RDMA/mlx5: Introduce UAPI to query PD attributes

Introduce UAPI to query PD attributes, this can be used to retrieve PD
attributes by having the PD handle of the created one and owning the
command FD for the ucontxet.

Link: https://lore.kernel.org/r/20200630093916.332097-7-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/mlx5/Makefile

@@ -23,4 +23,5 @@ mlx5_ib-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += odp.o
 mlx5_ib-$(CONFIG_MLX5_ESWITCH) += ib_rep.o
 mlx5_ib-$(CONFIG_INFINIBAND_USER_ACCESS) += devx.o \
 					    flow.o \
-					    qos.o
+					    qos.o \
+					    std_types.o

drivers/infiniband/hw/mlx5/main.c

@@ -6401,6 +6401,7 @@ static const struct uapi_definition mlx5_ib_defs[] = {
 	UAPI_DEF_CHAIN(mlx5_ib_devx_defs),
 	UAPI_DEF_CHAIN(mlx5_ib_flow_defs),
 	UAPI_DEF_CHAIN(mlx5_ib_qos_defs),
+	UAPI_DEF_CHAIN(mlx5_ib_std_types_defs),
 
 	UAPI_DEF_CHAIN_OBJ_TREE(UVERBS_OBJECT_FLOW_ACTION,
 				&mlx5_ib_flow_action),

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -1384,6 +1384,8 @@ int mlx5_ib_fill_stat_mr_entry(struct sk_buff *msg, struct ib_mr *ib_mr);
 extern const struct uapi_definition mlx5_ib_devx_defs[];
 extern const struct uapi_definition mlx5_ib_flow_defs[];
 extern const struct uapi_definition mlx5_ib_qos_defs[];
+extern const struct uapi_definition mlx5_ib_std_types_defs[];
+
 
 #if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
 int mlx5_ib_devx_create(struct mlx5_ib_dev *dev, bool is_user);

drivers/infiniband/hw/mlx5/std_types.c

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/*
+ * Copyright (c) 2020, Mellanox Technologies inc.  All rights reserved.
+ */
+
+#include <rdma/uverbs_ioctl.h>
+#include <rdma/mlx5_user_ioctl_cmds.h>
+#include <rdma/mlx5_user_ioctl_verbs.h>
+#include <linux/mlx5/driver.h>
+#include "mlx5_ib.h"
+
+#define UVERBS_MODULE_NAME mlx5_ib
+#include <rdma/uverbs_named_ioctl.h>
+
+static int UVERBS_HANDLER(MLX5_IB_METHOD_PD_QUERY)(
+	struct uverbs_attr_bundle *attrs)
+{
+	struct ib_pd *pd =
+		uverbs_attr_get_obj(attrs, MLX5_IB_ATTR_QUERY_PD_HANDLE);
+	struct mlx5_ib_pd *mpd = to_mpd(pd);
+
+	return uverbs_copy_to(attrs, MLX5_IB_ATTR_QUERY_PD_RESP_PDN,
+			      &mpd->pdn, sizeof(mpd->pdn));
+}
+
+DECLARE_UVERBS_NAMED_METHOD(
+	MLX5_IB_METHOD_PD_QUERY,
+	UVERBS_ATTR_IDR(MLX5_IB_ATTR_QUERY_PD_HANDLE,
+			UVERBS_OBJECT_PD,
+			UVERBS_ACCESS_READ,
+			UA_MANDATORY),
+	UVERBS_ATTR_PTR_OUT(MLX5_IB_ATTR_QUERY_PD_RESP_PDN,
+			   UVERBS_ATTR_TYPE(u32),
+			   UA_MANDATORY));
+
+ADD_UVERBS_METHODS(mlx5_ib_pd,
+		   UVERBS_OBJECT_PD,
+		   &UVERBS_METHOD(MLX5_IB_METHOD_PD_QUERY));
+
+const struct uapi_definition mlx5_ib_std_types_defs[] = {
+	UAPI_DEF_CHAIN_OBJ_TREE(
+		UVERBS_OBJECT_PD,
+		&mlx5_ib_pd),
+	{},
+};