1 files changed, 61 insertions, 55 deletions

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index 3f93624fc273..07f6baa15c0c 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -99,6 +99,9 @@
 #define PTP_V2_VERSION_LENGTH	1
 #define PTP_V2_VERSION_OFFSET	29
 
+#define PTP_V2_UUID_LENGTH	8
+#define PTP_V2_UUID_OFFSET	48
+
 /* Although PTP V2 UUIDs are comprised a ClockIdentity (8) and PortNumber (2),
  * the MC only captures the last six bytes of the clock identity. These values
  * reflect those, not the ones used in the standard.  The standard permits
@@ -429,13 +432,10 @@ static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
 	unsigned number_readings = (response_length /
 			       MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_LEN);
 	unsigned i;
-	unsigned min;
-	unsigned min_set = 0;
 	unsigned total;
 	unsigned ngood = 0;
 	unsigned last_good = 0;
 	struct efx_ptp_data *ptp = efx->ptp_data;
-	bool min_valid = false;
 	u32 last_sec;
 	u32 start_sec;
 	struct timespec delta;
@@ -443,35 +443,17 @@ static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
 	if (number_readings == 0)
 		return -EAGAIN;
 
-	/* Find minimum value in this set of results, discarding clearly
-	 * erroneous results.
+	/* Read the set of results and increment stats for any results that
+	 * appera to be erroneous.
 	 */
 	for (i = 0; i < number_readings; i++) {
 		efx_ptp_read_timeset(synch_buf, &ptp->timeset[i]);
 		synch_buf += MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_LEN;
-		if (ptp->timeset[i].window > SYNCHRONISATION_GRANULARITY_NS) {
-			if (min_valid) {
-				if (ptp->timeset[i].window < min_set)
-					min_set = ptp->timeset[i].window;
-			} else {
-				min_valid = true;
-				min_set = ptp->timeset[i].window;
-			}
-		}
-	}
-
-	if (min_valid) {
-		if (ptp->base_sync_valid && (min_set > ptp->base_sync_ns))
-			min = ptp->base_sync_ns;
-		else
-			min = min_set;
-	} else {
-		min = SYNCHRONISATION_GRANULARITY_NS;
 	}
 
-	/* Discard excessively long synchronise durations.  The MC times
-	 * when it finishes reading the host time so the corrected window
-	 * time should be fairly constant for a given platform.
+	/* Find the last good host-MC synchronization result. The MC times
+	 * when it finishes reading the host time so the corrected window time
+	 * should be fairly constant for a given platform.
 	 */
 	total = 0;
 	for (i = 0; i < number_readings; i++)
@@ -489,8 +471,8 @@ static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
 
 	if (ngood == 0) {
 		netif_warn(efx, drv, efx->net_dev,
-			   "PTP no suitable synchronisations %dns %dns\n",
-			   ptp->base_sync_ns, min_set);
+			   "PTP no suitable synchronisations %dns\n",
+			   ptp->base_sync_ns);
 		return -EAGAIN;
 	}
 
@@ -1006,43 +988,53 @@ bool efx_ptp_is_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
  * the receive timestamp from the MC - this will probably occur after the
  * packet arrival because of the processing in the MC.
  */
-static void efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
+static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
 {
 	struct efx_nic *efx = channel->efx;
 	struct efx_ptp_data *ptp = efx->ptp_data;
 	struct efx_ptp_match *match = (struct efx_ptp_match *)skb->cb;
-	u8 *data;
+	u8 *match_data_012, *match_data_345;
 	unsigned int version;
 
 	match->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS);
 
 	/* Correct version? */
 	if (ptp->mode == MC_CMD_PTP_MODE_V1) {
-		if (skb->len < PTP_V1_MIN_LENGTH) {
-			netif_receive_skb(skb);
-			return;
+		if (!pskb_may_pull(skb, PTP_V1_MIN_LENGTH)) {
+			return false;
 		}
 		version = ntohs(*(__be16 *)&skb->data[PTP_V1_VERSION_OFFSET]);
 		if (version != PTP_VERSION_V1) {
-			netif_receive_skb(skb);
-			return;
+			return false;
 		}
+
+		/* 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;
 	} else {
-		if (skb->len < PTP_V2_MIN_LENGTH) {
-			netif_receive_skb(skb);
-			return;
+		if (!pskb_may_pull(skb, PTP_V2_MIN_LENGTH)) {
+			return false;
 		}
 		version = skb->data[PTP_V2_VERSION_OFFSET];
-
-		BUG_ON(ptp->mode != MC_CMD_PTP_MODE_V2);
-		BUILD_BUG_ON(PTP_V1_UUID_OFFSET != PTP_V2_MC_UUID_OFFSET);
-		BUILD_BUG_ON(PTP_V1_UUID_LENGTH != PTP_V2_MC_UUID_LENGTH);
-		BUILD_BUG_ON(PTP_V1_SEQUENCE_OFFSET != PTP_V2_SEQUENCE_OFFSET);
-		BUILD_BUG_ON(PTP_V1_SEQUENCE_LENGTH != PTP_V2_SEQUENCE_LENGTH);
-
 		if ((version & PTP_VERSION_V2_MASK) != PTP_VERSION_V2) {
-			netif_receive_skb(skb);
-			return;
+			return false;
+		}
+
+		/* The original V2 implementation uses bytes 2-7 of
+		 * the UUID to match the packet to the timestamp. This
+		 * discards two of the bytes of the MAC address used
+		 * to create the UUID (SF bug 33070).  The PTP V2
+		 * 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;
+		if (ptp->mode == MC_CMD_PTP_MODE_V2) {
+			match_data_012 = skb->data + PTP_V2_UUID_OFFSET + 2;
+		} else {
+			match_data_012 = skb->data + PTP_V2_UUID_OFFSET + 0;
+			BUG_ON(ptp->mode != MC_CMD_PTP_MODE_V2_ENHANCED);
 		}
 	}
 
@@ -1056,14 +1048,19 @@ static void efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
 		timestamps = skb_hwtstamps(skb);
 		memset(timestamps, 0, sizeof(*timestamps));
 
+		/* We expect the sequence number to be in the same position in
+		 * the packet for PTP V1 and V2
+		 */
+		BUILD_BUG_ON(PTP_V1_SEQUENCE_OFFSET != PTP_V2_SEQUENCE_OFFSET);
+		BUILD_BUG_ON(PTP_V1_SEQUENCE_LENGTH != PTP_V2_SEQUENCE_LENGTH);
+
 		/* Extract UUID/Sequence information */
-		data = skb->data + PTP_V1_UUID_OFFSET;
-		match->words[0] = (data[0]         |
-				   (data[1] << 8)  |
-				   (data[2] << 16) |
-				   (data[3] << 24));
-		match->words[1] = (data[4]         |
-				   (data[5] << 8)  |
+		match->words[0] = (match_data_012[0]         |
+				   (match_data_012[1] << 8)  |
+				   (match_data_012[2] << 16) |
+				   (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] <<
 				    16));
@@ -1073,6 +1070,8 @@ static void efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
 
 	skb_queue_tail(&ptp->rxq, skb);
 	queue_work(ptp->workwq, &ptp->work);
+
+	return true;
 }
 
 /* Transmit a PTP packet.  This has to be transmitted by the MC
@@ -1167,7 +1166,7 @@ static int efx_ptp_ts_init(struct efx_nic *efx, struct hwtstamp_config *init)
 	 * timestamped
 	 */
 		init->rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_EVENT;
-		new_mode = MC_CMD_PTP_MODE_V2;
+		new_mode = MC_CMD_PTP_MODE_V2_ENHANCED;
 		enable_wanted = true;
 		break;
 	case HWTSTAMP_FILTER_PTP_V2_EVENT:
@@ -1186,7 +1185,14 @@ static int efx_ptp_ts_init(struct efx_nic *efx, struct hwtstamp_config *init)
 	if (init->tx_type != HWTSTAMP_TX_OFF)
 		enable_wanted = true;
 
+	/* Old versions of the firmware do not support the improved
+	 * UUID filtering option (SF bug 33070).  If the firmware does
+	 * not accept the enhanced mode, fall back to the standard PTP
+	 * v2 UUID filtering.
+	 */
 	rc = efx_ptp_change_mode(efx, enable_wanted, new_mode);
+	if ((rc != 0) && (new_mode == MC_CMD_PTP_MODE_V2_ENHANCED))
+		rc = efx_ptp_change_mode(efx, enable_wanted, MC_CMD_PTP_MODE_V2);
 	if (rc != 0)
 		return rc;