[PATCH net v7 1/2] octeontx2-pf: Fix aura BPID assignment when CONFIG_DCB is enabled

[Subrat Pandey <subratp@marvell.com>]

From: Geetha sowjanya <gakula@marvell.com>

Previously, BPID assignment under CONFIG_DCB assumed
`queue_to_pfc_map` was always initialized. For SDP VFs this leads to
invalid memory access as it was not initialized.

This patch adds a NULL check for `queue_to_pfc_map` before
dereferencing it. Also, simplifies the logic by always assigning a
default BPID first, then conditionally overriding it if CONFIG_DCB is
enabled and the map exists.

Fixes: 184fb40f731b ("octeontx2-pf: Avoid adding dcbnl_ops for LBK and SDP vf")
Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Signed-off-by: Subrat Pandey <subratp@marvell.com>
---
v7:
 - v6: https://lore.kernel.org/all/20260910062657.3712256-2-subratp@marvell.com/
 - Add NULL check for queue_to_pfc_map in otx2_get_bpid_idx().
v5:
 - Fixing the compilation issue when CONFIG_DCB is
   disabled.
v4:
 - Fix otx2_get_bpid_idx() to be static inline.
v3:
 - Unify BPID index logic into a shared otx2_get_bpid_idx() helper,
   dropping the per-file #ifdef CONFIG_DCB and cn20k_aura_bpid_idx().
 - Drop trailing period from the Fixes: tag.

 .../net/ethernet/marvell/octeontx2/nic/cn20k.c   | 11 +----------
 .../ethernet/marvell/octeontx2/nic/otx2_common.c | 16 ++++++----------
 .../ethernet/marvell/octeontx2/nic/otx2_common.h |  9 +++++++++
 3 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/cn20k.c b/drivers/net/ethernet/marvell/octeontx2/nic/cn20k.c
index 8e41431c7f9c..e92b77789f08 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/cn20k.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/cn20k.c
@@ -242,15 +242,6 @@ int cn20k_register_pfvf_mbox_intr(struct otx2_nic *pf, int numvfs)
 
 #define RQ_BP_LVL_AURA   (255 - ((85 * 256) / 100)) /* BP when 85% is full */
 
-static u8 cn20k_aura_bpid_idx(struct otx2_nic *pfvf, int aura_id)
-{
-#ifdef CONFIG_DCB
-	return pfvf->queue_to_pfc_map[aura_id];
-#else
-	return 0;
-#endif
-}
-
 static int cn20k_tc_get_entry_index(struct otx2_flow_config *flow_cfg,
 				    struct otx2_tc_flow *node)
 {
@@ -580,7 +571,7 @@ static int cn20k_aura_aq_init(struct otx2_nic *pfvf, int aura_id,
 		if (pfvf->nix_blkaddr == BLKADDR_NIX1)
 			aq->aura.bp_ena = 1;
 
-		bpid_idx = cn20k_aura_bpid_idx(pfvf, aura_id);
+		bpid_idx = otx2_get_bpid_idx(pfvf, aura_id);
 		aq->aura.bpid = pfvf->bpid[bpid_idx];
 
 		/* Set backpressure level for RQ's Aura */
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
index 175992188c18..0f3f405d9f1b 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
@@ -1055,6 +1055,7 @@ int otx2_cq_init(struct otx2_nic *pfvf, u16 qidx)
 	struct nix_aq_enq_req *aq;
 	struct otx2_cq_queue *cq;
 	struct otx2_pool *pool;
+	u8 bpid_idx;
 
 	cq = &qset->cq[qidx];
 	cq->cq_idx = qidx;
@@ -1132,11 +1133,8 @@ int otx2_cq_init(struct otx2_nic *pfvf, u16 qidx)
 		if (!is_otx2_lbkvf(pfvf->pdev)) {
 			/* Enable receive CQ backpressure */
 			aq->cq.bp_ena = 1;
-#ifdef CONFIG_DCB
-			aq->cq.bpid = pfvf->bpid[pfvf->queue_to_pfc_map[qidx]];
-#else
-			aq->cq.bpid = pfvf->bpid[0];
-#endif
+			bpid_idx = otx2_get_bpid_idx(pfvf, qidx);
+			aq->cq.bpid = pfvf->bpid[bpid_idx];
 
 			/* Set backpressure level is same as cq pass level */
 			aq->cq.bp = RQ_PASS_LVL_CQ(pfvf->hw.rq_skid, qset->rqe_cnt);
@@ -1378,6 +1376,7 @@ int otx2_aura_aq_init(struct otx2_nic *pfvf, int aura_id,
 {
 	struct npa_aq_enq_req *aq;
 	struct otx2_pool *pool;
+	u8 bpid_idx;
 	int err;
 
 	pool = &pfvf->qset.pool[pool_id];
@@ -1433,11 +1432,8 @@ int otx2_aura_aq_init(struct otx2_nic *pfvf, int aura_id,
 		 */
 		if (pfvf->nix_blkaddr == BLKADDR_NIX1)
 			aq->aura.bp_ena = 1;
-#ifdef CONFIG_DCB
-		aq->aura.nix0_bpid = pfvf->bpid[pfvf->queue_to_pfc_map[aura_id]];
-#else
-		aq->aura.nix0_bpid = pfvf->bpid[0];
-#endif
+		bpid_idx = otx2_get_bpid_idx(pfvf, aura_id);
+		aq->aura.nix0_bpid = pfvf->bpid[bpid_idx];
 
 		/* Set backpressure level for RQ's Aura */
 		aq->aura.bp = RQ_BP_LVL_AURA;
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h
index eecee612b7b2..44cd56a0c2c4 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h
@@ -1029,6 +1029,15 @@ static inline int otx2_tc_flower_rule_cnt(struct otx2_nic *pfvf)
 	return pfvf->flow_cfg->nr_flows;
 }
 
+static inline u8 otx2_get_bpid_idx(struct otx2_nic *pfvf, int qidx)
+{
+#ifdef CONFIG_DCB
+	if (pfvf->queue_to_pfc_map)
+		return pfvf->queue_to_pfc_map[qidx];
+#endif
+	return 0;
+}
+
 /* MSI-X APIs */
 void otx2_free_cints(struct otx2_nic *pfvf, int n);
 void otx2_set_cints_affinity(struct otx2_nic *pfvf);
-- 
2.43.0