igb: add xdp frags support to ndo_xdp_xmit

Add the capability to map non-linear xdp frames in XDP_TX and
ndo_xdp_xmit callback.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20220711230751.3124415-1-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 4f91a85..d8b836a 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -6260,74 +6260,108 @@ int igb_xmit_xdp_ring(struct igb_adapter *adapter,
                      struct igb_ring *tx_ring,
                      struct xdp_frame *xdpf)
 {
-       union e1000_adv_tx_desc *tx_desc;
-       u32 len, cmd_type, olinfo_status;
-       struct igb_tx_buffer *tx_buffer;
-       dma_addr_t dma;
-       u16 i;
+       struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf);
+       u8 nr_frags = unlikely(xdp_frame_has_frags(xdpf)) ? sinfo->nr_frags : 0;
+       u16 count, i, index = tx_ring->next_to_use;
+       struct igb_tx_buffer *tx_head = &tx_ring->tx_buffer_info[index];
+       struct igb_tx_buffer *tx_buffer = tx_head;
+       union e1000_adv_tx_desc *tx_desc = IGB_TX_DESC(tx_ring, index);
+       u32 len = xdpf->len, cmd_type, olinfo_status;
+       void *data = xdpf->data;
+
+       count = TXD_USE_COUNT(len);
+       for (i = 0; i < nr_frags; i++)
+               count += TXD_USE_COUNT(skb_frag_size(&sinfo->frags[i]));
+
+       if (igb_maybe_stop_tx(tx_ring, count + 3))
+               return IGB_XDP_CONSUMED;
 
-       len = xdpf->len;
+       i = 0;
+       /* record the location of the first descriptor for this packet */
+       tx_head->bytecount = xdp_get_frame_len(xdpf);
+       tx_head->type = IGB_TYPE_XDP;
+       tx_head->gso_segs = 1;
+       tx_head->xdpf = xdpf;
 
-       if (unlikely(!igb_desc_unused(tx_ring)))
-               return IGB_XDP_CONSUMED;
+       olinfo_status = tx_head->bytecount << E1000_ADVTXD_PAYLEN_SHIFT;
+       /* 82575 requires a unique index per ring */
+       if (test_bit(IGB_RING_FLAG_TX_CTX_IDX, &tx_ring->flags))
+               olinfo_status |= tx_ring->reg_idx << 4;
+       tx_desc->read.olinfo_status = cpu_to_le32(olinfo_status);
 
-       dma = dma_map_single(tx_ring->dev, xdpf->data, len, DMA_TO_DEVICE);
-       if (dma_mapping_error(tx_ring->dev, dma))
-               return IGB_XDP_CONSUMED;
+       for (;;) {
+               dma_addr_t dma;
 
-       /* record the location of the first descriptor for this packet */
-       tx_buffer = &tx_ring->tx_buffer_info[tx_ring->next_to_use];
-       tx_buffer->bytecount = len;
-       tx_buffer->gso_segs = 1;
-       tx_buffer->protocol = 0;
+               dma = dma_map_single(tx_ring->dev, data, len, DMA_TO_DEVICE);
+               if (dma_mapping_error(tx_ring->dev, dma))
+                       goto unmap;
 
-       i = tx_ring->next_to_use;
-       tx_desc = IGB_TX_DESC(tx_ring, i);
+               /* record length, and DMA address */
+               dma_unmap_len_set(tx_buffer, len, len);
+               dma_unmap_addr_set(tx_buffer, dma, dma);
 
-       dma_unmap_len_set(tx_buffer, len, len);
-       dma_unmap_addr_set(tx_buffer, dma, dma);
-       tx_buffer->type = IGB_TYPE_XDP;
-       tx_buffer->xdpf = xdpf;
+               /* put descriptor type bits */
+               cmd_type = E1000_ADVTXD_DTYP_DATA | E1000_ADVTXD_DCMD_DEXT |
+                          E1000_ADVTXD_DCMD_IFCS | len;
 
-       tx_desc->read.buffer_addr = cpu_to_le64(dma);
+               tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
+               tx_desc->read.buffer_addr = cpu_to_le64(dma);
 
-       /* put descriptor type bits */
-       cmd_type = E1000_ADVTXD_DTYP_DATA |
-                  E1000_ADVTXD_DCMD_DEXT |
-                  E1000_ADVTXD_DCMD_IFCS;
-       cmd_type |= len | IGB_TXD_DCMD;
-       tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
+               tx_buffer->protocol = 0;
 
-       olinfo_status = len << E1000_ADVTXD_PAYLEN_SHIFT;
-       /* 82575 requires a unique index per ring */
-       if (test_bit(IGB_RING_FLAG_TX_CTX_IDX, &tx_ring->flags))
-               olinfo_status |= tx_ring->reg_idx << 4;
+               if (++index == tx_ring->count)
+                       index = 0;
 
-       tx_desc->read.olinfo_status = cpu_to_le32(olinfo_status);
+               if (i == nr_frags)
+                       break;
+
+               tx_buffer = &tx_ring->tx_buffer_info[index];
+               tx_desc = IGB_TX_DESC(tx_ring, index);
+               tx_desc->read.olinfo_status = 0;
 
-       netdev_tx_sent_queue(txring_txq(tx_ring), tx_buffer->bytecount);
+               data = skb_frag_address(&sinfo->frags[i]);
+               len = skb_frag_size(&sinfo->frags[i]);
+               i++;
+       }
+       tx_desc->read.cmd_type_len |= cpu_to_le32(IGB_TXD_DCMD);
 
+       netdev_tx_sent_queue(txring_txq(tx_ring), tx_head->bytecount);
        /* set the timestamp */
-       tx_buffer->time_stamp = jiffies;
+       tx_head->time_stamp = jiffies;
 
        /* Avoid any potential race with xdp_xmit and cleanup */
        smp_wmb();
 
        /* set next_to_watch value indicating a packet is present */
-       i++;
-       if (i == tx_ring->count)
-               i = 0;
-
-       tx_buffer->next_to_watch = tx_desc;
-       tx_ring->next_to_use = i;
+       tx_head->next_to_watch = tx_desc;
+       tx_ring->next_to_use = index;
 
        /* Make sure there is space in the ring for the next send. */
        igb_maybe_stop_tx(tx_ring, DESC_NEEDED);
 
        if (netif_xmit_stopped(txring_txq(tx_ring)) || !netdev_xmit_more())
-               writel(i, tx_ring->tail);
+               writel(index, tx_ring->tail);
 
        return IGB_XDP_TX;
+
+unmap:
+       for (;;) {
+               tx_buffer = &tx_ring->tx_buffer_info[index];
+               if (dma_unmap_len(tx_buffer, len))
+                       dma_unmap_page(tx_ring->dev,
+                                      dma_unmap_addr(tx_buffer, dma),
+                                      dma_unmap_len(tx_buffer, len),
+                                      DMA_TO_DEVICE);
+               dma_unmap_len_set(tx_buffer, len, 0);
+               if (tx_buffer == tx_head)
+                       break;
+
+               if (!index)
+                       index += tx_ring->count;
+               index--;
+       }
+
+       return IGB_XDP_CONSUMED;
 }
 
 netdev_tx_t igb_xmit_frame_ring(struct sk_buff *skb,
@@ -8818,6 +8852,7 @@ static int igb_clean_rx_irq(struct igb_q_vector *q_vector, const int budget)
                        unsigned int offset = pkt_offset + igb_rx_offset(rx_ring);
 
                        xdp_prepare_buff(&xdp, hard_start, offset, size, true);
+                       xdp_buff_clear_frags_flag(&xdp);
 #if (PAGE_SIZE > 4096)
                        /* At larger PAGE_SIZE, frame_sz depend on len size */
                        xdp.frame_sz = igb_rx_frame_truesize(rx_ring, size);