IB/mlx5: Add CREATE_PSV/DESTROY_PSV for devx interface

Limit the number of PSV's created through devx to 1, to create a symmetry
between create/destroy cmds. In the kernel, one can create up to 4 PSV's
using CREATE_PSV cmd but the destruction is one by one. Add a protection
for this a-symmetric definition for devx.

Link: https://lore.kernel.org/r/20190723070412.6385-1-leon@kernel.orgSigned-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/devx.c

@@ -776,6 +776,14 @@ static bool devx_is_obj_create_cmd(const void *in, u16 *opcode)
 			return true;
 		return false;
 	}
+	case MLX5_CMD_OP_CREATE_PSV:
+	{
+		u8 num_psv = MLX5_GET(create_psv_in, in, num_psv);
+
+		if (num_psv == 1)
+			return true;
+		return false;
+	}
 	default:
 		return false;
 	}
@@ -1215,6 +1223,12 @@ static void devx_obj_build_destroy_cmd(void *in, void *out, void *din,
 	case MLX5_CMD_OP_ALLOC_XRCD:
 		MLX5_SET(general_obj_in_cmd_hdr, din, opcode, MLX5_CMD_OP_DEALLOC_XRCD);
 		break;
+	case MLX5_CMD_OP_CREATE_PSV:
+		MLX5_SET(general_obj_in_cmd_hdr, din, opcode,
+			 MLX5_CMD_OP_DESTROY_PSV);
+		MLX5_SET(destroy_psv_in, din, psvn,
+			 MLX5_GET(create_psv_out, out, psv0_index));
+		break;
 	default:
 		/* The entry must match to one of the devx_is_obj_create_cmd */
 		WARN_ON(true);