bnxt_en: Implement new scheme to reserve tx rings.

In order to properly support TX rate limiting in SRIOV VF functions or
NPAR functions, firmware needs better control over tx ring allocations.
The new scheme requires the driver to reserve the number of tx rings
and to query to see if the requested number of tx rings is reserved.
The driver will use the new scheme when the firmware interface spec is
1.6.1 or newer.

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

1 files changed, 57 insertions, 2 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 4d478e79d424..338dbd03ff58 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -4045,6 +4045,50 @@ static void bnxt_hwrm_ring_free(struct bnxt *bp, bool close_path)
 	}
 }
 
+/* Caller must hold bp->hwrm_cmd_lock */
+int __bnxt_hwrm_get_tx_rings(struct bnxt *bp, u16 fid, int *tx_rings)
+{
+	struct hwrm_func_qcfg_output *resp = bp->hwrm_cmd_resp_addr;
+	struct hwrm_func_qcfg_input req = {0};
+	int rc;
+
+	if (bp->hwrm_spec_code < 0x10601)
+		return 0;
+
+	bnxt_hwrm_cmd_hdr_init(bp, &req, HWRM_FUNC_QCFG, -1, -1);
+	req.fid = cpu_to_le16(fid);
+	rc = _hwrm_send_message(bp, &req, sizeof(req), HWRM_CMD_TIMEOUT);
+	if (!rc)
+		*tx_rings = le16_to_cpu(resp->alloc_tx_rings);
+
+	return rc;
+}
+
+int bnxt_hwrm_reserve_tx_rings(struct bnxt *bp, int *tx_rings)
+{
+	struct hwrm_func_cfg_input req = {0};
+	int rc;
+
+	if (bp->hwrm_spec_code < 0x10601)
+		return 0;
+
+	if (BNXT_VF(bp))
+		return 0;
+
+	bnxt_hwrm_cmd_hdr_init(bp, &req, HWRM_FUNC_CFG, -1, -1);
+	req.fid = cpu_to_le16(0xffff);
+	req.enables = cpu_to_le32(FUNC_CFG_REQ_ENABLES_NUM_TX_RINGS);
+	req.num_tx_rings = cpu_to_le16(*tx_rings);
+	rc = hwrm_send_message(bp, &req, sizeof(req), HWRM_CMD_TIMEOUT);
+	if (rc)
+		return rc;
+
+	mutex_lock(&bp->hwrm_cmd_lock);
+	rc = __bnxt_hwrm_get_tx_rings(bp, 0xffff, tx_rings);
+	mutex_unlock(&bp->hwrm_cmd_lock);
+	return rc;
+}
+
 static void bnxt_hwrm_set_coal_params(struct bnxt *bp, u32 max_bufs,
 	u32 buf_tmrs, u16 flags,
 	struct hwrm_ring_cmpl_ring_cfg_aggint_params_input *req)
@@ -6509,10 +6553,16 @@ int bnxt_setup_mq_tc(struct net_device *dev, u8 tc)
 		sh = true;
 
 	if (tc) {
-		int max_rx_rings, max_tx_rings, rc;
+		int max_rx_rings, max_tx_rings, req_tx_rings, rsv_tx_rings, rc;
 
+		req_tx_rings = bp->tx_nr_rings_per_tc * tc;
 		rc = bnxt_get_max_rings(bp, &max_rx_rings, &max_tx_rings, sh);
-		if (rc || bp->tx_nr_rings_per_tc * tc > max_tx_rings)
+		if (rc || req_tx_rings > max_tx_rings)
+			return -ENOMEM;
+
+		rsv_tx_rings = req_tx_rings;
+		if (bnxt_hwrm_reserve_tx_rings(bp, &rsv_tx_rings) ||
+		    rsv_tx_rings < req_tx_rings)
 			return -ENOMEM;
 	}
 
@@ -7000,6 +7050,11 @@ static int bnxt_set_dflt_rings(struct bnxt *bp)
 		return rc;
 	bp->rx_nr_rings = min_t(int, dflt_rings, max_rx_rings);
 	bp->tx_nr_rings_per_tc = min_t(int, dflt_rings, max_tx_rings);
+
+	rc = bnxt_hwrm_reserve_tx_rings(bp, &bp->tx_nr_rings_per_tc);
+	if (rc)
+		netdev_warn(bp->dev, "Unable to reserve tx rings\n");
+
 	bp->tx_nr_rings = bp->tx_nr_rings_per_tc;
 	bp->cp_nr_rings = sh ? max_t(int, bp->tx_nr_rings, bp->rx_nr_rings) :
 			       bp->tx_nr_rings + bp->rx_nr_rings;