+/**
+ * get_packet - return the next ingress packet buffer from a free list
+ * @adap: the adapter that received the packet
+ * @fl: the SGE free list holding the packet
+ * @len: the packet length including any SGE padding
+ * @drop_thres: # of remaining buffers before we start dropping packets
+ *
+ * Get the next packet from a free list and complete setup of the
+ * sk_buff. If the packet is small we make a copy and recycle the
+ * original buffer, otherwise we use the original buffer itself. If a
+ * positive drop threshold is supplied packets are dropped and their
+ * buffers recycled if (a) the number of remaining buffers is under the
+ * threshold and the packet is too big to copy, or (b) the packet should
+ * be copied but there is no memory for the copy.
+ */
+static struct sk_buff *get_packet(struct adapter *adap, struct sge_fl *fl,
+ unsigned int len, unsigned int drop_thres)
+{
+ struct sk_buff *skb = NULL;
+ struct rx_sw_desc *sd = &fl->sdesc[fl->cidx];
+
+ prefetch(sd->skb->data);
+ fl->credits--;
+
+ if (len <= SGE_RX_COPY_THRES) {
+ skb = alloc_skb(len, GFP_ATOMIC);
+ if (likely(skb != NULL)) {
+ __skb_put(skb, len);
+ pci_dma_sync_single_for_cpu(adap->pdev,
+ pci_unmap_addr(sd, dma_addr), len,
+ PCI_DMA_FROMDEVICE);
+ memcpy(skb->data, sd->skb->data, len);
+ pci_dma_sync_single_for_device(adap->pdev,
+ pci_unmap_addr(sd, dma_addr), len,
+ PCI_DMA_FROMDEVICE);
+ } else if (!drop_thres)
+ goto use_orig_buf;
+recycle:
+ recycle_rx_buf(adap, fl, fl->cidx);
+ return skb;
+ }
+
+ if (unlikely(fl->credits < drop_thres))
+ goto recycle;
+
+use_orig_buf:
+ pci_unmap_single(adap->pdev, pci_unmap_addr(sd, dma_addr),
+ fl->buf_size, PCI_DMA_FROMDEVICE);
+ skb = sd->skb;
+ skb_put(skb, len);
+ __refill_fl(adap, fl);
+ return skb;
+}
+
+/**
+ * get_packet_pg - return the next ingress packet buffer from a free list
+ * @adap: the adapter that received the packet
+ * @fl: the SGE free list holding the packet
+ * @len: the packet length including any SGE padding
+ * @drop_thres: # of remaining buffers before we start dropping packets
+ *
+ * Get the next packet from a free list populated with page chunks.
+ * If the packet is small we make a copy and recycle the original buffer,
+ * otherwise we attach the original buffer as a page fragment to a fresh
+ * sk_buff. If a positive drop threshold is supplied packets are dropped
+ * and their buffers recycled if (a) the number of remaining buffers is
+ * under the threshold and the packet is too big to copy, or (b) there's
+ * no system memory.
+ *
+ * Note: this function is similar to @get_packet but deals with Rx buffers
+ * that are page chunks rather than sk_buffs.
+ */
+static struct sk_buff *get_packet_pg(struct adapter *adap, struct sge_fl *fl,
+ unsigned int len, unsigned int drop_thres)
+{
+ struct sk_buff *skb = NULL;
+ struct rx_sw_desc *sd = &fl->sdesc[fl->cidx];
+
+ if (len <= SGE_RX_COPY_THRES) {
+ skb = alloc_skb(len, GFP_ATOMIC);
+ if (likely(skb != NULL)) {
+ __skb_put(skb, len);
+ pci_dma_sync_single_for_cpu(adap->pdev,
+ pci_unmap_addr(sd, dma_addr), len,
+ PCI_DMA_FROMDEVICE);
+ memcpy(skb->data, sd->pg_chunk.va, len);
+ pci_dma_sync_single_for_device(adap->pdev,
+ pci_unmap_addr(sd, dma_addr), len,
+ PCI_DMA_FROMDEVICE);
+ } else if (!drop_thres)
+ return NULL;
+recycle:
+ fl->credits--;
+ recycle_rx_buf(adap, fl, fl->cidx);
+ return skb;
+ }
+
+ if (unlikely(fl->credits <= drop_thres))
+ goto recycle;
+
+ skb = alloc_skb(SGE_RX_PULL_LEN, GFP_ATOMIC);
+ if (unlikely(!skb)) {
+ if (!drop_thres)
+ return NULL;
+ goto recycle;
+ }
+
+ pci_unmap_single(adap->pdev, pci_unmap_addr(sd, dma_addr),
+ fl->buf_size, PCI_DMA_FROMDEVICE);
+ __skb_put(skb, SGE_RX_PULL_LEN);
+ memcpy(skb->data, sd->pg_chunk.va, SGE_RX_PULL_LEN);
+ skb_fill_page_desc(skb, 0, sd->pg_chunk.page,
+ sd->pg_chunk.offset + SGE_RX_PULL_LEN,
+ len - SGE_RX_PULL_LEN);
+ skb->len = len;
+ skb->data_len = len - SGE_RX_PULL_LEN;
+ skb->truesize += skb->data_len;
+
+ fl->credits--;
+ /*
+ * We do not refill FLs here, we let the caller do it to overlap a
+ * prefetch.
+ */
+ return skb;
+}
+