dpaa2-eth: extract the S/G table buffer cache interaction into functions

The dpaa2-eth driver uses in certain circumstances a buffer cache for
the S/G tables needed in case of a S/G FD. At the moment, the
interraction with the cache is open-coded and couldn't be reused easily.

Add two new functions - dpaa2_eth_sgt_get and dpaa2_eth_sgt_recycle -
which help with code reusability.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index 6ccbec2..006ab35 100644 (file)
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -760,6 +760,38 @@ static void dpaa2_eth_enable_tx_tstamp(struct dpaa2_eth_priv *priv,
        }
 }
 
+static void *dpaa2_eth_sgt_get(struct dpaa2_eth_priv *priv)
+{
+       struct dpaa2_eth_sgt_cache *sgt_cache;
+       void *sgt_buf = NULL;
+       int sgt_buf_size;
+
+       sgt_cache = this_cpu_ptr(priv->sgt_cache);
+       sgt_buf_size = priv->tx_data_offset + sizeof(struct dpaa2_sg_entry);
+
+       if (sgt_cache->count == 0)
+               sgt_buf = napi_alloc_frag_align(sgt_buf_size, DPAA2_ETH_TX_BUF_ALIGN);
+       else
+               sgt_buf = sgt_cache->buf[--sgt_cache->count];
+       if (!sgt_buf)
+               return NULL;
+
+       memset(sgt_buf, 0, sgt_buf_size);
+
+       return sgt_buf;
+}
+
+static void dpaa2_eth_sgt_recycle(struct dpaa2_eth_priv *priv, void *sgt_buf)
+{
+       struct dpaa2_eth_sgt_cache *sgt_cache;
+
+       sgt_cache = this_cpu_ptr(priv->sgt_cache);
+       if (sgt_cache->count >= DPAA2_ETH_SGT_CACHE_SIZE)
+               skb_free_frag(sgt_buf);
+       else
+               sgt_cache->buf[sgt_cache->count++] = sgt_buf;
+}
+
 /* Create a frame descriptor based on a fragmented skb */
 static int dpaa2_eth_build_sg_fd(struct dpaa2_eth_priv *priv,
                                 struct sk_buff *skb,
@@ -810,7 +842,6 @@ static int dpaa2_eth_build_sg_fd(struct dpaa2_eth_priv *priv,
                err = -ENOMEM;
                goto sgt_buf_alloc_failed;
        }
-       memset(sgt_buf, 0, sgt_buf_size);
 
        sgt = (struct dpaa2_sg_entry *)(sgt_buf + priv->tx_data_offset);
 
@@ -875,7 +906,6 @@ static int dpaa2_eth_build_sg_fd_single_buf(struct dpaa2_eth_priv *priv,
                                            void **swa_addr)
 {
        struct device *dev = priv->net_dev->dev.parent;
-       struct dpaa2_eth_sgt_cache *sgt_cache;
        struct dpaa2_sg_entry *sgt;
        struct dpaa2_eth_swa *swa;
        dma_addr_t addr, sgt_addr;
@@ -884,17 +914,10 @@ static int dpaa2_eth_build_sg_fd_single_buf(struct dpaa2_eth_priv *priv,
        int err;
 
        /* Prepare the HW SGT structure */
-       sgt_cache = this_cpu_ptr(priv->sgt_cache);
        sgt_buf_size = priv->tx_data_offset + sizeof(struct dpaa2_sg_entry);
-
-       if (sgt_cache->count == 0)
-               sgt_buf = napi_alloc_frag_align(sgt_buf_size, DPAA2_ETH_TX_BUF_ALIGN);
-       else
-               sgt_buf = sgt_cache->buf[--sgt_cache->count];
+       sgt_buf = dpaa2_eth_sgt_get(priv);
        if (unlikely(!sgt_buf))
                return -ENOMEM;
-       memset(sgt_buf, 0, sgt_buf_size);
-
        sgt = (struct dpaa2_sg_entry *)(sgt_buf + priv->tx_data_offset);
 
        addr = dma_map_single(dev, skb->data, skb->len, DMA_BIDIRECTIONAL);
@@ -933,10 +956,7 @@ static int dpaa2_eth_build_sg_fd_single_buf(struct dpaa2_eth_priv *priv,
 sgt_map_failed:
        dma_unmap_single(dev, addr, skb->len, DMA_BIDIRECTIONAL);
 data_map_failed:
-       if (sgt_cache->count >= DPAA2_ETH_SGT_CACHE_SIZE)
-               skb_free_frag(sgt_buf);
-       else
-               sgt_cache->buf[sgt_cache->count++] = sgt_buf;
+       dpaa2_eth_sgt_recycle(priv, sgt_buf);
 
        return err;
 }
@@ -1004,8 +1024,6 @@ static void dpaa2_eth_free_tx_fd(struct dpaa2_eth_priv *priv,
        struct dpaa2_eth_swa *swa;
        u8 fd_format = dpaa2_fd_get_format(fd);
        u32 fd_len = dpaa2_fd_get_len(fd);
-
-       struct dpaa2_eth_sgt_cache *sgt_cache;
        struct dpaa2_sg_entry *sgt;
 
        fd_addr = dpaa2_fd_get_addr(fd);
@@ -1082,15 +1100,10 @@ static void dpaa2_eth_free_tx_fd(struct dpaa2_eth_priv *priv,
 
        /* Free SGT buffer allocated on tx */
        if (fd_format != dpaa2_fd_single) {
-               sgt_cache = this_cpu_ptr(priv->sgt_cache);
-               if (swa->type == DPAA2_ETH_SWA_SG) {
+               if (swa->type == DPAA2_ETH_SWA_SG)
                        skb_free_frag(buffer_start);
-               } else {
-                       if (sgt_cache->count >= DPAA2_ETH_SGT_CACHE_SIZE)
-                               skb_free_frag(buffer_start);
-                       else
-                               sgt_cache->buf[sgt_cache->count++] = buffer_start;
-               }
+               else
+                       dpaa2_eth_sgt_recycle(priv, buffer_start);
        }
 
        /* Move on with skb release */