Revert "net: dsa: move sja1110_process_meta_tstamp inside the tagging protocol driver"

This reverts commit 6d709cadfde68dbd12bef12fcced6222226dcb06.

The above change was done to avoid calling symbols exported by the
switch driver from the tagging protocol driver.

With the tagger-owned storage model, we have a new option on our hands,
and that is for the switch driver to provide a data consumer handler in
the form of a function pointer inside the ->connect_tag_protocol()
method. Having a function pointer avoids the problems of the exported
symbols approach.

By creating a handler for metadata frames holding TX timestamps on
SJA1110, we are able to eliminate an skb queue from the tagger data, and
replace it with a simple, and stateless, function pointer. This skb
queue is now handled exclusively by sja1105_ptp.c, which makes the code
easier to follow, as it used to be before the reverted patch.

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

1 files changed, 7 insertions, 43 deletions

diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
index f3c1b31645f5..fe6a6d95bb26 100644
--- a/net/dsa/tag_sja1105.c
+++ b/net/dsa/tag_sja1105.c
@@ -4,7 +4,6 @@
 #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"
 
@@ -54,11 +53,6 @@
 #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)
 {
@@ -539,44 +533,12 @@ 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 sja1105_tagger_data *tagger_data = sja1105_tagger_data(ds);
-	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(&tagger_data->skb_txtstamp_queue.lock);
-
-	skb_queue_walk_safe(&tagger_data->skb_txtstamp_queue, skb, skb_tmp) {
-		if (SJA1105_SKB_CB(skb)->ts_id != ts_id)
-			continue;
-
-		__skb_unlink(skb, &tagger_data->skb_txtstamp_queue);
-		skb_match = skb;
-
-		break;
-	}
-
-	spin_unlock(&tagger_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;
 	int switch_id = SJA1110_RX_HEADER_SWITCH_ID(rx_header);
 	int n_ts = SJA1110_RX_HEADER_N_TS(rx_header);
+	struct sja1105_tagger_data *tagger_data;
 	struct net_device *master = skb->dev;
 	struct dsa_port *cpu_dp;
 	struct dsa_switch *ds;
@@ -590,6 +552,10 @@ static struct sk_buff *sja1110_rcv_meta(struct sk_buff *skb, u16 rx_header)
 		return NULL;
 	}
 
+	tagger_data = sja1105_tagger_data(ds);
+	if (!tagger_data->meta_tstamp_handler)
+		return NULL;
+
 	for (i = 0; i <= n_ts; i++) {
 		u8 ts_id, source_port, dir;
 		u64 tstamp;
@@ -599,8 +565,8 @@ static struct sk_buff *sja1110_rcv_meta(struct sk_buff *skb, u16 rx_header)
 		dir = (buf[1] & BIT(3)) >> 3;
 		tstamp = be64_to_cpu(*(__be64 *)(buf + 2));
 
-		sja1110_process_meta_tstamp(ds, source_port, ts_id, dir,
-					    tstamp);
+		tagger_data->meta_tstamp_handler(ds, source_port, ts_id, dir,
+						 tstamp);
 
 		buf += SJA1110_META_TSTAMP_SIZE;
 	}
@@ -767,8 +733,6 @@ static int sja1105_connect(struct dsa_switch_tree *dst)
 			goto out;
 		}
 
-		/* Only used on SJA1110 */
-		skb_queue_head_init(&tagger_data->skb_txtstamp_queue);
 		spin_lock_init(&tagger_data->meta_lock);
 
 		xmit_worker = kthread_create_worker(0, "dsa%d:%d_xmit",