[PATCH net-next v6 14/15] bnxt_en: Add support for inline transmit BDs

[Michael Chan <michael.chan@broadcom.com>]

Newer chips (P5_PLUS) support inline transmit BDs that contain extra
data.  One such use case is to transmit out-of-sequence kTLS packets
with encryption enabled.  To account for these inline BDs during TX
completion, we add the inline_data_bds field to struct bnxt_sw_tx_bd
(tx_buf).  tx_buf->is_push will always be set when sending these
inline BDs as the operation is similar to push packets.  tx_buf->skb
will always be NULL as there is no associated SKB.

The next patch will make use of this feature.

Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
v6:
Clear is_push and inline_data_bds during TX ring free.
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 21 ++++++++++++++++++---
 drivers/net/ethernet/broadcom/bnxt/bnxt.h |  1 +
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 15b329ee878b..55f999dbe7ad 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -848,7 +848,7 @@ static bool __bnxt_tx_int(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
 		head_buf = tx_buf;
 		skb = tx_buf->skb;
 
-		if (unlikely(!skb)) {
+		if (unlikely(!skb && !tx_buf->is_push)) {
 			bnxt_sched_reset_txr(bp, txr, cons);
 			return rc;
 		}
@@ -860,13 +860,22 @@ static bool __bnxt_tx_int(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
 		}
 
 		cons = NEXT_TX(cons);
-		tx_pkts++;
-		tx_bytes += skb->len;
+		if (skb) {
+			tx_pkts++;
+			tx_bytes += skb->len;
+		}
 		tx_buf->skb = NULL;
 		tx_buf->is_ts_pkt = 0;
 
 		if (tx_buf->is_push) {
 			tx_buf->is_push = 0;
+			cons += tx_buf->inline_data_bds;
+			tx_buf->inline_data_bds = 0;
+			if (!skb) {
+				/* presync BD */
+				cons = NEXT_TX(cons);
+				continue;
+			}
 			goto next_tx_int;
 		}
 
@@ -3481,6 +3490,10 @@ static void bnxt_free_one_tx_ring_skbs(struct bnxt *bp,
 
 		skb = tx_buf->skb;
 		if (!skb) {
+			if (tx_buf->is_push) {
+				tx_buf->is_push = 0;
+				tx_buf->inline_data_bds = 0;
+			}
 			i++;
 			continue;
 		}
@@ -3489,6 +3502,8 @@ static void bnxt_free_one_tx_ring_skbs(struct bnxt *bp,
 
 		if (tx_buf->is_push) {
 			dev_kfree_skb(skb);
+			tx_buf->is_push = 0;
+			tx_buf->inline_data_bds = 0;
 			i += 2;
 			continue;
 		}
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 5ff70623e849..e500178d5f80 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -918,6 +918,7 @@ struct bnxt_sw_tx_bd {
 	u8			is_push;
 	u8			is_sw_gso;
 	u8			action;
+	u8			inline_data_bds;
 	unsigned short		nr_frags;
 	union {
 		u16			rx_prod;
-- 
2.51.0