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Versions: 00 01 02 03 04 05 06 07 08 09 10 RFC 7306

Storage Maintenance (storm) Working Group                    Hemal Shah
Internet Draft                                     Broadcom Corporation
Intended status: Standards Track                            Felix Marti
Expires: July 2012                                      Wael Noureddine
                                                       Asgeir Eiriksson
                                            Chelsio Communications, Inc.
                                                           Robert Sharp
                                                      Intel Corporation
                                                        January 9, 2012




                         RDMA Protocol Extensions
                     draft-ietf-storm-rdmap-ext-02.txt


Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with
   the provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF). Note that other groups may also distribute
   working documents as Internet-Drafts. The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current.

   Internet-Drafts are draft documents valid for a maximum of six
   months and may be updated, replaced, or obsoleted by other documents
   at any time.  It is inappropriate to use Internet-Drafts as
   reference material or to cite them other than as "work in progress."

   This Internet-Draft will expire on July 9, 2012.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors. All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with
   respect to this document. Code Components extracted from this
   document must include Simplified BSD License text as described in



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   Section 4.e of the Trust Legal Provisions and are provided without
   warranty as described in the Simplified BSD License.



Abstract

   This document specifies extensions to the IETF Remote Direct Memory
   Access Protocol (RDMAP [RFC5040]). RDMAP provides read and write
   services directly to applications and enables data to be transferred
   directly into Upper Layer Protocol (ULP) Buffers without
   intermediate data copies. The extensions specified in this document
   provide the following capabilities and/or improvements: Atomic
   Operations and Immediate Data.



Table of Contents


   1. Introduction...................................................3
   2. Requirements Language..........................................3
   3. Glossary.......................................................3
   4. Header Format Extensions.......................................5
      4.1. RDMAP Control and Invalidate STag Fields..................5
      4.2. RDMA Message Definitions..................................6
   5. Atomic Operations..............................................7
      5.1. Atomic Operation Details..................................8
         5.1.1. FetchAdd.............................................8
         5.1.2. Swap.................................................9
         5.1.3. CmpSwap.............................................10
      5.2. Atomic Operations........................................11
         5.2.1. Atomic Operation Request Message....................12
         5.2.2. Atomic Operation Response Message...................15
      5.3. Atomicity Guarantees.....................................17
      5.4. Atomic Operations Ordering and Completion Rules..........17
   6. Immediate Data................................................18
      6.1. RDMAP Interactions with ULP for Immediate Data...........18
      6.2. Immediate Data Header Format.............................18
      6.3. Immediate Data or Immediate Data with SE Message.........19
      6.4. Ordering and Completions.................................20
   7. Ordering and Completions Table................................20
   8. Error Processing..............................................23
      8.1. Errors Detected at the Local Peer........................23
      8.2. Errors Detected at the Remote Peer.......................24


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   9. Security Considerations.......................................24
   10. IANA Considerations..........................................24
      10.1. Atomic Operation Codes..................................25
   11. References...................................................26
      11.1. Normative References....................................26
      11.2. Informative References..................................26
   12. Acknowledgments..............................................26
   Appendix A. DDP Segment Formats for RDMA Messages................27
      A.1. DDP Segment for Atomic Operation Request.................27
      A.2. DDP Segment for Atomic Response..........................29
      A.3. DDP Segment for Immediate Data and Immediate Data with SE29


1. Introduction

   The RDMA Protocol [RFC5040] provides capabilities for zero copy and
   kernel bypass data communications.  This document specifies the
   following extensions to the RDMA Protocol (RDMAP):

   o  Atomic operations on remote memory locations. Support for atomic
      operation enhances the usability of RDMAP in distributed shared
      memory environments.

   o  Immediate Data messages allow the ULP at the sender to provide a
      small amount of data following an RDMA Message.

   Other RDMA transport protocols define the functionality added by
   these extensions leading to differences in RDMA applications and/or
   Upper Layer Protocols. Removing these differences in the transport
   protocols simplifies these applications and ULPs and that is the
   main motivation for the extensions specified in this document.

2. Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC-2119 [RFC2119].

3. Glossary

   This document is an extension of [RFC5040] and key words are defined
   in the glossary of the referenced document.

   Atomic Operation - is an operation that results in an execution of a
   64-bit operation at a specific address on a remote node. The


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   consumer can use Atomic Operations to read, modify and write at the
   destination address while at the same time guarantee that no other
   read or write operation will occur across any other RDMAP Streams on
   an RNIC at the Data Sink.

   Atomic Operation Request - An RDMA Message used by the Data Source
   to perform an Atomic Operation at the Data Sink.

   Atomic Operation Response - An RDMA Message used by the Data Sink to
   describe the completion of an Atomic Operation at the Data Sink.

   CmpSwap - is an Atomic Operation that is used to compare and swap a
   value at a specific address on a remote node.

   FetchAdd - is an Atomic Operation that is used to atomically
   increment a value at a specific address on a remote node.

   Immediate Data - a small fixed size portion of data sent from the
   Data Source to a Data Sink

   Immediate Data Message - An RDMA Message used by the Data Source to
   send Immediate Data to the Data Sink

   Immediate Data with Solicited Event (SE) Message - An RDMA Message
   used by the Data Source to send Immediate Data with Solicited Event
   to the Data Sink

   Requester - the sender of an RDMA Atomic Operation request.

   Responder - the receiver of an RDMA Atomic Operation request.

   Swap - is an Atomic Operation that is used to swap a value at a
   specific address on a remote node.














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4. Header Format Extensions

   The control information of RDMA Messages is included in DDP protocol
   [RFC5041] defined header fields, with the following new formats:
   .  Four new RDMA Messages carry additional RDMAP headers. The
      Immediate Data operation and Immediate Data with Solicited Event
      operation include 8 bytes of data following the RDMAP header.
      Atomic Operations include Atomic Request or Atomic Response
      headers following the RDMAP header.

4.1. RDMAP Control and Invalidate STag Fields

   The RDMA Messages defined by this specification use all 8 bits of
   the RDMAP Control Field. The first octet reserved for ULP use in the
   DDP Protocol MUST be used by the RDMAP to carry the RDMAP Control
   Field. The ordering of the bits in the first octet MUST be as shown
   in Figure 1.

   Figure 1 depicts the format of the DDP Control and RDMAP Control
   fields, in the style and convention of [RFC5040]:


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                   |T|L| Resrv | DV| RV|Rsv| Opcode|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     Invalidate STag                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 1 DDP Control and RDMAP Control Fields

   Figure 2 defines the values of RDMA Opcode field that MUST be used
   for the RDMA Messages defined in this specification.

   Figure 2 also defines when the STag, Tagged Offset, and Queue Number
   fields MUST be provided for the RDMA Messages defined in this
   specification.

   All RDMA Messages defined in this specification MUST have:

   The RDMA Version (RV) field: 01b.

   Opcode field: See Figure 2.


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   Invalidate STag: MUST be set to zero by the sender, ignored by the
   receiver.



-------+-----------+-------+------+-------+-----------+--------------
RDMA   | Message   | Tagged| STag | Queue | Invalidate| Message
Opcode | Type      | Flag  | and  | Number| STag      | Length
       |           |       | TO   |       |           | Communicated
       |           |       |      |       |           | between DDP
       |           |       |      |       |           | and RDMAP
-------+-----------+-------+------+-------+-----------+--------------
1000b  | Immediate | 0     | N/A  | 0     | N/A       | Yes
       | Data      |       |      |       |           |
-------+-----------+-------------------------------------------------
1001b  | Immediate | 0     | N/A  | 1     | N/A       | Yes
       | Data with |       |      |       |           |
       | SE        |       |      |       |           |
-------+-----------+-------------------------------------------------
1010b  | Atomic    | 0     | N/A  | 1     | N/A       | Yes
       | Request   |       |      |       |           |
-------+-----------+-------------------------------------------------
1011b  | Atomic    | 0     | N/A  | 1     | N/A       | Yes
       | Response  |       |      |       |           |
-------+-----------+-------------------------------------------------

               Figure 2 Additional RDMA Usage of DDP Fields

   Note:  N/A means Not Applicable.

   All other DDP and RDMAP control fields MUST be set as described in
   [RFC5040].

4.2. RDMA Message Definitions

   The following figure defines which RDMA Headers MUST be used on each
   new RDMA Message and which new RDMA Messages are allowed to carry
   ULP payload:








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-------+-----------+-------------------+-------------------------
RDMA   | Message   | RDMA Header Used  | ULP Message allowed in
Message| Type      |                   | the RDMA Message
OpCode |           |                   |
       |           |                   |
-------+-----------+-------------------+-------------------------
1000b  | Immediate | Immediate Data    | No
       | Data      | Header            |
-------+-----------+-------------------+-------------------------
1001b  | Immediate | Immediate Data    | No
       | Data with | Header            |
       | SE        |                   |
-------+-----------+-------------------+-------------------------
1010b  | Atomic    | Atomic Request    | No
       | Request   | Header            |
-------+-----------+-------------------+-------------------------
1011b  | Atomic    | Atomic Response   | No
       | Response  | Header            |
-------+-----------+-------------------+-------------------------
                     Figure 3 RDMA Message Definitions



5. Atomic Operations

   The RDMA Protocol Specification in [RFC5040] does not include
   support for Atomic Operations which are an important building block
   for implementing distributed shared memory.

   This document extends the RDMA Protocol specification with a set of
   basic Atomic Operations, and specifies their resource and ordering
   rules.

   Atomic operations as specified in this document execute a 64-bit
   operation at a specified destination address on a remote node. The
   operations atomically read, modify and write back the contents of
   the destination address and guarantee that Atomic Operations on this
   address by other RDMAP Streams on the same RNIC do not occur between
   the read and the write. Atomic Operations as specified in this
   document MAY be implemented. The discovery of whether the Atomic
   Operations are implemented or not is outside the scope of this
   specification and it should be handled by the ULPs or applications.
   The advertisement of Tagged Buffer information for Atomic Operations
   is outside the scope of this specification and it must be handled by
   the ULPs.


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   Implementation note: It is recommended that the applications do not
   use the buffer addresses used for Atomic Operations for other RDMA
   operations.

   Atomic Operations use the same remote addressing mechanism as RDMA
   Reads and Writes. The buffer address specified in the request is in
   the address space of the Remote Peer that the Atomic Operation is
   targeted at.

5.1. Atomic Operation Details

   The following sub-sections describe the Atomic Operations in more
   details.

5.1.1. FetchAdd

   The FetchAdd Atomic Operation requests the Responder to read a 64-
   bit Original Remote Data value at a 64-bit aligned buffer address in
   the Responder's memory, to perform FetchAdd operation on multiple
   fields of selectable length specified by 64-bit "Add Mask", and
   write the result back to the same virtual address. The Atomic
   addition is performed independently on each one of these fields. A
   bit set in the Add Mask field specifies the field boundary. FetchAdd
   Atomic Operations MUST target buffer addresses that are 64-bit
   aligned. FetchAdd Atomic Operations that target buffer addresses
   that are not 64-bit aligned MUST be surfaced as errors and the
   Responder's memory MUST NOT modified in such cases.  Additionally an
   error MUST be surfaced and a terminate message MUST be generated.
   The setting of "Add Mask" field to 0x0000000000000000 results in
   Atomic Add of 64-bit Original Remote Data Value and 64-bit "Add
   Data".

   The pseudo code below describes masked FetchAdd Atomic Operation.

   bit_location = 1

   carry = 0

   Remote Data Value = 0

   for bit = 0 to 63

   {

      if (bit != 0 ) bit_location = bit_location << 1


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      val1 = !(!(Original Remote Data Value & bit_location))

      val2 = !(!(Add Data & bit_location))

      sum = carry + val1 + val2

      carry = !(!(sum & 2))

      sum = sum & 1

      if (sum)

         Remote Data Value |= bit_location

      carry = ((carry) && (!(Add Mask & bit_location)))

   }

   The FetchAdd operation is performed in the endian format of the
   target memory. The "Original Remote Data" is converted from the
   endian format of the target memory for return and returned to the
   Requester. The fields are in big-endian format on the wire.

   The Requester specifies:

   o  Remote STag

   o  Remote Tagged Offset

   o  Add Data

   o  Add Mask

   The Responder returns:

   o  Original Remote Data

5.1.2. Swap

   The Swap Atomic Operation requires the Responder to read a 64-bit
   value at a 64-bit aligned buffer address in the Responder's memory,
   then to write the "Swap Data" fields into the same buffer address.
   The "Original Remote Data" is converted from the endian format of
   the target memory for return and returned to the Requester. The
   fields are in big-endian format on the wire.


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   The Requester specifies:

   o  Remote STag

   o  Remote Tagged Offset

   o  Swap Data

   The Responder returns:

   o  Original Remote Data

   After the successful completion of Swap operation, the Responder's
   memory at the specified buffer address MUST contain the "Swap Data"
   field in the header. Swap Atomic Operations MUST target buffer
   addresses that are 64-bit aligned. Swap Atomic Operations that
   target buffer addresses that are not 64-bit aligned MUST be surfaced
   as errors and the Responder's memory MUST NOT be modified in such
   cases.  Additionally an error MUST be surfaced and a terminate
   message MUST be generated.

5.1.3. CmpSwap

   The CmpSwap Atomic Operation requires the Responder to read a 64-bit
   value at a 64-bit aligned buffer address in the Responder's memory,
   to perform an AND logical operation using the 64 bit "Compare Mask"
   field in the Atomic Operation Request header, then to compare it
   with the result of a logical AND operation of the "Compare Mask" and
   the "Compare Data" fields in the header, and, if the two values are
   equal, to swap masked bits in the same buffer address with the
   masked Swap Data. If the two masked compare values are not equal,
   the contents of the Responder's memory are not changed. In either
   case, the original value read from the buffer address is converted
   from the endian format of the target memory for return and returned
   to the Requester. The fields are in big-endian format on the wire.

   The Requester specifies:

   o  Remote STag

   o  Remote Tagged Offset

   o  Swap Data

   o  Swap Mask


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   o  Compare Data

   o  Compare Mask

   The Responder returns:

   o  Original Remote Data Value

   The following pseudo code describes the masked CmpSwap operation
   result.

      if (!((Compare Data ^ Original Remote Data value) & Compare Mask)

      then

         Remote Data Value =

           (Original Remote Data Value & ~(Swap Mask))

                             | (Swap Data & Swap Mask)

      else

         Remote Data Value = Original Remote Data Value

   After the operation, the remote data buffer MUST contain the
   "Original Remote Data Value" (if comparison did not match) or the
   masked "Swap Data" (if the comparison did match). CmpSwap Atomic
   Operations MUST target buffer addresses that are 64-bit aligned.
   CmpSwap Atomic Operations that target buffer addresses that are not
   64-bit aligned MUST be surfaced as errors and the remote data buffer
   MUST NOT be modified in such cases.  Additionally an error MUST be
   surfaced and a terminate message MUST be generated.

5.2. Atomic Operations

   The Atomic Operation Request and Response are RDMA Messages.  An
   Atomic Operation makes use of the DDP Untagged Buffer Model. Atomic
   Operations use the same Queue Number as RDMA Read Requests (QN=1).
   Reusing the same Queue Number allows the Atomic Operations to reuse
   the same infrastructure (e.g. ORD/IRD flow control) as defined for
   RDMA Read Requests.

   The RDMA Message OpCode for an Atomic Request Message is 1010b. The
   RDMA Message OpCode for an Atomic Response Message is 1011b.


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5.2.1. Atomic Operation Request Message

   The Atomic Operation Request Message carries an Atomic Operation
   Header that describes the buffer address in the Responder's memory.
   The Atomic Operation Request header immediately follows the DDP
   header. The RDMAP layer passes to the DDP layer a RDMAP Control
   Field. The following figure depicts the Atomic Operation Request
   Header that MUST be used for all Atomic Operation Request Messages:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Reserved (Not Used)              |AOpCode|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Request Identifier                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          Remote STag                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Remote Tagged Offset                     |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Add or Swap Data                        |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Add or Swap Mask                        |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Compare Data                          |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Compare Mask                          |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



                 Figure 4 Atomic Operation Request Header

     Reserved (Not Used): 28 bits



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         This field MUST be set to zero on transmit, ignored on
         receive.

     Atomic Operation Code (AOpCode): 4 bits.

         See Figure 5.

     Request Identifier: 32 bits.

         The Request Identifier specifies a number that is used to
         identify Atomic Operation Request Message. The use of this
         field is implementation dependent and outside the scope of
         this specification.

     Remote STag: 32 bits.

         The Remote STag identifies the Remote Peer's Tagged Buffer
         targeted by the Atomic Operation. The Remote STag is
         associated with the RDMAP Stream through a mechanism that is
         outside the scope of the RDMAP specification.

     Remote Tagged Offset: 64 bits.

         The Remote Tagged Offset specifies the starting offset, in
         octets, from the base of the Remote Peer's Tagged Buffer
         targeted by the Atomic Operation. The Remote Tagged Offset MAY
         start at an arbitrary offset.

     Add or Swap Data: 64 bits.

         The Add or Swap Data field specifies the 64-bit "Add Data"
         value in an Atomic FetchAdd Operation or the 64-bit "Swap
         Data" value in an Atomic Swap or CmpSwap Operation.

     Add or Swap Mask: 64 bits

     This field is used in masked Atomic Operations (FetchAdd and
     CmpSwap) to perform a bitwise logical AND operation as specified
     in the definition of these operations. For non-masked Atomic
     Operations (Swap), this field MUST be set to ffffffffffffffffh on
     transmit and ignored by the receiver.

     Compare Data: 64 bits.




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         The Compare Data field specifies the 64-bit "Compare Data"
         value in an Atomic CmpSwap Operation. For Atomic FetchAdd and
         Atomic Swap operation, the Compare Data field MUST be set to
         zero on transmit and ignored by the receiver.

     Compare Mask: 64 bits

         This field is used in masked Atomic Operation CmpSwap to
         perform a bitwise logical AND operation as specified in the
         definition of these operations. For Atomic Operations FetchAdd
         and Swap, this field MUST be set to ffffffffffffffffh on
         transmit and ignored by the receiver.



   ---------+-----------+----------+----------+---------+---------
   Atomic   | Atomic    | Add or   | Add or   | Compare | Compare
   Operation| Operation | Swap     | Swap     | Data    | Mask
   Code     |           | Data     | Mask     |         |
   ---------+-----------+----------+----------+---------+---------
   0000b    | FetchAdd  | Add Data | Add Mask | N/A     | N/A
   ---------+-----------+----------+----------+---------+---------
   0001b    | Swap      | Swap Data| N/A      | N/A     | N/A
   ---------+-----------+----------+----------+---------+---------
   0010b    | CmpSwap   | Swap Data| Swap Mask| Valid   | Valid
   ---------+-----------+----------+----------+---------+---------
   0011b    |           |
   to       | Reserved  |            Not Specified
   1111b    |           |
   ---------+-----------+-----------------------------------------

               Figure 5 Atomic Operation Message Definitions

   The Atomic Operation Request Message has the following semantics:

   1. An Atomic Operation Request Message MUST reference an Untagged
      Buffer. That is, the Local Peer's RDMAP layer MUST request that
      the DDP mark the Message as Untagged.

   2. One Atomic Operation Request Message MUST consume one Untagged
      Buffer.






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   3. The Responder's RDMAP layer MUST process an Atomic Operation
      Request Message. A valid Atomic Operation Request Message MUST
      NOT be delivered to the Responder's ULP (i.e., it is processed by
      the RDMAP layer).

   4. At the Responder, when an invalid Atomic Operation Request
      Message is delivered to the Remote Peer's RDMAP layer, an error
      is surfaced.

   5. An Atomic Operation Request Message MUST reference the RDMA Read
      Request Queue.  That is, the Requester's RDMAP layer MUST request
      that the DDP layer set the Queue Number field to one.

   6. The Requester MUST pass to the DDP layer Atomic Operation Request
      Messages in the order they were submitted by the ULP.

   7. The Responder MUST process the Atomic Operation Request Messages
      in the order they were sent.

   8. If the Responder receives a valid Atomic Operation Request
      Message, it MUST respond with a valid Atomic Operation Response
      Message.

5.2.2. Atomic Operation Response Message

   The Atomic Operation Response Message carries an Atomic Operation
   Response Header that contains the "Original Request Identifier" and
   "Original Remote Data Value". The Atomic Operation Response Header
   immediately follows the DDP header. The RDMAP layer passes to the
   DDP layer a RDMAP Control Field. The following figure depicts the
   Atomic Operation Response header that MUST be used for all Atomic
   Operation Response Messages:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Original Request Identifier                |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Original Remote Data Value                 |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                 Figure 6 Atomic Operation Response Header



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   Original Request Identifier: 32 bits.

         The Original Request Identifier MUST be set to the value
         specified in the Request Identifier field that was originally
         provided in the corresponding Atomic Operation Request
         Message.

   Original Remote Data Value: 64 bits.

         The Original Remote Value specifies the original 64-bit value
         stored at the buffer address targeted by the Atomic Operation.

   The Atomic Operation Response Message has the following semantics:

   1. The Atomic Operation Response Message for the associated Atomic
      Operation Request Message travels in the opposite direction.

   2. An Atomic Operation Response Message MUST consume an Untagged
      Buffer. That is, the Responder RDMAP layer MUST request that the
      DDP mark the Message as Untagged.

   3. An Atomic Operation Response Message MUST reference the Queue
      Number 3.  That is, the Responder's RDMAP layer MUST request that
      the DDP layer set the Queue Number field to 3.

   4. The Responder MUST ensure that a sufficient number of Untagged
      Buffers are available on the RDMA Read Request Queue (Queue with
      DDP Queue Number 1) to support the maximum number of Atomic
      Operation Requests negotiated by the ULP.

   5. The RDMAP layer MUST Deliver the Atomic Operation Response
      Message to the ULP.

   6. At the Requester, when an invalid Atomic Operation Response
      Message is delivered to the Remote Peer's RDMAP layer, an error
      is surfaced.

   7. The Responder RDMAP layer MUST pass Atomic Operation Response
      Messages to the DDP layer, in the order that the Atomic Operation
      Request Messages were received by the RDMAP layer, at the
      Responder.






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5.3. Atomicity Guarantees

   Atomicity of the Read-Modify-Write (RMW) on the Responder's node by
   the Atomic Operation MUST be assured in the presence of concurrent
   atomic accesses by other RDMAP Streams on the same RNIC.

5.4. Atomic Operations Ordering and Completion Rules

   In addition to the ordering and completion rules described in
   [RFC5040], the following rules apply to implementations of the
   Atomic operations.

   1. For an Atomic operation, the contents of the Tagged Buffer at the
      Responder MAY be indeterminate until the Atomic Operation
      Response Message has been Delivered at the Requester.

   2. Atomic Operation Request Messages MUST NOT start processing at
      the Responder until they have been Delivered to RDMAP by DDP.

   3. Atomic Operation Response Messages MAY be generated at the
      Responder after subsequent RDMA Write Messages or Send Messages
      have been Placed or Delivered.

   4. Atomic Operation Response Message processing at the Responder
      MUST be started only after the Atomic Operation Request Message
      has been Delivered by the DDP layer (thus, all previous RDMA
      Messages have been properly submitted for ordered Placement).

   5. Send Messages MAY be Completed at the Responder before prior
      incoming Atomic Operation Request Messages have completed their
      response processing.

   6. An Atomic Operation MUST NOT be Completed at the Requester until
      the DDP layer Delivers the associated incoming Atomic Operation
      Response Message.

   7. If more than one outstanding Atomic Request Messages are
      supported by both peers, the Atomic Operation Request Messages
      MUST be processed in the order they were delivered by the DDP
      layer on the Responder. Atomic Operation Response Messages MUST
      be submitted to the DDP layer on the Responder in the order the
      Atomic Operation Request Messages were Delivered by DDP.





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6. Immediate Data

   The Immediate Data operation is used in conjunction with an RDMA
   Operation to improve ULP processing efficiency by allowing 8 bytes
   of immediate data to be delivered with the completion of the
   previous operation after the previous operation has been delivered
   at the Remote Peer.

6.1. RDMAP Interactions with ULP for Immediate Data

   For Immediate Data operations, the following are the interactions
   between the RDMAP Layer and the ULP:
   .  At the Data Source:

       .   The ULP passes to the RDMAP Layer the following:

           .   Eight bytes of ULP Immediate Data

       .   When the Immediate Data operation Completes, an indication
           of the Completion results.

   .  At the Data Sink:

       .   If the Immediate Data operation is Completed successfully,
           the RDMAP Layer passes the following information to the ULP
           Layer:

           .   Eight bytes of Immediate Data

           .   An Event, if the Data Sink is configured to generate an
               Event and the RDMA Message Opcode indicates Message Type
               Immediate Data with Solicited Event.

       .   If the Immediate Data operation is Completed in error, the
           Data Sink RDMAP Layer will pass up the corresponding error
           information to the Data Sink ULP and send a Terminate
           Message to the Data Source RDMAP Layer. The Data Source
           RDMAP Layer will then pass up the Terminate Message to the
           ULP.

6.2. Immediate Data Header Format

   The  Immediate  Data  and  Immediate  Data  with  SE  Messages  carry
   immediate data as shown in Figure 7.  The RDMAP layer passes to the


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   DDP layer an RDMAP Control Field and 8 bytes of Immediate Data.  The
   first 8 bytes of the data following the DDP header contains the
   Immediate Data. See section A.3. for the DDP segment format of an
   Immediate Data or Immediate Data with SE Message.

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Immediate Data                         |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     Figure 7 Immediate Data or Immediate Data with SE Message Header

   Immediate Data: 64 bits.
        Eight bytes of data transferred from the Requester to an
        untagged buffer at the Responder.


6.3. Immediate Data or Immediate Data with SE Message

   The Immediate Data or Immediate Data with SE Message uses the DDP
   Untagged Buffer Model to transfer Immediate data from the Data
   Source to the Data Sink.
   .  An Immediate Data or Immediate Data with SE Message MUST
      reference an Untagged Buffer. That is, the Local Peer's RDMAP
      Layer MUST request that the DDP layer mark the Message as
      Untagged.

   .  One Immediate Data or Immediate Data with SE Message MUST consume
      one Untagged Buffer.

   .  At the Remote Peer, the Immediate Data or Immediate Data with SE
      Message MUST be Delivered to the Remote Peer's ULP in the order
      they were sent.

   .  For an Immediate Data or Immediate Data with SE Message, the
      Local Peer's RDMAP Layer MUST request that the DDP layer set the
      Queue Number field to zero.





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   .  For an Immediate Data or Immediate Data with SE Message, the
      Local Peer's RDMAP Layer MUST request that the DDP layer transmit
      8 bytes of data.

   .  The Local Peer MUST issue Immediate Data and Immediate Data with
      SE Messages in the order they were submitted by the ULP.

   .  The Remote Peer MUST check that Immediate Data and Immediate Data
      with SE Messages include exactly 8 bytes of data from the DDP
      layer.

6.4. Ordering and Completions

   Ordering and completion rules for Immediate Data are the same as
   those for a Send operation as described in section 5.5 of RFC 5040.

7. Ordering and Completions Table

The following table summarizes the ordering relationships for Atomic
and Immediate Data operations from the standpoint of Local Peer issuing
the Operations. Note that in the table that follows, Send includes
Send, Send with Invalidate, Send with Solicited Event, and Send with
Solicited Event and Invalidate. Also note that in the table below,
Immediate Data includes Immediate Data and Immediate Data with
Solicited Event.

----------+------------+-------------+-------------+-------------------
First     | Second     | Placement   | Placement   | Ordering
Operation | Operation  | Guarantee at| Guarantee at| Guarantee at
          |            | Remote Peer | Local Peer  | Remote Peer
----------+------------+-------------+-------------+-------------------
Immediate | Send       | No Placement| Not         | Completed in
Data      |            | Guarantee   | Applicable  | Order
          |            | between Send|             |
          |            | Payload and |             |
          |            | Immediate   |             |
          |            | Data        |             |
----------+------------+-------------+-------------+-------------------
Immediate | RDMA       | No Placement| Not         | Not
Data      | Write      | Guarantee   | Applicable  | Applicable
          |            | between RDMA|             |
          |            | Write       |             |
          |            | Payload and |             |



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          |            | Immediate   |             |
          |            | Data        |             |
----------+------------+-------------+-------------+-------------------
Immediate | RDMA       | No Placement| RDMA Read   | RDMA Read
Data      | Read       | Guarantee   | Response    | Response
          |            | between     | will not be | Message will
          |            | Immediate   | Placed until| not be
          |            | Data and    | Immediate   | generated
          |            | RDMA Read   | Data is     | until
          |            | Request     | Placed at   | Immediate Data
          |            |             | Remote Peer | has been
          |            |             |             | Completed
----------+------------+-------------+-------------+-------------------
Immediate | Atomic     | No Placement| Atomic      | Atomic
Data      |            | Guarantee   | Response    | Response
          |            | between     | will not be | Message will
          |            | Immediate   | Placed until| not be
          |            | Data and    | Immediate   | generated
          |            | Atomic      | Data is     | until
          |            | Request     | Placed at   | Immediate Data
          |            |             | Remote Peer | has been
          |            |             |             | Completed
----------+------------+-------------+-------------+-------------------
Immediate | Immediate  | No Placement| Not         | Completed in
Data or   | Data       | Guarantee   | Applicable  | Order
Send      |            |             |             |
----------+------------+-------------+-------------+-------------------
RDMA Write| Immediate  | No Placement| Not         | Immediate Data
          | Data       | Guarantee   | Applicable  | is Completed
          |            |             |             | after RDMA
          |            |             |             | Write is Placed
          |            |             |             | and Delivered
----------+------------+-------------+-------------+-------------------
RDMA Read | Immediate  | No Placement| Immediate   | Not Applicable
          | Data       | Guarantee   | Data MAY be |
          |            | between     | Placed      |
          |            | Immediate   | before      |
          |            | Data and    | RDMA Read   |
          |            | RDMA Read   | Response is |
          |            | Request     | generated   |
----------+------------+-------------+-------------+-------------------
Atomic    | Immediate  | No Placement| Immediate   | Not Applicable
          | Data       | Guarantee   | Data MAY be |
          |            | between     | Placed      |
          |            | Immediate   | before      |


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          |            | Data and    | Atomic      |
          |            | Atomic      | Response is |
          |            | Request     | generated   |
----------+------------+-------------+-------------+-------------------
Atomic    | Send       | No Placement| Send Payload| Not Applicable
          |            | Guarantee   | MAY be      |
          |            | between Send| Placed      |
          |            | Payload and | before      |
          |            | Atomic      | Atomic      |
          |            | Request     | Response is |
          |            |             | generated   |
----------+------------+-------------+-------------+-------------------
Atomic    | RDMA       | No Placement| RDMA Write  | Not
          | Write      | Guarantee   | Payload MAY | Applicable
          |            | between RDMA| be Placed   |
          |            | Write       | before      |
          |            | Payload and | Atomic      |
          |            | Atomic      | Response is |
          |            | Request     | generated   |
----------+------------+-------------+-------------+-------------------
Atomic    | RDMA       | No Placement| No Placement| RDMA Read
          | Read       | Guarantee   | Guarantee   | Response
          |            | between     | between     | Message will
          |            | Atomic      | Atomic      | not be
          |            | Request and | Response    | generated
          |            | RDMA Read   | and RDMA    | until Atomic
          |            | Request     | Read        | Response Message
          |            |             | Response    | has been
          |            |             |             | generated
----------+------------+-------------+-------------+-------------------
Atomic    | Atomic     | No Placement| No Placement| Second Atomic
          |            | Guarantee   | Guarantee   | Response
          |            | between two | between two | Message will
          |            | Atomic      | Atomic      | not be
          |            | Requests    | Responses   | generated
          |            |             |             | until first
          |            |             |             | Atomic Response
          |            |             |             | has been
          |            |             |             | generated
----------+------------+-------------+-------------+-------------------
Send      | Atomic     | No Placement| Atomic      | Atomic Response
          |            | Guarantee   | Response    | Message will not
          |            | between Send| will not be | be generated until
          |            | Payload and | Placed at   | Send has been
          |            | Atomic      | the Local   | Completed


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          |            | Request     | Peer Until  |
          |            |             | Send Payload|
          |            |             | is Placed   |
          |            |             | at the      |
          |            |             | Remote Peer |
----------+------------+-------------+-------------+-------------------
RDMA      | Atomic     | No Placement| Atomic      | Not
Write     |            | Guarantee   | Response    | Applicable
          |            | between RDMA| will not be |
          |            | Write       | Placed at   |
          |            | Payload and | the Local   |
          |            | Atomic      | Peer Until  |
          |            | Request     | Send Payload|
          |            |             | is Placed   |
          |            |             | at the      |
          |            |             | Remote Peer |
----------+------------+-------------+-------------+-------------------
RDMA      | Atomic     | No Placement| No Placement| Atomic Response
Read      |            | Guarantee   | Guarantee   | Message will
          |            | between     | between     | not be generated
          |            | Atomic      | Atomic      | until RDMA
          |            | Request and | Response    | Read Response
          |            | RDMA Read   | and RDMA    | has been
          |            | Request     | Read        | generated
          |            |             | Response    |
----------+------------+-------------+-------------+-------------------

8. Error Processing

   In addition to error processing described in section 7 of [RFC5040],
   the following rules apply for the new RDMA Messages defined in this
   specification.

8.1. Errors Detected at the Local Peer

   The Local Peer MUST send a Terminate Message for each of the
   following cases:

   1. For errors detected while creating an Atomic Request, Atomic
      Response, Immediate Data, or Immediate Data with SE Message, or
      other reasons not directly associated with an incoming Message,
      the Terminate Message and Error code are sent instead of the
      Message. In this case, the Error Type and Error Code fields are
      included in the Terminate Message, but the Terminated DDP Header
      and Terminated RDMA Header fields are set to zero.


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   2. For errors detected on an incoming Atomic Request, Atomic
      Response, Immediate Data, or Immediate Data with Solicited Event
      (after the Message has been Delivered by DDP), the Terminate
      Message is sent at the earliest possible opportunity, preferably
      in the next outgoing RDMA Message.  In this case, the Error Type,
      Error Code, and Terminated DDP Header fields are included in the
      Terminate Message, but the Terminated RDMA Header field is set to
      zero.

8.2. Errors Detected at the Remote Peer

   On incoming Atomic Requests, Atomic Responses, Immediate Data, and
   Immediate Data with Solicited Event, the following MUST be
   validated:


   .  The DDP layer MUST validate all DDP Segment fields.

   .  The RDMA OpCode MUST be valid.

   .  The RDMA Version MUST be valid.

   On incoming Atomic requests the following additional validation MUST
   be performed:

   .  The RDMAP layer MUST validate that the Remote Peer's Tagged
      Buffer address references a 64-bit aligned ULP buffer address. In
      the case of an error, the RDMAP layer MUST generate a Terminate
      Message indicating RDMA Layer Remote Operation Error with Error
      Code Name "Catastrophic Error, Localized to RDMAP Stream" as
      described in Section 4.8 of [RFC5040]. Implementation Note: A ULP
      implementation can avoid this error by having the target ULP
      buffer of an atomic operation 64-bit aligned.

9. Security Considerations

   This document specifies extensions to the RDMA Protocol
   specification in [RFC5040], and as such the Security Considerations
   discussed in Section 8 of [RFC5040] apply.

10. IANA Considerations

   IANA is requested to add the following entries to the "RDMA Message
   Operation Codes" registry of "RDDP Registries":



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   0x8, Immediate Data, [RFCXXXX]

   0x9, Immediate Data with SE, [RFCXXXX]

   0xA, Atomic Request, [RFCXXXX]

   0xB, Atomic Response, [RFCXXXX]

   In addition, the following registry is requested to be added to
   "RDDP Registries". The following section specifies the registry, its
   initial contents and the administration policy in more detail.

10.1. Atomic Operation Codes

   Name of the registry: "Atomic Operation Codes"

   Namespace details: Atomic Operation Codes are 4-bit values
   [RFCXXXX].

   Information that must be provided to assign a new value: An IESG-
   approved standards-track specification defining the semantics and
   interoperability requirements of the proposed new value and the
   fields to be recorded in the registry.

   Assignment policy: If the requested value is not already assigned,
   it may be assigned to the requester.

   Fields to record in the registry: Atomic Operation Code, Atomic
   Operation, RFC Reference.

   Initial registry contents:

   0x0, FetchAdd, [RFCXXXX]

   0x1, Swap, [RFCXXXX]

   0x2, CmpSwap, [RFCXXXX]

   All other values are Unassigned and available to IANA for
   assignment.

   Allocation Policy: Standards Action ([RFC5226])

   RFC Editor: Please replace XXXX in all instances of [RFCXXXX] above
   with the RFC number of this document and remove this note.


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11. References

11.1. Normative References

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC5040] Recio, R. et al., "A Remote Direct Memory Access Protocol
             Specification", RFC 5040, October 2007.

   [RFC5041] Shah, H. et al., "Direct Data Placement over Reliable
             Transports", RFC 5041, October 2007.

   [RFC5226] T. Narten and H. Alvestrand, "Guidelines for Writing an
             IANA Considerations Section in RFCs", RFC 5226, BCP 26,
             May 2008.

11.2. Informative References



12. Acknowledgments

   The authors would like to acknowledge the following contributors who
   provided valuable comments and suggestions.

   o  Steve Wise.

   This document was prepared using 2-Word-v2.0.template.dot.


















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Appendix A.                 DDP Segment Formats for RDMA Messages

   This appendix is for information only and is NOT part of the
   standard. It simply depicts the DDP Segment format for the various
   RDMA Messages.

A.1. DDP Segment for Atomic Operation Request

   The following figure depicts an Atomic Operation Request, DDP
   Segment:





































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    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                   |  DDP Control  | RDMA Control  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Reserved (Not Used)                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              DDP (Atomic Operation Request) Queue Number      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        DDP (Atomic Operation Request) Message Sequence Number |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |             DDP (Atomic Operation Request) Message Offset     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Reserved (Not Used)              |AOpCode|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Request Identifier                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          Remote STag                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Remote Tagged Offset                     |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Add or Swap Data                        |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Add or Swap Mask                        |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Compare Data                          |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Compare Mask                          |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+








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A.2. DDP Segment for Atomic Response

   The following figure depicts an Atomic Operation Response, DDP
   Segment:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                   |  DDP Control  | RDMA Control  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Reserved (Not Used)                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              DDP (Atomic Operation Request) Queue Number      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        DDP (Atomic Operation Request) Message Sequence Number |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |             DDP (Atomic Operation Request) Message Offset     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Original Request Identifier                |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Original Remote Value                   |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


A.3. DDP Segment for Immediate Data and Immediate Data with SE

   The following figure depicts an Immediate Data or Immediate data
   with SE, DDP Segment:

















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    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                   |  DDP Control  | RDMA Control  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Reserved (Not Used)                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    DDP (Send) Queue Number                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                DDP (Send) Message Sequence Number             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       DDP Message Offset                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Immediate Data                         |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+






























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Authors' Addresses

   Hemal Shah
   Broadcom Corporation
   5300 California Avenue
   Irvine, CA 92617
   Phone: 1-949-926-6941
   Email: hemal@broadcom.com

   Felix Marti
   Chelsio Communications, Inc.
   370 San Aleso Ave.
   Sunnyvale, CA 94085
   Phone: 1-408-962-3600
   Email: felix@chelsio.com

   Asgeir Eiriksson
   Chelsio Communications, Inc.
   370 San Aleso Ave.
   Sunnyvale, CA 94085
   Phone: 1-408-962-3600
   Email: asgeir@chelsio.com

   Wael Noureddine
   Chelsio Communications, Inc.
   370 San Aleso Ave.
   Sunnyvale, CA 94085
   Phone: 1-408-962-3600
   Email: wael@chelsio.com

   Robert Sharp
   Intel Corporation
   1501 South Mopac, Suite 400, Mailstop: AN1-WTR1
   Austin, TX  78746
   Phone: 1-512-493-3242
   Email: robert.o.sharp@intel.com











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