RDMA/bnxt_re: Reorg the bar mapping

Reorganize the code for allocation and mapping of Doorbell
pages. Implements new HW command to get the BAR length used by L2
driver. These changes are used by the future patch which maps the WC
Doorbell pages.

Also, introduced a new lock dpi_tbl_lock for synchronize the DB page
allocation from users.

Link: https://lore.kernel.org/r/1686679943-17117-7-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/bnxt_re/ib_verbs.c

@@ -618,8 +618,8 @@ int bnxt_re_alloc_pd(struct ib_pd *ibpd, struct ib_udata *udata)
 			 * ibv_devinfo and family of application when DPIs
 			 * are depleted.
 			 */
-			if (bnxt_qplib_alloc_dpi(&rdev->qplib_res.dpi_tbl,
-						 &ucntx->dpi, ucntx)) {
+			if (bnxt_qplib_alloc_dpi(&rdev->qplib_res,
+						 &ucntx->dpi, ucntx, BNXT_QPLIB_DPI_TYPE_UC)) {
 				rc = -ENOMEM;
 				goto dbfail;
 			}
@@ -4095,8 +4095,7 @@ void bnxt_re_dealloc_ucontext(struct ib_ucontext *ib_uctx)
 		/* Free DPI only if this is the first PD allocated by the
 		 * application and mark the context dpi as NULL
 		 */
-		bnxt_qplib_dealloc_dpi(&rdev->qplib_res,
-				       &rdev->qplib_res.dpi_tbl, &uctx->dpi);
+		bnxt_qplib_dealloc_dpi(&rdev->qplib_res, &uctx->dpi);
 		uctx->dpi.dbr = NULL;
 	}
 }

drivers/infiniband/hw/bnxt_re/main.c

@@ -85,6 +85,40 @@ static struct bnxt_re_dev *bnxt_re_from_netdev(struct net_device *netdev);
 static void bnxt_re_dev_uninit(struct bnxt_re_dev *rdev);
 static int bnxt_re_hwrm_qcaps(struct bnxt_re_dev *rdev);
 
+static int bnxt_re_hwrm_qcfg(struct bnxt_re_dev *rdev, u32 *db_len,
+			     u32 *offset);
+static void bnxt_re_set_db_offset(struct bnxt_re_dev *rdev)
+{
+	struct bnxt_qplib_chip_ctx *cctx;
+	struct bnxt_en_dev *en_dev;
+	struct bnxt_qplib_res *res;
+	u32 l2db_len = 0;
+	u32 offset = 0;
+	u32 barlen;
+	int rc;
+
+	res = &rdev->qplib_res;
+	en_dev = rdev->en_dev;
+	cctx = rdev->chip_ctx;
+
+	/* Issue qcfg */
+	rc = bnxt_re_hwrm_qcfg(rdev, &l2db_len, &offset);
+	if (rc)
+		dev_info(rdev_to_dev(rdev),
+			 "Couldn't get DB bar size, Low latency framework is disabled\n");
+	/* set register offsets for both UC and WC */
+	res->dpi_tbl.ucreg.offset = res->is_vf ? BNXT_QPLIB_DBR_VF_DB_OFFSET :
+						 BNXT_QPLIB_DBR_PF_DB_OFFSET;
+	res->dpi_tbl.wcreg.offset = res->dpi_tbl.ucreg.offset;
+
+	/* If WC mapping is disabled by L2 driver then en_dev->l2_db_size
+	 * is equal to the DB-Bar actual size. This indicates that L2
+	 * is mapping entire bar as UC-. RoCE driver can't enable WC mapping
+	 * in such cases and DB-push will be disabled.
+	 */
+	barlen = pci_resource_len(res->pdev, RCFW_DBR_PCI_BAR_REGION);
+}
+
 static void bnxt_re_set_drv_mode(struct bnxt_re_dev *rdev, u8 mode)
 {
 	struct bnxt_qplib_chip_ctx *cctx;
@@ -116,6 +150,7 @@ static int bnxt_re_setup_chip_ctx(struct bnxt_re_dev *rdev, u8 wqe_mode)
 {
 	struct bnxt_qplib_chip_ctx *chip_ctx;
 	struct bnxt_en_dev *en_dev;
+	int rc;
 
 	en_dev = rdev->en_dev;
 
@@ -134,6 +169,12 @@ static int bnxt_re_setup_chip_ctx(struct bnxt_re_dev *rdev, u8 wqe_mode)
 	rdev->qplib_res.is_vf = BNXT_EN_VF(en_dev);
 
 	bnxt_re_set_drv_mode(rdev, wqe_mode);
+
+	bnxt_re_set_db_offset(rdev);
+	rc = bnxt_qplib_map_db_bar(&rdev->qplib_res);
+	if (rc)
+		return rc;
+
 	if (bnxt_qplib_determine_atomics(en_dev->pdev))
 		ibdev_info(&rdev->ibdev,
 			   "platform doesn't support global atomics.");
@@ -343,6 +384,30 @@ static void bnxt_re_fill_fw_msg(struct bnxt_fw_msg *fw_msg, void *msg,
 	fw_msg->timeout = timeout;
 }
 
+/* Query device config using common hwrm */
+static int bnxt_re_hwrm_qcfg(struct bnxt_re_dev *rdev, u32 *db_len,
+			     u32 *offset)
+{
+	struct bnxt_en_dev *en_dev = rdev->en_dev;
+	struct hwrm_func_qcfg_output resp = {0};
+	struct hwrm_func_qcfg_input req = {0};
+	struct bnxt_fw_msg fw_msg;
+	int rc;
+
+	memset(&fw_msg, 0, sizeof(fw_msg));
+	bnxt_re_init_hwrm_hdr(rdev, (void *)&req,
+			      HWRM_FUNC_QCFG, -1, -1);
+	req.fid = cpu_to_le16(0xffff);
+	bnxt_re_fill_fw_msg(&fw_msg, (void *)&req, sizeof(req), (void *)&resp,
+			    sizeof(resp), DFLT_HWRM_CMD_TIMEOUT);
+	rc = bnxt_send_msg(en_dev, &fw_msg);
+	if (!rc) {
+		*db_len = PAGE_ALIGN(le16_to_cpu(resp.l2_doorbell_bar_size_kb) * 1024);
+		*offset = PAGE_ALIGN(le16_to_cpu(resp.legacy_l2_db_size_kb) * 1024);
+	}
+	return rc;
+}
+
 /* Query function capabilities using common hwrm */
 int bnxt_re_hwrm_qcaps(struct bnxt_re_dev *rdev)
 {
@@ -847,7 +912,6 @@ static void bnxt_re_free_res(struct bnxt_re_dev *rdev)
 
 	if (rdev->qplib_res.dpi_tbl.max) {
 		bnxt_qplib_dealloc_dpi(&rdev->qplib_res,
-				       &rdev->qplib_res.dpi_tbl,
 				       &rdev->dpi_privileged);
 	}
 	if (rdev->qplib_res.rcfw) {
@@ -875,9 +939,9 @@ static int bnxt_re_alloc_res(struct bnxt_re_dev *rdev)
 	if (rc)
 		goto fail;
 
-	rc = bnxt_qplib_alloc_dpi(&rdev->qplib_res.dpi_tbl,
+	rc = bnxt_qplib_alloc_dpi(&rdev->qplib_res,
 				  &rdev->dpi_privileged,
-				  rdev);
+				  rdev, BNXT_QPLIB_DPI_TYPE_KERNEL);
 	if (rc)
 		goto dealloc_res;
 
@@ -917,7 +981,6 @@ static int bnxt_re_alloc_res(struct bnxt_re_dev *rdev)
 		bnxt_qplib_free_nq(&rdev->nq[i]);
 	}
 	bnxt_qplib_dealloc_dpi(&rdev->qplib_res,
-			       &rdev->qplib_res.dpi_tbl,
 			       &rdev->dpi_privileged);
 dealloc_res:
 	bnxt_qplib_free_res(&rdev->qplib_res);

drivers/infiniband/hw/bnxt_re/qplib_fp.c

@@ -668,7 +668,7 @@ int bnxt_qplib_create_srq(struct bnxt_qplib_res *res,
 	srq->dbinfo.xid = srq->id;
 	srq->dbinfo.db = srq->dpi->dbr;
 	srq->dbinfo.max_slot = 1;
-	srq->dbinfo.priv_db = res->dpi_tbl.dbr_bar_reg_iomem;
+	srq->dbinfo.priv_db = res->dpi_tbl.priv_db;
 	if (srq->threshold)
 		bnxt_qplib_armen_db(&srq->dbinfo, DBC_DBC_TYPE_SRQ_ARMENA);
 	srq->arm_req = false;
@@ -2104,7 +2104,7 @@ int bnxt_qplib_create_cq(struct bnxt_qplib_res *res, struct bnxt_qplib_cq *cq)
 	cq->dbinfo.hwq = &cq->hwq;
 	cq->dbinfo.xid = cq->id;
 	cq->dbinfo.db = cq->dpi->dbr;
-	cq->dbinfo.priv_db = res->dpi_tbl.dbr_bar_reg_iomem;
+	cq->dbinfo.priv_db = res->dpi_tbl.priv_db;
 
 	bnxt_qplib_armen_db(&cq->dbinfo, DBC_DBC_TYPE_CQ_ARMENA);
 

drivers/infiniband/hw/bnxt_re/qplib_rcfw.h

@@ -130,6 +130,8 @@ static inline u32 bnxt_qplib_set_cmd_slots(struct cmdq_base *req)
 #define RCFW_MAX_COOKIE_VALUE		(BNXT_QPLIB_CMDQE_MAX_CNT - 1)
 #define RCFW_CMD_IS_BLOCKING		0x8000
 
+#define HWRM_VERSION_DEV_ATTR_MAX_DPI  0x1000A0000000DULL
+
 /* Crsq buf is 1024-Byte */
 struct bnxt_qplib_crsbe {
 	u8			data[1024];

drivers/infiniband/hw/bnxt_re/qplib_res.c

@@ -704,44 +704,73 @@ static int bnxt_qplib_alloc_pd_tbl(struct bnxt_qplib_res *res,
 }
 
 /* DPIs */
-int bnxt_qplib_alloc_dpi(struct bnxt_qplib_dpi_tbl *dpit,
+int bnxt_qplib_alloc_dpi(struct bnxt_qplib_res *res,
 			 struct bnxt_qplib_dpi *dpi,
-			 void                      *app)
+			 void *app, u8 type)
 {
+	struct bnxt_qplib_dpi_tbl *dpit = &res->dpi_tbl;
+	struct bnxt_qplib_reg_desc *reg;
 	u32 bit_num;
+	u64 umaddr;
+
+	reg = &dpit->wcreg;
+	mutex_lock(&res->dpi_tbl_lock);
 
 	bit_num = find_first_bit(dpit->tbl, dpit->max);
-	if (bit_num == dpit->max)
+	if (bit_num == dpit->max) {
+		mutex_unlock(&res->dpi_tbl_lock);
 		return -ENOMEM;
+	}
 
 	/* Found unused DPI */
 	clear_bit(bit_num, dpit->tbl);
 	dpit->app_tbl[bit_num] = app;
 
-	dpi->dpi = bit_num;
-	dpi->dbr = dpit->dbr_bar_reg_iomem + (bit_num * PAGE_SIZE);
-	dpi->umdbr = dpit->unmapped_dbr + (bit_num * PAGE_SIZE);
+	dpi->bit = bit_num;
+	dpi->dpi = bit_num + (reg->offset - dpit->ucreg.offset) / PAGE_SIZE;
+
+	umaddr = reg->bar_base + reg->offset + bit_num * PAGE_SIZE;
+	dpi->umdbr = umaddr;
+
+	switch (type) {
+	case BNXT_QPLIB_DPI_TYPE_KERNEL:
+		/* priviledged dbr was already mapped just initialize it. */
+		dpi->umdbr = dpit->ucreg.bar_base +
+			     dpit->ucreg.offset + bit_num * PAGE_SIZE;
+		dpi->dbr = dpit->priv_db;
+		dpi->dpi = dpi->bit;
+		break;
+	default:
+		dpi->dbr = ioremap(umaddr, PAGE_SIZE);
+		break;
+	}
 
+	dpi->type = type;
+	mutex_unlock(&res->dpi_tbl_lock);
 	return 0;
+
 }
 
 int bnxt_qplib_dealloc_dpi(struct bnxt_qplib_res *res,
-			   struct bnxt_qplib_dpi_tbl *dpit,
 			   struct bnxt_qplib_dpi *dpi)
 {
-	if (dpi->dpi >= dpit->max) {
-		dev_warn(&res->pdev->dev, "Invalid DPI? dpi = %d\n", dpi->dpi);
-		return -EINVAL;
-	}
-	if (test_and_set_bit(dpi->dpi, dpit->tbl)) {
-		dev_warn(&res->pdev->dev, "Freeing an unused DPI? dpi = %d\n",
-			 dpi->dpi);
+	struct bnxt_qplib_dpi_tbl *dpit = &res->dpi_tbl;
+
+	mutex_lock(&res->dpi_tbl_lock);
+	if (dpi->dpi && dpi->type != BNXT_QPLIB_DPI_TYPE_KERNEL)
+		pci_iounmap(res->pdev, dpi->dbr);
+
+	if (test_and_set_bit(dpi->bit, dpit->tbl)) {
+		dev_warn(&res->pdev->dev,
+			 "Freeing an unused DPI? dpi = %d, bit = %d\n",
+				dpi->dpi, dpi->bit);
+		mutex_unlock(&res->dpi_tbl_lock);
 		return -EINVAL;
 	}
 	if (dpit->app_tbl)
-		dpit->app_tbl[dpi->dpi] = NULL;
+		dpit->app_tbl[dpi->bit] = NULL;
 	memset(dpi, 0, sizeof(*dpi));
-
+	mutex_unlock(&res->dpi_tbl_lock);
 	return 0;
 }
 
@@ -750,52 +779,38 @@ static void bnxt_qplib_free_dpi_tbl(struct bnxt_qplib_res     *res,
 {
 	kfree(dpit->tbl);
 	kfree(dpit->app_tbl);
-	if (dpit->dbr_bar_reg_iomem)
-		pci_iounmap(res->pdev, dpit->dbr_bar_reg_iomem);
-	memset(dpit, 0, sizeof(*dpit));
+	dpit->tbl = NULL;
+	dpit->app_tbl = NULL;
+	dpit->max = 0;
 }
 
 static int bnxt_qplib_alloc_dpi_tbl(struct bnxt_qplib_res *res,
-				    struct bnxt_qplib_dpi_tbl *dpit,
-				    u32                       dbr_offset)
+				    struct bnxt_qplib_dev_attr *dev_attr)
 {
-	u32 dbr_bar_reg = RCFW_DBR_PCI_BAR_REGION;
-	resource_size_t bar_reg_base;
-	u32 dbr_len, bytes;
-
-	if (dpit->dbr_bar_reg_iomem) {
-		dev_err(&res->pdev->dev, "DBR BAR region %d already mapped\n",
-			dbr_bar_reg);
-		return -EALREADY;
-	}
-
-	bar_reg_base = pci_resource_start(res->pdev, dbr_bar_reg);
-	if (!bar_reg_base) {
-		dev_err(&res->pdev->dev, "BAR region %d resc start failed\n",
-			dbr_bar_reg);
-		return -ENOMEM;
-	}
+	struct bnxt_qplib_dpi_tbl *dpit;
+	struct bnxt_qplib_reg_desc *reg;
+	unsigned long bar_len;
+	u32 dbr_offset;
+	u32 bytes;
 
-	dbr_len = pci_resource_len(res->pdev, dbr_bar_reg) - dbr_offset;
-	if (!dbr_len || ((dbr_len & (PAGE_SIZE - 1)) != 0)) {
-		dev_err(&res->pdev->dev, "Invalid DBR length %d\n", dbr_len);
-		return -ENOMEM;
-	}
+	dpit = &res->dpi_tbl;
+	reg = &dpit->wcreg;
 
-	dpit->dbr_bar_reg_iomem = ioremap(bar_reg_base + dbr_offset,
-						  dbr_len);
-	if (!dpit->dbr_bar_reg_iomem) {
-		dev_err(&res->pdev->dev,
-			"FP: DBR BAR region %d mapping failed\n", dbr_bar_reg);
-		return -ENOMEM;
+	if (!bnxt_qplib_is_chip_gen_p5(res->cctx)) {
+		/* Offest should come from L2 driver */
+		dbr_offset = dev_attr->l2_db_size;
+		dpit->ucreg.offset = dbr_offset;
+		dpit->wcreg.offset = dbr_offset;
 	}
 
-	dpit->unmapped_dbr = bar_reg_base + dbr_offset;
-	dpit->max = dbr_len / PAGE_SIZE;
+	bar_len = pci_resource_len(res->pdev, reg->bar_id);
+	dpit->max = (bar_len - reg->offset) / PAGE_SIZE;
+	if (dev_attr->max_dpi)
+		dpit->max = min_t(u32, dpit->max, dev_attr->max_dpi);
 
 	dpit->app_tbl = kcalloc(dpit->max,  sizeof(void *), GFP_KERNEL);
 	if (!dpit->app_tbl)
-		goto unmap_io;
+		return -ENOMEM;
 
 	bytes = dpit->max >> 3;
 	if (!bytes)
@@ -805,17 +820,14 @@ static int bnxt_qplib_alloc_dpi_tbl(struct bnxt_qplib_res     *res,
 	if (!dpit->tbl) {
 		kfree(dpit->app_tbl);
 		dpit->app_tbl = NULL;
-		goto unmap_io;
+		return -ENOMEM;
 	}
 
 	memset((u8 *)dpit->tbl, 0xFF, bytes);
+	dpit->priv_db = dpit->ucreg.bar_reg + dpit->ucreg.offset;
 
 	return 0;
 
-unmap_io:
-	iounmap(dpit->dbr_bar_reg_iomem);
-	dpit->dbr_bar_reg_iomem = NULL;
-	return -ENOMEM;
 }
 
 /* Stats */
@@ -882,7 +894,7 @@ int bnxt_qplib_alloc_res(struct bnxt_qplib_res *res, struct pci_dev *pdev,
 	if (rc)
 		goto fail;
 
-	rc = bnxt_qplib_alloc_dpi_tbl(res, &res->dpi_tbl, dev_attr->l2_db_size);
+	rc = bnxt_qplib_alloc_dpi_tbl(res, dev_attr);
 	if (rc)
 		goto fail;
 
@@ -892,6 +904,46 @@ int bnxt_qplib_alloc_res(struct bnxt_qplib_res *res, struct pci_dev *pdev,
 	return rc;
 }
 
+void bnxt_qplib_unmap_db_bar(struct bnxt_qplib_res *res)
+{
+	struct bnxt_qplib_reg_desc *reg;
+
+	reg = &res->dpi_tbl.ucreg;
+	if (reg->bar_reg)
+		pci_iounmap(res->pdev, reg->bar_reg);
+	reg->bar_reg = NULL;
+	reg->bar_base = 0;
+	reg->len = 0;
+	reg->bar_id = 0;
+}
+
+int bnxt_qplib_map_db_bar(struct bnxt_qplib_res *res)
+{
+	struct bnxt_qplib_reg_desc *ucreg;
+	struct bnxt_qplib_reg_desc *wcreg;
+
+	wcreg = &res->dpi_tbl.wcreg;
+	wcreg->bar_id = RCFW_DBR_PCI_BAR_REGION;
+	wcreg->bar_base = pci_resource_start(res->pdev, wcreg->bar_id);
+
+	ucreg = &res->dpi_tbl.ucreg;
+	ucreg->bar_id = RCFW_DBR_PCI_BAR_REGION;
+	ucreg->bar_base = pci_resource_start(res->pdev, ucreg->bar_id);
+	ucreg->len = ucreg->offset + PAGE_SIZE;
+	if (!ucreg->len || ((ucreg->len & (PAGE_SIZE - 1)) != 0)) {
+		dev_err(&res->pdev->dev, "QPLIB: invalid dbr length %d",
+			(int)ucreg->len);
+		return -EINVAL;
+	}
+	ucreg->bar_reg = ioremap(ucreg->bar_base, ucreg->len);
+	if (!ucreg->bar_reg) {
+		dev_err(&res->pdev->dev, "priviledged dpi map failed!");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
 int bnxt_qplib_determine_atomics(struct pci_dev *dev)
 {
 	int comp;

drivers/infiniband/hw/bnxt_re/qplib_res.h

@@ -60,6 +60,9 @@ struct bnxt_qplib_chip_ctx {
 	u64	hwrm_intf_ver;
 };
 
+#define BNXT_QPLIB_DBR_PF_DB_OFFSET     0x10000
+#define BNXT_QPLIB_DBR_VF_DB_OFFSET     0x4000
+
 #define PTR_CNT_PER_PG		(PAGE_SIZE / sizeof(void *))
 #define PTR_MAX_IDX_PER_PG	(PTR_CNT_PER_PG - 1)
 #define PTR_PG(x)		(((x) & ~PTR_MAX_IDX_PER_PG) / PTR_CNT_PER_PG)
@@ -111,6 +114,7 @@ enum bnxt_qplib_hwrm_pg_size {
 struct bnxt_qplib_reg_desc {
 	u8		bar_id;
 	resource_size_t	bar_base;
+	unsigned long	offset;
 	void __iomem	*bar_reg;
 	size_t		len;
 };
@@ -187,18 +191,26 @@ struct bnxt_qplib_sgid_tbl {
 	u8				*vlan;
 };
 
+enum {
+	BNXT_QPLIB_DPI_TYPE_KERNEL      = 0,
+	BNXT_QPLIB_DPI_TYPE_UC          = 1,
+};
+
 struct bnxt_qplib_dpi {
 	u32				dpi;
+	u32				bit;
 	void __iomem			*dbr;
 	u64				umdbr;
+	u8				type;
 };
 
 struct bnxt_qplib_dpi_tbl {
 	void				**app_tbl;
 	unsigned long			*tbl;
 	u16				max;
-	void __iomem			*dbr_bar_reg_iomem;
-	u64				unmapped_dbr;
+	struct bnxt_qplib_reg_desc	ucreg; /* Hold entire DB bar. */
+	struct bnxt_qplib_reg_desc	wcreg;
+	void __iomem			*priv_db;
 };
 
 struct bnxt_qplib_stats {
@@ -254,6 +266,8 @@ struct bnxt_qplib_res {
 	struct bnxt_qplib_pd_tbl	pd_tbl;
 	struct bnxt_qplib_sgid_tbl	sgid_tbl;
 	struct bnxt_qplib_dpi_tbl	dpi_tbl;
+	/* To protect the dpi table bit map */
+	struct mutex                    dpi_tbl_lock;
 	bool				prio;
 	bool                            is_vf;
 };
@@ -345,11 +359,10 @@ int bnxt_qplib_alloc_pd(struct bnxt_qplib_pd_tbl *pd_tbl,
 int bnxt_qplib_dealloc_pd(struct bnxt_qplib_res *res,
 			  struct bnxt_qplib_pd_tbl *pd_tbl,
 			  struct bnxt_qplib_pd *pd);
-int bnxt_qplib_alloc_dpi(struct bnxt_qplib_dpi_tbl *dpit,
+int bnxt_qplib_alloc_dpi(struct bnxt_qplib_res *res,
 			 struct bnxt_qplib_dpi *dpi,
-			 void                      *app);
+			 void *app, u8 type);
 int bnxt_qplib_dealloc_dpi(struct bnxt_qplib_res *res,
-			   struct bnxt_qplib_dpi_tbl *dpi_tbl,
 			   struct bnxt_qplib_dpi *dpi);
 void bnxt_qplib_cleanup_res(struct bnxt_qplib_res *res);
 int bnxt_qplib_init_res(struct bnxt_qplib_res *res);
@@ -362,6 +375,9 @@ void bnxt_qplib_free_ctx(struct bnxt_qplib_res *res,
 int bnxt_qplib_alloc_ctx(struct bnxt_qplib_res *res,
 			 struct bnxt_qplib_ctx *ctx,
 			 bool virt_fn, bool is_p5);
+int bnxt_qplib_map_db_bar(struct bnxt_qplib_res *res);
+void bnxt_qplib_unmap_db_bar(struct bnxt_qplib_res *res);
+
 int bnxt_qplib_determine_atomics(struct pci_dev *dev);
 
 static inline void bnxt_qplib_hwq_incr_prod(struct bnxt_qplib_hwq *hwq, u32 cnt)

drivers/infiniband/hw/bnxt_re/qplib_sp.c

@@ -170,6 +170,9 @@ int bnxt_qplib_get_dev_attr(struct bnxt_qplib_rcfw *rcfw,
 		attr->tqm_alloc_reqs[i * 4 + 3] = *(++tqm_alloc);
 	}
 
+	if (rcfw->res->cctx->hwrm_intf_ver >= HWRM_VERSION_DEV_ATTR_MAX_DPI)
+		attr->max_dpi = le32_to_cpu(sb->max_dpi);
+
 	attr->is_atomic = bnxt_qplib_is_atomic_cap(rcfw);
 bail:
 	bnxt_qplib_rcfw_free_sbuf(rcfw, sbuf);

drivers/infiniband/hw/bnxt_re/qplib_sp.h

@@ -72,6 +72,7 @@ struct bnxt_qplib_dev_attr {
 	u8				tqm_alloc_reqs[MAX_TQM_ALLOC_REQ];
 	bool				is_atomic;
 	u16                             dev_cap_flags;
+	u32                             max_dpi;
 };
 
 struct bnxt_qplib_pd {