i40e: convert to use generic xdp_frame and xdp_return_frame API

Also convert driver i40e, which very recently got XDP_REDIRECT support
in commit d9314c47 ("i40e: add support for XDP_REDIRECT").

V7: This patch got added in V7 of this patchset.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -638,7 +638,8 @@ static void i40e_unmap_and_free_tx_resource(struct i40e_ring *ring,
 		if (tx_buffer->tx_flags & I40E_TX_FLAGS_FD_SB)
 			kfree(tx_buffer->raw_buf);
 		else if (ring_is_xdp(ring))
-			page_frag_free(tx_buffer->raw_buf);
+			xdp_return_frame(tx_buffer->xdpf->data,
+					 &tx_buffer->xdpf->mem);
 		else
 			dev_kfree_skb_any(tx_buffer->skb);
 		if (dma_unmap_len(tx_buffer, len))
@@ -841,7 +842,7 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 
 		/* free the skb/XDP data */
 		if (ring_is_xdp(tx_ring))
-			page_frag_free(tx_buf->raw_buf);
+			xdp_return_frame(tx_buf->xdpf->data, &tx_buf->xdpf->mem);
 		else
 			napi_consume_skb(tx_buf->skb, napi_budget);
 
@@ -2225,6 +2226,8 @@ static struct sk_buff *i40e_run_xdp(struct i40e_ring *rx_ring,
 	if (!xdp_prog)
 		goto xdp_out;
 
+	prefetchw(xdp->data_hard_start); /* xdp_frame write */
+
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
 	switch (act) {
 	case XDP_PASS:
@@ -3481,25 +3484,32 @@ static inline int i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
 static int i40e_xmit_xdp_ring(struct xdp_buff *xdp,
 			      struct i40e_ring *xdp_ring)
 {
-	u32 size = xdp->data_end - xdp->data;
 	u16 i = xdp_ring->next_to_use;
 	struct i40e_tx_buffer *tx_bi;
 	struct i40e_tx_desc *tx_desc;
+	struct xdp_frame *xdpf;
 	dma_addr_t dma;
+	u32 size;
+
+	xdpf = convert_to_xdp_frame(xdp);
+	if (unlikely(!xdpf))
+		return I40E_XDP_CONSUMED;
+
+	size = xdpf->len;
 
 	if (!unlikely(I40E_DESC_UNUSED(xdp_ring))) {
 		xdp_ring->tx_stats.tx_busy++;
 		return I40E_XDP_CONSUMED;
 	}
 
-	dma = dma_map_single(xdp_ring->dev, xdp->data, size, DMA_TO_DEVICE);
+	dma = dma_map_single(xdp_ring->dev, xdpf->data, size, DMA_TO_DEVICE);
 	if (dma_mapping_error(xdp_ring->dev, dma))
 		return I40E_XDP_CONSUMED;
 
 	tx_bi = &xdp_ring->tx_bi[i];
 	tx_bi->bytecount = size;
 	tx_bi->gso_segs = 1;
-	tx_bi->raw_buf = xdp->data;
+	tx_bi->xdpf = xdpf;
 
 	/* record length, and DMA address */
 	dma_unmap_len_set(tx_bi, len, size);

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

@@ -306,6 +306,7 @@ static inline unsigned int i40e_txd_use_count(unsigned int size)
 struct i40e_tx_buffer {
 	struct i40e_tx_desc *next_to_watch;
 	union {
+		struct xdp_frame *xdpf;
 		struct sk_buff *skb;
 		void *raw_buf;
 	};