Merge branch 'fix-circular-dependency-between-sja1105-and-tag_sja1105'

Vladimir Oltean says:

====================
Fix circular dependency between sja1105 and tag_sja1105

As discussed here:
https://lore.kernel.org/netdev/20210908220834.d7gmtnwrorhharna@skbuf/
DSA tagging protocols cannot use symbols exported by switch drivers.

Eliminate the two instances of that from tag_sja1105, and that allows us
to have a working setup with modules again.
====================

Re-applying to net, this was mistakenly applied to net-next,
see first Link.

Link: https://lore.kernel.org/r/20211012114044.2526146-1-vladimir.oltean@nxp.com/
Link: https://lore.kernel.org/r/20210922143726.2431036-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

6 files changed, 63 insertions, 88 deletions

diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c
index 7c0db80eff00..924c3f129992 100644
--- a/drivers/net/dsa/sja1105/sja1105_main.c
+++ b/drivers/net/dsa/sja1105/sja1105_main.c
@@ -3117,7 +3117,7 @@ static void sja1105_teardown(struct dsa_switch *ds)
 	sja1105_static_config_free(&priv->static_config);
 }
 
-const struct dsa_switch_ops sja1105_switch_ops = {
+static const struct dsa_switch_ops sja1105_switch_ops = {
 	.get_tag_protocol	= sja1105_get_tag_protocol,
 	.setup			= sja1105_setup,
 	.teardown		= sja1105_teardown,
@@ -3166,7 +3166,6 @@ 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/drivers/net/dsa/sja1105/sja1105_ptp.c b/drivers/net/dsa/sja1105/sja1105_ptp.c
index 691f6dd7e669..54396992a919 100644
--- a/drivers/net/dsa/sja1105/sja1105_ptp.c
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.c
@@ -64,6 +64,7 @@ enum sja1105_ptp_clk_mode {
 static int sja1105_change_rxtstamping(struct sja1105_private *priv,
 				      bool on)
 {
+	struct sja1105_tagger_data *tagger_data = &priv->tagger_data;
 	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
 	struct sja1105_general_params_entry *general_params;
 	struct sja1105_table *table;
@@ -79,7 +80,7 @@ static int sja1105_change_rxtstamping(struct sja1105_private *priv,
 		priv->tagger_data.stampable_skb = NULL;
 	}
 	ptp_cancel_worker_sync(ptp_data->clock);
-	skb_queue_purge(&ptp_data->skb_txtstamp_queue);
+	skb_queue_purge(&tagger_data->skb_txtstamp_queue);
 	skb_queue_purge(&ptp_data->skb_rxtstamp_queue);
 
 	return sja1105_static_config_reload(priv, SJA1105_RX_HWTSTAMPING);
@@ -452,40 +453,6 @@ bool sja1105_port_rxtstamp(struct dsa_switch *ds, int port,
 	return priv->info->rxtstamp(ds, port, skb);
 }
 
-void sja1110_process_meta_tstamp(struct dsa_switch *ds, int port, u8 ts_id,
-				 enum sja1110_meta_tstamp dir, u64 tstamp)
-{
-	struct sja1105_private *priv = ds->priv;
-	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
-	struct sk_buff *skb, *skb_tmp, *skb_match = NULL;
-	struct skb_shared_hwtstamps shwt = {0};
-
-	/* We don't care about RX timestamps on the CPU port */
-	if (dir == SJA1110_META_TSTAMP_RX)
-		return;
-
-	spin_lock(&ptp_data->skb_txtstamp_queue.lock);
-
-	skb_queue_walk_safe(&ptp_data->skb_txtstamp_queue, skb, skb_tmp) {
-		if (SJA1105_SKB_CB(skb)->ts_id != ts_id)
-			continue;
-
-		__skb_unlink(skb, &ptp_data->skb_txtstamp_queue);
-		skb_match = skb;
-
-		break;
-	}
-
-	spin_unlock(&ptp_data->skb_txtstamp_queue.lock);
-
-	if (WARN_ON(!skb_match))
-		return;
-
-	shwt.hwtstamp = ns_to_ktime(sja1105_ticks_to_ns(tstamp));
-	skb_complete_tx_timestamp(skb_match, &shwt);
-}
-EXPORT_SYMBOL_GPL(sja1110_process_meta_tstamp);
-
 /* In addition to cloning the skb which is done by the common
  * sja1105_port_txtstamp, we need to generate a timestamp ID and save the
  * packet to the TX timestamping queue.
@@ -494,7 +461,6 @@ void sja1110_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb)
 {
 	struct sk_buff *clone = SJA1105_SKB_CB(skb)->clone;
 	struct sja1105_private *priv = ds->priv;
-	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
 	struct sja1105_port *sp = &priv->ports[port];
 	u8 ts_id;
 
@@ -510,7 +476,7 @@ void sja1110_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb)
 
 	spin_unlock(&sp->data->meta_lock);
 
-	skb_queue_tail(&ptp_data->skb_txtstamp_queue, clone);
+	skb_queue_tail(&sp->data->skb_txtstamp_queue, clone);
 }
 
 /* Called from dsa_skb_tx_timestamp. This callback is just to clone
@@ -953,7 +919,7 @@ int sja1105_ptp_clock_register(struct dsa_switch *ds)
 	/* Only used on SJA1105 */
 	skb_queue_head_init(&ptp_data->skb_rxtstamp_queue);
 	/* Only used on SJA1110 */
-	skb_queue_head_init(&ptp_data->skb_txtstamp_queue);
+	skb_queue_head_init(&tagger_data->skb_txtstamp_queue);
 	spin_lock_init(&tagger_data->meta_lock);
 
 	ptp_data->clock = ptp_clock_register(&ptp_data->caps, ds->dev);
@@ -971,6 +937,7 @@ int sja1105_ptp_clock_register(struct dsa_switch *ds)
 void sja1105_ptp_clock_unregister(struct dsa_switch *ds)
 {
 	struct sja1105_private *priv = ds->priv;
+	struct sja1105_tagger_data *tagger_data = &priv->tagger_data;
 	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
 
 	if (IS_ERR_OR_NULL(ptp_data->clock))
@@ -978,7 +945,7 @@ void sja1105_ptp_clock_unregister(struct dsa_switch *ds)
 
 	del_timer_sync(&ptp_data->extts_timer);
 	ptp_cancel_worker_sync(ptp_data->clock);
-	skb_queue_purge(&ptp_data->skb_txtstamp_queue);
+	skb_queue_purge(&tagger_data->skb_txtstamp_queue);
 	skb_queue_purge(&ptp_data->skb_rxtstamp_queue);
 	ptp_clock_unregister(ptp_data->clock);
 	ptp_data->clock = NULL;
diff --git a/drivers/net/dsa/sja1105/sja1105_ptp.h b/drivers/net/dsa/sja1105/sja1105_ptp.h
index 3c874bb4c17b..3ae6b9fdd492 100644
--- a/drivers/net/dsa/sja1105/sja1105_ptp.h
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.h
@@ -8,21 +8,6 @@
 
 #if IS_ENABLED(CONFIG_NET_DSA_SJA1105_PTP)
 
-/* Timestamps are in units of 8 ns clock ticks (equivalent to
- * a fixed 125 MHz clock).
- */
-#define SJA1105_TICK_NS			8
-
-static inline s64 ns_to_sja1105_ticks(s64 ns)
-{
-	return ns / SJA1105_TICK_NS;
-}
-
-static inline s64 sja1105_ticks_to_ns(s64 ticks)
-{
-	return ticks * SJA1105_TICK_NS;
-}
-
 /* Calculate the first base_time in the future that satisfies this
  * relationship:
  *
@@ -77,10 +62,6 @@ struct sja1105_ptp_data {
 	struct timer_list extts_timer;
 	/* Used only on SJA1105 to reconstruct partial timestamps */
 	struct sk_buff_head skb_rxtstamp_queue;
-	/* Used on SJA1110 where meta frames are generated only for
-	 * 2-step TX timestamps
-	 */
-	struct sk_buff_head skb_txtstamp_queue;
 	struct ptp_clock_info caps;
 	struct ptp_clock *clock;
 	struct sja1105_ptp_cmd cmd;
diff --git a/include/linux/dsa/sja1105.h b/include/linux/dsa/sja1105.h
index 171106202fe5..9e07079528a5 100644
--- a/include/linux/dsa/sja1105.h
+++ b/include/linux/dsa/sja1105.h
@@ -48,6 +48,10 @@ struct sja1105_tagger_data {
 	spinlock_t meta_lock;
 	unsigned long state;
 	u8 ts_id;
+	/* Used on SJA1110 where meta frames are generated only for
+	 * 2-step TX timestamps
+	 */
+	struct sk_buff_head skb_txtstamp_queue;
 };
 
 struct sja1105_skb_cb {
@@ -69,42 +73,24 @@ struct sja1105_port {
 	bool hwts_tx_en;
 };
 
-enum sja1110_meta_tstamp {
-	SJA1110_META_TSTAMP_TX = 0,
-	SJA1110_META_TSTAMP_RX = 1,
-};
-
-#if IS_ENABLED(CONFIG_NET_DSA_SJA1105_PTP)
-
-void sja1110_process_meta_tstamp(struct dsa_switch *ds, int port, u8 ts_id,
-				 enum sja1110_meta_tstamp dir, u64 tstamp);
-
-#else
+/* Timestamps are in units of 8 ns clock ticks (equivalent to
+ * a fixed 125 MHz clock).
+ */
+#define SJA1105_TICK_NS			8
 
-static inline void sja1110_process_meta_tstamp(struct dsa_switch *ds, int port,
-					       u8 ts_id, enum sja1110_meta_tstamp dir,
-					       u64 tstamp)
+static inline s64 ns_to_sja1105_ticks(s64 ns)
 {
+	return ns / SJA1105_TICK_NS;
 }
 
-#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)
+static inline s64 sja1105_ticks_to_ns(s64 ticks)
 {
-	return dp->ds->ops == &sja1105_switch_ops;
+	return ticks * SJA1105_TICK_NS;
 }
 
-#else
-
 static inline bool dsa_port_is_sja1105(struct dsa_port *dp)
 {
-	return false;
+	return true;
 }
 
-#endif
-
 #endif /* _NET_DSA_SJA1105_H */
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index 548285539752..bca1b5d66df2 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -138,7 +138,6 @@ 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
 	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 c054f48541c8..2edede9ddac9 100644
--- a/net/dsa/tag_sja1105.c
+++ b/net/dsa/tag_sja1105.c
@@ -4,6 +4,7 @@
 #include <linux/if_vlan.h>
 #include <linux/dsa/sja1105.h>
 #include <linux/dsa/8021q.h>
+#include <linux/skbuff.h>
 #include <linux/packing.h>
 #include "dsa_priv.h"
 
@@ -53,6 +54,11 @@
 #define SJA1110_TX_TRAILER_LEN			4
 #define SJA1110_MAX_PADDING_LEN			15
 
+enum sja1110_meta_tstamp {
+	SJA1110_META_TSTAMP_TX = 0,
+	SJA1110_META_TSTAMP_RX = 1,
+};
+
 /* Similar to is_link_local_ether_addr(hdr->h_dest) but also covers PTP */
 static inline bool sja1105_is_link_local(const struct sk_buff *skb)
 {
@@ -520,6 +526,43 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
 					      is_meta);
 }
 
+static void sja1110_process_meta_tstamp(struct dsa_switch *ds, int port,
+					u8 ts_id, enum sja1110_meta_tstamp dir,
+					u64 tstamp)
+{
+	struct sk_buff *skb, *skb_tmp, *skb_match = NULL;
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct skb_shared_hwtstamps shwt = {0};
+	struct sja1105_port *sp = dp->priv;
+
+	if (!dsa_port_is_sja1105(dp))
+		return;
+
+	/* We don't care about RX timestamps on the CPU port */
+	if (dir == SJA1110_META_TSTAMP_RX)
+		return;
+
+	spin_lock(&sp->data->skb_txtstamp_queue.lock);
+
+	skb_queue_walk_safe(&sp->data->skb_txtstamp_queue, skb, skb_tmp) {
+		if (SJA1105_SKB_CB(skb)->ts_id != ts_id)
+			continue;
+
+		__skb_unlink(skb, &sp->data->skb_txtstamp_queue);
+		skb_match = skb;
+
+		break;
+	}
+
+	spin_unlock(&sp->data->skb_txtstamp_queue.lock);
+
+	if (WARN_ON(!skb_match))
+		return;
+
+	shwt.hwtstamp = ns_to_ktime(sja1105_ticks_to_ns(tstamp));
+	skb_complete_tx_timestamp(skb_match, &shwt);
+}
+
 static struct sk_buff *sja1110_rcv_meta(struct sk_buff *skb, u16 rx_header)
 {
 	u8 *buf = dsa_etype_header_pos_rx(skb) + SJA1110_HEADER_LEN;