[for-next 1/3] RDMA/ionic: size the MR PTE reservation to max_sg

[Abhijit Gangurde <abhijit.gangurde@amd.com>]

From: Amit Kumar <a.k@amd.com>

CREATE_MR with map_count zero makes firmware reserve its default number
of PTEs. A fast-registration memory region (MR) whose max_sg is larger
than that default fails at REG_MR.

Pass max_sg as map_count. The virtual address (VA) and length stay zero
because no buffer is mapped yet.

Fixes: e8521822c733 ("RDMA/ionic: Register device ops for control path")
Signed-off-by: Amit Kumar <a.k@amd.com>
Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
---
 .../infiniband/hw/ionic/ionic_controlpath.c    | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/hw/ionic/ionic_controlpath.c b/drivers/infiniband/hw/ionic/ionic_controlpath.c
index 18ad967812f5..00f9086f3bab 100644
--- a/drivers/infiniband/hw/ionic/ionic_controlpath.c
+++ b/drivers/infiniband/hw/ionic/ionic_controlpath.c
@@ -1121,21 +1121,25 @@ struct ib_mr *ionic_alloc_mr(struct ib_pd *ibpd, enum ib_mr_type type,
 
 	mr->flags = IONIC_MRF_PHYS_MR;
 
-	rc = ionic_pgtbl_init(dev, &mr->buf, mr->umem, 0, max_sg, PAGE_SIZE);
+	mr->buf.tbl_pages = max_sg;
+	rc = ionic_create_mr_cmd(dev, pd, mr, 0, 0);
+	if (rc)
+		goto err_cmd;
+
+	rc = ionic_pgtbl_init(dev, &mr->buf, NULL, 0, max_sg, 0);
 	if (rc)
 		goto err_pgtbl;
 
+	/* NIC reservation was already posted. tbl_pages means "mapped". */
 	mr->buf.tbl_pages = 0;
 
-	rc = ionic_create_mr_cmd(dev, pd, mr, 0, 0);
-	if (rc)
-		goto err_cmd;
-
 	return &mr->ibmr;
 
-err_cmd:
-	ionic_pgtbl_unbuf(dev, &mr->buf);
 err_pgtbl:
+	/* Keep the id if the NIC still holds the MR. */
+	if (ionic_destroy_mr_cmd(dev, mr->mrid))
+		goto err_mrid;
+err_cmd:
 	ionic_put_mrid(dev, mr->mrid);
 err_mrid:
 	kfree(mr);
-- 
2.43.0