ice: add E830 HW VF mailbox message limit support

E830 adds hardware support to prevent the VF from overflowing the PF
mailbox with VIRTCHNL messages. E830 will use the hardware feature
(ICE_F_MBX_LIMIT) instead of the software solution ice_is_malicious_vf().

To prevent a VF from overflowing the PF, the PF sets the number of
messages per VF that can be in the PF's mailbox queue
(ICE_MBX_OVERFLOW_WATERMARK). When the PF processes a message from a VF,
the PF decrements the per VF message count using the E830_MBX_VF_DEC_TRIG
register.

Signed-off-by: Paul Greenwalt <paul.greenwalt@intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_vf_mbx.c b/drivers/net/ethernet/intel/ice/ice_vf_mbx.c
index 40cb4ba0789c..75c8113e58ee 100644
--- a/drivers/net/ethernet/intel/ice/ice_vf_mbx.c
+++ b/drivers/net/ethernet/intel/ice/ice_vf_mbx.c
@@ -211,6 +211,38 @@ ice_mbx_detect_malvf(struct ice_hw *hw, struct ice_mbx_vf_info *vf_info,
 }
 
 /**
+ * ice_mbx_vf_dec_trig_e830 - Decrements the VF mailbox queue counter
+ * @hw: pointer to the HW struct
+ * @event: pointer to the control queue receive event
+ *
+ * This function triggers to decrement the counter
+ * MBX_VF_IN_FLIGHT_MSGS_AT_PF_CNT when the driver replenishes
+ * the buffers at the PF mailbox queue.
+ */
+void ice_mbx_vf_dec_trig_e830(const struct ice_hw *hw,
+			      const struct ice_rq_event_info *event)
+{
+	u16 vfid = le16_to_cpu(event->desc.retval);
+
+	wr32(hw, E830_MBX_VF_DEC_TRIG(vfid), 1);
+}
+
+/**
+ * ice_mbx_vf_clear_cnt_e830 - Clear the VF mailbox queue count
+ * @hw: pointer to the HW struct
+ * @vf_id: VF ID in the PF space
+ *
+ * This function clears the counter MBX_VF_IN_FLIGHT_MSGS_AT_PF_CNT, and should
+ * be called when a VF is created and on VF reset.
+ */
+void ice_mbx_vf_clear_cnt_e830(const struct ice_hw *hw, u16 vf_id)
+{
+	u32 reg = rd32(hw, E830_MBX_VF_IN_FLIGHT_MSGS_AT_PF_CNT(vf_id));
+
+	wr32(hw, E830_MBX_VF_DEC_TRIG(vf_id), reg);
+}
+
+/**
  * ice_mbx_vf_state_handler - Handle states of the overflow algorithm
  * @hw: pointer to the HW struct
  * @mbx_data: pointer to structure containing mailbox data