[PATCH rdma-next v3 1/1] RDMA/mana_ib: return PD number to the user

[Konstantin Taranov <kotaranov@linux.microsoft.com>]

From: Konstantin Taranov <kotaranov@microsoft.com>

Implement returning to userspace applications PDNs of created PDs.
The PDN is used by applications that build work requests outside of the
rdma-core code base. The PDN is used to build work requests that require
mentioning the PD. The MANA HW still ensures PD isolation using PDN attached
to MRs and WRs, therefore the PDN mentioned in the work request must match
the PDN of the used work queue. The work requests can fit only 16 bit PDNs.
Allow users to request short PDNs which are 16 bits.

Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
---
v3: updated commit message
v2: updated commit message
 drivers/infiniband/hw/mana/main.c | 19 ++++++++++++++++++-
 include/net/mana/gdma.h           |  4 ++--
 include/uapi/rdma/mana-abi.h      | 14 ++++++++++++++
 3 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/mana/main.c b/drivers/infiniband/hw/mana/main.c
index fac159f71..7ee4493cb 100644
--- a/drivers/infiniband/hw/mana/main.c
+++ b/drivers/infiniband/hw/mana/main.c
@@ -69,9 +69,11 @@ int mana_ib_cfg_vport(struct mana_ib_dev *dev, u32 port, struct mana_ib_pd *pd,
 int mana_ib_alloc_pd(struct ib_pd *ibpd, struct ib_udata *udata)
 {
 	struct mana_ib_pd *pd = container_of(ibpd, struct mana_ib_pd, ibpd);
+	struct mana_ib_alloc_pd_resp cmd_resp = {};
 	struct ib_device *ibdev = ibpd->device;
 	struct gdma_create_pd_resp resp = {};
 	struct gdma_create_pd_req req = {};
+	struct mana_ib_alloc_pd ucmd = {};
 	enum gdma_pd_flags flags = 0;
 	struct mana_ib_dev *dev;
 	struct gdma_context *gc;
@@ -83,8 +85,15 @@ int mana_ib_alloc_pd(struct ib_pd *ibpd, struct ib_udata *udata)
 	mana_gd_init_req_hdr(&req.hdr, GDMA_CREATE_PD, sizeof(req),
 			     sizeof(resp));
 
-	if (!udata)
+	if (!udata) {
 		flags |= GDMA_PD_FLAG_ALLOW_GPA_MR;
+	} else {
+		err = ib_copy_from_udata(&ucmd, udata, min(sizeof(ucmd), udata->inlen));
+		if (err)
+			return err;
+		if (ucmd.flags & MANA_IB_PD_SHORT_PDN)
+			flags |= GDMA_PD_FLAG_SHORT_PDN;
+	}
 
 	req.flags = flags;
 	err = mana_gd_send_request(gc, sizeof(req), &req,
@@ -107,6 +116,14 @@ int mana_ib_alloc_pd(struct ib_pd *ibpd, struct ib_udata *udata)
 
 	mutex_init(&pd->vport_mutex);
 	pd->vport_use_count = 0;
+
+	if (udata) {
+		cmd_resp.pdn = resp.pd_id;
+		err = ib_copy_to_udata(udata, &cmd_resp, min(sizeof(cmd_resp), udata->outlen));
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 8649eb789..cebb9b2bd 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -824,8 +824,8 @@ struct gdma_destroy_dma_region_req {
 }; /* HW DATA */
 
 enum gdma_pd_flags {
-	GDMA_PD_FLAG_INVALID = 0,
-	GDMA_PD_FLAG_ALLOW_GPA_MR = 1,
+	GDMA_PD_FLAG_ALLOW_GPA_MR = BIT(0),
+	GDMA_PD_FLAG_SHORT_PDN = BIT(2),
 };
 
 struct gdma_create_pd_req {
diff --git a/include/uapi/rdma/mana-abi.h b/include/uapi/rdma/mana-abi.h
index a75bf32b8..88b24ae50 100644
--- a/include/uapi/rdma/mana-abi.h
+++ b/include/uapi/rdma/mana-abi.h
@@ -87,4 +87,18 @@ struct mana_ib_create_qp_rss_resp {
 	struct rss_resp_entry entries[64];
 };
 
+enum mana_ib_create_pd_flags {
+	MANA_IB_PD_SHORT_PDN = 1 << 0,
+};
+
+struct mana_ib_alloc_pd {
+	__u32 flags;
+	__u32 reserved;
+};
+
+struct mana_ib_alloc_pd_resp {
+	__u32 pdn;
+	__u32 reserved;
+};
+
 #endif
-- 
2.43.0