bnxt_en: Utilize ulp client resources if RoCE is not registered

If the RoCE driver is not registered for a RoCE capable device, add
flexibility to use the RoCE resources (MSIX/NQs) for L2 purposes,
such as additional rings configured by the user or for XDP.

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/20240409215431.41424-7-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -7470,14 +7470,27 @@ static bool bnxt_rings_ok(struct bnxt *bp, struct bnxt_hw_rings *hwr)
 static int __bnxt_reserve_rings(struct bnxt *bp)
 {
 	struct bnxt_hw_rings hwr = {0};
+	int cp = bp->cp_nr_rings;
 	int rx_rings, rc;
+	int ulp_msix = 0;
 	bool sh = false;
 	int tx_cp;
 
 	if (!bnxt_need_reserve_rings(bp))
 		return 0;
 
-	hwr.cp = bnxt_nq_rings_in_use(bp);
+	if (!bnxt_ulp_registered(bp->edev)) {
+		ulp_msix = bnxt_get_avail_msix(bp, bp->ulp_num_msix_want);
+		if (!ulp_msix)
+			bnxt_set_ulp_stat_ctxs(bp, 0);
+
+		if (ulp_msix > bp->ulp_num_msix_want)
+			ulp_msix = bp->ulp_num_msix_want;
+		hwr.cp = cp + ulp_msix;
+	} else {
+		hwr.cp = bnxt_nq_rings_in_use(bp);
+	}
+
 	hwr.tx = bp->tx_nr_rings;
 	hwr.rx = bp->rx_nr_rings;
 	if (bp->flags & BNXT_FLAG_SHARED_RINGS)
@@ -7550,12 +7563,11 @@ static int __bnxt_reserve_rings(struct bnxt *bp)
 		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;
+		int resv_msix, resv_ctx, 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;
@@ -10609,13 +10621,23 @@ int bnxt_reserve_rings(struct bnxt *bp, bool irq_re_init)
 {
 	bool irq_cleared = false;
 	int tcs = bp->num_tc;
+	int irqs_required;
 	int rc;
 
 	if (!bnxt_need_reserve_rings(bp))
 		return 0;
 
-	if (irq_re_init && BNXT_NEW_RM(bp) &&
+	if (!bnxt_ulp_registered(bp->edev)) {
-	    bnxt_get_num_msix(bp) != bp->total_irqs) {
+		int ulp_msix = bnxt_get_avail_msix(bp, bp->ulp_num_msix_want);
+
+		if (ulp_msix > bp->ulp_num_msix_want)
+			ulp_msix = bp->ulp_num_msix_want;
+		irqs_required = ulp_msix + bp->cp_nr_rings;
+	} else {
+		irqs_required = bnxt_get_num_msix(bp);
+	}
+
+	if (irq_re_init && BNXT_NEW_RM(bp) && irqs_required != bp->total_irqs) {
 		bnxt_ulp_irq_stop(bp);
 		bnxt_clear_int_mode(bp);
 		irq_cleared = true;
@@ -13625,8 +13647,8 @@ int bnxt_check_rings(struct bnxt *bp, int tx, int rx, bool sh, int tcs,
 		return -ENOMEM;
 	hwr.stat = hwr.cp;
 	if (BNXT_NEW_RM(bp)) {
-		hwr.cp += bnxt_get_ulp_msix_num(bp);
+		hwr.cp += bnxt_get_ulp_msix_num_in_use(bp);
-		hwr.stat += bnxt_get_ulp_stat_ctxs(bp);
+		hwr.stat += bnxt_get_ulp_stat_ctxs_in_use(bp);
 		hwr.grp = rx;
 		hwr.rss_ctx = bnxt_get_total_rss_ctxs(bp, &hwr);
 	}
@@ -14899,8 +14921,9 @@ static void _bnxt_get_max_rings(struct bnxt *bp, int *max_rx, int *max_tx,
 	*max_rx = hw_resc->max_rx_rings;
 	*max_cp = bnxt_get_max_func_cp_rings_for_en(bp);
 	max_irq = min_t(int, bnxt_get_max_func_irqs(bp) -
-			bnxt_get_ulp_msix_num(bp),
+			bnxt_get_ulp_msix_num_in_use(bp),
-			hw_resc->max_stat_ctxs - bnxt_get_ulp_stat_ctxs(bp));
+			hw_resc->max_stat_ctxs -
+			bnxt_get_ulp_stat_ctxs_in_use(bp));
 	if (!(bp->flags & BNXT_FLAG_CHIP_P5_PLUS))
 		*max_cp = min_t(int, *max_cp, max_irq);
 	max_ring_grps = hw_resc->max_hw_ring_grps;

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

@@ -61,6 +61,13 @@ void bnxt_set_ulp_msix_num(struct bnxt *bp, int num)
 		bp->edev->ulp_num_msix_vec = num;
 }
 
+int bnxt_get_ulp_msix_num_in_use(struct bnxt *bp)
+{
+	if (bnxt_ulp_registered(bp->edev))
+		return bp->edev->ulp_num_msix_vec;
+	return 0;
+}
+
 int bnxt_get_ulp_stat_ctxs(struct bnxt *bp)
 {
 	if (bp->edev)
@@ -74,6 +81,13 @@ void bnxt_set_ulp_stat_ctxs(struct bnxt *bp, int num_ulp_ctx)
 		bp->edev->ulp_num_ctxs = num_ulp_ctx;
 }
 
+int bnxt_get_ulp_stat_ctxs_in_use(struct bnxt *bp)
+{
+	if (bnxt_ulp_registered(bp->edev))
+		return bp->edev->ulp_num_ctxs;
+	return 0;
+}
+
 void bnxt_set_dflt_ulp_stat_ctxs(struct bnxt *bp)
 {
 	if (bp->edev) {

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

@@ -98,9 +98,11 @@ static inline bool bnxt_ulp_registered(struct bnxt_en_dev *edev)
 }
 
 int bnxt_get_ulp_msix_num(struct bnxt *bp);
+int bnxt_get_ulp_msix_num_in_use(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);
+int bnxt_get_ulp_stat_ctxs_in_use(struct bnxt *bp);
 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);