bnxt_en: Do not use the CNP CoS queue for networking traffic.

The CNP CoS queue is reserved for internal RDMA Congestion Notification
Packets (CNP) and should not be used for a TC.  Modify the CoS queue
discovery code to skip over the CNP CoS queue and to reduce
bp->max_tc accordingly.  However, if RDMA is disabled in NVRAM, the
the CNP CoS queue can be used for a TC.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 18 insertions, 8 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index dde904bccab9..d7f51ab85b45 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -5281,7 +5281,8 @@ static int bnxt_hwrm_queue_qportcfg(struct bnxt *bp)
         int rc = 0;
         struct hwrm_queue_qportcfg_input req = {0};
         struct hwrm_queue_qportcfg_output *resp = bp->hwrm_cmd_resp_addr;
-        u8 i, *qptr;
+        u8 i, j, *qptr;
+        bool no_rdma;
 
         bnxt_hwrm_cmd_hdr_init(bp, &req, HWRM_QUEUE_QPORTCFG, -1, -1);
 
@@ -5299,19 +5300,24 @@ static int bnxt_hwrm_queue_qportcfg(struct bnxt *bp)
         if (bp->max_tc > BNXT_MAX_QUEUE)
                 bp->max_tc = BNXT_MAX_QUEUE;
 
+        no_rdma = !(bp->flags & BNXT_FLAG_ROCE_CAP);
+        qptr = &resp->queue_id0;
+        for (i = 0, j = 0; i < bp->max_tc; i++) {
+                bp->q_info[j].queue_id = *qptr++;
+                bp->q_info[j].queue_profile = *qptr++;
+                bp->tc_to_qidx[j] = j;
+                if (!BNXT_CNPQ(bp->q_info[j].queue_profile) ||
+                    (no_rdma && BNXT_PF(bp)))
+                        j++;
+        }
+        bp->max_tc = max_t(u8, j, 1);
+
         if (resp->queue_cfg_info & QUEUE_QPORTCFG_RESP_QUEUE_CFG_INFO_ASYM_CFG)
                 bp->max_tc = 1;
 
         if (bp->max_lltc > bp->max_tc)
                 bp->max_lltc = bp->max_tc;
 
-        qptr = &resp->queue_id0;
-        for (i = 0; i < bp->max_tc; i++) {
-                bp->q_info[i].queue_id = *qptr++;
-                bp->q_info[i].queue_profile = *qptr++;
-                bp->tc_to_qidx[i] = i;
-        }
-
 qportcfg_exit:
         mutex_unlock(&bp->hwrm_cmd_lock);
         return rc;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h
index c0e16c03195a..6eed231de565 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h
@@ -43,6 +43,10 @@ struct bnxt_dscp2pri_entry {
         ((q_profile) ==         \
          QUEUE_QPORTCFG_RESP_QUEUE_ID0_SERVICE_PROFILE_LOSSLESS_ROCE)
 
+#define BNXT_CNPQ(q_profile)    \
+        ((q_profile) ==         \
+         QUEUE_QPORTCFG_RESP_QUEUE_ID0_SERVICE_PROFILE_LOSSY_ROCE_CNP)
+
 #define HWRM_STRUCT_DATA_SUBTYPE_HOST_OPERATIONAL       0x0300
 
 void bnxt_dcb_init(struct bnxt *bp);