libeth: support native XDP and register memory model

Expand libeth's Page Pool functionality by adding native XDP support.
This means picking the appropriate headroom and DMA direction.
Also, register all the created &page_pools as XDP memory models.
A driver then can call xdp_rxq_info_attach_page_pool() when registering
its RxQ info.

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

diff --git a/drivers/net/ethernet/intel/libeth/rx.c b/drivers/net/ethernet/intel/libeth/rx.c
index 2afa6e33f1609ab25859c9f3e4393689af4c4f6f..62521a1f4ec93b151e0e6397dc6116e53b6f0d9b 100644 (file)
--- a/drivers/net/ethernet/intel/libeth/rx.c
+++ b/drivers/net/ethernet/intel/libeth/rx.c
@@ -72,7 +72,7 @@ static u32 libeth_rx_hw_len_truesize(const struct page_pool_params *pp,
 static bool libeth_rx_page_pool_params(struct libeth_fq *fq,
                                       struct page_pool_params *pp)
 {
-       pp->offset = LIBETH_SKB_HEADROOM;
+       pp->offset = fq->xdp ? LIBETH_XDP_HEADROOM : LIBETH_SKB_HEADROOM;
        /* HW-writeable / syncable length per one page */
        pp->max_len = LIBETH_RX_PAGE_LEN(pp->offset);
 
@@ -159,11 +159,12 @@ int libeth_rx_fq_create(struct libeth_fq *fq, struct napi_struct *napi)
                .dev            = napi->dev->dev.parent,
                .netdev         = napi->dev,
                .napi           = napi,
-               .dma_dir        = DMA_FROM_DEVICE,
        };
        struct libeth_fqe *fqes;
        struct page_pool *pool;
-       bool ret;
+       int ret;
+
+       pp.dma_dir = fq->xdp ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE;
 
        if (!fq->hsplit)
                ret = libeth_rx_page_pool_params(fq, &pp);
@@ -177,18 +178,26 @@ int libeth_rx_fq_create(struct libeth_fq *fq, struct napi_struct *napi)
                return PTR_ERR(pool);
 
        fqes = kvcalloc_node(fq->count, sizeof(*fqes), GFP_KERNEL, fq->nid);
-       if (!fqes)
+       if (!fqes) {
+               ret = -ENOMEM;
                goto err_buf;
+       }
+
+       ret = xdp_reg_page_pool(pool);
+       if (ret)
+               goto err_mem;
 
        fq->fqes = fqes;
        fq->pp = pool;
 
        return 0;
 
+err_mem:
+       kvfree(fqes);
 err_buf:
        page_pool_destroy(pool);
 
-       return -ENOMEM;
+       return ret;
 }
 EXPORT_SYMBOL_GPL(libeth_rx_fq_create);
 
@@ -198,6 +207,7 @@ EXPORT_SYMBOL_GPL(libeth_rx_fq_create);
  */
 void libeth_rx_fq_destroy(struct libeth_fq *fq)
 {
+       xdp_unreg_page_pool(fq->pp);
        kvfree(fq->fqes);
        page_pool_destroy(fq->pp);
 }

diff --git a/include/net/libeth/rx.h b/include/net/libeth/rx.h
index 7d5dc58984b1840e5fababbe5e5b5399b64229a3..5d991404845e6584e93f79629a273d93f1e76c31 100644 (file)
--- a/include/net/libeth/rx.h
+++ b/include/net/libeth/rx.h
@@ -13,8 +13,10 @@
 
 /* Space reserved in front of each frame */
 #define LIBETH_SKB_HEADROOM    (NET_SKB_PAD + NET_IP_ALIGN)
+#define LIBETH_XDP_HEADROOM    (ALIGN(XDP_PACKET_HEADROOM, NET_SKB_PAD) + \
+                                NET_IP_ALIGN)
 /* Maximum headroom for worst-case calculations */
-#define LIBETH_MAX_HEADROOM    LIBETH_SKB_HEADROOM
+#define LIBETH_MAX_HEADROOM    LIBETH_XDP_HEADROOM
 /* Link layer / L2 overhead: Ethernet, 2 VLAN tags (C + S), FCS */
 #define LIBETH_RX_LL_LEN       (ETH_HLEN + 2 * VLAN_HLEN + ETH_FCS_LEN)
 /* Maximum supported L2-L4 header length */
@@ -66,6 +68,7 @@ enum libeth_fqe_type {
  * @count: number of descriptors/buffers the queue has
  * @type: type of the buffers this queue has
  * @hsplit: flag whether header split is enabled
+ * @xdp: flag indicating whether XDP is enabled
  * @buf_len: HW-writeable length per each buffer
  * @nid: ID of the closest NUMA node with memory
  */
@@ -81,6 +84,7 @@ struct libeth_fq {
        /* Cold fields */
        enum libeth_fqe_type    type:2;
        bool                    hsplit:1;
+       bool                    xdp:1;
 
        u32                     buf_len;
        int                     nid;