bnxt_en: Reallocate RX completion ring for TPH support

In order to program the correct Steering Tag during an IRQ affinity
change, we need to free/re-allocate the RX completion ring during
queue_restart.  If TPH is enabled, call FW to free the Rx completion
ring and clear the ring entries in queue_stop().  Re-allocate it in
queue_start() if TPH is enabled.  Note that TPH mode is not enabled
in this patch and will be enabled later in the patch series.

While modifying bnxt_queue_start(), remove the unnecessary zeroing of
rxr->rx_next_cons.  It gets overwritten by the clone in
bnxt_queue_start().  Remove the rx_reset counter increment since
restart is not reset.  Add comment to clarify that the ring
allocations in queue_start should never fail.

Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250213011240.1640031-9-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 34 insertions, 6 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index c6cf575af53f..04980718c287 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -7426,6 +7426,19 @@ static void bnxt_hwrm_cp_ring_free(struct bnxt *bp,
 	ring->fw_ring_id = INVALID_HW_RING_ID;
 }
 
+static void bnxt_clear_one_cp_ring(struct bnxt *bp, struct bnxt_cp_ring_info *cpr)
+{
+	struct bnxt_ring_struct *ring = &cpr->cp_ring_struct;
+	int i, size = ring->ring_mem.page_size;
+
+	cpr->cp_raw_cons = 0;
+	cpr->toggle = 0;
+
+	for (i = 0; i < bp->cp_nr_pages; i++)
+		if (cpr->cp_desc_ring[i])
+			memset(cpr->cp_desc_ring[i], 0, size);
+}
+
 static void bnxt_hwrm_ring_free(struct bnxt *bp, bool close_path)
 {
 	u32 type;
@@ -15623,7 +15636,6 @@ static int bnxt_queue_start(struct net_device *dev, void *qmem, int idx)
 {
 	struct bnxt *bp = netdev_priv(dev);
 	struct bnxt_rx_ring_info *rxr, *clone;
-	struct bnxt_cp_ring_info *cpr;
 	struct bnxt_vnic_info *vnic;
 	int i, rc;
 
@@ -15642,20 +15654,27 @@ static int bnxt_queue_start(struct net_device *dev, void *qmem, int idx)
 
 	bnxt_copy_rx_ring(bp, rxr, clone);
 
+	/* All rings have been reserved and previously allocated.
+	 * Reallocating with the same parameters should never fail.
+	 */
 	rc = bnxt_hwrm_rx_ring_alloc(bp, rxr);
 	if (rc)
 		return rc;
+
+	if (bp->tph_mode) {
+		rc = bnxt_hwrm_cp_ring_alloc_p5(bp, rxr->rx_cpr);
+		if (rc)
+			goto err_free_hwrm_rx_ring;
+	}
+
 	rc = bnxt_hwrm_rx_agg_ring_alloc(bp, rxr);
 	if (rc)
-		goto err_free_hwrm_rx_ring;
+		goto err_free_hwrm_cp_ring;
 
 	bnxt_db_write(bp, &rxr->rx_db, rxr->rx_prod);
 	if (bp->flags & BNXT_FLAG_AGG_RINGS)
 		bnxt_db_write(bp, &rxr->rx_agg_db, rxr->rx_agg_prod);
 
-	cpr = &rxr->bnapi->cp_ring;
-	cpr->sw_stats->rx.rx_resets++;
-
 	for (i = 0; i <= BNXT_VNIC_NTUPLE; i++) {
 		vnic = &bp->vnic_info[i];
 
@@ -15672,6 +15691,9 @@ static int bnxt_queue_start(struct net_device *dev, void *qmem, int idx)
 
 	return 0;
 
+err_free_hwrm_cp_ring:
+	if (bp->tph_mode)
+		bnxt_hwrm_cp_ring_free(bp, rxr->rx_cpr);
 err_free_hwrm_rx_ring:
 	bnxt_hwrm_rx_ring_free(bp, rxr, false);
 	return rc;
@@ -15696,11 +15718,15 @@ static int bnxt_queue_stop(struct net_device *dev, void *qmem, int idx)
 	cancel_work_sync(&rxr->bnapi->cp_ring.dim.work);
 	bnxt_hwrm_rx_ring_free(bp, rxr, false);
 	bnxt_hwrm_rx_agg_ring_free(bp, rxr, false);
-	rxr->rx_next_cons = 0;
 	page_pool_disable_direct_recycling(rxr->page_pool);
 	if (bnxt_separate_head_pool())
 		page_pool_disable_direct_recycling(rxr->head_pool);
 
+	if (bp->tph_mode) {
+		bnxt_hwrm_cp_ring_free(bp, rxr->rx_cpr);
+		bnxt_clear_one_cp_ring(bp, rxr->rx_cpr);
+	}
+
 	memcpy(qmem, rxr, sizeof(*rxr));
 	bnxt_init_rx_ring_struct(bp, qmem);
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index db0be469a3db..4e20878e7714 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -2410,6 +2410,8 @@ struct bnxt {
 	u8			max_q;
 	u8			num_tc;
 
+	u8			tph_mode;
+
 	unsigned int		current_interval;
 #define BNXT_TIMER_INTERVAL	HZ