igb: add per-packet timestamping

This patch adds support for per-packet timestamping for the
82580 adapter. The rx timestamp code is also pulled out of the
inlined rx hotpath and instead moved to a seperate function.

This version adds a comment explaining the per-packet timestamping
code added to igb_hwtstamp_ioctl().

Signed-off-by: Nicholas Nunley <nicholasx.d.nunley@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 41 insertions, 8 deletions

diff --git a/drivers/net/igb/e1000_82575.h b/drivers/net/igb/e1000_82575.h
index c1cad8ae522e..cbd1e1259e4d 100644
--- a/drivers/net/igb/e1000_82575.h
+++ b/drivers/net/igb/e1000_82575.h
@@ -53,6 +53,7 @@ extern void igb_rx_fifo_flush_82575(struct e1000_hw *hw);
 #define E1000_SRRCTL_DESCTYPE_ADV_ONEBUF                0x02000000
 #define E1000_SRRCTL_DESCTYPE_HDR_SPLIT_ALWAYS          0x0A000000
 #define E1000_SRRCTL_DROP_EN                            0x80000000
+#define E1000_SRRCTL_TIMESTAMP                          0x40000000
 
 #define E1000_MRQC_ENABLE_RSS_4Q            0x00000002
 #define E1000_MRQC_ENABLE_VMDQ              0x00000003
@@ -109,6 +110,7 @@ union e1000_adv_rx_desc {
 #define E1000_RXDADV_HDRBUFLEN_MASK      0x7FE0
 #define E1000_RXDADV_HDRBUFLEN_SHIFT     5
 #define E1000_RXDADV_STAT_TS             0x10000 /* Pkt was time stamped */
+#define E1000_RXDADV_STAT_TSIP           0x08000 /* timestamp in packet */
 
 /* Transmit Descriptor - Advanced */
 union e1000_adv_tx_desc {
diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h
index a1775705b24c..4f69b6d951b3 100644
--- a/drivers/net/igb/igb.h
+++ b/drivers/net/igb/igb.h
@@ -107,6 +107,7 @@ struct vf_data_storage {
 #define MAXIMUM_ETHERNET_VLAN_SIZE 1522
 
 /* Supported Rx Buffer Sizes */
+#define IGB_RXBUFFER_64    64     /* Used for packet split */
 #define IGB_RXBUFFER_128   128    /* Used for packet split */
 #define IGB_RXBUFFER_1024  1024
 #define IGB_RXBUFFER_2048  2048
@@ -324,6 +325,7 @@ struct igb_adapter {
 
 #define IGB_82576_TSYNC_SHIFT 19
 #define IGB_82580_TSYNC_SHIFT 24
+#define IGB_TS_HDR_LEN        16
 enum e1000_state_t {
         __IGB_TESTING,
         __IGB_RESETTING,
diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 7d755dd2688d..ea875709f053 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -2576,6 +2576,8 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
                          E1000_SRRCTL_BSIZEPKT_SHIFT;
                 srrctl |= E1000_SRRCTL_DESCTYPE_ADV_ONEBUF;
         }
+        if (hw->mac.type == e1000_82580)
+                srrctl |= E1000_SRRCTL_TIMESTAMP;
         /* Only set Drop Enable if we are supporting multiple queues */
         if (adapter->vfs_allocated_count || adapter->num_rx_queues > 1)
                 srrctl |= E1000_SRRCTL_DROP_EN;
@@ -3910,6 +3912,9 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
          * i.e. RXBUFFER_2048 --> size-4096 slab
          */
 
+        if (adapter->hw.mac.type == e1000_82580)
+                max_frame += IGB_TS_HDR_LEN;
+
         if (max_frame <= IGB_RXBUFFER_1024)
                 rx_buffer_len = IGB_RXBUFFER_1024;
         else if (max_frame <= MAXIMUM_ETHERNET_VLAN_SIZE)
@@ -3917,6 +3922,14 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
         else
                 rx_buffer_len = IGB_RXBUFFER_128;
 
+        if ((max_frame == ETH_FRAME_LEN + ETH_FCS_LEN + IGB_TS_HDR_LEN) ||
+             (max_frame == MAXIMUM_ETHERNET_VLAN_SIZE + IGB_TS_HDR_LEN))
+                rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE + IGB_TS_HDR_LEN;
+
+        if ((adapter->hw.mac.type == e1000_82580) &&
+            (rx_buffer_len == IGB_RXBUFFER_128))
+                rx_buffer_len += IGB_RXBUFFER_64;
+
         if (netif_running(netdev))
                 igb_down(adapter);
 
@@ -5133,7 +5146,7 @@ static inline void igb_rx_checksum_adv(struct igb_ring *ring,
         dev_dbg(&ring->pdev->dev, "cksum success: bits %08X\n", status_err);
 }
 
-static inline void igb_rx_hwtstamp(struct igb_q_vector *q_vector, u32 staterr,
+static void igb_rx_hwtstamp(struct igb_q_vector *q_vector, u32 staterr,
                                    struct sk_buff *skb)
 {
         struct igb_adapter *adapter = q_vector->adapter;
@@ -5151,13 +5164,18 @@ static inline void igb_rx_hwtstamp(struct igb_q_vector *q_vector, u32 staterr,
          * If nothing went wrong, then it should have a skb_shared_tx that we
          * can turn into a skb_shared_hwtstamps.
          */
-        if (likely(!(staterr & E1000_RXDADV_STAT_TS)))
-                return;
-        if (!(rd32(E1000_TSYNCRXCTL) & E1000_TSYNCRXCTL_VALID))
-                return;
+        if (staterr & E1000_RXDADV_STAT_TSIP) {
+                u32 *stamp = (u32 *)skb->data;
+                regval = le32_to_cpu(*(stamp + 2));
+                regval |= (u64)le32_to_cpu(*(stamp + 3)) << 32;
+                skb_pull(skb, IGB_TS_HDR_LEN);
+        } else {
+                if(!(rd32(E1000_TSYNCRXCTL) & E1000_TSYNCRXCTL_VALID))
+                        return;
 
-        regval = rd32(E1000_RXSTMPL);
-        regval |= (u64)rd32(E1000_RXSTMPH) << 32;
+                regval = rd32(E1000_RXSTMPL);
+                regval |= (u64)rd32(E1000_RXSTMPH) << 32;
+        }
 
         igb_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
 }
@@ -5265,7 +5283,8 @@ send_up:
                         goto next_desc;
                 }
 
-                igb_rx_hwtstamp(q_vector, staterr, skb);
+                if (staterr & (E1000_RXDADV_STAT_TSIP | E1000_RXDADV_STAT_TS))
+                        igb_rx_hwtstamp(q_vector, staterr, skb);
                 total_bytes += skb->len;
                 total_packets++;
 
@@ -5545,6 +5564,16 @@ static int igb_hwtstamp_ioctl(struct net_device *netdev,
                 return 0;
         }
 
+        /*
+         * Per-packet timestamping only works if all packets are
+         * timestamped, so enable timestamping in all packets as
+         * long as one rx filter was configured.
+         */
+        if ((hw->mac.type == e1000_82580) && tsync_rx_ctl) {
+                tsync_rx_ctl = E1000_TSYNCRXCTL_ENABLED;
+                tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_ALL;
+        }
+
         /* enable/disable TX */
         regval = rd32(E1000_TSYNCTXCTL);
         regval &= ~E1000_TSYNCTXCTL_ENABLED;