[PATCH net-next 09/11] Revert "net: dsa: move sja1110_process_meta_tstamp inside the tagging protocol driver"

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

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>
---
drivers/net/dsa/sja1105/sja1105_main.c | 1 +
drivers/net/dsa/sja1105/sja1105_ptp.c | 44 ++++++++++++++++++++---
drivers/net/dsa/sja1105/sja1105_ptp.h | 24 +++++++++++++
include/linux/dsa/sja1105.h | 26 ++++----------
net/dsa/tag_sja1105.c | 50 ++++----------------------
5 files changed, 78 insertions(+), 67 deletions(-)

diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c
index 4f5ea5d6a623..9171fbea588c 100644
--- a/drivers/net/dsa/sja1105/sja1105_main.c
+++ b/drivers/net/dsa/sja1105/sja1105_main.c
@@ -2714,6 +2714,7 @@ static int sja1105_connect_tag_protocol(struct dsa_switch *ds,
case DSA_TAG_PROTO_SJA1105:
tagger_data = sja1105_tagger_data(ds);
tagger_data->xmit_work_fn = sja1105_port_deferred_xmit;
+ tagger_data->meta_tstamp_handler = sja1110_process_meta_tstamp;
return 0;
default:
return -EPROTONOSUPPORT;
diff --git a/drivers/net/dsa/sja1105/sja1105_ptp.c b/drivers/net/dsa/sja1105/sja1105_ptp.c
index b34e4674e217..a9f7e4ae0bb2 100644
--- a/drivers/net/dsa/sja1105/sja1105_ptp.c
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.c
@@ -80,7 +80,7 @@ static int sja1105_change_rxtstamping(struct sja1105_private *priv,
tagger_data->stampable_skb = NULL;
}
ptp_cancel_worker_sync(ptp_data->clock);
- skb_queue_purge(&tagger_data->skb_txtstamp_queue);
+ skb_queue_purge(&ptp_data->skb_txtstamp_queue);
skb_queue_purge(&ptp_data->skb_rxtstamp_queue);

return sja1105_static_config_reload(priv, SJA1105_RX_HWTSTAMPING);
@@ -456,15 +456,48 @@ 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);
+}
+
/* 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.
*/
void sja1110_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb)
{
- struct sja1105_tagger_data *tagger_data = sja1105_tagger_data(ds);
struct sk_buff *clone = SJA1105_SKB_CB(skb)->clone;
struct sja1105_private *priv = ds->priv;
+ struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
u8 ts_id;

skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
@@ -479,7 +512,7 @@ void sja1110_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb)

spin_unlock(&priv->ts_id_lock);

- skb_queue_tail(&tagger_data->skb_txtstamp_queue, clone);
+ skb_queue_tail(&ptp_data->skb_txtstamp_queue, clone);
}

/* Called from dsa_skb_tx_timestamp. This callback is just to clone
@@ -919,6 +952,8 @@ 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);

ptp_data->clock = ptp_clock_register(&ptp_data->caps, ds->dev);
if (IS_ERR_OR_NULL(ptp_data->clock))
@@ -934,7 +969,6 @@ int sja1105_ptp_clock_register(struct dsa_switch *ds)

void sja1105_ptp_clock_unregister(struct dsa_switch *ds)
{
- struct sja1105_tagger_data *tagger_data = sja1105_tagger_data(ds);
struct sja1105_private *priv = ds->priv;
struct sja1105_ptp_data *ptp_data = &priv->ptp_data;

@@ -943,7 +977,7 @@ 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(&tagger_data->skb_txtstamp_queue);
+ skb_queue_purge(&ptp_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 3ae6b9fdd492..416461ee95d2 100644
--- a/drivers/net/dsa/sja1105/sja1105_ptp.h
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.h
@@ -8,6 +8,21 @@

#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:
*
@@ -62,6 +77,10 @@ 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;
@@ -112,6 +131,9 @@ bool sja1105_rxtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb);
bool sja1110_rxtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb);
void sja1110_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb);

+void sja1110_process_meta_tstamp(struct dsa_switch *ds, int port, u8 ts_id,
+ enum sja1110_meta_tstamp dir, u64 tstamp);
+
#else

struct sja1105_ptp_cmd;
@@ -178,6 +200,8 @@ static inline int sja1105_ptp_commit(struct dsa_switch *ds,
#define sja1110_rxtstamp NULL
#define sja1110_txtstamp NULL

+#define sja1110_process_meta_tstamp NULL
+
#endif /* IS_ENABLED(CONFIG_NET_DSA_SJA1105_PTP) */

#endif /* _SJA1105_PTP_H */
diff --git a/include/linux/dsa/sja1105.h b/include/linux/dsa/sja1105.h
index 9f7d42cbbc08..d216211b64f8 100644
--- a/include/linux/dsa/sja1105.h
+++ b/include/linux/dsa/sja1105.h
@@ -37,6 +37,11 @@

#define SJA1105_HWTS_RX_EN 0

+enum sja1110_meta_tstamp {
+ SJA1110_META_TSTAMP_TX = 0,
+ SJA1110_META_TSTAMP_RX = 1,
+};
+
struct sja1105_deferred_xmit_work {
struct dsa_port *dp;
struct sk_buff *skb;
@@ -51,12 +56,10 @@ struct sja1105_tagger_data {
*/
spinlock_t meta_lock;
unsigned long state;
- /* Used on SJA1110 where meta frames are generated only for
- * 2-step TX timestamps
- */
- struct sk_buff_head skb_txtstamp_queue;
struct kthread_worker *xmit_worker;
void (*xmit_work_fn)(struct kthread_work *work);
+ void (*meta_tstamp_handler)(struct dsa_switch *ds, int port, u8 ts_id,
+ enum sja1110_meta_tstamp dir, u64 tstamp);
};

struct sja1105_skb_cb {
@@ -69,21 +72,6 @@ struct sja1105_skb_cb {
#define SJA1105_SKB_CB(skb) \
((struct sja1105_skb_cb *)((skb)->cb))

-/* 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;
-}
-
static inline struct sja1105_tagger_data *
sja1105_tagger_data(struct dsa_switch *ds)
{
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",
--
2.25.1