}
/**
+ * i40e_get_head - Retrieve head from head writeback
+ * @tx_ring: tx ring to fetch head of
+ *
+ * Returns value of Tx ring head based on value stored
+ * in head write-back location
+ **/
+static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
+{
+ void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
+
+ return le32_to_cpu(*(volatile __le32 *)head);
+}
+
+/**
* i40e_get_tx_pending - how many tx descriptors not processed
* @tx_ring: the ring of descriptors
*
**/
static u32 i40e_get_tx_pending(struct i40e_ring *ring)
{
- u32 ntu = ((ring->next_to_clean <= ring->next_to_use)
- ? ring->next_to_use
- : ring->next_to_use + ring->count);
- return ntu - ring->next_to_clean;
+ u32 head, tail;
+
+ head = i40e_get_head(ring);
+ tail = readl(ring->tail);
+
+ if (head != tail)
+ return (head < tail) ?
+ tail - head : (tail + ring->count - head);
+
+ return 0;
}
/**
**/
static bool i40e_check_tx_hang(struct i40e_ring *tx_ring)
{
+ u32 tx_done = tx_ring->stats.packets;
+ u32 tx_done_old = tx_ring->tx_stats.tx_done_old;
u32 tx_pending = i40e_get_tx_pending(tx_ring);
struct i40e_pf *pf = tx_ring->vsi->back;
bool ret = false;
* run the check_tx_hang logic with a transmit completion
* pending but without time to complete it yet.
*/
- if ((tx_ring->tx_stats.tx_done_old == tx_ring->stats.packets) &&
- (tx_pending >= I40E_MIN_DESC_PENDING)) {
+ if ((tx_done_old == tx_done) && tx_pending) {
/* make sure it is true for two checks in a row */
ret = test_and_set_bit(__I40E_HANG_CHECK_ARMED,
&tx_ring->state);
- } else if ((tx_ring->tx_stats.tx_done_old == tx_ring->stats.packets) &&
- (tx_pending < I40E_MIN_DESC_PENDING) &&
- (tx_pending > 0)) {
+ } else if (tx_done_old == tx_done &&
+ (tx_pending < I40E_MIN_DESC_PENDING) && (tx_pending > 0)) {
if (I40E_DEBUG_FLOW & pf->hw.debug_mask)
dev_info(tx_ring->dev, "HW needs some more descs to do a cacheline flush. tx_pending %d, queue %d",
tx_pending, tx_ring->queue_index);
pf->tx_sluggish_count++;
} else {
/* update completed stats and disarm the hang check */
- tx_ring->tx_stats.tx_done_old = tx_ring->stats.packets;
+ tx_ring->tx_stats.tx_done_old = tx_done;
clear_bit(__I40E_HANG_CHECK_ARMED, &tx_ring->state);
}
return ret;
}
-/**
- * i40e_get_head - Retrieve head from head writeback
- * @tx_ring: tx ring to fetch head of
- *
- * Returns value of Tx ring head based on value stored
- * in head write-back location
- **/
-static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
-{
- void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
-
- return le32_to_cpu(*(volatile __le32 *)head);
-}
-
#define WB_STRIDE 0x3
/**
}
/**
+ * i40e_chk_linearize - Check if there are more than 8 fragments per packet
+ * @skb: send buffer
+ * @tx_flags: collected send information
+ * @hdr_len: size of the packet header
+ *
+ * Note: Our HW can't scatter-gather more than 8 fragments to build
+ * a packet on the wire and so we need to figure out the cases where we
+ * need to linearize the skb.
+ **/
+static bool i40e_chk_linearize(struct sk_buff *skb, u32 tx_flags,
+ const u8 hdr_len)
+{
+ struct skb_frag_struct *frag;
+ bool linearize = false;
+ unsigned int size = 0;
+ u16 num_frags;
+ u16 gso_segs;
+
+ num_frags = skb_shinfo(skb)->nr_frags;
+ gso_segs = skb_shinfo(skb)->gso_segs;
+
+ if (tx_flags & (I40E_TX_FLAGS_TSO | I40E_TX_FLAGS_FSO)) {
+ u16 j = 1;
+
+ if (num_frags < (I40E_MAX_BUFFER_TXD))
+ goto linearize_chk_done;
+ /* try the simple math, if we have too many frags per segment */
+ if (DIV_ROUND_UP((num_frags + gso_segs), gso_segs) >
+ I40E_MAX_BUFFER_TXD) {
+ linearize = true;
+ goto linearize_chk_done;
+ }
+ frag = &skb_shinfo(skb)->frags[0];
+ size = hdr_len;
+ /* we might still have more fragments per segment */
+ do {
+ size += skb_frag_size(frag);
+ frag++; j++;
+ if (j == I40E_MAX_BUFFER_TXD) {
+ if (size < skb_shinfo(skb)->gso_size) {
+ linearize = true;
+ break;
+ }
+ j = 1;
+ size -= skb_shinfo(skb)->gso_size;
+ if (size)
+ j++;
+ size += hdr_len;
+ }
+ num_frags--;
+ } while (num_frags);
+ } else {
+ if (num_frags >= I40E_MAX_BUFFER_TXD)
+ linearize = true;
+ }
+
+linearize_chk_done:
+ return linearize;
+}
+
+/**
* i40e_tx_map - Build the Tx descriptor
* @tx_ring: ring to send buffer on
* @skb: send buffer
if (tsyn)
tx_flags |= I40E_TX_FLAGS_TSYN;
+ if (i40e_chk_linearize(skb, tx_flags, hdr_len))
+ if (skb_linearize(skb))
+ goto out_drop;
+
skb_tx_timestamp(skb);
/* always enable CRC insertion offload */
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