i40e: use frame_sz instead of recalculating truesize for building skb

In skb path truesize is calculated while building skb. This is now
avoided and xdp->frame_is used instead for both i40e_build_skb() and
i40e_construct_skb().
Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/i40e/i40e_txrx.c

@@ -2113,11 +2113,6 @@ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring,
 					  struct xdp_buff *xdp)
 {
 	unsigned int size = xdp->data_end - xdp->data;
-#if (PAGE_SIZE < 8192)
-	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
-#else
-	unsigned int truesize = SKB_DATA_ALIGN(size);
-#endif
 	unsigned int headlen;
 	struct sk_buff *skb;
 
@@ -2162,10 +2157,10 @@ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring,
 	if (size) {
 		skb_add_rx_frag(skb, 0, rx_buffer->page,
 				rx_buffer->page_offset + headlen,
-				size, truesize);
+				size, xdp->frame_sz);
 
 		/* buffer is used by skb, update page_offset */
-		i40e_rx_buffer_flip(rx_buffer, truesize);
+		i40e_rx_buffer_flip(rx_buffer, xdp->frame_sz);
 	} else {
 		/* buffer is unused, reset bias back to rx_buffer */
 		rx_buffer->pagecnt_bias++;
@@ -2188,13 +2183,6 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
 				      struct xdp_buff *xdp)
 {
 	unsigned int metasize = xdp->data - xdp->data_meta;
-#if (PAGE_SIZE < 8192)
-	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
-#else
-	unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
-				SKB_DATA_ALIGN(xdp->data_end -
-					       xdp->data_hard_start);
-#endif
 	struct sk_buff *skb;
 
 	/* Prefetch first cache line of first page. If xdp->data_meta
@@ -2205,7 +2193,7 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
 	net_prefetch(xdp->data_meta);
 
 	/* build an skb around the page buffer */
-	skb = napi_build_skb(xdp->data_hard_start, truesize);
+	skb = napi_build_skb(xdp->data_hard_start, xdp->frame_sz);
 	if (unlikely(!skb))
 		return NULL;
 
@@ -2216,7 +2204,7 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
 		skb_metadata_set(skb, metasize);
 
 	/* buffer is used by skb, update page_offset */
-	i40e_rx_buffer_flip(rx_buffer, truesize);
+	i40e_rx_buffer_flip(rx_buffer, xdp->frame_sz);
 
 	return skb;
 }