sfc: Add RX packet timestamping for EF10

The EF10 firmware can optionally insert RX timestamps in the packet
prefix.  These only include the clock minor value.  We must also
enable periodic time sync events on each event queue which provide
the high bits of the clock value.

[bwh: Combined and rebased several changes.
 Added the above description and some sanity checks for inline vs
 separate timestamps.
 Changed efx_rx_skb_attach_timestamp() to read the packet prefix
 from the skb head area.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

drivers/net/ethernet/sfc/ef10.c

@@ -1469,8 +1469,9 @@ static void efx_ef10_rx_init(struct efx_rx_queue *rx_queue)
 	MCDI_SET_DWORD(inbuf, INIT_RXQ_IN_LABEL, efx_rx_queue_index(rx_queue));
 	MCDI_SET_DWORD(inbuf, INIT_RXQ_IN_INSTANCE,
 		       efx_rx_queue_index(rx_queue));
-	MCDI_POPULATE_DWORD_1(inbuf, INIT_RXQ_IN_FLAGS,
-			      INIT_RXQ_IN_FLAG_PREFIX, 1);
+	MCDI_POPULATE_DWORD_2(inbuf, INIT_RXQ_IN_FLAGS,
+			      INIT_RXQ_IN_FLAG_PREFIX, 1,
+			      INIT_RXQ_IN_FLAG_TIMESTAMP, 1);
 	MCDI_SET_DWORD(inbuf, INIT_RXQ_IN_OWNER_ID, 0);
 	MCDI_SET_DWORD(inbuf, INIT_RXQ_IN_PORT_ID, EVB_PORT_ID_ASSIGNED);
 
@@ -3406,6 +3407,119 @@ static void efx_ef10_ptp_write_host_time(struct efx_nic *efx, u32 host_time)
 	_efx_writed(efx, cpu_to_le32(host_time), ER_DZ_MC_DB_LWRD);
 }
 
+static int efx_ef10_rx_enable_timestamping(struct efx_channel *channel,
+					   bool temp)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_TIME_EVENT_SUBSCRIBE_LEN);
+	int rc;
+
+	if (channel->sync_events_state == SYNC_EVENTS_REQUESTED ||
+	    channel->sync_events_state == SYNC_EVENTS_VALID ||
+	    (temp && channel->sync_events_state == SYNC_EVENTS_DISABLED))
+		return 0;
+	channel->sync_events_state = SYNC_EVENTS_REQUESTED;
+
+	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_TIME_EVENT_SUBSCRIBE);
+	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
+	MCDI_SET_DWORD(inbuf, PTP_IN_TIME_EVENT_SUBSCRIBE_QUEUE,
+		       channel->channel);
+
+	rc = efx_mcdi_rpc(channel->efx, MC_CMD_PTP,
+			  inbuf, sizeof(inbuf), NULL, 0, NULL);
+
+	if (rc != 0)
+		channel->sync_events_state = temp ? SYNC_EVENTS_QUIESCENT :
+						    SYNC_EVENTS_DISABLED;
+
+	return rc;
+}
+
+static int efx_ef10_rx_disable_timestamping(struct efx_channel *channel,
+					    bool temp)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_TIME_EVENT_UNSUBSCRIBE_LEN);
+	int rc;
+
+	if (channel->sync_events_state == SYNC_EVENTS_DISABLED ||
+	    (temp && channel->sync_events_state == SYNC_EVENTS_QUIESCENT))
+		return 0;
+	if (channel->sync_events_state == SYNC_EVENTS_QUIESCENT) {
+		channel->sync_events_state = SYNC_EVENTS_DISABLED;
+		return 0;
+	}
+	channel->sync_events_state = temp ? SYNC_EVENTS_QUIESCENT :
+					    SYNC_EVENTS_DISABLED;
+
+	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_TIME_EVENT_UNSUBSCRIBE);
+	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
+	MCDI_SET_DWORD(inbuf, PTP_IN_TIME_EVENT_UNSUBSCRIBE_CONTROL,
+		       MC_CMD_PTP_IN_TIME_EVENT_UNSUBSCRIBE_SINGLE);
+	MCDI_SET_DWORD(inbuf, PTP_IN_TIME_EVENT_UNSUBSCRIBE_QUEUE,
+		       channel->channel);
+
+	rc = efx_mcdi_rpc(channel->efx, MC_CMD_PTP,
+			  inbuf, sizeof(inbuf), NULL, 0, NULL);
+
+	return rc;
+}
+
+static int efx_ef10_ptp_set_ts_sync_events(struct efx_nic *efx, bool en,
+					   bool temp)
+{
+	int (*set)(struct efx_channel *channel, bool temp);
+	struct efx_channel *channel;
+
+	set = en ?
+	      efx_ef10_rx_enable_timestamping :
+	      efx_ef10_rx_disable_timestamping;
+
+	efx_for_each_channel(channel, efx) {
+		int rc = set(channel, temp);
+		if (en && rc != 0) {
+			efx_ef10_ptp_set_ts_sync_events(efx, false, temp);
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+static int efx_ef10_ptp_set_ts_config(struct efx_nic *efx,
+				      struct hwtstamp_config *init)
+{
+	int rc;
+
+	switch (init->rx_filter) {
+	case HWTSTAMP_FILTER_NONE:
+		efx_ef10_ptp_set_ts_sync_events(efx, false, false);
+		/* if TX timestamping is still requested then leave PTP on */
+		return efx_ptp_change_mode(efx,
+					   init->tx_type != HWTSTAMP_TX_OFF, 0);
+	case HWTSTAMP_FILTER_ALL:
+	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
+	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+		init->rx_filter = HWTSTAMP_FILTER_ALL;
+		rc = efx_ptp_change_mode(efx, true, 0);
+		if (!rc)
+			rc = efx_ef10_ptp_set_ts_sync_events(efx, true, false);
+		if (rc)
+			efx_ptp_change_mode(efx, false, 0);
+		return rc;
+	default:
+		return -ERANGE;
+	}
+}
+
 const struct efx_nic_type efx_hunt_a0_nic_type = {
 	.mem_map_size = efx_ef10_mem_map_size,
 	.probe = efx_ef10_probe,
@@ -3484,11 +3598,14 @@ const struct efx_nic_type efx_hunt_a0_nic_type = {
 	.mtd_sync = efx_mcdi_mtd_sync,
 #endif
 	.ptp_write_host_time = efx_ef10_ptp_write_host_time,
+	.ptp_set_ts_sync_events = efx_ef10_ptp_set_ts_sync_events,
+	.ptp_set_ts_config = efx_ef10_ptp_set_ts_config,
 
 	.revision = EFX_REV_HUNT_A0,
 	.max_dma_mask = DMA_BIT_MASK(ESF_DZ_TX_KER_BUF_ADDR_WIDTH),
 	.rx_prefix_size = ES_DZ_RX_PREFIX_SIZE,
 	.rx_hash_offset = ES_DZ_RX_PREFIX_HASH_OFST,
+	.rx_ts_offset = ES_DZ_RX_PREFIX_TSTAMP_OFST,
 	.can_rx_scatter = true,
 	.always_rx_scatter = true,
 	.max_interrupt_mode = EFX_INT_MODE_MSIX,
@@ -3497,4 +3614,6 @@ const struct efx_nic_type efx_hunt_a0_nic_type = {
 			     NETIF_F_RXHASH | NETIF_F_NTUPLE),
 	.mcdi_max_ver = 2,
 	.max_rx_ip_filters = HUNT_FILTER_TBL_ROWS,
+	.hwtstamp_filters = 1 << HWTSTAMP_FILTER_NONE |
+			    1 << HWTSTAMP_FILTER_ALL,
 };

drivers/net/ethernet/sfc/efx.c

@@ -2586,6 +2586,8 @@ static int efx_init_struct(struct efx_nic *efx,
 		NET_IP_ALIGN ? (efx->rx_prefix_size + NET_IP_ALIGN) % 4 : 0;
 	efx->rx_packet_hash_offset =
 		efx->type->rx_hash_offset - efx->type->rx_prefix_size;
+	efx->rx_packet_ts_offset =
+		efx->type->rx_ts_offset - efx->type->rx_prefix_size;
 	spin_lock_init(&efx->stats_lock);
 	mutex_init(&efx->mac_lock);
 	efx->phy_op = &efx_dummy_phy_operations;

drivers/net/ethernet/sfc/mcdi.c

@@ -1018,6 +1018,9 @@ void efx_mcdi_process_event(struct efx_channel *channel,
 	case MCDI_EVENT_CODE_PTP_PPS:
 		efx_ptp_event(efx, event);
 		break;
+	case MCDI_EVENT_CODE_PTP_TIME:
+		efx_time_sync_event(channel, event);
+		break;
 	case MCDI_EVENT_CODE_TX_FLUSH:
 	case MCDI_EVENT_CODE_RX_FLUSH:
 		/* Two flush events will be sent: one to the same event

drivers/net/ethernet/sfc/net_driver.h

@@ -369,6 +369,13 @@ enum efx_rx_alloc_method {
 	RX_ALLOC_METHOD_PAGE = 2,
 };
 
+enum efx_sync_events_state {
+	SYNC_EVENTS_DISABLED = 0,
+	SYNC_EVENTS_QUIESCENT,
+	SYNC_EVENTS_REQUESTED,
+	SYNC_EVENTS_VALID,
+};
+
 /**
  * struct efx_channel - An Efx channel
  *
@@ -408,6 +415,9 @@ enum efx_rx_alloc_method {
  *	by __efx_rx_packet(), if @rx_pkt_n_frags != 0
  * @rx_queue: RX queue for this channel
  * @tx_queue: TX queues for this channel
+ * @sync_events_state: Current state of sync events on this channel
+ * @sync_timestamp_major: Major part of the last ptp sync event
+ * @sync_timestamp_minor: Minor part of the last ptp sync event
  */
 struct efx_channel {
 	struct efx_nic *efx;
@@ -446,6 +456,10 @@ struct efx_channel {
 
 	struct efx_rx_queue rx_queue;
 	struct efx_tx_queue tx_queue[EFX_TXQ_TYPES];
+
+	enum efx_sync_events_state sync_events_state;
+	u32 sync_timestamp_major;
+	u32 sync_timestamp_minor;
 };
 
 /**
@@ -686,6 +700,8 @@ struct vfdi_status;
  *	(valid only if @rx_prefix_size != 0; always negative)
  * @rx_packet_len_offset: Offset of RX packet length from start of packet data
  *	(valid only for NICs that set %EFX_RX_PKT_PREFIX_LEN; always negative)
+ * @rx_packet_ts_offset: Offset of timestamp from start of packet data
+ *	(valid only if channel->sync_timestamps_enabled; always negative)
  * @rx_hash_key: Toeplitz hash key for RSS
  * @rx_indir_table: Indirection table for RSS
  * @rx_scatter: Scatter mode enabled for receives
@@ -820,6 +836,7 @@ struct efx_nic {
 	unsigned int rx_prefix_size;
 	int rx_packet_hash_offset;
 	int rx_packet_len_offset;
+	int rx_packet_ts_offset;
 	u8 rx_hash_key[40];
 	u32 rx_indir_table[128];
 	bool rx_scatter;
@@ -1035,6 +1052,8 @@ struct efx_mtd_partition {
  *	also notifies the driver that a writer has finished using this
  *	partition.
  * @ptp_write_host_time: Send host time to MC as part of sync protocol
+ * @ptp_set_ts_sync_events: Enable or disable sync events for inline RX
+ *	timestamping, possibly only temporarily for the purposes of a reset.
  * @ptp_set_ts_config: Set hardware timestamp configuration.  The flags
  *	and tx_type will already have been validated but this operation
  *	must validate and update rx_filter.
@@ -1047,6 +1066,7 @@ struct efx_mtd_partition {
  * @max_dma_mask: Maximum possible DMA mask
  * @rx_prefix_size: Size of RX prefix before packet data
  * @rx_hash_offset: Offset of RX flow hash within prefix
+ * @rx_ts_offset: Offset of timestamp within prefix
  * @rx_buffer_padding: Size of padding at end of RX packet
  * @can_rx_scatter: NIC is able to scatter packets to multiple buffers
  * @always_rx_scatter: NIC will always scatter packets to multiple buffers
@@ -1158,6 +1178,7 @@ struct efx_nic_type {
 	int (*mtd_sync)(struct mtd_info *mtd);
 #endif
 	void (*ptp_write_host_time)(struct efx_nic *efx, u32 host_time);
+	int (*ptp_set_ts_sync_events)(struct efx_nic *efx, bool en, bool temp);
 	int (*ptp_set_ts_config)(struct efx_nic *efx,
 				 struct hwtstamp_config *init);
 
@@ -1170,6 +1191,7 @@ struct efx_nic_type {
 	u64 max_dma_mask;
 	unsigned int rx_prefix_size;
 	unsigned int rx_hash_offset;
+	unsigned int rx_ts_offset;
 	unsigned int rx_buffer_padding;
 	bool can_rx_scatter;
 	bool always_rx_scatter;

drivers/net/ethernet/sfc/nic.h

@@ -566,6 +566,15 @@ int efx_ptp_change_mode(struct efx_nic *efx, bool enable_wanted,
 			unsigned int new_mode);
 int efx_ptp_tx(struct efx_nic *efx, struct sk_buff *skb);
 void efx_ptp_event(struct efx_nic *efx, efx_qword_t *ev);
+void efx_time_sync_event(struct efx_channel *channel, efx_qword_t *ev);
+void __efx_rx_skb_attach_timestamp(struct efx_channel *channel,
+				   struct sk_buff *skb);
+static inline void efx_rx_skb_attach_timestamp(struct efx_channel *channel,
+					       struct sk_buff *skb)
+{
+	if (channel->sync_events_state == SYNC_EVENTS_VALID)
+		__efx_rx_skb_attach_timestamp(channel, skb);
+}
 void efx_ptp_start_datapath(struct efx_nic *efx);
 void efx_ptp_stop_datapath(struct efx_nic *efx);