bnxt_en: Change MSIX/NQs allocation policy

The existing scheme sets aside a number of MSIX/NQs for the RoCE
driver whether the RoCE driver is registered or not.  This scheme
is not flexible and limits the resources available for the L2 rings
if RoCE is never used.

Modify the scheme so that the RoCE MSIX/NQs can be used by the L2
driver if they are not used for RoCE.  The MSIX/NQs are now
represented by 3 fields.  bp->ulp_num_msix_want contains the
desired default value, edev->ulp_num_msix_vec contains the
available value (but not necessarily in use), and
ulp_tbl->msix_requested contains the actual value in use by RoCE.

The L2 driver can dip into edev->ulp_num_msix_vec if necessary.

We need to add rtnl_lock() back in bnxt_register_dev() and
bnxt_unregister_dev() to synchronize the MSIX usage between L2 and
RoCE.
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20240409215431.41424-6-michael.chan@broadcom.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -7549,6 +7549,20 @@ static int __bnxt_reserve_rings(struct bnxt *bp)
 	if (!netif_is_rxfh_configured(bp->dev))
 		bnxt_set_dflt_rss_indir_tbl(bp, NULL);
 
+	if (!bnxt_ulp_registered(bp->edev) && BNXT_NEW_RM(bp)) {
+		int resv_msix, resv_ctx, ulp_msix, ulp_ctxs;
+		struct bnxt_hw_resc *hw_resc;
+
+		hw_resc = &bp->hw_resc;
+		resv_msix = hw_resc->resv_irqs - bp->cp_nr_rings;
+		ulp_msix = bnxt_get_ulp_msix_num(bp);
+		ulp_msix = min_t(int, resv_msix, ulp_msix);
+		bnxt_set_ulp_msix_num(bp, ulp_msix);
+		resv_ctx = hw_resc->resv_stat_ctxs  - bp->cp_nr_rings;
+		ulp_ctxs = min(resv_ctx, bnxt_get_ulp_stat_ctxs(bp));
+		bnxt_set_ulp_stat_ctxs(bp, ulp_ctxs);
+	}
+
 	return rc;
 }
 
@@ -14982,6 +14996,7 @@ static void bnxt_trim_dflt_sh_rings(struct bnxt *bp)
 static int bnxt_set_dflt_rings(struct bnxt *bp, bool sh)
 {
 	int dflt_rings, max_rx_rings, max_tx_rings, rc;
+	int avail_msix;
 
 	if (!bnxt_can_reserve_rings(bp))
 		return 0;
@@ -15009,6 +15024,14 @@ static int bnxt_set_dflt_rings(struct bnxt *bp, bool sh)
 		bp->cp_nr_rings = bp->tx_nr_rings_per_tc + bp->rx_nr_rings;
 	bp->tx_nr_rings = bp->tx_nr_rings_per_tc;
 
+	avail_msix = bnxt_get_max_func_irqs(bp) - bp->cp_nr_rings;
+	if (avail_msix >= BNXT_MIN_ROCE_CP_RINGS) {
+		int ulp_num_msix = min(avail_msix, bp->ulp_num_msix_want);
+
+		bnxt_set_ulp_msix_num(bp, ulp_num_msix);
+		bnxt_set_dflt_ulp_stat_ctxs(bp);
+	}
+
 	rc = __bnxt_reserve_rings(bp);
 	if (rc && rc != -ENODEV)
 		netdev_warn(bp->dev, "Unable to reserve tx rings\n");
@@ -15358,6 +15381,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	bnxt_set_rx_skb_mode(bp, false);
 	bnxt_set_tpa_flags(bp);
 	bnxt_set_ring_params(bp);
+	bnxt_rdma_aux_device_init(bp);
 	rc = bnxt_set_dflt_rings(bp, true);
 	if (rc) {
 		if (BNXT_VF(bp) && rc == -ENODEV) {
@@ -15411,7 +15435,6 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (BNXT_SUPPORTS_NTUPLE_VNIC(bp))
 		bnxt_init_multi_rss_ctx(bp);
 
-	bnxt_rdma_aux_device_init(bp);
 
 	rc = register_netdev(dev);
 	if (rc)

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -2303,6 +2303,7 @@ struct bnxt {
 
 	struct bnxt_irq	*irq_tbl;
 	int			total_irqs;
+	int			ulp_num_msix_want;
 	u8			mac_addr[ETH_ALEN];
 
 #ifdef CONFIG_BNXT_DCB

drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c

@@ -48,6 +48,46 @@ static void bnxt_fill_msix_vecs(struct bnxt *bp, struct bnxt_msix_entry *ent)
 	}
 }
 
+int bnxt_get_ulp_msix_num(struct bnxt *bp)
+{
+	if (bp->edev)
+		return bp->edev->ulp_num_msix_vec;
+	return 0;
+}
+
+void bnxt_set_ulp_msix_num(struct bnxt *bp, int num)
+{
+	if (bp->edev)
+		bp->edev->ulp_num_msix_vec = num;
+}
+
+int bnxt_get_ulp_stat_ctxs(struct bnxt *bp)
+{
+	if (bp->edev)
+		return bp->edev->ulp_num_ctxs;
+	return 0;
+}
+
+void bnxt_set_ulp_stat_ctxs(struct bnxt *bp, int num_ulp_ctx)
+{
+	if (bp->edev)
+		bp->edev->ulp_num_ctxs = num_ulp_ctx;
+}
+
+void bnxt_set_dflt_ulp_stat_ctxs(struct bnxt *bp)
+{
+	if (bp->edev) {
+		bp->edev->ulp_num_ctxs = BNXT_MIN_ROCE_STAT_CTXS;
+		/* Reserve one additional stat_ctx for PF0 (except
+		 * on 1-port NICs) as it also creates one stat_ctx
+		 * for PF1 in case of RoCE bonding.
+		 */
+		if (BNXT_PF(bp) && !bp->pf.port_id &&
+		    bp->port_count > 1)
+			bp->edev->ulp_num_ctxs++;
+	}
+}
+
 int bnxt_register_dev(struct bnxt_en_dev *edev,
 		      struct bnxt_ulp_ops *ulp_ops,
 		      void *handle)
@@ -56,11 +96,19 @@ int bnxt_register_dev(struct bnxt_en_dev *edev,
 	struct bnxt *bp = netdev_priv(dev);
 	unsigned int max_stat_ctxs;
 	struct bnxt_ulp *ulp;
+	int rc = 0;
 
+	rtnl_lock();
+	if (!bp->irq_tbl) {
+		rc = -ENODEV;
+		goto exit;
+	}
 	max_stat_ctxs = bnxt_get_max_func_stat_ctxs(bp);
 	if (max_stat_ctxs <= BNXT_MIN_ROCE_STAT_CTXS ||
-	    bp->cp_nr_rings == max_stat_ctxs)
-		return -ENOMEM;
+	    bp->cp_nr_rings == max_stat_ctxs) {
+		rc = -ENOMEM;
+		goto exit;
+	}
 
 	ulp = edev->ulp_tbl;
 	ulp->handle = handle;
@@ -69,9 +117,13 @@ int bnxt_register_dev(struct bnxt_en_dev *edev,
 	if (test_bit(BNXT_STATE_OPEN, &bp->state))
 		bnxt_hwrm_vnic_cfg(bp, &bp->vnic_info[BNXT_VNIC_DEFAULT]);
 
+	edev->ulp_tbl->msix_requested = bnxt_get_ulp_msix_num(bp);
+
 	bnxt_fill_msix_vecs(bp, bp->edev->msix_entries);
 	edev->flags |= BNXT_EN_FLAG_MSIX_REQUESTED;
-	return 0;
+exit:
+	rtnl_unlock();
+	return rc;
 }
 EXPORT_SYMBOL(bnxt_register_dev);
 
@@ -83,8 +135,10 @@ void bnxt_unregister_dev(struct bnxt_en_dev *edev)
 	int i = 0;
 
 	ulp = edev->ulp_tbl;
+	rtnl_lock();
 	if (ulp->msix_requested)
 		edev->flags &= ~BNXT_EN_FLAG_MSIX_REQUESTED;
+	edev->ulp_tbl->msix_requested = 0;
 
 	if (ulp->max_async_event_id)
 		bnxt_hwrm_func_drv_rgtr(bp, NULL, 0, true);
@@ -97,11 +151,12 @@ void bnxt_unregister_dev(struct bnxt_en_dev *edev)
 		msleep(100);
 		i++;
 	}
+	rtnl_unlock();
 	return;
 }
 EXPORT_SYMBOL(bnxt_unregister_dev);
 
-int bnxt_get_ulp_msix_num(struct bnxt *bp)
+static int bnxt_set_dflt_ulp_msix(struct bnxt *bp)
 {
 	u32 roce_msix = BNXT_VF(bp) ?
 			BNXT_MAX_VF_ROCE_MSIX : BNXT_MAX_ROCE_MSIX;
@@ -110,18 +165,6 @@ int bnxt_get_ulp_msix_num(struct bnxt *bp)
 		min_t(u32, roce_msix, num_online_cpus()) : 0);
 }
 
-int bnxt_get_ulp_stat_ctxs(struct bnxt *bp)
-{
-	if (bnxt_ulp_registered(bp->edev)) {
-		struct bnxt_en_dev *edev = bp->edev;
-
-		if (edev->ulp_tbl->msix_requested)
-			return BNXT_MIN_ROCE_STAT_CTXS;
-	}
-
-	return 0;
-}
-
 int bnxt_send_msg(struct bnxt_en_dev *edev,
 			 struct bnxt_fw_msg *fw_msg)
 {
@@ -336,7 +379,6 @@ static void bnxt_set_edev_info(struct bnxt_en_dev *edev, struct bnxt *bp)
 	edev->pf_port_id = bp->pf.port_id;
 	edev->en_state = bp->state;
 	edev->bar0 = bp->bar0;
-	edev->ulp_tbl->msix_requested = bnxt_get_ulp_msix_num(bp);
 }
 
 void bnxt_rdma_aux_device_add(struct bnxt *bp)
@@ -409,6 +451,7 @@ void bnxt_rdma_aux_device_init(struct bnxt *bp)
 	aux_priv->edev = edev;
 	bp->edev = edev;
 	bnxt_set_edev_info(edev, bp);
+	bp->ulp_num_msix_want = bnxt_set_dflt_ulp_msix(bp);
 
 	return;
 

drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.h

@@ -85,17 +85,23 @@ struct bnxt_en_dev {
 							 * updated in resume.
 							 */
 	void __iomem                    *bar0;
+
+	u16				ulp_num_msix_vec;
+	u16				ulp_num_ctxs;
 };
 
 static inline bool bnxt_ulp_registered(struct bnxt_en_dev *edev)
 {
-	if (edev && edev->ulp_tbl)
+	if (edev && rcu_access_pointer(edev->ulp_tbl->ulp_ops))
 		return true;
 	return false;
 }
 
 int bnxt_get_ulp_msix_num(struct bnxt *bp);
+void bnxt_set_ulp_msix_num(struct bnxt *bp, int num);
 int bnxt_get_ulp_stat_ctxs(struct bnxt *bp);
+void bnxt_set_ulp_stat_ctxs(struct bnxt *bp, int num_ctxs);
+void bnxt_set_dflt_ulp_stat_ctxs(struct bnxt *bp);
 void bnxt_ulp_stop(struct bnxt *bp);
 void bnxt_ulp_start(struct bnxt *bp, int err);
 void bnxt_ulp_sriov_cfg(struct bnxt *bp, int num_vfs);