net/bnxt: fix max rings computation

The current max_rings computation does not take into account the case
when max_nq_rings is <= num_async_cpr. This results in a wrong value
like 0, when max_nq_rings is 1. Fix this by subtracting num_async_cpr
only when max_cp_rings > num_async_cpr.

Apart from this, the entire logic is currently spread across a few
macros, making it hard to read and debug this code. Move this code
into an inline function.

max_msix is not used in the max_rings calculation.
Apparently the max_msix field returned in HWRM_RESC_QCAPS is only valid
for Thor and newer chips. On Wh+ it will be equal to min_compl_rings.
Also, when a function reset is performed on an application quit, FW
will not reset the VF resource pool as per design.
This can lead to a strange condition wherein the max_msix field
on Wh+ keeps changing on each application re-load thereby throwing
throwing off the max_rings computation.

Fixes: f03e66cb64ce ("net/bnxt: limit queue count for NS3/Stingray devices")
Cc: stable@dpdk.org
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>

diff --git a/drivers/net/bnxt/bnxt.h b/drivers/net/bnxt/bnxt.h
index 9c1c874..bc09352 100644 (file)
--- a/drivers/net/bnxt/bnxt.h
+++ b/drivers/net/bnxt/bnxt.h
@@ -752,19 +752,6 @@ struct bnxt {
        uint16_t                max_tx_rings;
        uint16_t                max_rx_rings;
 #define MAX_STINGRAY_RINGS             128U
-/* For sake of symmetry, max Tx rings == max Rx rings, one stat ctx for each */
-#define BNXT_MAX_RX_RINGS(bp) \
-       (BNXT_STINGRAY(bp) ? RTE_MIN(RTE_MIN(bp->max_rx_rings / 2U, \
-                                            MAX_STINGRAY_RINGS), \
-                                    bp->max_stat_ctx / 2U) : \
-                               RTE_MIN(bp->max_rx_rings / 2U, \
-                                       bp->max_stat_ctx / 2U))
-#define BNXT_MAX_TX_RINGS(bp) \
-       (RTE_MIN((bp)->max_tx_rings, BNXT_MAX_RX_RINGS(bp)))
-
-#define BNXT_MAX_RINGS(bp) \
-       (RTE_MIN((((bp)->max_cp_rings - BNXT_NUM_ASYNC_CPR(bp)) / 2U), \
-                BNXT_MAX_TX_RINGS(bp)))
 
 #define BNXT_MAX_VF_REP_RINGS  8
 
@@ -822,6 +809,34 @@ struct bnxt {
        uint16_t                tx_cfa_action;
 };
 
+static
+inline uint16_t bnxt_max_rings(struct bnxt *bp)
+{
+       uint16_t max_tx_rings = bp->max_tx_rings;
+       uint16_t max_rx_rings = bp->max_rx_rings;
+       uint16_t max_cp_rings = bp->max_cp_rings;
+       uint16_t max_rings;
+
+       /* For the sake of symmetry:
+        * max Tx rings == max Rx rings, one stat ctx for each.
+        */
+       if (BNXT_STINGRAY(bp)) {
+               max_rx_rings = RTE_MIN(RTE_MIN(max_rx_rings / 2U,
+                                              MAX_STINGRAY_RINGS),
+                                      bp->max_stat_ctx / 2U);
+       } else {
+               max_rx_rings = RTE_MIN(max_rx_rings / 2U,
+                                      bp->max_stat_ctx / 2U);
+       }
+
+       max_tx_rings = RTE_MIN(max_tx_rings, max_rx_rings);
+       if (max_cp_rings > BNXT_NUM_ASYNC_CPR(bp))
+               max_cp_rings -= BNXT_NUM_ASYNC_CPR(bp);
+       max_rings = RTE_MIN(max_cp_rings / 2U, max_tx_rings);
+
+       return max_rings;
+}
+
 #define BNXT_FC_TIMER  1 /* Timer freq in Sec Flow Counters */
 
 /**

diff --git a/drivers/net/bnxt/bnxt_ethdev.c b/drivers/net/bnxt/bnxt_ethdev.c
index 0b14ca2..bf89635 100644 (file)
--- a/drivers/net/bnxt/bnxt_ethdev.c
+++ b/drivers/net/bnxt/bnxt_ethdev.c
@@ -920,7 +920,7 @@ static int bnxt_dev_info_get_op(struct rte_eth_dev *eth_dev,
        if (BNXT_PF(bp))
                dev_info->max_vfs = pdev->max_vfs;
 
-       max_rx_rings = BNXT_MAX_RINGS(bp);
+       max_rx_rings = bnxt_max_rings(bp);
        /* For the sake of symmetry, max_rx_queues = max_tx_queues */
        dev_info->max_rx_queues = max_rx_rings;
        dev_info->max_tx_queues = max_rx_rings;

diff --git a/drivers/net/bnxt/bnxt_rxq.c b/drivers/net/bnxt/bnxt_rxq.c
index 328cc99..19e11e4 100644 (file)
--- a/drivers/net/bnxt/bnxt_rxq.c
+++ b/drivers/net/bnxt/bnxt_rxq.c
@@ -311,7 +311,7 @@ int bnxt_rx_queue_setup_op(struct rte_eth_dev *eth_dev,
        if (rc)
                return rc;
 
-       if (queue_idx >= BNXT_MAX_RINGS(bp)) {
+       if (queue_idx >= bnxt_max_rings(bp)) {
                PMD_DRV_LOG(ERR,
                        "Cannot create Rx ring %d. Only %d rings available\n",
                        queue_idx, bp->max_rx_rings);
@@ -364,8 +364,9 @@ int bnxt_rx_queue_setup_op(struct rte_eth_dev *eth_dev,
 
        eth_dev->data->rx_queues[queue_idx] = rxq;
        /* Allocate RX ring hardware descriptors */
-       if (bnxt_alloc_rings(bp, queue_idx, NULL, rxq, rxq->cp_ring, NULL,
-                            "rxr")) {
+       rc = bnxt_alloc_rings(bp, queue_idx, NULL, rxq, rxq->cp_ring, NULL,
+                            "rxr");
+       if (rc) {
                PMD_DRV_LOG(ERR,
                            "ring_dma_zone_reserve for rx_ring failed!\n");
                goto err;

diff --git a/drivers/net/bnxt/bnxt_txq.c b/drivers/net/bnxt/bnxt_txq.c
index c9792a2..99a31ce 100644 (file)
--- a/drivers/net/bnxt/bnxt_txq.c
+++ b/drivers/net/bnxt/bnxt_txq.c
@@ -98,7 +98,7 @@ int bnxt_tx_queue_setup_op(struct rte_eth_dev *eth_dev,
        if (rc)
                return rc;
 
-       if (queue_idx >= BNXT_MAX_RINGS(bp)) {
+       if (queue_idx >= bnxt_max_rings(bp)) {
                PMD_DRV_LOG(ERR,
                        "Cannot create Tx ring %d. Only %d rings available\n",
                        queue_idx, bp->max_tx_rings);