@@ -531,29 +531,32 @@ static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
return ring->buf + index * TXBB_SIZE;
}
+/* Decide if skb can be inlined in tx descriptor to avoid dma mapping
+ *
+ * It seems strange we do not simply use skb_copy_bits().
+ * This would allow to inline all skbs iff skb->len <= inline_thold
+ *
+ * Note that caller already checked skb was not a gso packet
+ */
static bool is_inline(int inline_thold, const struct sk_buff *skb,
const struct skb_shared_info *shinfo,
void **pfrag)
{
void *ptr;
- if (inline_thold && !skb_is_gso(skb) && skb->len <= inline_thold) {
- if (shinfo->nr_frags == 1) {
- ptr = skb_frag_address_safe(&shinfo->frags[0]);
- if (unlikely(!ptr))
- return 0;
-
- if (pfrag)
- *pfrag = ptr;
+ if (skb->len > inline_thold || !inline_thold)
+ return false;
- return 1;
- } else if (unlikely(shinfo->nr_frags))
- return 0;
- else
- return 1;
+ if (shinfo->nr_frags == 1) {
+ ptr = skb_frag_address_safe(&shinfo->frags[0]);
+ if (unlikely(!ptr))
+ return false;
+ *pfrag = ptr;
+ return true;
}
-
- return 0;
+ if (shinfo->nr_frags)
+ return false;
+ return true;
}
static int inline_size(const struct sk_buff *skb)
@@ -570,12 +573,15 @@ static int inline_size(const struct sk_buff *skb)
static int get_real_size(const struct sk_buff *skb,
const struct skb_shared_info *shinfo,
struct net_device *dev,
- int *lso_header_size)
+ int *lso_header_size,
+ bool *inline_ok,
+ void **pfrag)
{
struct mlx4_en_priv *priv = netdev_priv(dev);
int real_size;
if (shinfo->gso_size) {
+ *inline_ok = false;
if (skb->encapsulation)
*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);
else
@@ -595,10 +601,14 @@ static int get_real_size(const struct sk_buff *skb,
}
} else {
*lso_header_size = 0;
- if (!is_inline(priv->prof->inline_thold, skb, shinfo, NULL))
- real_size = CTRL_SIZE + (shinfo->nr_frags + 1) * DS_SIZE;
- else
+ *inline_ok = is_inline(priv->prof->inline_thold, skb,
+ shinfo, pfrag);
+
+ if (*inline_ok)
real_size = inline_size(skb);
+ else
+ real_size = CTRL_SIZE +
+ (shinfo->nr_frags + 1) * DS_SIZE;
}
return real_size;
@@ -694,9 +704,10 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
u16 vlan_tag = 0;
int i_frag;
int lso_header_size;
- void *fragptr;
+ void *fragptr = NULL;
bool bounce = false;
bool send_doorbell;
+ bool inline_ok;
u32 ring_cons;
if (!priv->port_up)
@@ -708,7 +719,8 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
/* fetch ring->cons far ahead before needing it to avoid stall */
ring_cons = ACCESS_ONCE(ring->cons);
- real_size = get_real_size(skb, shinfo, dev, &lso_header_size);
+ real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
+ &inline_ok, &fragptr);
if (unlikely(!real_size))
goto tx_drop;
@@ -781,15 +793,15 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
/* valid only for none inline segments */
tx_info->data_offset = (void *)data - (void *)tx_desc;
+ tx_info->inl = inline_ok;
+
tx_info->linear = (lso_header_size < skb_headlen(skb) &&
- !is_inline(ring->inline_thold, skb, shinfo, NULL)) ? 1 : 0;
+ !inline_ok) ? 1 : 0;
tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
data += tx_info->nr_maps - 1;
- if (is_inline(ring->inline_thold, skb, shinfo, &fragptr)) {
- tx_info->inl = 1;
- } else {
+ if (!tx_info->inl) {
dma_addr_t dma = 0;
u32 byte_count = 0;
@@ -827,7 +839,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
wmb();
data->byte_count = cpu_to_be32(byte_count);
}
- tx_info->inl = 0;
/* tx completion can avoid cache line miss for common cases */
tx_info->map0_dma = dma;
tx_info->map0_byte_count = byte_count;
@@ -899,11 +910,9 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
netdev_tx_sent_queue(ring->tx_queue, tx_info->nr_bytes);
AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len);
- if (tx_info->inl) {
+ if (tx_info->inl)
build_inline_wqe(tx_desc, skb, shinfo, real_size, &vlan_tag,
tx_ind, fragptr);
- tx_info->inl = 1;
- }
if (skb->encapsulation) {
struct iphdr *ipv4 = (struct iphdr *)skb_inner_network_header(skb);