1 files changed, 39 insertions, 54 deletions

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index d7a36829649a..6b861e3de4b0 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -223,7 +223,6 @@ struct efx_ptp_timeset {
  * @evt_list: List of MC receive events awaiting packets
  * @evt_free_list: List of free events
  * @evt_lock: Lock for manipulating evt_list and evt_free_list
- * @evt_overflow: Boolean indicating that event list has overflowed
  * @rx_evts: Instantiated events (on evt_list and evt_free_list)
  * @workwq: Work queue for processing pending PTP operations
  * @work: Work task
@@ -275,7 +274,6 @@ struct efx_ptp_data {
         struct list_head evt_list;
         struct list_head evt_free_list;
         spinlock_t evt_lock;
-        bool evt_overflow;
         struct efx_ptp_event_rx rx_evts[MAX_RECEIVE_EVENTS];
         struct workqueue_struct *workwq;
         struct work_struct work;
@@ -768,37 +766,36 @@ efx_ptp_process_times(struct efx_nic *efx, MCDI_DECLARE_STRUCT_PTR(synch_buf),
                 return -EAGAIN;
         }
 
-        /* Convert the NIC time into kernel time. No correction is required-
-         * this time is the output of a firmware process.
-         */
-        mc_time = ptp->nic_to_kernel_time(ptp->timeset[last_good].major,
-                                          ptp->timeset[last_good].minor, 0);
-
-        /* Calculate delay from actual PPS to last_time */
-        delta = ktime_to_timespec(mc_time);
-        delta.tv_nsec +=
-                last_time->ts_real.tv_nsec -
-                (ptp->timeset[last_good].host_start & MC_NANOSECOND_MASK);
-
-        /* It is possible that the seconds rolled over between taking
+        /* Calculate delay from last good sync (host time) to last_time.
+         * It is possible that the seconds rolled over between taking
          * the start reading and the last value written by the host.  The
          * timescales are such that a gap of more than one second is never
-         * expected.
+         * expected.  delta is *not* normalised.
          */
         start_sec = ptp->timeset[last_good].host_start >> MC_NANOSECOND_BITS;
         last_sec = last_time->ts_real.tv_sec & MC_SECOND_MASK;
-        if (start_sec != last_sec) {
-                if (((start_sec + 1) & MC_SECOND_MASK) != last_sec) {
-                        netif_warn(efx, hw, efx->net_dev,
-                                   "PTP bad synchronisation seconds\n");
-                        return -EAGAIN;
-                } else {
-                        delta.tv_sec = 1;
-                }
-        } else {
-                delta.tv_sec = 0;
+        if (start_sec != last_sec &&
+            ((start_sec + 1) & MC_SECOND_MASK) != last_sec) {
+                netif_warn(efx, hw, efx->net_dev,
+                           "PTP bad synchronisation seconds\n");
+                return -EAGAIN;
         }
+        delta.tv_sec = (last_sec - start_sec) & 1;
+        delta.tv_nsec =
+                last_time->ts_real.tv_nsec -
+                (ptp->timeset[last_good].host_start & MC_NANOSECOND_MASK);
+
+        /* Convert the NIC time at last good sync into kernel time.
+         * No correction is required - this time is the output of a
+         * firmware process.
+         */
+        mc_time = ptp->nic_to_kernel_time(ptp->timeset[last_good].major,
+                                          ptp->timeset[last_good].minor, 0);
+
+        /* Calculate delay from NIC top of second to last_time */
+        delta.tv_nsec += ktime_to_timespec(mc_time).tv_nsec;
 
+        /* Set PPS timestamp to match NIC top of second */
         ptp->host_time_pps = *last_time;
         pps_sub_ts(&ptp->host_time_pps, delta);
 
@@ -941,11 +938,6 @@ static void efx_ptp_drop_time_expired_events(struct efx_nic *efx)
                         }
                 }
         }
-        /* If the event overflow flag is set and the event list is now empty
-         * clear the flag to re-enable the overflow warning message.
-         */
-        if (ptp->evt_overflow && list_empty(&ptp->evt_list))
-                ptp->evt_overflow = false;
         spin_unlock_bh(&ptp->evt_lock);
 }
 
@@ -989,11 +981,6 @@ static enum ptp_packet_state efx_ptp_match_rx(struct efx_nic *efx,
                         break;
                 }
         }
-        /* If the event overflow flag is set and the event list is now empty
-         * clear the flag to re-enable the overflow warning message.
-         */
-        if (ptp->evt_overflow && list_empty(&ptp->evt_list))
-                ptp->evt_overflow = false;
         spin_unlock_bh(&ptp->evt_lock);
 
         return rc;
@@ -1147,7 +1134,6 @@ static int efx_ptp_stop(struct efx_nic *efx)
         list_for_each_safe(cursor, next, &efx->ptp_data->evt_list) {
                 list_move(cursor, &efx->ptp_data->evt_free_list);
         }
-        ptp->evt_overflow = false;
         spin_unlock_bh(&efx->ptp_data->evt_lock);
 
         return rc;
@@ -1208,6 +1194,7 @@ static const struct ptp_clock_info efx_phc_clock_info = {
         .n_alarm        = 0,
         .n_ext_ts       = 0,
         .n_per_out      = 0,
+        .n_pins         = 0,
         .pps            = 1,
         .adjfreq        = efx_phc_adjfreq,
         .adjtime        = efx_phc_adjtime,
@@ -1253,7 +1240,6 @@ int efx_ptp_probe(struct efx_nic *efx, struct efx_channel *channel)
         spin_lock_init(&ptp->evt_lock);
         for (pos = 0; pos < MAX_RECEIVE_EVENTS; pos++)
                 list_add(&ptp->rx_evts[pos].link, &ptp->evt_free_list);
-        ptp->evt_overflow = false;
 
         /* Get the NIC PTP attributes and set up time conversions */
         rc = efx_ptp_get_attributes(efx);
@@ -1380,6 +1366,7 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
         struct efx_ptp_match *match = (struct efx_ptp_match *)skb->cb;
         u8 *match_data_012, *match_data_345;
         unsigned int version;
+        u8 *data;
 
         match->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS);
 
@@ -1388,7 +1375,8 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
                 if (!pskb_may_pull(skb, PTP_V1_MIN_LENGTH)) {
                         return false;
                 }
-                version = ntohs(*(__be16 *)&skb->data[PTP_V1_VERSION_OFFSET]);
+                data = skb->data;
+                version = ntohs(*(__be16 *)&data[PTP_V1_VERSION_OFFSET]);
                 if (version != PTP_VERSION_V1) {
                         return false;
                 }
@@ -1396,13 +1384,14 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
                 /* PTP V1 uses all six bytes of the UUID to match the packet
                  * to the timestamp
                  */
-                match_data_012 = skb->data + PTP_V1_UUID_OFFSET;
-                match_data_345 = skb->data + PTP_V1_UUID_OFFSET + 3;
+                match_data_012 = data + PTP_V1_UUID_OFFSET;
+                match_data_345 = data + PTP_V1_UUID_OFFSET + 3;
         } else {
                 if (!pskb_may_pull(skb, PTP_V2_MIN_LENGTH)) {
                         return false;
                 }
-                version = skb->data[PTP_V2_VERSION_OFFSET];
+                data = skb->data;
+                version = data[PTP_V2_VERSION_OFFSET];
                 if ((version & PTP_VERSION_V2_MASK) != PTP_VERSION_V2) {
                         return false;
                 }
@@ -1414,17 +1403,17 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
                  * enhanced mode fixes this issue and uses bytes 0-2
                  * and byte 5-7 of the UUID.
                  */
-                match_data_345 = skb->data + PTP_V2_UUID_OFFSET + 5;
+                match_data_345 = data + PTP_V2_UUID_OFFSET + 5;
                 if (ptp->mode == MC_CMD_PTP_MODE_V2) {
-                        match_data_012 = skb->data + PTP_V2_UUID_OFFSET + 2;
+                        match_data_012 = data + PTP_V2_UUID_OFFSET + 2;
                 } else {
-                        match_data_012 = skb->data + PTP_V2_UUID_OFFSET + 0;
+                        match_data_012 = data + PTP_V2_UUID_OFFSET + 0;
                         BUG_ON(ptp->mode != MC_CMD_PTP_MODE_V2_ENHANCED);
                 }
         }
 
         /* Does this packet require timestamping? */
-        if (ntohs(*(__be16 *)&skb->data[PTP_DPORT_OFFSET]) == PTP_EVENT_PORT) {
+        if (ntohs(*(__be16 *)&data[PTP_DPORT_OFFSET]) == PTP_EVENT_PORT) {
                 match->state = PTP_PACKET_STATE_UNMATCHED;
 
                 /* We expect the sequence number to be in the same position in
@@ -1440,8 +1429,8 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
                                    (match_data_345[0] << 24));
                 match->words[1] = (match_data_345[1]         |
                                    (match_data_345[2] << 8)  |
-                                   (skb->data[PTP_V1_SEQUENCE_OFFSET +
-                                              PTP_V1_SEQUENCE_LENGTH - 1] <<
+                                   (data[PTP_V1_SEQUENCE_OFFSET +
+                                         PTP_V1_SEQUENCE_LENGTH - 1] <<
                                     16));
         } else {
                 match->state = PTP_PACKET_STATE_MATCH_UNWANTED;
@@ -1635,13 +1624,9 @@ static void ptp_event_rx(struct efx_nic *efx, struct efx_ptp_data *ptp)
                 list_add_tail(&evt->link, &ptp->evt_list);
 
                 queue_work(ptp->workwq, &ptp->work);
-        } else if (!ptp->evt_overflow) {
-                /* Log a warning message and set the event overflow flag.
-                 * The message won't be logged again until the event queue
-                 * becomes empty.
-                 */
+        } else if (net_ratelimit()) {
+                /* Log a rate-limited warning message. */
                 netif_err(efx, rx_err, efx->net_dev, "PTP event queue overflow\n");
-                ptp->evt_overflow = true;
         }
         spin_unlock_bh(&ptp->evt_lock);
 }