net: dsa: tag_sja1105: be dsa_loop-safe

Add support for tag_sja1105 running on non-sja1105 DSA ports, by making
sure that every time we dereference dp->priv, we check the switch's
dsa_switch_ops (otherwise we access a struct sja1105_port structure that
is in fact something else).

This adds an unconditional build-time dependency between sja1105 being
built as module => tag_sja1105 must also be built as module. This was
there only for PTP before.

Some sane defaults must also take place when not running on sja1105
hardware. These are:

- sja1105_xmit_tpid: the sja1105 driver uses different VLAN protocols
  depending on VLAN awareness and switch revision (when an encapsulated
  VLAN must be sent). Default to 0x8100.

- sja1105_rcv_meta_state_machine: this aggregates PTP frames with their
  metadata timestamp frames. When running on non-sja1105 hardware, don't
  do that and accept all frames unmodified.

- sja1105_defer_xmit: calls sja1105_port_deferred_xmit in sja1105_main.c
  which writes a management route over SPI. When not running on sja1105
  hardware, bypass the SPI write and send the frame as-is.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c
index fe894dc..05ba650 100644 (file)
--- a/drivers/net/dsa/sja1105/sja1105_main.c
+++ b/drivers/net/dsa/sja1105/sja1105_main.c
@@ -28,8 +28,6 @@
 #define SJA1105_UNKNOWN_MULTICAST      0x010000000000ull
 #define SJA1105_DEFAULT_VLAN           (VLAN_N_VID - 1)
 
-static const struct dsa_switch_ops sja1105_switch_ops;
-
 static void sja1105_hw_reset(struct gpio_desc *gpio, unsigned int pulse_len,
                             unsigned int startup_delay)
 {
@@ -3100,7 +3098,7 @@ static void sja1105_teardown(struct dsa_switch *ds)
        sja1105_static_config_free(&priv->static_config);
 }
 
-static const struct dsa_switch_ops sja1105_switch_ops = {
+const struct dsa_switch_ops sja1105_switch_ops = {
        .get_tag_protocol       = sja1105_get_tag_protocol,
        .setup                  = sja1105_setup,
        .teardown               = sja1105_teardown,
@@ -3149,6 +3147,7 @@ static const struct dsa_switch_ops sja1105_switch_ops = {
        .port_bridge_tx_fwd_offload = dsa_tag_8021q_bridge_tx_fwd_offload,
        .port_bridge_tx_fwd_unoffload = dsa_tag_8021q_bridge_tx_fwd_unoffload,
 };
+EXPORT_SYMBOL_GPL(sja1105_switch_ops);
 
 static const struct of_device_id sja1105_dt_ids[];
 

diff --git a/include/linux/dsa/sja1105.h b/include/linux/dsa/sja1105.h
index 0eadc7a..6b0dc9f 100644 (file)
--- a/include/linux/dsa/sja1105.h
+++ b/include/linux/dsa/sja1105.h
@@ -88,4 +88,22 @@ static inline void sja1110_process_meta_tstamp(struct dsa_switch *ds, int port,
 
 #endif /* IS_ENABLED(CONFIG_NET_DSA_SJA1105_PTP) */
 
+#if IS_ENABLED(CONFIG_NET_DSA_SJA1105)
+
+extern const struct dsa_switch_ops sja1105_switch_ops;
+
+static inline bool dsa_port_is_sja1105(struct dsa_port *dp)
+{
+       return dp->ds->ops == &sja1105_switch_ops;
+}
+
+#else
+
+static inline bool dsa_port_is_sja1105(struct dsa_port *dp)
+{
+       return false;
+}
+
+#endif
+
 #endif /* _NET_DSA_SJA1105_H */

diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index 970906e..5482855 100644 (file)
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -138,7 +138,7 @@ config NET_DSA_TAG_LAN9303
 
 config NET_DSA_TAG_SJA1105
        tristate "Tag driver for NXP SJA1105 switches"
-       depends on (NET_DSA_SJA1105 && NET_DSA_SJA1105_PTP) || !NET_DSA_SJA1105 || !NET_DSA_SJA1105_PTP
+       depends on NET_DSA_SJA1105 || !NET_DSA_SJA1105
        select PACKING
        help
          Say Y or M if you want to enable support for tagging frames with the

diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
index 1406bc4..5b80a90 100644 (file)
--- a/net/dsa/tag_sja1105.c
+++ b/net/dsa/tag_sja1105.c
@@ -116,9 +116,14 @@ static inline bool sja1105_is_meta_frame(const struct sk_buff *skb)
 }
 
 /* Calls sja1105_port_deferred_xmit in sja1105_main.c */
-static struct sk_buff *sja1105_defer_xmit(struct sja1105_port *sp,
+static struct sk_buff *sja1105_defer_xmit(struct dsa_port *dp,
                                          struct sk_buff *skb)
 {
+       struct sja1105_port *sp = dp->priv;
+
+       if (!dsa_port_is_sja1105(dp))
+               return skb;
+
        /* Increase refcount so the kfree_skb in dsa_slave_xmit
         * won't really free the packet.
         */
@@ -128,8 +133,13 @@ static struct sk_buff *sja1105_defer_xmit(struct sja1105_port *sp,
        return NULL;
 }
 
-static u16 sja1105_xmit_tpid(struct sja1105_port *sp)
+static u16 sja1105_xmit_tpid(struct dsa_port *dp)
 {
+       struct sja1105_port *sp = dp->priv;
+
+       if (unlikely(!dsa_port_is_sja1105(dp)))
+               return ETH_P_8021Q;
+
        return sp->xmit_tpid;
 }
 
@@ -155,7 +165,7 @@ static struct sk_buff *sja1105_imprecise_xmit(struct sk_buff *skb,
         */
        tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(dp->bridge_num);
 
-       return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp->priv), tx_vid);
+       return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp), tx_vid);
 }
 
 static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
@@ -174,9 +184,9 @@ static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
         * is the .port_deferred_xmit driver callback.
         */
        if (unlikely(sja1105_is_link_local(skb)))
-               return sja1105_defer_xmit(dp->priv, skb);
+               return sja1105_defer_xmit(dp, skb);
 
-       return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp->priv),
+       return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
                             ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
 }
 
@@ -200,7 +210,7 @@ static struct sk_buff *sja1110_xmit(struct sk_buff *skb,
         * tag_8021q TX VLANs.
         */
        if (likely(!sja1105_is_link_local(skb)))
-               return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp->priv),
+               return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
                                     ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
 
        skb_push(skb, SJA1110_HEADER_LEN);
@@ -265,16 +275,16 @@ static struct sk_buff
                                bool is_link_local,
                                bool is_meta)
 {
-       struct sja1105_port *sp;
-       struct dsa_port *dp;
-
-       dp = dsa_slave_to_port(skb->dev);
-       sp = dp->priv;
-
        /* Step 1: A timestampable frame was received.
         * Buffer it until we get its meta frame.
         */
        if (is_link_local) {
+               struct dsa_port *dp = dsa_slave_to_port(skb->dev);
+               struct sja1105_port *sp = dp->priv;
+
+               if (unlikely(!dsa_port_is_sja1105(dp)))
+                       return skb;
+
                if (!test_bit(SJA1105_HWTS_RX_EN, &sp->data->state))
                        /* Do normal processing. */
                        return skb;
@@ -307,8 +317,13 @@ static struct sk_buff
         * frame, which serves no further purpose).
         */
        } else if (is_meta) {
+               struct dsa_port *dp = dsa_slave_to_port(skb->dev);
+               struct sja1105_port *sp = dp->priv;
                struct sk_buff *stampable_skb;
 
+               if (unlikely(!dsa_port_is_sja1105(dp)))
+                       return skb;
+
                /* Drop the meta frame if we're not in the right state
                 * to process it.
                 */