octeontx2-af: NPC: Clear Unicast rule on nixlf detach

The AF driver assigns reserved MCAM entries (for unicast, broadcast,
etc.) based on the NIXLF number. When a NIXLF is detached, these entries
are disabled.

For example,

         PF           NIXLF
        --------------------
         PF0             0
         SDP-VF0         1

If the user unbinds both PF0 and SDP-VF0 interfaces and then binds them in
reverse order

         PF            NIXLF
        ---------------------
         SDP-VF0         0
         PF0             1

In this scenario, the PF0 unicast entry is getting corrupted because
the MCAM entry contains stale data (SDP-VF0 ucast data)

This patch resolves the issue by clearing the unicast MCAM entry during
NIXLF detach

Signed-off-by: Hariprasad Kelam <[email protected]>
Signed-off-by: NipaLocal <nipa@local>

Author: Hariprasad Kelam

drivers/net/ethernet/marvell/octeontx2/af/rvu.c

@@ -1393,8 +1393,6 @@ static void rvu_detach_block(struct rvu *rvu, int pcifunc, int blktype)
 	if (blkaddr < 0)
 		return;
 
-	if (blktype == BLKTYPE_NIX)
-		rvu_nix_reset_mac(pfvf, pcifunc);
 
 	block = &hw->block[blkaddr];
 
@@ -1407,6 +1405,10 @@ static void rvu_detach_block(struct rvu *rvu, int pcifunc, int blktype)
 		if (lf < 0) /* This should never happen */
 			continue;
 
+		if (blktype == BLKTYPE_NIX) {
+			rvu_nix_reset_mac(pfvf, pcifunc);
+			rvu_npc_clear_ucast_entry(rvu, pcifunc, lf);
+		}
 		/* Disable the LF */
 		rvu_write64(rvu, blkaddr, block->lfcfg_reg |
 			    (lf << block->lfshift), 0x00ULL);

drivers/net/ethernet/marvell/octeontx2/af/rvu.h

@@ -994,6 +994,8 @@ void rvu_npc_get_mcam_entry_alloc_info(struct rvu *rvu, u16 pcifunc,
 void rvu_npc_get_mcam_counter_alloc_info(struct rvu *rvu, u16 pcifunc,
 					 int blkaddr, int *alloc_cnt,
 					 int *enable_cnt);
+void rvu_npc_clear_ucast_entry(struct rvu *rvu, int pcifunc, int nixlf);
+
 bool is_npc_intf_tx(u8 intf);
 bool is_npc_intf_rx(u8 intf);
 bool is_npc_interface_valid(struct rvu *rvu, u8 intf);

drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c

@@ -1107,6 +1107,7 @@ void npc_enadis_default_mce_entry(struct rvu *rvu, u16 pcifunc,
 static void npc_enadis_default_entries(struct rvu *rvu, u16 pcifunc,
 				       int nixlf, bool enable)
 {
+	struct rvu_pfvf *pfvf = rvu_get_pfvf(rvu, pcifunc);
 	struct npc_mcam *mcam = &rvu->hw->mcam;
 	int index, blkaddr;
 
@@ -1115,9 +1116,12 @@ static void npc_enadis_default_entries(struct rvu *rvu, u16 pcifunc,
 		return;
 
 	/* Ucast MCAM match entry of this PF/VF */
-	index = npc_get_nixlf_mcam_index(mcam, pcifunc,
-					 nixlf, NIXLF_UCAST_ENTRY);
-	npc_enable_mcam_entry(rvu, mcam, blkaddr, index, enable);
+	if (npc_is_feature_supported(rvu, BIT_ULL(NPC_DMAC),
+				     pfvf->nix_rx_intf)) {
+		index = npc_get_nixlf_mcam_index(mcam, pcifunc,
+						 nixlf, NIXLF_UCAST_ENTRY);
+		npc_enable_mcam_entry(rvu, mcam, blkaddr, index, enable);
+	}
 
 	/* Nothing to do for VFs, on platforms where pkt replication
 	 * is not supported
@@ -3570,3 +3574,33 @@ int rvu_mbox_handler_npc_mcam_entry_stats(struct rvu *rvu,
 
 	return 0;
 }
+
+void rvu_npc_clear_ucast_entry(struct rvu *rvu, int pcifunc, int nixlf)
+{
+	struct npc_mcam *mcam = &rvu->hw->mcam;
+	struct rvu_npc_mcam_rule *rule;
+	int ucast_idx, blkaddr;
+
+	blkaddr = rvu_get_blkaddr(rvu, BLKTYPE_NPC, 0);
+	if (blkaddr < 0)
+		return;
+
+	ucast_idx = npc_get_nixlf_mcam_index(mcam, pcifunc,
+					     nixlf, NIXLF_UCAST_ENTRY);
+
+	npc_enable_mcam_entry(rvu, mcam, blkaddr, ucast_idx, false);
+
+	npc_set_mcam_action(rvu, mcam, blkaddr, ucast_idx, 0);
+
+	npc_clear_mcam_entry(rvu, mcam, blkaddr, ucast_idx);
+
+	mutex_lock(&mcam->lock);
+	list_for_each_entry(rule, &mcam->mcam_rules, list) {
+		if (rule->entry == ucast_idx) {
+			list_del(&rule->list);
+			kfree(rule);
+			break;
+		}
+	}
+	mutex_unlock(&mcam->lock);
+}