octeontx2-af: npc: cn20k: Tear down default MCAM rules explicitly on free

npc_cn20k_dft_rules_free() used the NPC MCAM mbox "free all" path, which
does not match how cn20k tracks default-rule MCAM slots indexes.

Resolve the default-rule indices, then for each valid slot clear the bitmap
entry, drop the PF/VF map, disable the MCAM line, clear the target
function, and npc_cn20k_idx_free(). Remove any matching software mcam_rules
nodes. On hard failure from idx_free, WARN and stop so the box stays up for
analysis.

In npc_mcam_free_all_entries(), prefetch the same default-rule indices and,
on cn20k, skip bitmap clear and idx_free when the scanned entry is one of
those reserved defaults (they are released by npc_cn20k_dft_rules_free).

Fixes: 09d3b7a1403f ("octeontx2-af: npc: cn20k: Allocate default MCAM indexes")
Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
Link: https://patch.msgid.link/20260429022722.1110289-10-rkannoth@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 82 insertions, 28 deletions

diff --git a/drivers/net/ethernet/marvell/octeontx2/af/cn20k/npc.c b/drivers/net/ethernet/marvell/octeontx2/af/cn20k/npc.c
index b3f34b84c114..1129565a01bd 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/cn20k/npc.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/cn20k/npc.c
@@ -4178,11 +4178,11 @@ static bool npc_is_cgx_or_lbk(struct rvu *rvu, u16 pcifunc)
 
 void npc_cn20k_dft_rules_free(struct rvu *rvu, u16 pcifunc)
 {
-	struct npc_mcam_free_entry_req free_req = { 0 };
+	struct npc_mcam *mcam = &rvu->hw->mcam;
+	u16 ptr[4] = {[0 ... 3] = USHRT_MAX};
+	struct rvu_npc_mcam_rule *rule, *tmp;
 	unsigned long index;
-	struct msg_rsp rsp;
-	u16 ptr[4];
-	int rc, i;
+	int blkaddr, rc, i;
 	void *map;
 
 	if (!npc_priv.init_done)
@@ -4240,14 +4240,43 @@ void npc_cn20k_dft_rules_free(struct rvu *rvu, u16 pcifunc)
 	}
 
 free_rules:
+	blkaddr = rvu_get_blkaddr(rvu, BLKTYPE_NPC, 0);
+	if (blkaddr < 0)
+		return;
+	for (int i = 0; i < 4; i++) {
+		if (ptr[i] == USHRT_MAX)
+			continue;
 
-	free_req.hdr.pcifunc = pcifunc;
-	free_req.all = 1;
-	rc = rvu_mbox_handler_npc_mcam_free_entry(rvu, &free_req, &rsp);
-	if (rc)
-		dev_err(rvu->dev,
-			"%s: Error deleting default entries (pcifunc=%#x\n",
-			__func__, pcifunc);
+		mutex_lock(&mcam->lock);
+		npc_mcam_clear_bit(mcam, ptr[i]);
+		mcam->entry2pfvf_map[ptr[i]] = NPC_MCAM_INVALID_MAP;
+		npc_cn20k_enable_mcam_entry(rvu, blkaddr, ptr[i], false);
+		mcam->entry2target_pffunc[ptr[i]] = 0x0;
+		mutex_unlock(&mcam->lock);
+
+		rc = npc_cn20k_idx_free(rvu, &ptr[i], 1);
+		if (rc) {
+			/* Non recoverable error. Let us WARN and return. Keep system alive to
+			 * enable debugging
+			 */
+			WARN(1, "%s Error deleting default entries (pcifunc=%#x) mcam_idx=%u\n",
+			     __func__, pcifunc, ptr[i]);
+			return;
+		}
+	}
+
+	mutex_lock(&mcam->lock);
+	list_for_each_entry_safe(rule, tmp, &mcam->mcam_rules, list) {
+		for (int i = 0; i < 4; i++) {
+			if (ptr[i] != rule->entry)
+				continue;
+
+			list_del(&rule->list);
+			kfree(rule);
+			break;
+		}
+	}
+	mutex_unlock(&mcam->lock);
 }
 
 int npc_cn20k_dft_rules_alloc(struct rvu *rvu, u16 pcifunc)
diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
index 44ca65efc80f..5d349d131fdb 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
@@ -2521,33 +2521,58 @@ void npc_mcam_clear_bit(struct npc_mcam *mcam, u16 index)
 static void npc_mcam_free_all_entries(struct rvu *rvu, struct npc_mcam *mcam,
 				      int blkaddr, u16 pcifunc)
 {
+	u16 dft_idxs[NPC_DFT_RULE_MAX_ID] = {[0 ... NPC_DFT_RULE_MAX_ID - 1] = USHRT_MAX};
+	bool cn20k_dft_rl;
 	u16 index, cntr;
 	int rc;
 
+	npc_cn20k_dft_rules_idx_get(rvu, pcifunc,
+				    &dft_idxs[NPC_DFT_RULE_BCAST_ID],
+				    &dft_idxs[NPC_DFT_RULE_MCAST_ID],
+				    &dft_idxs[NPC_DFT_RULE_PROMISC_ID],
+				    &dft_idxs[NPC_DFT_RULE_UCAST_ID]);
+
 	/* Scan all MCAM entries and free the ones mapped to 'pcifunc' */
 	for (index = 0; index < mcam->bmap_entries; index++) {
-		if (mcam->entry2pfvf_map[index] == pcifunc) {
+		if (mcam->entry2pfvf_map[index] != pcifunc)
+			continue;
+
+		cn20k_dft_rl = false;
+
+		if (is_cn20k(rvu->pdev)) {
+			if (dft_idxs[NPC_DFT_RULE_BCAST_ID] == index ||
+			    dft_idxs[NPC_DFT_RULE_MCAST_ID] == index ||
+			    dft_idxs[NPC_DFT_RULE_PROMISC_ID] == index ||
+			    dft_idxs[NPC_DFT_RULE_UCAST_ID] == index) {
+				cn20k_dft_rl = true;
+			}
+		}
+
+		/* Disable the entry */
+		npc_enable_mcam_entry(rvu, mcam, blkaddr, index, false);
+
+		if (!cn20k_dft_rl) {
 			mcam->entry2pfvf_map[index] = NPC_MCAM_INVALID_MAP;
 			/* Free the entry in bitmap */
 			npc_mcam_clear_bit(mcam, index);
-			/* Disable the entry */
-			npc_enable_mcam_entry(rvu, mcam, blkaddr, index, false);
-
-			/* Update entry2counter mapping */
-			cntr = mcam->entry2cntr_map[index];
-			if (cntr != NPC_MCAM_INVALID_MAP)
-				npc_unmap_mcam_entry_and_cntr(rvu, mcam,
-							      blkaddr, index,
-							      cntr);
 			mcam->entry2target_pffunc[index] = 0x0;
-			if (is_cn20k(rvu->pdev)) {
-				rc = npc_cn20k_idx_free(rvu, &index, 1);
-				if (rc)
-					dev_err(rvu->dev,
-						"Failed to free mcam idx=%u pcifunc=%#x\n",
-						index, pcifunc);
-			}
 		}
+
+		/* Update entry2counter mapping */
+		cntr = mcam->entry2cntr_map[index];
+		if (cntr != NPC_MCAM_INVALID_MAP)
+			npc_unmap_mcam_entry_and_cntr(rvu, mcam,
+						      blkaddr, index,
+						      cntr);
+
+		if (!is_cn20k(rvu->pdev) || cn20k_dft_rl)
+			continue;
+
+		rc = npc_cn20k_idx_free(rvu, &index, 1);
+		if (rc)
+			dev_err(rvu->dev,
+				"Failed to free mcam idx=%u pcifunc=%#x\n",
+				index, pcifunc);
 	}
 }