enetc: support PTP Sync packet one-step timestamping

This patch is to add support for PTP Sync packet one-step timestamping.
Since ENETC single-step register has to be configured dynamically per
packet for correctionField offeset and UDP checksum update, current
one-step timestamping packet has to be sent only when the last one
completes transmitting on hardware. So, on the TX, this patch handles
one-step timestamping packet as below:

- Trasmit packet immediately if no other one in transfer, or queue to
  skb queue if there is already one in transfer.
  The test_and_set_bit_lock() is used here to lock and check state.
- Start a work when complete transfer on hardware, to release the bit
  lock and to send one skb in skb queue if has.

And the configuration for one-step timestamping on ENETC before
transmitting is,

- Set one-step timestamping flag in extension BD.
- Write 30 bits current timestamp in tstamp field of extension BD.
- Update PTP Sync packet originTimestamp field with current timestamp.
- Configure single-step register for correctionField offeset and UDP
  checksum update.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 5 deletions

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 96889529383e..d52717bc73c7 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -30,7 +30,7 @@ struct enetc_tx_swbd {
 	enum dma_data_direction dir;
 	u8 is_dma_page:1;
 	u8 check_wb:1;
-	u8 do_tstamp:1;
+	u8 do_twostep_tstamp:1;
 	u8 is_eof:1;
 	u8 is_xdp_tx:1;
 	u8 is_xdp_redirect:1;
@@ -275,11 +275,16 @@ struct psfp_cap {
 /* TODO: more hardware offloads */
 enum enetc_active_offloads {
 	/* 8 bits reserved for TX timestamp types (hwtstamp_tx_types) */
-	ENETC_F_TX_TSTAMP	= BIT(0),
+	ENETC_F_TX_TSTAMP		= BIT(0),
+	ENETC_F_TX_ONESTEP_SYNC_TSTAMP	= BIT(1),
 
-	ENETC_F_RX_TSTAMP	= BIT(8),
-	ENETC_F_QBV		= BIT(9),
-	ENETC_F_QCI		= BIT(10),
+	ENETC_F_RX_TSTAMP		= BIT(8),
+	ENETC_F_QBV			= BIT(9),
+	ENETC_F_QCI			= BIT(10),
+};
+
+enum enetc_flags_bit {
+	ENETC_TX_ONESTEP_TSTAMP_IN_PROGRESS = 0,
 };
 
 /* interrupt coalescing modes */
@@ -324,6 +329,11 @@ struct enetc_ndev_priv {
 	u32 tx_ictt;
 
 	struct bpf_prog *xdp_prog;
+
+	unsigned long flags;
+
+	struct work_struct	tx_onestep_tstamp;
+	struct sk_buff_head	tx_skbs;
 };
 
 /* Messaging */