[PATCH net-next v3] e1000e: Be drop monitor friendly

e1000e_put_txbuf() can be called from normal reclamation path as well as
when a DMA mapping failure, so we need to differentiate these two cases
when freeing SKBs to be drop monitor friendly. e1000e_tx_hwtstamp_work()
and e1000_remove() are processing TX timestamped SKBs and those should
not be accounted as drops either.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
Changes in v3:

- differentiate normal reclamation from TX DMA fragment mapping errors
- removed a few invalid dev_kfree_skb() replacements (those are already
   drop monitor friendly)

Changes in v2:

- make it compile

  drivers/net/ethernet/intel/e1000e/netdev.c | 18 +++++++++++-------
  1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 327dfe5bedc0..cfd21858c095 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c

@@ -1071,7 +1071,8 @@ static bool e1000_clean_rx_irq(struct e1000_ring *rx_ring, int *work_done,
  }
  
  static void e1000_put_txbuf(struct e1000_ring *tx_ring,
-			    struct e1000_buffer *buffer_info)
+			    struct e1000_buffer *buffer_info,
+			    bool drop)
  {
  	struct e1000_adapter *adapter = tx_ring->adapter;
  

@@ -1085,7 +1086,10 @@ static void e1000_put_txbuf(struct e1000_ring *tx_ring,
  		buffer_info->dma = 0;
  	}
  	if (buffer_info->skb) {
-		dev_kfree_skb_any(buffer_info->skb);
+		if (drop)
+			dev_kfree_skb_any(buffer_info->skb);
+		else
+			dev_consume_skb_any(buffer_info->skb);
  		buffer_info->skb = NULL;
  	}
  	buffer_info->time_stamp = 0;

@@ -1199,7 +1203,7 @@ static void e1000e_tx_hwtstamp_work(struct work_struct *work)
  		wmb(); /* force write prior to skb_tstamp_tx */
  
  		skb_tstamp_tx(skb, &shhwtstamps);
-		dev_kfree_skb_any(skb);
+		dev_consume_skb_any(skb);
  	} else if (time_after(jiffies, adapter->tx_hwtstamp_start
  			      + adapter->tx_timeout_factor * HZ)) {
  		dev_kfree_skb_any(adapter->tx_hwtstamp_skb);

@@ -1254,7 +1258,7 @@ static bool e1000_clean_tx_irq(struct e1000_ring *tx_ring)
  				}
  			}
  
-			e1000_put_txbuf(tx_ring, buffer_info);
+			e1000_put_txbuf(tx_ring, buffer_info, false);
  			tx_desc->upper.data = 0;
  
  			i++;

@@ -2421,7 +2425,7 @@ static void e1000_clean_tx_ring(struct e1000_ring *tx_ring)
  
  	for (i = 0; i < tx_ring->count; i++) {
  		buffer_info = &tx_ring->buffer_info[i];
-		e1000_put_txbuf(tx_ring, buffer_info);
+		e1000_put_txbuf(tx_ring, buffer_info, false);
  	}
  
  	netdev_reset_queue(adapter->netdev);

@@ -5614,7 +5618,7 @@ static int e1000_tx_map(struct e1000_ring *tx_ring, struct sk_buff *skb,
  			i += tx_ring->count;
  		i--;
  		buffer_info = &tx_ring->buffer_info[i];
-		e1000_put_txbuf(tx_ring, buffer_info);
+		e1000_put_txbuf(tx_ring, buffer_info, true);
  	}
  
  	return 0;

@@ -7411,7 +7415,7 @@ static void e1000_remove(struct pci_dev *pdev)
  	if (adapter->flags & FLAG_HAS_HW_TIMESTAMP) {
  		cancel_work_sync(&adapter->tx_hwtstamp_work);
  		if (adapter->tx_hwtstamp_skb) {
-			dev_kfree_skb_any(adapter->tx_hwtstamp_skb);
+			dev_consume_skb_any(adapter->tx_hwtstamp_skb);
  			adapter->tx_hwtstamp_skb = NULL;
  		}
  	}