Re: [net-next,v4,11/13] octeontx2-pf: cn20k: Add TC rules support
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-01-18 00:40:30
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This is an AI-generated review of your patch. The human sending this email has considered the AI review valid, or at least plausible. For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html --- octeontx2-pf: cn20k: Add TC rules support This patch adds dynamic MCAM entry allocation for TC rules on CN20K silicon, with support for X2/X4 key widths and entry shifting based on rule priorities.
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c index 26a08d2cfbb1..866d9451f5d6 100644 --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
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quoted hunk ↗ jump to hunk
@@ -1292,7 +1277,23 @@ static int otx2_tc_add_flow(struct otx2_nic *nic, if (old_node) otx2_tc_del_flow(nic, tc_flow_cmd); + if (is_cn20k(nic->pdev)) { + rc = cn20k_tc_alloc_entry(nic, tc_flow_cmd, new_node, &dummy); + if (rc) { + NL_SET_ERR_MSG_MOD(extack, + "MCAM rule allocation failed"); + kfree_rcu(new_node, rcu); + return rc; + } + } + + entry = otx2_tc_update_mcam_table(nic, flow_cfg, new_node, true); + if (entry < 0) { + NL_SET_ERR_MSG_MOD(extack, "Adding rule failed"); + rc = entry; + goto free_leaf; + } + mutex_lock(&nic->mbox.lock); req = otx2_mbox_alloc_msg_npc_install_flow(&nic->mbox); if (!req) { mutex_unlock(&nic->mbox.lock); rc = -ENOMEM; goto free_leaf;
^^^^^^^^^^^^^^ For CN20K, if cn20k_tc_alloc_entry() succeeds (allocating an MCAM entry from AF) but then otx2_mbox_alloc_msg_npc_install_flow() or otx2_sync_mbox_msg() fails, the code goes to free_leaf. Looking at the free_leaf cleanup path below, it calls otx2_tc_del_from_flow_list() and kfree_rcu() but does not call cn20k_tc_free_mcam_entry() to return the AF-allocated entry. Is this leaking the MCAM entry on CN20K when these error paths are taken? The cn20k_tc_update_mcam_table_add_req() function does call cn20k_tc_free_mcam_entry() when it fails internally (due to X2/X4 mix), suggesting MCAM entry cleanup is expected.
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@@ -1304,7 +1305,7 @@ static int otx2_tc_add_flow(struct otx2_nic *nic, memcpy(&dummy.hdr, &req->hdr, sizeof(struct mbox_msghdr)); memcpy(req, &dummy, sizeof(struct npc_install_flow_req));
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