igc: Refactor Rx timestamp handling

Refactor the Rx timestamp handling in preparation to land
XDP support.

Rx timestamps are put in the Rx buffer by hardware, before the packet
data. When creating the xdp buffer, we will need to check the Rx
descriptor to determine if the buffer contains timestamp information
and consider the offset when setting xdp.data.

The Rx descriptor check is already done in igc_construct_skb(). To
avoid code duplication, this patch moves the timestamp handling to
igc_clean_rx_irq() so both skb and xdp paths can reuse it.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 20 insertions, 10 deletions

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index d6947c1d6f49..1eacb4ebd9f6 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1581,10 +1581,11 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
 
 static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 					 struct igc_rx_buffer *rx_buffer,
-					 union igc_adv_rx_desc *rx_desc,
-					 unsigned int size)
+					 unsigned int size, int pkt_offset,
+					 ktime_t timestamp)
 {
-	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
+	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset +
+		   pkt_offset;
 	unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size);
 	unsigned int headlen;
 	struct sk_buff *skb;
@@ -1597,11 +1598,8 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 	if (unlikely(!skb))
 		return NULL;
 
-	if (unlikely(igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP))) {
-		igc_ptp_rx_pktstamp(rx_ring->q_vector, va, skb);
-		va += IGC_TS_HDR_LEN;
-		size -= IGC_TS_HDR_LEN;
-	}
+	if (timestamp)
+		skb_hwtstamps(skb)->hwtstamp = timestamp;
 
 	/* Determine available headroom for copy */
 	headlen = size;
@@ -1895,6 +1893,8 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 	while (likely(total_packets < budget)) {
 		union igc_adv_rx_desc *rx_desc;
 		struct igc_rx_buffer *rx_buffer;
+		ktime_t timestamp = 0;
+		int pkt_offset = 0;
 		unsigned int size;
 
 		/* return some buffers to hardware, one at a time is too slow */
@@ -1916,14 +1916,24 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 
 		rx_buffer = igc_get_rx_buffer(rx_ring, size);
 
+		if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) {
+			void *pktbuf = page_address(rx_buffer->page) +
+				       rx_buffer->page_offset;
+
+			timestamp = igc_ptp_rx_pktstamp(q_vector->adapter,
+							pktbuf);
+			pkt_offset = IGC_TS_HDR_LEN;
+			size -= IGC_TS_HDR_LEN;
+		}
+
 		/* retrieve a buffer from the ring */
 		if (skb)
 			igc_add_rx_frag(rx_ring, rx_buffer, skb, size);
 		else if (ring_uses_build_skb(rx_ring))
 			skb = igc_build_skb(rx_ring, rx_buffer, rx_desc, size);
 		else
-			skb = igc_construct_skb(rx_ring, rx_buffer,
-						rx_desc, size);
+			skb = igc_construct_skb(rx_ring, rx_buffer, size,
+						pkt_offset, timestamp);
 
 		/* exit if we failed to retrieve a buffer */
 		if (!skb) {