idpf: use generic functions to build xdp_buff and skb

In preparation of XDP support, move from having skb as the main frame
container during the Rx polling to &xdp_buff.
This allows to use generic and libeth helpers for building an XDP
buffer and changes the logics: now we try to allocate an skb only
when we processed all the descriptors related to the frame.
Store &libeth_xdp_stash instead of the skb pointer on the Rx queue.
It's only 8 bytes wider, but contains everything we may need.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Tested-by: Ramu R <ramu.r@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 36 insertions, 109 deletions

diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
index c17fd475eaf3..7ae7c03b3974 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
@@ -422,10 +422,7 @@ static void idpf_rx_desc_rel(struct idpf_rx_queue *rxq, struct device *dev,
 	if (!rxq)
 		return;
 
-	if (rxq->skb) {
-		dev_kfree_skb_any(rxq->skb);
-		rxq->skb = NULL;
-	}
+	libeth_xdp_return_stash(&rxq->xdp);
 
 	if (!idpf_is_queue_model_split(model))
 		idpf_rx_buf_rel_all(rxq);
@@ -2998,7 +2995,7 @@ idpf_rx_hwtstamp(const struct idpf_rx_queue *rxq,
 }
 
 /**
- * idpf_rx_process_skb_fields - Populate skb header fields from Rx descriptor
+ * __idpf_rx_process_skb_fields - Populate skb header fields from Rx descriptor
  * @rxq: Rx descriptor ring packet is being transacted on
  * @skb: pointer to current skb being populated
  * @rx_desc: Receive descriptor
@@ -3008,8 +3005,8 @@ idpf_rx_hwtstamp(const struct idpf_rx_queue *rxq,
  * other fields within the skb.
  */
 static int
-idpf_rx_process_skb_fields(struct idpf_rx_queue *rxq, struct sk_buff *skb,
-			   const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc)
+__idpf_rx_process_skb_fields(struct idpf_rx_queue *rxq, struct sk_buff *skb,
+			     const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc)
 {
 	struct libeth_rx_csum csum_bits;
 	struct libeth_rx_pt decoded;
@@ -3025,9 +3022,6 @@ idpf_rx_process_skb_fields(struct idpf_rx_queue *rxq, struct sk_buff *skb,
 	if (idpf_queue_has(PTP, rxq))
 		idpf_rx_hwtstamp(rxq, rx_desc, skb);
 
-	skb->protocol = eth_type_trans(skb, rxq->xdp_rxq.dev);
-	skb_record_rx_queue(skb, rxq->idx);
-
 	if (le16_get_bits(rx_desc->hdrlen_flags,
 			  VIRTCHNL2_RX_FLEX_DESC_ADV_RSC_M))
 		return idpf_rx_rsc(rxq, skb, rx_desc, decoded);
@@ -3038,23 +3032,24 @@ idpf_rx_process_skb_fields(struct idpf_rx_queue *rxq, struct sk_buff *skb,
 	return 0;
 }
 
-/**
- * idpf_rx_add_frag - Add contents of Rx buffer to sk_buff as a frag
- * @rx_buf: buffer containing page to add
- * @skb: sk_buff to place the data into
- * @size: packet length from rx_desc
- *
- * This function will add the data contained in rx_buf->page to the skb.
- * It will just attach the page as a frag to the skb.
- * The function will then update the page offset.
- */
-void idpf_rx_add_frag(struct idpf_rx_buf *rx_buf, struct sk_buff *skb,
-		      unsigned int size)
+static bool idpf_rx_process_skb_fields(struct sk_buff *skb,
+				       const struct libeth_xdp_buff *xdp,
+				       struct libeth_rq_napi_stats *rs)
 {
-	u32 hr = netmem_get_pp(rx_buf->netmem)->p.offset;
+	struct idpf_rx_queue *rxq;
+
+	rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
 
-	skb_add_rx_frag_netmem(skb, skb_shinfo(skb)->nr_frags, rx_buf->netmem,
-			       rx_buf->offset + hr, size, rx_buf->truesize);
+	return !__idpf_rx_process_skb_fields(rxq, skb, xdp->desc);
+}
+
+static void
+idpf_xdp_run_pass(struct libeth_xdp_buff *xdp, struct napi_struct *napi,
+		  struct libeth_rq_napi_stats *ss,
+		  const struct virtchnl2_rx_flex_desc_adv_nic_3 *desc)
+{
+	libeth_xdp_run_pass(xdp, NULL, napi, ss, desc, NULL,
+			    idpf_rx_process_skb_fields);
 }
 
 /**
@@ -3099,36 +3094,6 @@ static u32 idpf_rx_hsplit_wa(const struct libeth_fqe *hdr,
 }
 
 /**
- * idpf_rx_build_skb - Allocate skb and populate it from header buffer
- * @buf: Rx buffer to pull data from
- * @size: the length of the packet
- *
- * This function allocates an skb. It then populates it with the page data from
- * the current receive descriptor, taking care to set up the skb correctly.
- */
-struct sk_buff *idpf_rx_build_skb(const struct libeth_fqe *buf, u32 size)
-{
-	struct page *buf_page = __netmem_to_page(buf->netmem);
-	u32 hr = pp_page_to_nmdesc(buf_page)->pp->p.offset;
-	struct sk_buff *skb;
-	void *va;
-
-	va = page_address(buf_page) + buf->offset;
-	prefetch(va + hr);
-
-	skb = napi_build_skb(va, buf->truesize);
-	if (unlikely(!skb))
-		return NULL;
-
-	skb_mark_for_recycle(skb);
-
-	skb_reserve(skb, hr);
-	__skb_put(skb, size);
-
-	return skb;
-}
-
-/**
  * idpf_rx_splitq_test_staterr - tests bits in Rx descriptor
  * status and error fields
  * @stat_err_field: field from descriptor to test bits in
@@ -3169,13 +3134,15 @@ static bool idpf_rx_splitq_is_eop(struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_de
  */
 static int idpf_rx_splitq_clean(struct idpf_rx_queue *rxq, int budget)
 {
-	int total_rx_bytes = 0, total_rx_pkts = 0;
 	struct idpf_buf_queue *rx_bufq = NULL;
-	struct sk_buff *skb = rxq->skb;
+	struct libeth_rq_napi_stats rs = { };
 	u16 ntc = rxq->next_to_clean;
+	LIBETH_XDP_ONSTACK_BUFF(xdp);
+
+	libeth_xdp_init_buff(xdp, &rxq->xdp, &rxq->xdp_rxq);
 
 	/* Process Rx packets bounded by budget */
-	while (likely(total_rx_pkts < budget)) {
+	while (likely(rs.packets < budget)) {
 		struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc;
 		struct libeth_fqe *hdr, *rx_buf = NULL;
 		struct idpf_sw_queue *refillq = NULL;
@@ -3241,7 +3208,7 @@ static int idpf_rx_splitq_clean(struct idpf_rx_queue *rxq, int budget)
 
 		hdr = &rx_bufq->hdr_buf[buf_id];
 
-		if (unlikely(!hdr_len && !skb)) {
+		if (unlikely(!hdr_len && !xdp->data)) {
 			hdr_len = idpf_rx_hsplit_wa(hdr, rx_buf, pkt_len);
 			/* If failed, drop both buffers by setting len to 0 */
 			pkt_len -= hdr_len ? : pkt_len;
@@ -3251,75 +3218,35 @@ static int idpf_rx_splitq_clean(struct idpf_rx_queue *rxq, int budget)
 			u64_stats_update_end(&rxq->stats_sync);
 		}
 
-		if (libeth_rx_sync_for_cpu(hdr, hdr_len)) {
-			skb = idpf_rx_build_skb(hdr, hdr_len);
-			if (!skb)
-				break;
-
-			u64_stats_update_begin(&rxq->stats_sync);
-			u64_stats_inc(&rxq->q_stats.hsplit_pkts);
-			u64_stats_update_end(&rxq->stats_sync);
-		}
+		if (libeth_xdp_process_buff(xdp, hdr, hdr_len))
+			rs.hsplit++;
 
 		hdr->netmem = 0;
 
 payload:
-		if (!libeth_rx_sync_for_cpu(rx_buf, pkt_len))
-			goto skip_data;
-
-		if (skb)
-			idpf_rx_add_frag(rx_buf, skb, pkt_len);
-		else
-			skb = idpf_rx_build_skb(rx_buf, pkt_len);
-
-		/* exit if we failed to retrieve a buffer */
-		if (!skb)
-			break;
-
-skip_data:
+		libeth_xdp_process_buff(xdp, rx_buf, pkt_len);
 		rx_buf->netmem = 0;
 
 		idpf_post_buf_refill(refillq, buf_id);
 		IDPF_RX_BUMP_NTC(rxq, ntc);
 
 		/* skip if it is non EOP desc */
-		if (!idpf_rx_splitq_is_eop(rx_desc) || unlikely(!skb))
-			continue;
-
-		/* pad skb if needed (to make valid ethernet frame) */
-		if (eth_skb_pad(skb)) {
-			skb = NULL;
-			continue;
-		}
-
-		/* probably a little skewed due to removing CRC */
-		total_rx_bytes += skb->len;
-
-		/* protocol */
-		if (unlikely(idpf_rx_process_skb_fields(rxq, skb, rx_desc))) {
-			dev_kfree_skb_any(skb);
-			skb = NULL;
+		if (!idpf_rx_splitq_is_eop(rx_desc) || unlikely(!xdp->data))
 			continue;
-		}
 
-		/* send completed skb up the stack */
-		napi_gro_receive(rxq->napi, skb);
-		skb = NULL;
-
-		/* update budget accounting */
-		total_rx_pkts++;
+		idpf_xdp_run_pass(xdp, rxq->napi, &rs, rx_desc);
 	}
 
 	rxq->next_to_clean = ntc;
+	libeth_xdp_save_buff(&rxq->xdp, xdp);
 
-	rxq->skb = skb;
 	u64_stats_update_begin(&rxq->stats_sync);
-	u64_stats_add(&rxq->q_stats.packets, total_rx_pkts);
-	u64_stats_add(&rxq->q_stats.bytes, total_rx_bytes);
+	u64_stats_add(&rxq->q_stats.packets, rs.packets);
+	u64_stats_add(&rxq->q_stats.bytes, rs.bytes);
+	u64_stats_add(&rxq->q_stats.hsplit_pkts, rs.hsplit);
 	u64_stats_update_end(&rxq->stats_sync);
 
-	/* guarantee a trip back through this routine if there was a failure */
-	return total_rx_pkts;
+	return rs.packets;
 }
 
 /**