IB/uverbs: Add alloc/free dm uverbs ioctl support

This change adds uverbs support for allocation/freeing
of device memory commands.

A new uverbs object is defined of type idr to represent
and track the new resource type allocation per context.

The API requires provider driver to implement 2 new ib_device
callbacks - one for allocation and one for deallocation which
return and accept (respectively) the ib_dm object which represents
the allocated memory on the device.

The support is added via the ioctl command infrastructure
only.
Signed-off-by: Ariel Levkovich <lariel@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/Makefile

@@ -35,4 +35,4 @@ ib_ucm-y :=			ucm.o
 ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
 				rdma_core.o uverbs_std_types.o uverbs_ioctl.o \
 				uverbs_ioctl_merge.o uverbs_std_types_cq.o \
-				uverbs_std_types_flow_action.o
+				uverbs_std_types_flow_action.o uverbs_std_types_dm.o

drivers/infiniband/core/uverbs.h

@@ -286,6 +286,7 @@ extern const struct uverbs_object_def UVERBS_OBJECT(UVERBS_OBJECT_WQ);
 extern const struct uverbs_object_def UVERBS_OBJECT(UVERBS_OBJECT_RWQ_IND_TBL);
 extern const struct uverbs_object_def UVERBS_OBJECT(UVERBS_OBJECT_XRCD);
 extern const struct uverbs_object_def UVERBS_OBJECT(UVERBS_OBJECT_FLOW_ACTION);
+extern const struct uverbs_object_def UVERBS_OBJECT(UVERBS_OBJECT_DM);
 
 #define IB_UVERBS_DECLARE_CMD(name)					\
 	ssize_t ib_uverbs_##name(struct ib_uverbs_file *file,		\

drivers/infiniband/core/uverbs_std_types.c

@@ -311,7 +311,8 @@ static DECLARE_UVERBS_OBJECT_TREE(uverbs_default_objects,
 				  &UVERBS_OBJECT(UVERBS_OBJECT_WQ),
 				  &UVERBS_OBJECT(UVERBS_OBJECT_RWQ_IND_TBL),
 				  &UVERBS_OBJECT(UVERBS_OBJECT_XRCD),
-				  &UVERBS_OBJECT(UVERBS_OBJECT_FLOW_ACTION));
+				  &UVERBS_OBJECT(UVERBS_OBJECT_FLOW_ACTION),
+				  &UVERBS_OBJECT(UVERBS_OBJECT_DM));
 
 const struct uverbs_object_tree_def *uverbs_default_get_objects(void)
 {

drivers/infiniband/core/uverbs_std_types_dm.c

+/*
+ * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "uverbs.h"
+#include <rdma/uverbs_std_types.h>
+
+static int uverbs_free_dm(struct ib_uobject *uobject,
+			  enum rdma_remove_reason why)
+{
+	struct ib_dm *dm = uobject->object;
+
+	if (why == RDMA_REMOVE_DESTROY && atomic_read(&dm->usecnt))
+		return -EBUSY;
+
+	return dm->device->dealloc_dm(dm);
+}
+
+static int UVERBS_HANDLER(UVERBS_METHOD_DM_ALLOC)(struct ib_device *ib_dev,
+						  struct ib_uverbs_file *file,
+						  struct uverbs_attr_bundle *attrs)
+{
+	struct ib_ucontext *ucontext = file->ucontext;
+	struct ib_dm_alloc_attr attr = {};
+	struct ib_uobject *uobj;
+	struct ib_dm *dm;
+	int ret;
+
+	if (!ib_dev->alloc_dm)
+		return -EOPNOTSUPP;
+
+	ret = uverbs_copy_from(&attr.length, attrs,
+			       UVERBS_ATTR_ALLOC_DM_LENGTH);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&attr.alignment, attrs,
+			       UVERBS_ATTR_ALLOC_DM_ALIGNMENT);
+	if (ret)
+		return ret;
+
+	uobj = uverbs_attr_get(attrs, UVERBS_ATTR_ALLOC_DM_HANDLE)->obj_attr.uobject;
+
+	dm = ib_dev->alloc_dm(ib_dev, ucontext, &attr, attrs);
+	if (IS_ERR(dm))
+		return PTR_ERR(dm);
+
+	dm->device  = ib_dev;
+	dm->length  = attr.length;
+	dm->uobject = uobj;
+	atomic_set(&dm->usecnt, 0);
+
+	uobj->object = dm;
+
+	return 0;
+}
+
+static DECLARE_UVERBS_NAMED_METHOD(UVERBS_METHOD_DM_ALLOC,
+	&UVERBS_ATTR_IDR(UVERBS_ATTR_ALLOC_DM_HANDLE, UVERBS_OBJECT_DM,
+			 UVERBS_ACCESS_NEW,
+			 UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_PTR_IN(UVERBS_ATTR_ALLOC_DM_LENGTH,
+			    UVERBS_ATTR_TYPE(u64),
+			    UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_PTR_IN(UVERBS_ATTR_ALLOC_DM_ALIGNMENT,
+			    UVERBS_ATTR_TYPE(u32),
+			    UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)));
+
+static DECLARE_UVERBS_NAMED_METHOD_WITH_HANDLER(UVERBS_METHOD_DM_FREE,
+	uverbs_destroy_def_handler,
+	&UVERBS_ATTR_IDR(UVERBS_ATTR_FREE_DM_HANDLE,
+			 UVERBS_OBJECT_DM,
+			 UVERBS_ACCESS_DESTROY,
+			 UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)));
+
+DECLARE_UVERBS_NAMED_OBJECT(UVERBS_OBJECT_DM,
+			    /* 1 is used in order to free the DM after MRs */
+			    &UVERBS_TYPE_ALLOC_IDR(1, uverbs_free_dm),
+			    &UVERBS_METHOD(UVERBS_METHOD_DM_ALLOC),
+			    &UVERBS_METHOD(UVERBS_METHOD_DM_FREE));

include/rdma/ib_verbs.h

@@ -321,6 +321,12 @@ struct ib_cq_caps {
 	u16     max_cq_moderation_period;
 };
 
+struct ib_dm_alloc_attr {
+	u64	length;
+	u32	alignment;
+	u32	flags;
+};
+
 struct ib_device_attr {
 	u64			fw_ver;
 	__be64			sys_image_guid;
@@ -1769,6 +1775,14 @@ struct ib_qp {
 	struct rdma_restrack_entry     res;
 };
 
+struct ib_dm {
+	struct ib_device  *device;
+	u32		   length;
+	u32		   flags;
+	struct ib_uobject *uobject;
+	atomic_t	   usecnt;
+};
+
 struct ib_mr {
 	struct ib_device  *device;
 	struct ib_pd	  *pd;
@@ -2425,7 +2439,11 @@ struct ib_device {
 	int			   (*modify_flow_action_esp)(struct ib_flow_action *action,
 							     const struct ib_flow_action_attrs_esp *attr,
 							     struct uverbs_attr_bundle *attrs);
-
+	struct ib_dm *             (*alloc_dm)(struct ib_device *device,
+					       struct ib_ucontext *context,
+					       struct ib_dm_alloc_attr *attr,
+					       struct uverbs_attr_bundle *attrs);
+	int                        (*dealloc_dm)(struct ib_dm *dm);
 	/**
 	 * rdma netdev operation
 	 *

include/uapi/rdma/ib_user_ioctl_cmds.h

@@ -54,6 +54,7 @@ enum uverbs_default_objects {
 	UVERBS_OBJECT_RWQ_IND_TBL,
 	UVERBS_OBJECT_WQ,
 	UVERBS_OBJECT_FLOW_ACTION,
+	UVERBS_OBJECT_DM,
 };
 
 enum {
@@ -100,4 +101,18 @@ enum uverbs_methods_actions_flow_action_ops {
 	UVERBS_METHOD_FLOW_ACTION_ESP_MODIFY,
 };
 
+enum uverbs_attrs_alloc_dm_cmd_attr_ids {
+	UVERBS_ATTR_ALLOC_DM_HANDLE,
+	UVERBS_ATTR_ALLOC_DM_LENGTH,
+	UVERBS_ATTR_ALLOC_DM_ALIGNMENT,
+};
+
+enum uverbs_attrs_free_dm_cmd_attr_ids {
+	UVERBS_ATTR_FREE_DM_HANDLE,
+};
+
+enum uverbs_methods_dm {
+	UVERBS_METHOD_DM_ALLOC,
+	UVERBS_METHOD_DM_FREE,
+};
 #endif