ice: Support RSS configure removal for AVF

Add the handler for virtchnl message VIRTCHNL_OP_DEL_RSS_CFG to remove
an existing RSS configuration with matching hashed fields.

Signed-off-by: Vignesh Sridhar <[e-mail]>
Co-developed-by: Jia Guo <[e-mail]>
Signed-off-by: Jia Guo <[e-mail]>
Signed-off-by: Qi Zhang <[e-mail]>
Signed-off-by: Haiyue Wang <[e-mail]>
Tested-by: Bo Chen <[e-mail]>
Signed-off-by: Tony Nguyen <[e-mail]>

drivers/net/ethernet/intel/ice/ice_flow.c

···
 	return status;
 }
 
+/**
+ * ice_rem_rss_cfg_sync - remove an existing RSS configuration
+ * @hw: pointer to the hardware structure
+ * @vsi_handle: software VSI handle
+ * @hashed_flds: Packet hash types (ICE_FLOW_HASH_*) to remove
+ * @addl_hdrs: Protocol header fields within a packet segment
+ * @segs_cnt: packet segment count
+ *
+ * Assumption: lock has already been acquired for RSS list
+ */
+static enum ice_status
+ice_rem_rss_cfg_sync(struct ice_hw *hw, u16 vsi_handle, u64 hashed_flds,
+		     u32 addl_hdrs, u8 segs_cnt)
+{
+	const enum ice_block blk = ICE_BLK_RSS;
+	struct ice_flow_seg_info *segs;
+	struct ice_flow_prof *prof;
+	enum ice_status status;
+
+	segs = kcalloc(segs_cnt, sizeof(*segs), GFP_KERNEL);
+	if (!segs)
+		return ICE_ERR_NO_MEMORY;
+
+	/* Construct the packet segment info from the hashed fields */
+	status = ice_flow_set_rss_seg_info(&segs[segs_cnt - 1], hashed_flds,
+					   addl_hdrs);
+	if (status)
+		goto out;
+
+	prof = ice_flow_find_prof_conds(hw, blk, ICE_FLOW_RX, segs, segs_cnt,
+					vsi_handle,
+					ICE_FLOW_FIND_PROF_CHK_FLDS);
+	if (!prof) {
+		status = ICE_ERR_DOES_NOT_EXIST;
+		goto out;
+	}
+
+	status = ice_flow_disassoc_prof(hw, blk, prof, vsi_handle);
+	if (status)
+		goto out;
+
+	/* Remove RSS configuration from VSI context before deleting
+	 * the flow profile.
+	 */
+	ice_rem_rss_list(hw, vsi_handle, prof);
+
+	if (bitmap_empty(prof->vsis, ICE_MAX_VSI))
+		status = ice_flow_rem_prof(hw, blk, prof->id);
+
+out:
+	kfree(segs);
+	return status;
+}
+
+/**
+ * ice_rem_rss_cfg - remove an existing RSS config with matching hashed fields
+ * @hw: pointer to the hardware structure
+ * @vsi_handle: software VSI handle
+ * @hashed_flds: Packet hash types (ICE_FLOW_HASH_*) to remove
+ * @addl_hdrs: Protocol header fields within a packet segment
+ *
+ * This function will lookup the flow profile based on the input
+ * hash field bitmap, iterate through the profile entry list of
+ * that profile and find entry associated with input VSI to be
+ * removed. Calls are made to underlying flow s which will APIs
+ * turn build or update buffers for RSS XLT1 section.
+ */
+enum ice_status __maybe_unused
+ice_rem_rss_cfg(struct ice_hw *hw, u16 vsi_handle, u64 hashed_flds,
+		u32 addl_hdrs)
+{
+	enum ice_status status;
+
+	if (hashed_flds == ICE_HASH_INVALID ||
+	    !ice_is_vsi_valid(hw, vsi_handle))
+		return ICE_ERR_PARAM;
+
+	mutex_lock(&hw->rss_locks);
+	status = ice_rem_rss_cfg_sync(hw, vsi_handle, hashed_flds, addl_hdrs,
+				      ICE_RSS_OUTER_HEADERS);
+	if (!status)
+		status = ice_rem_rss_cfg_sync(hw, vsi_handle, hashed_flds,
+					      addl_hdrs, ICE_RSS_INNER_HEADERS);
+	mutex_unlock(&hw->rss_locks);
+
+	return status;
+}
+
 /* Mapping of AVF hash bit fields to an L3-L4 hash combination.
  * As the ice_flow_avf_hdr_field represent individual bit shifts in a hash,
  * convert its values to their appropriate flow L3, L4 values.

drivers/net/ethernet/intel/ice/ice_flow.h

···
 enum ice_status
 ice_add_rss_cfg(struct ice_hw *hw, u16 vsi_handle, u64 hashed_flds,
 		u32 addl_hdrs);
+enum ice_status
+ice_rem_rss_cfg(struct ice_hw *hw, u16 vsi_handle, u64 hashed_flds,
+		u32 addl_hdrs);
 u64 ice_get_rss_cfg(struct ice_hw *hw, u16 vsi_handle, u32 hdrs);
 #endif /* _ICE_FLOW_H_ */

drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c

···
 					vsi->vsi_num, v_ret);
 			}
 		} else {
-			v_ret = VIRTCHNL_STATUS_ERR_NOT_SUPPORTED;
-			dev_err(dev, "RSS removal not supported\n");
+			enum ice_status status;
+
+			status = ice_rem_rss_cfg(hw, vsi->idx, hash_flds,
+						 addl_hdrs);
+			/* We just ignore ICE_ERR_DOES_NOT_EXIST, because
+			 * if two configurations share the same profile remove
+			 * one of them actually removes both, since the
+			 * profile is deleted.
+			 */
+			if (status && status != ICE_ERR_DOES_NOT_EXIST) {
+				v_ret = VIRTCHNL_STATUS_ERR_PARAM;
+				dev_err(dev, "ice_rem_rss_cfg failed for VF ID:%d, error:%s\n",
+					vf->vf_id, ice_stat_str(status));
+			}
 		}
 	}