ixgbe: Force QDE via PFQDE for VFs during reset

This change makes it so that the QDE bits are set for a VF before the Rx
queues are enabled.  As such we avoid head of line blocking in the event
that the VF stops cleaning Rx descriptors for whatever reason.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>

 drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c |   14 ++++++++++++++
 drivers/net/ethernet/intel/ixgbe/ixgbe_type.h  |    7 ++++---
 2 files changed, 18 insertions(+), 3 deletions(-)
Signed-off-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 18 insertions, 3 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
index 359f6e60320d..43e10c67ac4e 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
@@ -631,11 +631,14 @@ int ixgbe_vf_configuration(struct pci_dev *pdev, unsigned int event_mask)
 
 static int ixgbe_vf_reset_msg(struct ixgbe_adapter *adapter, u32 vf)
 {
+        struct ixgbe_ring_feature *vmdq = &adapter->ring_feature[RING_F_VMDQ];
         struct ixgbe_hw *hw = &adapter->hw;
         unsigned char *vf_mac = adapter->vfinfo[vf].vf_mac_addresses;
         u32 reg, reg_offset, vf_shift;
         u32 msgbuf[4] = {0, 0, 0, 0};
         u8 *addr = (u8 *)(&msgbuf[1]);
+        u32 q_per_pool = __ALIGN_MASK(1, ~vmdq->mask);
+        int i;
 
         e_info(probe, "VF Reset msg received from vf %d\n", vf);
 
@@ -654,6 +657,17 @@ static int ixgbe_vf_reset_msg(struct ixgbe_adapter *adapter, u32 vf)
         reg |= 1 << vf_shift;
         IXGBE_WRITE_REG(hw, IXGBE_VFTE(reg_offset), reg);
 
+        /* force drop enable for all VF Rx queues */
+        for (i = vf * q_per_pool; i < ((vf + 1) * q_per_pool); i++) {
+                /* flush previous write */
+                IXGBE_WRITE_FLUSH(hw);
+
+                /* indicate to hardware that we want to set drop enable */
+                reg = IXGBE_QDE_WRITE | IXGBE_QDE_ENABLE;
+                reg |= i <<  IXGBE_QDE_IDX_SHIFT;
+                IXGBE_WRITE_REG(hw, IXGBE_QDE, reg);
+        }
+
         /* enable receive for vf */
         reg = IXGBE_READ_REG(hw, IXGBE_VFRE(reg_offset));
         reg |= 1 << vf_shift;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
index 7c19e969576f..d8e59f42b85c 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
@@ -1980,9 +1980,10 @@ enum {
 #define IXGBE_FWSM_TS_ENABLED   0x1
 
 /* Queue Drop Enable */
-#define IXGBE_QDE_ENABLE     0x00000001
-#define IXGBE_QDE_IDX_MASK   0x00007F00
-#define IXGBE_QDE_IDX_SHIFT           8
+#define IXGBE_QDE_ENABLE        0x00000001
+#define IXGBE_QDE_IDX_MASK      0x00007F00
+#define IXGBE_QDE_IDX_SHIFT     8
+#define IXGBE_QDE_WRITE         0x00010000
 
 #define IXGBE_TXD_POPTS_IXSM 0x01       /* Insert IP checksum */
 #define IXGBE_TXD_POPTS_TXSM 0x02       /* Insert TCP/UDP checksum */