_ptr is a dsa_port instance, there is no need to keep
the tag operations in the dsa_switch_tree structure. Remove it.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
 include/net/dsa.h | 11 -----------
 net/dsa/dsa2.c    |  2 --
 net/dsa/legacy.c  |  2 --
 3 files changed, 15 deletions(-)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 6bda01fa5747..10dceccd9ce8 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -130,11 +130,6 @@ struct dsa_switch_tree {
 	 */
 	struct dsa_platform_data	*pd;
 
-	/* Copy of tag_ops->rcv for faster access in hot path */
-	struct sk_buff *	(*rcv)(struct sk_buff *skb,
-				       struct net_device *dev,
-				       struct packet_type *pt);
-
 	/*
 	 * The switch port to which the CPU is attached.
 	 */
@@ -144,12 +139,6 @@ struct dsa_switch_tree {
 	 * Data for the individual switch chips.
 	 */
 	struct dsa_switch	*ds[DSA_MAX_SWITCHES];
-
-	/*
-	 * Tagging protocol operations for adding and removing an
-	 * encapsulation tag.
-	 */
-	const struct dsa_device_ops *tag_ops;
 };
 
 /* TC matchall action types, only mirroring for now */
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 62302558f38c..54ed054777bd 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -523,11 +523,9 @@ static int dsa_cpu_parse(struct dsa_port *port, u32 index,
 	}
 
 	dst->cpu_dp->tag_ops = tag_ops;
-	dst->tag_ops = tag_ops;
 
 	/* Make a few copies for faster access in master receive hot path */
 	dst->cpu_dp->rcv = dst->cpu_dp->tag_ops->rcv;
-	dst->rcv = dst->tag_ops->rcv;
 	dst->cpu_dp->dst = dst;
 
 	return 0;
diff --git a/net/dsa/legacy.c b/net/dsa/legacy.c
index 71917505a5cc..19ff6e0a21dc 100644
--- a/net/dsa/legacy.c
+++ b/net/dsa/legacy.c
@@ -153,11 +153,9 @@ static int dsa_switch_setup_one(struct dsa_switch *ds,
 			return PTR_ERR(tag_ops);
 
 		dst->cpu_dp->tag_ops = tag_ops;
-		dst->tag_ops = tag_ops;
 
 		/* Few copies for faster access in master receive hot path */
 		dst->cpu_dp->rcv = dst->cpu_dp->tag_ops->rcv;
-		dst->rcv = dst->tag_ops->rcv;
 		dst->cpu_dp->dst = dst;
 	}
 
-- 
2.14.1

Re: [PATCH net-next v2 1/7] net: dsa: add master helper to look up slaves

[Florian Fainelli]

On 09/29/2017 02:19 PM, Vivien Didelot wrote:
> The DSA tagging code does not need to know about the DSA architecture,
> it only needs to return the slave device corresponding to the source
> port index (and eventually the source device index for cascade-capable
> switches) parsed from the frame received on the master device.
> 
> For this purpose, provide an inline dsa_master_get_slave helper which
> validates the device and port indexes and look up the slave device.
> 
> This makes the tagging rcv functions more concise and robust, and also
> makes dsa_get_cpu_port obsolete.
> 
> Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH net-next v2 0/7] net: dsa: change dsa_ptr for a dsa_port

[David Miller]

From: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Date: Fri, 29 Sep 2017 17:19:14 -0400

> With DSA, a master net_device is physically wired to a dedicated CPU
> switch port. For interaction with the DSA layer, the struct net_device
> contains a dsa_ptr, which currently points to a dsa_switch_tree object.
> 
> This is only valid for a switch fabric with a single CPU port. In order
> to support switch fabrics with multiple CPU ports, we first need to
> change the type of dsa_ptr to what it really is: a dsa_port object.
> 
> This is what this patchset does. The first patches adds a
> dsa_master_get_slave helper and cleans up portions of DSA core to make
> the next patches more readable. These next patches prepare the xmit and
> receive hot paths and finally change dsa_ptr.
> 
> Changes in v2:
>   - introduce dsa_master_get_slave helper to simplify patch 6
>   - keep hot path data at beginning of dsa_port for cacheline 1

Series applied, thank you.