net/funeth: Unify skb/XDP packet mapping.

Instead of passing an skb to the mapping function pass an
skb_shared_info plus an additional address/length pair. This makes it
usable for both skbs and XDP. Call it from the XDP path and adjust the
skb path.

Signed-off-by: Dimitris Michailidis <dmichail@fungible.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/fungible/funeth/funeth_tx.c b/drivers/net/ethernet/fungible/funeth/funeth_tx.c
index a815432..3128db8 100644 (file)
--- a/drivers/net/ethernet/fungible/funeth/funeth_tx.c
+++ b/drivers/net/ethernet/fungible/funeth/funeth_tx.c
@@ -16,23 +16,24 @@
 #define FUN_XDP_CLEAN_BATCH 16
 
 /* DMA-map a packet and return the (length, DMA_address) pairs for its
- * segments. If a mapping error occurs -ENOMEM is returned.
+ * segments. If a mapping error occurs -ENOMEM is returned. The packet
+ * consists of an skb_shared_info and one additional address/length pair.
  */
-static int map_skb(const struct sk_buff *skb, struct device *dev,
-                  dma_addr_t *addr, unsigned int *len)
+static int fun_map_pkt(struct device *dev, const struct skb_shared_info *si,
+                      void *data, unsigned int data_len,
+                      dma_addr_t *addr, unsigned int *len)
 {
-       const struct skb_shared_info *si;
        const skb_frag_t *fp, *end;
 
-       *len = skb_headlen(skb);
-       *addr = dma_map_single(dev, skb->data, *len, DMA_TO_DEVICE);
+       *len = data_len;
+       *addr = dma_map_single(dev, data, *len, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, *addr))
                return -ENOMEM;
 
-       si = skb_shinfo(skb);
-       end = &si->frags[si->nr_frags];
+       if (!si)
+               return 0;
 
-       for (fp = si->frags; fp < end; fp++) {
+       for (fp = si->frags, end = fp + si->nr_frags; fp < end; fp++) {
                *++len = skb_frag_size(fp);
                *++addr = skb_frag_dma_map(dev, fp, 0, *len, DMA_TO_DEVICE);
                if (dma_mapping_error(dev, *addr))
@@ -44,7 +45,7 @@ unwind:
        while (fp-- > si->frags)
                dma_unmap_page(dev, *--addr, skb_frag_size(fp), DMA_TO_DEVICE);
 
-       dma_unmap_single(dev, addr[-1], skb_headlen(skb), DMA_TO_DEVICE);
+       dma_unmap_single(dev, addr[-1], data_len, DMA_TO_DEVICE);
        return -ENOMEM;
 }
 
@@ -160,7 +161,9 @@ static unsigned int write_pkt_desc(struct sk_buff *skb, struct funeth_txq *q,
        unsigned int ngle;
        u16 flags;
 
-       if (unlikely(map_skb(skb, q->dma_dev, addrs, lens))) {
+       shinfo = skb_shinfo(skb);
+       if (unlikely(fun_map_pkt(q->dma_dev, shinfo, skb->data,
+                                skb_headlen(skb), addrs, lens))) {
                FUN_QSTAT_INC(q, tx_map_err);
                return 0;
        }
@@ -173,7 +176,6 @@ static unsigned int write_pkt_desc(struct sk_buff *skb, struct funeth_txq *q,
        req->repr_idn = 0;
        req->encap_proto = 0;
 
-       shinfo = skb_shinfo(skb);
        if (likely(shinfo->gso_size)) {
                if (skb->encapsulation) {
                        u16 ol4_ofst;
@@ -512,6 +514,7 @@ static unsigned int fun_xdpq_clean(struct funeth_txq *q, unsigned int budget)
 
 bool fun_xdp_tx(struct funeth_txq *q, struct xdp_frame *xdpf)
 {
+       const struct skb_shared_info *si = NULL;
        struct fun_eth_tx_req *req;
        unsigned int idx, len;
        dma_addr_t dma;
@@ -524,9 +527,8 @@ bool fun_xdp_tx(struct funeth_txq *q, struct xdp_frame *xdpf)
                return false;
        }
 
-       len = xdpf->len;
-       dma = dma_map_single(q->dma_dev, xdpf->data, len, DMA_TO_DEVICE);
-       if (unlikely(dma_mapping_error(q->dma_dev, dma))) {
+       if (unlikely(fun_map_pkt(q->dma_dev, si, xdpf->data, xdpf->len, &dma,
+                                &len))) {
                FUN_QSTAT_INC(q, tx_map_err);
                return false;
        }