From: Michael Chan <michael.chan@broadcom.com>
Date: Mon, 4 May 2020 04:50:37 -0400
Subject: bnxt_en: Add support for L2 doorbell size.
Patch-mainline: v5.8-rc1
Git-commit: 8ae2473842bdbb95bfb451b130dad6a650b3ad1b
References: jsc#SLE-15075

Read the L2 doorbell size from the firmware and only map the portion
of the doorbell BAR for L2 use.  This will leave the remaining doorbell
BAR available for the RoCE driver to use.  The RoCE driver can map
the remaining portion as write-combining to support the push feature.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c |   43 +++++++++++++++++++++++++-----
 drivers/net/ethernet/broadcom/bnxt/bnxt.h |    1 
 2 files changed, 37 insertions(+), 7 deletions(-)

--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -6362,6 +6362,7 @@ static int bnxt_hwrm_func_qcfg(struct bn
 {
 	struct hwrm_func_qcfg_input req = {0};
 	struct hwrm_func_qcfg_output *resp = bp->hwrm_cmd_resp_addr;
+	u32 min_db_offset = 0;
 	u16 flags;
 	int rc;
 
@@ -6410,6 +6411,21 @@ static int bnxt_hwrm_func_qcfg(struct bn
 	if (!bp->max_mtu)
 		bp->max_mtu = BNXT_MAX_MTU;
 
+	if (bp->db_size)
+		goto func_qcfg_exit;
+
+	if (bp->flags & BNXT_FLAG_CHIP_P5) {
+		if (BNXT_PF(bp))
+			min_db_offset = DB_PF_OFFSET_P5;
+		else
+			min_db_offset = DB_VF_OFFSET_P5;
+	}
+	bp->db_size = PAGE_ALIGN(le16_to_cpu(resp->l2_doorbell_bar_size_kb) *
+				 1024);
+	if (!bp->db_size || bp->db_size > pci_resource_len(bp->pdev, 2) ||
+	    bp->db_size <= min_db_offset)
+		bp->db_size = pci_resource_len(bp->pdev, 2);
+
 func_qcfg_exit:
 	mutex_unlock(&bp->hwrm_cmd_lock);
 	return rc;
@@ -10899,6 +10915,9 @@ static int bnxt_init_board(struct pci_de
 	bp->dev = dev;
 	bp->pdev = pdev;
 
+	/* Doorbell BAR bp->bar1 is mapped after bnxt_fw_init_one_p2()
+	 * determines the BAR size.
+	 */
 	bp->bar0 = pci_ioremap_bar(pdev, 0);
 	if (!bp->bar0) {
 		dev_err(&pdev->dev, "Cannot map device registers, aborting\n");
@@ -10906,13 +10925,6 @@ static int bnxt_init_board(struct pci_de
 		goto init_err_release;
 	}
 
-	bp->bar1 = pci_ioremap_bar(pdev, 2);
-	if (!bp->bar1) {
-		dev_err(&pdev->dev, "Cannot map doorbell registers, aborting\n");
-		rc = -ENOMEM;
-		goto init_err_release;
-	}
-
 	bp->bar2 = pci_ioremap_bar(pdev, 4);
 	if (!bp->bar2) {
 		dev_err(&pdev->dev, "Cannot map bar4 registers, aborting\n");
@@ -11834,6 +11846,16 @@ static int bnxt_pcie_dsn_get(struct bnxt
 	return 0;
 }
 
+static int bnxt_map_db_bar(struct bnxt *bp)
+{
+	if (!bp->db_size)
+		return -ENODEV;
+	bp->bar1 = pci_iomap(bp->pdev, 2, bp->db_size);
+	if (!bp->bar1)
+		return -ENOMEM;
+	return 0;
+}
+
 static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	static int version_printed;
@@ -11898,6 +11920,13 @@ static int bnxt_init_one(struct pci_dev
 	if (rc)
 		goto init_err_pci_clean;
 
+	rc = bnxt_map_db_bar(bp);
+	if (rc) {
+		dev_err(&pdev->dev, "Cannot map doorbell BAR rc = %d, aborting\n",
+			rc);
+		goto init_err_pci_clean;
+	}
+
 	dev->hw_features = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_SG |
 			   NETIF_F_TSO | NETIF_F_TSO6 |
 			   NETIF_F_GSO_UDP_TUNNEL | NETIF_F_GSO_GRE |
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1812,6 +1812,7 @@ struct bnxt {
 	/* ensure atomic 64-bit doorbell writes on 32-bit systems. */
 	spinlock_t		db_lock;
 #endif
+	int			db_size;
 
 #define BNXT_NTP_FLTR_MAX_FLTR	4096
 #define BNXT_NTP_FLTR_HASH_SIZE	512