IB/mlx5: Introduce DEVX

Introduce DEVX to enable direct device commands in downstream patches
from this series.

In that mode of work the firmware manages the isolation between
processes' resources and as such a DEVX user id is created and assigned
to the given user context upon allocation request.

A capability check is done to make sure that this feature is really
supported by the firmware prior to creating the DEVX user id.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mlx5/devx.c b/drivers/infiniband/hw/mlx5/devx.c
new file mode 100644
index 000000000000..775448910ad1
--- /dev/null
+++ b/drivers/infiniband/hw/mlx5/devx.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/*
+ * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
+ */
+
+#include <rdma/ib_user_verbs.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/uverbs_types.h>
+#include <rdma/uverbs_ioctl.h>
+#include <rdma/mlx5_user_ioctl_cmds.h>
+#include <rdma/ib_umem.h>
+#include <linux/mlx5/driver.h>
+#include <linux/mlx5/fs.h>
+#include "mlx5_ib.h"
+
+int mlx5_ib_devx_create(struct mlx5_ib_dev *dev, struct mlx5_ib_ucontext *context)
+{
+	u32 in[MLX5_ST_SZ_DW(create_uctx_in)] = {0};
+	u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)] = {0};
+	u64 general_obj_types;
+	void *uctx;
+	void *hdr;
+	int err;
+
+	uctx = MLX5_ADDR_OF(create_uctx_in, in, uctx);
+	hdr = MLX5_ADDR_OF(create_uctx_in, in, hdr);
+
+	general_obj_types = MLX5_CAP_GEN_64(dev->mdev, general_obj_types);
+	if (!(general_obj_types & MLX5_GENERAL_OBJ_TYPES_CAP_UCTX) ||
+	    !(general_obj_types & MLX5_GENERAL_OBJ_TYPES_CAP_UMEM))
+		return -EINVAL;
+
+	if (!capable(CAP_NET_RAW))
+		return -EPERM;
+
+	MLX5_SET(general_obj_in_cmd_hdr, hdr, opcode, MLX5_CMD_OP_CREATE_GENERAL_OBJECT);
+	MLX5_SET(general_obj_in_cmd_hdr, hdr, obj_type, MLX5_OBJ_TYPE_UCTX);
+
+	err = mlx5_cmd_exec(dev->mdev, in, sizeof(in), out, sizeof(out));
+	if (err)
+		return err;
+
+	context->devx_uid = MLX5_GET(general_obj_out_cmd_hdr, out, obj_id);
+	return 0;
+}
+
+void mlx5_ib_devx_destroy(struct mlx5_ib_dev *dev,
+			  struct mlx5_ib_ucontext *context)
+{
+	u32 in[MLX5_ST_SZ_DW(general_obj_in_cmd_hdr)] = {0};
+	u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)] = {0};
+
+	MLX5_SET(general_obj_in_cmd_hdr, in, opcode, MLX5_CMD_OP_DESTROY_GENERAL_OBJECT);
+	MLX5_SET(general_obj_in_cmd_hdr, in, obj_type, MLX5_OBJ_TYPE_UCTX);
+	MLX5_SET(general_obj_in_cmd_hdr, in, obj_id, context->devx_uid);
+
+	mlx5_cmd_exec(dev->mdev, in, sizeof(in), out, sizeof(out));
+}