ixgbe: Pass staterr instead of re-reading status and error bits from descriptor

This change is meant to address possible race conditions from the status
and error bits on the RX descriptors being re-read by multiple functions in
the RX cleanup path.  To resolve this I have added code that will pass the
staterr value to those functions.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

3 files changed, 37 insertions, 42 deletions

diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h
index fbae7352b036..0d610c73164d 100644
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -600,8 +600,9 @@ extern int ixgbe_fso(struct ixgbe_ring *tx_ring, struct sk_buff *skb,
                      u32 tx_flags, u8 *hdr_len);
 extern void ixgbe_cleanup_fcoe(struct ixgbe_adapter *adapter);
 extern int ixgbe_fcoe_ddp(struct ixgbe_adapter *adapter,
-                          union ixgbe_adv_rx_desc *rx_desc,
-                          struct sk_buff *skb);
+                          union ixgbe_adv_rx_desc *rx_desc,
+                          struct sk_buff *skb,
+                          u32 staterr);
 extern int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
                               struct scatterlist *sgl, unsigned int sgc);
 extern int ixgbe_fcoe_ddp_target(struct net_device *netdev, u16 xid,
diff --git a/drivers/net/ixgbe/ixgbe_fcoe.c b/drivers/net/ixgbe/ixgbe_fcoe.c
index f0c1018bbf31..824edae77865 100644
--- a/drivers/net/ixgbe/ixgbe_fcoe.c
+++ b/drivers/net/ixgbe/ixgbe_fcoe.c
@@ -37,25 +37,6 @@
 #include <scsi/libfcoe.h>
 
 /**
- * ixgbe_rx_is_fcoe - check the rx desc for incoming pkt type
- * @rx_desc: advanced rx descriptor
- *
- * Returns : true if it is FCoE pkt
- */
-static inline bool ixgbe_rx_is_fcoe(union ixgbe_adv_rx_desc *rx_desc)
-{
-        u16 p;
-
-        p = le16_to_cpu(rx_desc->wb.lower.lo_dword.hs_rss.pkt_info);
-        if (p & IXGBE_RXDADV_PKTTYPE_ETQF) {
-                p &= IXGBE_RXDADV_PKTTYPE_ETQF_MASK;
-                p >>= IXGBE_RXDADV_PKTTYPE_ETQF_SHIFT;
-                return p == IXGBE_ETQF_FILTER_FCOE;
-        }
-        return false;
-}
-
-/**
  * ixgbe_fcoe_clear_ddp - clear the given ddp context
  * @ddp - ptr to the ixgbe_fcoe_ddp
  *
@@ -136,7 +117,6 @@ out_ddp_put:
         return len;
 }
 
-
 /**
  * ixgbe_fcoe_ddp_setup - called to set up ddp context
  * @netdev: the corresponding net_device
@@ -380,23 +360,20 @@ int ixgbe_fcoe_ddp_target(struct net_device *netdev, u16 xid,
  */
 int ixgbe_fcoe_ddp(struct ixgbe_adapter *adapter,
                    union ixgbe_adv_rx_desc *rx_desc,
-                   struct sk_buff *skb)
+                   struct sk_buff *skb,
+                   u32 staterr)
 {
         u16 xid;
         u32 fctl;
-        u32 sterr, fceofe, fcerr, fcstat;
+        u32 fceofe, fcerr, fcstat;
         int rc = -EINVAL;
         struct ixgbe_fcoe *fcoe;
         struct ixgbe_fcoe_ddp *ddp;
         struct fc_frame_header *fh;
         struct fcoe_crc_eof *crc;
 
-        if (!ixgbe_rx_is_fcoe(rx_desc))
-                goto ddp_out;
-
-        sterr = le32_to_cpu(rx_desc->wb.upper.status_error);
-        fcerr = (sterr & IXGBE_RXDADV_ERR_FCERR);
-        fceofe = (sterr & IXGBE_RXDADV_ERR_FCEOFE);
+        fcerr = (staterr & IXGBE_RXDADV_ERR_FCERR);
+        fceofe = (staterr & IXGBE_RXDADV_ERR_FCEOFE);
         if (fcerr == IXGBE_FCERR_BADCRC)
                 skb_checksum_none_assert(skb);
         else
@@ -425,7 +402,7 @@ int ixgbe_fcoe_ddp(struct ixgbe_adapter *adapter,
         if (fcerr | fceofe)
                 goto ddp_out;
 
-        fcstat = (sterr & IXGBE_RXDADV_STAT_FCSTAT);
+        fcstat = (staterr & IXGBE_RXDADV_STAT_FCSTAT);
         if (fcstat) {
                 /* update length of DDPed data */
                 ddp->len = le32_to_cpu(rx_desc->wb.lower.hi_dword.rss);
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 298c95b1480f..a222af378a32 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -1039,6 +1039,24 @@ static inline void ixgbe_rx_hash(union ixgbe_adv_rx_desc *rx_desc,
 }
 
 /**
+ * ixgbe_rx_is_fcoe - check the rx desc for incoming pkt type
+ * @adapter: address of board private structure
+ * @rx_desc: advanced rx descriptor
+ *
+ * Returns : true if it is FCoE pkt
+ */
+static inline bool ixgbe_rx_is_fcoe(struct ixgbe_adapter *adapter,
+                                    union ixgbe_adv_rx_desc *rx_desc)
+{
+        __le16 pkt_info = rx_desc->wb.lower.lo_dword.hs_rss.pkt_info;
+
+        return (adapter->flags & IXGBE_FLAG_FCOE_ENABLED) &&
+               ((pkt_info & cpu_to_le16(IXGBE_RXDADV_PKTTYPE_ETQF_MASK)) ==
+                (cpu_to_le16(IXGBE_ETQF_FILTER_FCOE <<
+                             IXGBE_RXDADV_PKTTYPE_ETQF_SHIFT)));
+}
+
+/**
  * ixgbe_receive_skb - Send a completed packet up the stack
  * @adapter: board private structure
  * @skb: packet to send up
@@ -1070,14 +1088,14 @@ static void ixgbe_receive_skb(struct ixgbe_q_vector *q_vector,
  * @adapter: address of board private structure
  * @status_err: hardware indication of status of receive
  * @skb: skb currently being received and modified
+ * @status_err: status error value of last descriptor in packet
  **/
 static inline void ixgbe_rx_checksum(struct ixgbe_adapter *adapter,
                                      union ixgbe_adv_rx_desc *rx_desc,
-                                     struct sk_buff *skb)
+                                     struct sk_buff *skb,
+                                     u32 status_err)
 {
-        u32 status_err = le32_to_cpu(rx_desc->wb.upper.status_error);
-
-        skb_checksum_none_assert(skb);
+        skb->ip_summed = CHECKSUM_NONE;
 
         /* Rx csum disabled */
         if (!(adapter->flags & IXGBE_FLAG_RX_CSUM_ENABLED))
@@ -1421,14 +1439,12 @@ static void ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
                 }
 
                 /* ERR_MASK will only have valid bits if EOP set */
-                if (staterr & IXGBE_RXDADV_ERR_FRAME_ERR_MASK) {
-                        /* trim packet back to size 0 and recycle it */
-                        __pskb_trim(skb, 0);
-                        rx_buffer_info->skb = skb;
+                if (unlikely(staterr & IXGBE_RXDADV_ERR_FRAME_ERR_MASK)) {
+                        dev_kfree_skb_any(skb);
                         goto next_desc;
                 }
 
-                ixgbe_rx_checksum(adapter, rx_desc, skb);
+                ixgbe_rx_checksum(adapter, rx_desc, skb, staterr);
                 if (adapter->netdev->features & NETIF_F_RXHASH)
                         ixgbe_rx_hash(rx_desc, skb);
 
@@ -1439,8 +1455,9 @@ static void ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
                 skb->protocol = eth_type_trans(skb, rx_ring->netdev);
 #ifdef IXGBE_FCOE
                 /* if ddp, not passing to ULD unless for FCP_RSP or error */
-                if (adapter->flags & IXGBE_FLAG_FCOE_ENABLED) {
-                        ddp_bytes = ixgbe_fcoe_ddp(adapter, rx_desc, skb);
+                if (ixgbe_rx_is_fcoe(adapter, rx_desc)) {
+                        ddp_bytes = ixgbe_fcoe_ddp(adapter, rx_desc, skb,
+                                                   staterr);
                         if (!ddp_bytes)
                                 goto next_desc;
                 }