IB/uverbs: Add device memory registration ioctl support

Adding new ioctl method for the MR object - REG_DM_MR.

This command can be used by users to register an allocated
device memory buffer as an MR and receive lkey and rkey
to be used within work requests.

It is added as a new method under the MR object and using a new
ib_device callback - reg_dm_mr.
The command creates a standard ib_mr object which represents the
registered memory.

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 +35,5 @@ 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_dm.o
+				uverbs_std_types_flow_action.o uverbs_std_types_dm.o \
+				uverbs_std_types_mr.o

drivers/infiniband/core/uverbs_std_types.c

@@ -144,12 +144,6 @@ static int uverbs_free_srq(struct ib_uobject *uobject,
 	return ret;
 }
 
-static int uverbs_free_mr(struct ib_uobject *uobject,
-			  enum rdma_remove_reason why)
-{
-	return ib_dereg_mr((struct ib_mr *)uobject->object);
-}
-
 static int uverbs_free_xrcd(struct ib_uobject *uobject,
 			    enum rdma_remove_reason why)
 {
@@ -265,10 +259,6 @@ DECLARE_UVERBS_NAMED_OBJECT(UVERBS_OBJECT_QP,
 DECLARE_UVERBS_NAMED_OBJECT(UVERBS_OBJECT_MW,
 			    &UVERBS_TYPE_ALLOC_IDR(0, uverbs_free_mw));
 
-DECLARE_UVERBS_NAMED_OBJECT(UVERBS_OBJECT_MR,
-			    /* 1 is used in order to free the MR after all the MWs */
-			    &UVERBS_TYPE_ALLOC_IDR(1, uverbs_free_mr));
-
 DECLARE_UVERBS_NAMED_OBJECT(UVERBS_OBJECT_SRQ,
 			    &UVERBS_TYPE_ALLOC_IDR_SZ(sizeof(struct ib_usrq_object), 0,
 						      uverbs_free_srq));

drivers/infiniband/core/uverbs_std_types_mr.c

@@ -0,0 +1,147 @@
+/*
+ * 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_mr(struct ib_uobject *uobject,
+			  enum rdma_remove_reason why)
+{
+	return ib_dereg_mr((struct ib_mr *)uobject->object);
+}
+
+static int UVERBS_HANDLER(UVERBS_METHOD_DM_MR_REG)(struct ib_device *ib_dev,
+						   struct ib_uverbs_file *file,
+						   struct uverbs_attr_bundle *attrs)
+{
+	struct ib_dm_mr_attr attr = {};
+	struct ib_uobject *uobj;
+	struct ib_dm *dm;
+	struct ib_pd *pd;
+	struct ib_mr *mr;
+	int ret;
+
+	if (!ib_dev->reg_dm_mr)
+		return -EOPNOTSUPP;
+
+	ret = uverbs_copy_from(&attr.offset, attrs, UVERBS_ATTR_REG_DM_MR_OFFSET);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&attr.length, attrs,
+			       UVERBS_ATTR_REG_DM_MR_LENGTH);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_from(&attr.access_flags, attrs,
+			       UVERBS_ATTR_REG_DM_MR_ACCESS_FLAGS);
+	if (ret)
+		return ret;
+
+	if (!(attr.access_flags & IB_ZERO_BASED))
+		return -EINVAL;
+
+	ret = ib_check_mr_access(attr.access_flags);
+	if (ret)
+		return ret;
+
+	pd = uverbs_attr_get_obj(attrs, UVERBS_ATTR_REG_DM_MR_PD_HANDLE);
+
+	dm = uverbs_attr_get_obj(attrs, UVERBS_ATTR_REG_DM_MR_DM_HANDLE);
+
+	uobj = uverbs_attr_get(attrs, UVERBS_ATTR_REG_DM_MR_HANDLE)->obj_attr.uobject;
+
+	if (attr.offset > dm->length || attr.length > dm->length ||
+	    attr.length > dm->length - attr.offset)
+		return -EINVAL;
+
+	mr = pd->device->reg_dm_mr(pd, dm, &attr, attrs);
+	if (IS_ERR(mr))
+		return PTR_ERR(mr);
+
+	mr->device  = pd->device;
+	mr->pd      = pd;
+	mr->dm      = dm;
+	mr->uobject = uobj;
+	atomic_inc(&pd->usecnt);
+	atomic_inc(&dm->usecnt);
+
+	uobj->object = mr;
+
+	ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DM_MR_RESP_LKEY, &mr->lkey,
+			     sizeof(mr->lkey));
+	if (ret)
+		goto err_dereg;
+
+	ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DM_MR_RESP_RKEY,
+			     &mr->rkey, sizeof(mr->rkey));
+	if (ret)
+		goto err_dereg;
+
+	return 0;
+
+err_dereg:
+	ib_dereg_mr(mr);
+
+	return ret;
+}
+
+static DECLARE_UVERBS_NAMED_METHOD(UVERBS_METHOD_DM_MR_REG,
+	&UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DM_MR_HANDLE, UVERBS_OBJECT_MR,
+			 UVERBS_ACCESS_NEW,
+			 UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DM_MR_OFFSET,
+			    UVERBS_ATTR_TYPE(u64),
+			    UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DM_MR_LENGTH,
+			    UVERBS_ATTR_TYPE(u64),
+			    UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DM_MR_PD_HANDLE, UVERBS_OBJECT_PD,
+			 UVERBS_ACCESS_READ,
+			 UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DM_MR_ACCESS_FLAGS,
+			    UVERBS_ATTR_TYPE(u32),
+			    UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DM_MR_DM_HANDLE, UVERBS_OBJECT_DM,
+			 UVERBS_ACCESS_READ,
+			 UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_REG_DM_MR_RESP_LKEY,
+			     UVERBS_ATTR_TYPE(u32),
+			     UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+	&UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_REG_DM_MR_RESP_RKEY,
+			     UVERBS_ATTR_TYPE(u32),
+			     UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)));
+
+DECLARE_UVERBS_NAMED_OBJECT(UVERBS_OBJECT_MR,
+			    /* 1 is used in order to free the MR after all the MWs */
+			    &UVERBS_TYPE_ALLOC_IDR(1, uverbs_free_mr),
+			    &UVERBS_METHOD(UVERBS_METHOD_DM_MR_REG));

drivers/infiniband/core/verbs.c

@@ -1616,12 +1616,16 @@ EXPORT_SYMBOL(ib_resize_cq);
 int ib_dereg_mr(struct ib_mr *mr)
 {
 	struct ib_pd *pd = mr->pd;
+	struct ib_dm *dm = mr->dm;
 	int ret;
 
 	rdma_restrack_del(&mr->res);
 	ret = mr->device->dereg_mr(mr);
-	if (!ret)
+	if (!ret) {
 		atomic_dec(&pd->usecnt);
+		if (dm)
+			atomic_dec(&dm->usecnt);
+	}
 
 	return ret;
 }

include/rdma/ib_verbs.h

@@ -321,6 +321,12 @@ struct ib_cq_caps {
 	u16     max_cq_moderation_period;
 };
 
+struct ib_dm_mr_attr {
+	u64		length;
+	u64		offset;
+	u32		access_flags;
+};
+
 struct ib_dm_alloc_attr {
 	u64	length;
 	u32	alignment;
@@ -1797,6 +1803,8 @@ struct ib_mr {
 		struct list_head	qp_entry;	/* FR */
 	};
 
+	struct ib_dm      *dm;
+
 	/*
 	 * Implementation details of the RDMA core, don't use in drivers:
 	 */
@@ -2444,6 +2452,9 @@ struct ib_device {
 					       struct ib_dm_alloc_attr *attr,
 					       struct uverbs_attr_bundle *attrs);
 	int                        (*dealloc_dm)(struct ib_dm *dm);
+	struct ib_mr *             (*reg_dm_mr)(struct ib_pd *pd, struct ib_dm *dm,
+						struct ib_dm_mr_attr *attr,
+						struct uverbs_attr_bundle *attrs);
 	/**
 	 * rdma netdev operation
 	 *

include/rdma/uverbs_ioctl.h

@@ -408,6 +408,18 @@ static inline int uverbs_attr_get_enum_id(const struct uverbs_attr_bundle *attrs
 	return attr->ptr_attr.enum_id;
 }
 
+static inline void *uverbs_attr_get_obj(const struct uverbs_attr_bundle *attrs_bundle,
+					u16 idx)
+{
+	struct ib_uobject *uobj =
+		uverbs_attr_get(attrs_bundle, idx)->obj_attr.uobject;
+
+	if (IS_ERR(uobj))
+		return uobj;
+
+	return uobj->object;
+}
+
 static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
 				 size_t idx, const void *from, size_t size)
 {

include/uapi/rdma/ib_user_ioctl_cmds.h

@@ -115,4 +115,20 @@ enum uverbs_methods_dm {
 	UVERBS_METHOD_DM_ALLOC,
 	UVERBS_METHOD_DM_FREE,
 };
+
+enum uverbs_attrs_reg_dm_mr_cmd_attr_ids {
+	UVERBS_ATTR_REG_DM_MR_HANDLE,
+	UVERBS_ATTR_REG_DM_MR_OFFSET,
+	UVERBS_ATTR_REG_DM_MR_LENGTH,
+	UVERBS_ATTR_REG_DM_MR_PD_HANDLE,
+	UVERBS_ATTR_REG_DM_MR_ACCESS_FLAGS,
+	UVERBS_ATTR_REG_DM_MR_DM_HANDLE,
+	UVERBS_ATTR_REG_DM_MR_RESP_LKEY,
+	UVERBS_ATTR_REG_DM_MR_RESP_RKEY,
+};
+
+enum uverbs_methods_mr {
+	UVERBS_METHOD_DM_MR_REG,
+};
+
 #endif