[PATCH v5 net 09/10] octeontx2-af: npc: cn20k: Tear down default MCAM rules explicitly on free

Ratheesh Kannoth
2026-04-29T02:28:12Z

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>
---
.../ethernet/marvell/octeontx2/af/cn20k/npc.c | 51 ++++++++++++----
.../ethernet/marvell/octeontx2/af/rvu_npc.c | 59 +++++++++++++------
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);
}
}

--
2.43.0