ice: Add code to keep track of current dflt_vsi

We can't have more than one default VSI so prevent another VSI from
overwriting the current dflt_vsi. This was achieved by adding the
following functions:

ice_is_dflt_vsi_in_use()
- Used to check if the default VSI is already being used.

ice_is_vsi_dflt_vsi()
- Used to check if VSI passed in is in fact the default VSI.

ice_set_dflt_vsi()
- Used to set the default VSI via a switch rule

ice_clear_dflt_vsi()
- Used to clear the default VSI via a switch rule.

Also, there was no need to introduce any locking because all mailbox
events and synchronization of switch filters for the PF happen in the
service task.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 118 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index a47241e92d0b..b5cd275606bb 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -2742,3 +2742,121 @@ cfg_mac_fltr_exit:
 	ice_free_fltr_list(&vsi->back->pdev->dev, &tmp_add_list);
 	return status;
 }
+
+/**
+ * ice_is_dflt_vsi_in_use - check if the default forwarding VSI is being used
+ * @sw: switch to check if its default forwarding VSI is free
+ *
+ * Return true if the default forwarding VSI is already being used, else returns
+ * false signalling that it's available to use.
+ */
+bool ice_is_dflt_vsi_in_use(struct ice_sw *sw)
+{
+	return (sw->dflt_vsi && sw->dflt_vsi_ena);
+}
+
+/**
+ * ice_is_vsi_dflt_vsi - check if the VSI passed in is the default VSI
+ * @sw: switch for the default forwarding VSI to compare against
+ * @vsi: VSI to compare against default forwarding VSI
+ *
+ * If this VSI passed in is the default forwarding VSI then return true, else
+ * return false
+ */
+bool ice_is_vsi_dflt_vsi(struct ice_sw *sw, struct ice_vsi *vsi)
+{
+	return (sw->dflt_vsi == vsi && sw->dflt_vsi_ena);
+}
+
+/**
+ * ice_set_dflt_vsi - set the default forwarding VSI
+ * @sw: switch used to assign the default forwarding VSI
+ * @vsi: VSI getting set as the default forwarding VSI on the switch
+ *
+ * If the VSI passed in is already the default VSI and it's enabled just return
+ * success.
+ *
+ * If there is already a default VSI on the switch and it's enabled then return
+ * -EEXIST since there can only be one default VSI per switch.
+ *
+ *  Otherwise try to set the VSI passed in as the switch's default VSI and
+ *  return the result.
+ */
+int ice_set_dflt_vsi(struct ice_sw *sw, struct ice_vsi *vsi)
+{
+	enum ice_status status;
+	struct device *dev;
+
+	if (!sw || !vsi)
+		return -EINVAL;
+
+	dev = ice_pf_to_dev(vsi->back);
+
+	/* the VSI passed in is already the default VSI */
+	if (ice_is_vsi_dflt_vsi(sw, vsi)) {
+		dev_dbg(dev, "VSI %d passed in is already the default forwarding VSI, nothing to do\n",
+			vsi->vsi_num);
+		return 0;
+	}
+
+	/* another VSI is already the default VSI for this switch */
+	if (ice_is_dflt_vsi_in_use(sw)) {
+		dev_err(dev,
+			"Default forwarding VSI %d already in use, disable it and try again\n",
+			sw->dflt_vsi->vsi_num);
+		return -EEXIST;
+	}
+
+	status = ice_cfg_dflt_vsi(&vsi->back->hw, vsi->idx, true, ICE_FLTR_RX);
+	if (status) {
+		dev_err(dev,
+			"Failed to set VSI %d as the default forwarding VSI, error %d\n",
+			vsi->vsi_num, status);
+		return -EIO;
+	}
+
+	sw->dflt_vsi = vsi;
+	sw->dflt_vsi_ena = true;
+
+	return 0;
+}
+
+/**
+ * ice_clear_dflt_vsi - clear the default forwarding VSI
+ * @sw: switch used to clear the default VSI
+ *
+ * If the switch has no default VSI or it's not enabled then return error.
+ *
+ * Otherwise try to clear the default VSI and return the result.
+ */
+int ice_clear_dflt_vsi(struct ice_sw *sw)
+{
+	struct ice_vsi *dflt_vsi;
+	enum ice_status status;
+	struct device *dev;
+
+	if (!sw)
+		return -EINVAL;
+
+	dev = ice_pf_to_dev(sw->pf);
+
+	dflt_vsi = sw->dflt_vsi;
+
+	/* there is no default VSI configured */
+	if (!ice_is_dflt_vsi_in_use(sw))
+		return -ENODEV;
+
+	status = ice_cfg_dflt_vsi(&dflt_vsi->back->hw, dflt_vsi->idx, false,
+				  ICE_FLTR_RX);
+	if (status) {
+		dev_err(dev,
+			"Failed to clear the default forwarding VSI %d, error %d\n",
+			dflt_vsi->vsi_num, status);
+		return -EIO;
+	}
+
+	sw->dflt_vsi = NULL;
+	sw->dflt_vsi_ena = false;
+
+	return 0;
+}