bnxt: refactor bnxt_rx_pages operate on skb_shared_info

Rather than operating on an sk_buff, add frags from the aggregation
ring into the frags of an skb_shared_info.  This will allow the
caller to use either an sk_buff or xdp_buff.

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -1038,22 +1038,23 @@ static struct sk_buff *bnxt_rx_skb(struct bnxt *bp,
 	return skb;
 }
 
-static struct sk_buff *bnxt_rx_pages(struct bnxt *bp,
-				     struct bnxt_cp_ring_info *cpr,
-				     struct sk_buff *skb, u16 idx,
-				     u32 agg_bufs, bool tpa)
+static u32 __bnxt_rx_pages(struct bnxt *bp,
+			   struct bnxt_cp_ring_info *cpr,
+			   struct skb_shared_info *shinfo,
+			   u16 idx, u32 agg_bufs, bool tpa)
 {
 	struct bnxt_napi *bnapi = cpr->bnapi;
 	struct pci_dev *pdev = bp->pdev;
 	struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
 	u16 prod = rxr->rx_agg_prod;
+	u32 i, total_frag_len = 0;
 	bool p5_tpa = false;
-	u32 i;
 
 	if ((bp->flags & BNXT_FLAG_CHIP_P5) && tpa)
 		p5_tpa = true;
 
 	for (i = 0; i < agg_bufs; i++) {
+		skb_frag_t *frag = &shinfo->frags[i];
 		u16 cons, frag_len;
 		struct rx_agg_cmp *agg;
 		struct bnxt_sw_rx_agg_bd *cons_rx_buf;
@@ -1069,8 +1070,10 @@ static struct sk_buff *bnxt_rx_pages(struct bnxt *bp,
 			    RX_AGG_CMP_LEN) >> RX_AGG_CMP_LEN_SHIFT;
 
 		cons_rx_buf = &rxr->rx_agg_ring[cons];
-		skb_fill_page_desc(skb, i, cons_rx_buf->page,
-				   cons_rx_buf->offset, frag_len);
+		skb_frag_off_set(frag, cons_rx_buf->offset);
+		skb_frag_size_set(frag, frag_len);
+		__skb_frag_set_page(frag, cons_rx_buf->page);
+		shinfo->nr_frags = i + 1;
 		__clear_bit(cons, rxr->rx_agg_bmap);
 
 		/* It is possible for bnxt_alloc_rx_page() to allocate
@@ -1082,36 +1085,49 @@ static struct sk_buff *bnxt_rx_pages(struct bnxt *bp,
 		cons_rx_buf->page = NULL;
 
 		if (bnxt_alloc_rx_page(bp, rxr, prod, GFP_ATOMIC) != 0) {
-			struct skb_shared_info *shinfo;
 			unsigned int nr_frags;
 
-			shinfo = skb_shinfo(skb);
 			nr_frags = --shinfo->nr_frags;
 			__skb_frag_set_page(&shinfo->frags[nr_frags], NULL);
-
-			dev_kfree_skb(skb);
-
 			cons_rx_buf->page = page;
 
 			/* Update prod since possibly some pages have been
 			 * allocated already.
 			 */
 			rxr->rx_agg_prod = prod;
 			bnxt_reuse_rx_agg_bufs(cpr, idx, i, agg_bufs - i, tpa);
-			return NULL;
+			return 0;
 		}
 
 		dma_unmap_page_attrs(&pdev->dev, mapping, BNXT_RX_PAGE_SIZE,
 				     DMA_FROM_DEVICE,
 				     DMA_ATTR_WEAK_ORDERING);
 
-		skb->data_len += frag_len;
-		skb->len += frag_len;
-		skb->truesize += PAGE_SIZE;
-
+		total_frag_len += frag_len;
 		prod = NEXT_RX_AGG(prod);
 	}
 	rxr->rx_agg_prod = prod;
+	return total_frag_len;
+}
+
+static struct sk_buff *bnxt_rx_pages(struct bnxt *bp,
+				     struct bnxt_cp_ring_info *cpr,
+				     struct sk_buff *skb, u16 idx,
+				     u32 agg_bufs, bool tpa)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(skb);
+	u32 total_frag_len = 0;
+
+	total_frag_len = __bnxt_rx_pages(bp, cpr, shinfo, idx, agg_bufs, tpa);
+
+	if (!total_frag_len) {
+		dev_kfree_skb(skb);
+		return NULL;
+	}
+
+	skb->data_len += total_frag_len;
+	skb->len += total_frag_len;
+	skb->truesize += PAGE_SIZE * agg_bufs;
 	return skb;
 }