[src/trunk]: src/sys/dev/pci/ixgbe - Apply ixgbe.c rev. 1.124 to ixv.c. Fix a...

[msaitoh <msaitoh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/bd2294cff8a1
branches:  trunk
changeset: 359717:bd2294cff8a1
user:      msaitoh <msaitoh%NetBSD.org@localhost>
date:      Thu Feb 22 08:49:42 2018 +0000

description:
- Apply ixgbe.c rev. 1.124 to ixv.c. Fix a bug that RX may stall on heavy load
 on ixv(4) derived from FreeBSD's AIM (Auto Interrupt Moderation) bug.
 ITR_INTERVAL value must be larger than 4us.

- The bitfield of EITR register is different between 82598 and others.
 ixv.c had a bug that it accessed 82598's way even though only 82599 and
 newer support virtual function. Fix it using with new ixv_eitr_write()
 function.

diffstat:

 sys/dev/pci/ixgbe/ixv.c |  38 ++++++++++++++++++++++++++++++++------
 1 files changed, 32 insertions(+), 6 deletions(-)

diffs (86 lines):

diff -r 5a95b75921f1 -r bd2294cff8a1 sys/dev/pci/ixgbe/ixv.c
--- a/sys/dev/pci/ixgbe/ixv.c   Thu Feb 22 08:36:31 2018 +0000
+++ b/sys/dev/pci/ixgbe/ixv.c   Thu Feb 22 08:49:42 2018 +0000
@@ -1,4 +1,4 @@
-/*$NetBSD: ixv.c,v 1.79 2018/02/16 10:11:21 msaitoh Exp $*/
+/*$NetBSD: ixv.c,v 1.80 2018/02/22 08:49:42 msaitoh Exp $*/
 
 /******************************************************************************
 
@@ -118,6 +118,7 @@
 static void    ixv_set_ivar(struct adapter *, u8, u8, s8);
 static void    ixv_configure_ivars(struct adapter *);
 static u8 *    ixv_mc_array_itr(struct ixgbe_hw *, u8 **, u32 *);
+static void    ixv_eitr_write(struct ix_queue *, uint32_t);
 
 static void    ixv_setup_vlan_support(struct adapter *);
 #if 0
@@ -867,8 +868,7 @@
         *    the last interval.
         */
        if (que->eitr_setting)
-               IXGBE_WRITE_REG(&adapter->hw, IXGBE_VTEITR(que->msix),
-                   que->eitr_setting);
+               ixv_eitr_write(que, que->eitr_setting);
 
        que->eitr_setting = 0;
 
@@ -891,7 +891,17 @@
        else
                newitr = (newitr / 2);
 
-       newitr |= newitr << 16;
+       /*
+        * When RSC is used, ITR interval must be larger than RSC_DELAY.
+        * Currently, we use 2us for RSC_DELAY. The minimum value is always
+        * greater than 2us on 100M (and 10M?(not documented)), but it's not
+        * on 1G and higher.
+        */
+       if ((adapter->link_speed != IXGBE_LINK_SPEED_100_FULL)
+           && (adapter->link_speed != IXGBE_LINK_SPEED_10_FULL)) {
+               if (newitr < IXGBE_MIN_RSC_EITR_10G1G)
+                       newitr = IXGBE_MIN_RSC_EITR_10G1G;
+       }
 
        /* save for next interrupt */
        que->eitr_setting = newitr;
@@ -932,6 +942,21 @@
        return 1;
 } /* ixv_msix_mbx */
 
+static void
+ixv_eitr_write(struct ix_queue *que, uint32_t itr)
+{
+       struct adapter *adapter = que->adapter;
+
+       /*
+        * Newer devices than 82598 have VF function, so this function is
+        * simple.
+        */
+       itr |= IXGBE_EITR_CNT_WDIS;
+
+       IXGBE_WRITE_REG(&adapter->hw, IXGBE_VTEITR(que->msix), itr);
+}
+
+
 /************************************************************************
  * ixv_media_status - Media Ioctl callback
  *
@@ -1943,14 +1968,15 @@
 {
        struct ix_queue *que = adapter->queues;
 
+       /* XXX We should sync EITR value calculation with ixgbe.c? */
+
        for (int i = 0; i < adapter->num_queues; i++, que++) {
                /* First the RX queue entry */
                ixv_set_ivar(adapter, i, que->msix, 0);
                /* ... and the TX */
                ixv_set_ivar(adapter, i, que->msix, 1);
                /* Set an initial value in EITR */
-               IXGBE_WRITE_REG(&adapter->hw, IXGBE_VTEITR(que->msix),
-                   IXGBE_EITR_DEFAULT);
+               ixv_eitr_write(que, IXGBE_EITR_DEFAULT);
        }
 
        /* For the mailbox interrupt */