[PATCH v4 net-next 11/15] net: enetc: extract enetc_update_ptp_sync_msg() to handle PTP Sync packets

[Wei Fang <wei.fang@nxp.com>]

Move PTP Sync packet processing from enetc_map_tx_buffs() to a new helper
function enetc_update_ptp_sync_msg() to simplify the original function.
Prepare for upcoming ENETC v4 one-step support. There is no functional
change. It is worth mentioning that ENETC_TXBD_TSTAMP is added to replace
0x3fffffff.

Prepare for upcoming ENETC v4 one-step support.

Signed-off-by: Wei Fang <wei.fang@nxp.com>

---
v2: no changes
v3: Change the subject and improve the commit message
v4: Add ENETC_TXBD_TSTAMP to the commit message
---
 drivers/net/ethernet/freescale/enetc/enetc.c  | 129 ++++++++++--------
 .../net/ethernet/freescale/enetc/enetc_hw.h   |   1 +
 2 files changed, 71 insertions(+), 59 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 54ccd7c57961..ef002ed2fdb9 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -221,12 +221,79 @@ static void enetc_unwind_tx_frame(struct enetc_bdr *tx_ring, int count, int i)
 	}
 }
 
+static u32 enetc_update_ptp_sync_msg(struct enetc_ndev_priv *priv,
+				     struct sk_buff *skb)
+{
+	struct enetc_skb_cb *enetc_cb = ENETC_SKB_CB(skb);
+	u16 tstamp_off = enetc_cb->origin_tstamp_off;
+	u16 corr_off = enetc_cb->correction_off;
+	struct enetc_si *si = priv->si;
+	struct enetc_hw *hw = &si->hw;
+	__be32 new_sec_l, new_nsec;
+	__be16 new_sec_h;
+	u32 lo, hi, nsec;
+	u8 *data;
+	u64 sec;
+	u32 val;
+
+	lo = enetc_rd_hot(hw, ENETC_SICTR0);
+	hi = enetc_rd_hot(hw, ENETC_SICTR1);
+	sec = (u64)hi << 32 | lo;
+	nsec = do_div(sec, 1000000000);
+
+	/* Update originTimestamp field of Sync packet
+	 * - 48 bits seconds field
+	 * - 32 bits nanseconds field
+	 *
+	 * In addition, the UDP checksum needs to be updated
+	 * by software after updating originTimestamp field,
+	 * otherwise the hardware will calculate the wrong
+	 * checksum when updating the correction field and
+	 * update it to the packet.
+	 */
+
+	data = skb_mac_header(skb);
+	new_sec_h = htons((sec >> 32) & 0xffff);
+	new_sec_l = htonl(sec & 0xffffffff);
+	new_nsec = htonl(nsec);
+	if (enetc_cb->udp) {
+		struct udphdr *uh = udp_hdr(skb);
+		__be32 old_sec_l, old_nsec;
+		__be16 old_sec_h;
+
+		old_sec_h = *(__be16 *)(data + tstamp_off);
+		inet_proto_csum_replace2(&uh->check, skb, old_sec_h,
+					 new_sec_h, false);
+
+		old_sec_l = *(__be32 *)(data + tstamp_off + 2);
+		inet_proto_csum_replace4(&uh->check, skb, old_sec_l,
+					 new_sec_l, false);
+
+		old_nsec = *(__be32 *)(data + tstamp_off + 6);
+		inet_proto_csum_replace4(&uh->check, skb, old_nsec,
+					 new_nsec, false);
+	}
+
+	*(__be16 *)(data + tstamp_off) = new_sec_h;
+	*(__be32 *)(data + tstamp_off + 2) = new_sec_l;
+	*(__be32 *)(data + tstamp_off + 6) = new_nsec;
+
+	/* Configure single-step register */
+	val = ENETC_PM0_SINGLE_STEP_EN;
+	val |= ENETC_SET_SINGLE_STEP_OFFSET(corr_off);
+	if (enetc_cb->udp)
+		val |= ENETC_PM0_SINGLE_STEP_CH;
+
+	enetc_port_mac_wr(priv->si, ENETC_PM0_SINGLE_STEP, val);
+
+	return lo & ENETC_TXBD_TSTAMP;
+}
+
 static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
 {
 	bool do_vlan, do_onestep_tstamp = false, do_twostep_tstamp = false;
 	struct enetc_ndev_priv *priv = netdev_priv(tx_ring->ndev);
 	struct enetc_skb_cb *enetc_cb = ENETC_SKB_CB(skb);
-	struct enetc_hw *hw = &priv->si->hw;
 	struct enetc_tx_swbd *tx_swbd;
 	int len = skb_headlen(skb);
 	union enetc_tx_bd temp_bd;
@@ -326,67 +393,11 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
 		}
 
 		if (do_onestep_tstamp) {
-			u16 tstamp_off = enetc_cb->origin_tstamp_off;
-			u16 corr_off = enetc_cb->correction_off;
-			__be32 new_sec_l, new_nsec;
-			u32 lo, hi, nsec, val;
-			__be16 new_sec_h;
-			u8 *data;
-			u64 sec;
-
-			lo = enetc_rd_hot(hw, ENETC_SICTR0);
-			hi = enetc_rd_hot(hw, ENETC_SICTR1);
-			sec = (u64)hi << 32 | lo;
-			nsec = do_div(sec, 1000000000);
+			u32 tstamp = enetc_update_ptp_sync_msg(priv, skb);
 
 			/* Configure extension BD */
-			temp_bd.ext.tstamp = cpu_to_le32(lo & 0x3fffffff);
+			temp_bd.ext.tstamp = cpu_to_le32(tstamp);
 			e_flags |= ENETC_TXBD_E_FLAGS_ONE_STEP_PTP;
-
-			/* Update originTimestamp field of Sync packet
-			 * - 48 bits seconds field
-			 * - 32 bits nanseconds field
-			 *
-			 * In addition, the UDP checksum needs to be updated
-			 * by software after updating originTimestamp field,
-			 * otherwise the hardware will calculate the wrong
-			 * checksum when updating the correction field and
-			 * update it to the packet.
-			 */
-			data = skb_mac_header(skb);
-			new_sec_h = htons((sec >> 32) & 0xffff);
-			new_sec_l = htonl(sec & 0xffffffff);
-			new_nsec = htonl(nsec);
-			if (enetc_cb->udp) {
-				struct udphdr *uh = udp_hdr(skb);
-				__be32 old_sec_l, old_nsec;
-				__be16 old_sec_h;
-
-				old_sec_h = *(__be16 *)(data + tstamp_off);
-				inet_proto_csum_replace2(&uh->check, skb, old_sec_h,
-							 new_sec_h, false);
-
-				old_sec_l = *(__be32 *)(data + tstamp_off + 2);
-				inet_proto_csum_replace4(&uh->check, skb, old_sec_l,
-							 new_sec_l, false);
-
-				old_nsec = *(__be32 *)(data + tstamp_off + 6);
-				inet_proto_csum_replace4(&uh->check, skb, old_nsec,
-							 new_nsec, false);
-			}
-
-			*(__be16 *)(data + tstamp_off) = new_sec_h;
-			*(__be32 *)(data + tstamp_off + 2) = new_sec_l;
-			*(__be32 *)(data + tstamp_off + 6) = new_nsec;
-
-			/* Configure single-step register */
-			val = ENETC_PM0_SINGLE_STEP_EN;
-			val |= ENETC_SET_SINGLE_STEP_OFFSET(corr_off);
-			if (enetc_cb->udp)
-				val |= ENETC_PM0_SINGLE_STEP_CH;
-
-			enetc_port_mac_wr(priv->si, ENETC_PM0_SINGLE_STEP,
-					  val);
 		} else if (do_twostep_tstamp) {
 			skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 			e_flags |= ENETC_TXBD_E_FLAGS_TWO_STEP_PTP;
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index 73763e8f4879..377c96325814 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -614,6 +614,7 @@ enum enetc_txbd_flags {
 #define ENETC_TXBD_STATS_WIN	BIT(7)
 #define ENETC_TXBD_TXSTART_MASK GENMASK(24, 0)
 #define ENETC_TXBD_FLAGS_OFFSET 24
+#define ENETC_TXBD_TSTAMP	GENMASK(29, 0)
 
 static inline __le32 enetc_txbd_set_tx_start(u64 tx_start, u8 flags)
 {
-- 
2.34.1