Hardware interface between a switch adapter and a communications subsystem in a data processing system

• US 6,111,894 A
• Filed: 08/26/1997
• Issued: 08/29/2000
• Est. Priority Date: 08/26/1997
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Govindaraju, Rama K., Kim, Chulho, Bender, Carl A., Gildea, Kevin J., DiNicola, Paul D., Shah, Gautam H., Mirza, Jamshed H.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Pezzlo, John
• Application Number:
  US08/920,084
• Time in Patent Office: 1,099 Days
• Field of Search: 370/535, 370/465, 370/400, 370/412, 370/259, 370/351, 370/469, 370/467, 709/226, 709/229, 709/220, 709/230, 709/329, 709/301, 395/500.47, 395/500.46, 379/90.01, 710/127, 710/8, 712/35, 712/36
• US Class Current: 370/469
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/164 Adaptation or special uses of UDP protocol
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

Method, apparatus and program product for communicating from a node to a communications device. A Hardware Abstraction Layer (HAL) provides functions which can be called from user space in a node to access the communications device. An instance of HAL is created in the node. Device specific characteristics from the communications device and a pointer pointing to HAL functions for accessing the communications device are obtained by HAL. HAL then opens multiple ports on the communications device using the functions pointed to by the pointer, and messages are sent between the node and the communications device. The messages thus sent are optimized with respect to the communications device as determined by the obtained device specific characteristics. Multiple processes and protocol stacks may be associated with each port in a single instance of HAL. A further embodiment provides that multiple virtual ports may be associated with a port, with a multiple protocol stacks associated with each virtual port. A further embodiment provides that multiple communications devices may be associated with a single instance of HAL.

Claims

1. A method for communicating from a node to a communications device in a multinode network, the node having a user space and a Kernel space, and further comprising a communications protocol layer above said communications device, said method comprising:

creating an instance of a hardware abstraction layer (HAL) interface in the node, said HAL interface comprising a communications layer between the communications device and the communications protocol layer and providing for functions that control access to the communications devices from said user space in the node;

obtaining device specific characteristics from the communications device and a pointer pointing to access functions in said functions for accessing said communications device;

opening multiple ports on the communications device through the instance of said HAL interface using said functions; and

sending messages between the node and the communications device using said access functions pointed to by said pointer, wherein the messages are optimized with respect to the communications device as determined by the obtained device specific characteristics, and said messages are communicated directly to said communications layer below said communications protocol layer thereby bypassing said Kernel space.

2. The method of claim 1 further comprising:

establishing a protocol stack to be used in sending messages between the node and the communications device;

requesting a set of nodes in the network of nodes, said set of nodes to be assigned to said protocol stack;

encapsulating said set of nodes into a partition; and

said opening of multiple ports includes opening a port on the communications device and associating that port with said partition through said functions such that a single protocol stack is associated with a single port.

3. The method of claim 1 wherein said messages are packetized, and further comprising:

sending one packet of a message with a single function call of said instance of said HAL interface.

4. The method of claim 1 further comprising:

establishing multiple instances of the HAL interface in a single node, each instance having a separate set of ports to said communications device, each instance associated with a separate process on said node.

5. The method of claim 4 further comprising associating multiple ports with a single process on said node.

6. The method of claim 4 further comprising associating multiple virtual ports to a separate one of said ports in a single process.

7. The method of claim 6 further comprising associating a separate protocol stack to each virtual port such that multiple protocol stacks are associated with a single port.

8. The method of claim 4 further comprising:

sending a notification from an instance of the HAL interface to its associated process for both send and receive events in the communication of messages between said node and said communications device.

9. The method of claim 8 wherein said messages are sent in multiple packets and said receive notification is delivered after some specified number of packets have been received from the network.

10. The method of claim 1 wherein an instance of said HAL interface comprises caching packets in a cache at said node until some specified number of packets from a message being sent have been accumulated by said instance to said communications device, and thereafter injecting packets from said cache with a function call in said HAL interface.

11. The method of claim 1 wherein an instance of said HAL interface comprises peeking at a specified number of specified bytes in a packet associated with one of said ports of said instance, and providing said peeked at bytes to the process associated with said instance.

12. The method of claim 1 further comprising:

creating a second instance of said HAL interface in the node;

additionally obtaining device specific characteristics from a second communications device and a second pointer pointing to access functions in said functions for accessing said second communications device;

opening multiple ports on the second communications device through said functions of said second instance; and

sending messages between the node and said second communications device using said access functions pointed to by said second pointer, wherein the messages are optimized with respect to the second communications device as determined by the additionally obtained device specific characteristics.

37. The method of claim 1 further comprising:

directly assembling protocol headers in network buffers, thereby avoiding copy operations during sending of messages.

40. The method of claim 1 wherein said HAL may further receive messages via said communications device from said multinode network, said method further comprising:

handling network messages received from said communications device in said communications layer without involvement of said communications protocol layer.

13. A program product on a computer readable media, said program product including a method for communicating from a node to a communications device in a multinode network, the node having a user space and a Kernel space, and further comprising a communications protocol layer above said communications device, said method comprising:

creating an instance of a hardware abstraction layer (HAL) interface in the node, said HAL interface comprising a communications layer between the communications device and the communications protocol layer and providing for functions that control access to communications devices from said user space in the node;

obtaining device specific characteristics from the communications device and a pointer pointing to access functions in said functions for accessing said communications device;

opening multiple ports on the communications device through the instance of said HAL interface using said functions; and

sending messages between the node and the communications device using said access functions pointed to by said pointer, wherein the messages are optimized with respect to the communications device as determined by the obtained device specific characteristics, and said messages are communicated directly to said communications layer below said communications protocol layer thereby bypassing said Kernel space.

14. The product of claim 13 further comprising:

establishing a protocol stack to be used in sending messages between the node and the communications device;

requesting a set of nodes in the network of nodes, said set of nodes to be assigned to said protocol stack;

encapsulating said set of nodes into a partition; and

said opening of multiple ports includes opening a port on the communications device and associating that port with said partition through said functions such that a single protocol stack is associated with a single port.

15. The program product of claim 13 wherein said messages are packetized, and further comprising:

sending one packet of a message with a single function call of said instance of said HAL interface.

16. The program product of claim 13 further comprising:

establishing multiple instances of the HAL interface in a single node, each instance having a separate set of ports to said communications device, each instance associated with a separate process on said node.

17. The program product of claim 16 further comprising associating multiple ports with a single process on said node.

18. The program product of claim 16 further comprising associating multiple virtual ports to a separate one of said ports in a single process.

19. The program product of claim 18 further comprising associating a separate protocol stack to each virtual port such that multiple protocol stacks are associated with a single port.

20. The program product of claim 16 further comprising:

sending a notification from an instance of the HAL interface to its associated process for both send and receive events in the communication of messages between said node and said communications device.

21. The program product of claim 20 wherein said messages are sent in multiple packets and said receive notification is delivered after some specified number of packets have been received from the network.

22. The program product of claim 13 wherein an instance of said HAL interface comprises caching packets in a cache at said node until some specified number of packets from a message being sent have been accumulated by said instance to said communications device, and thereafter injecting packets from said cache with a function call in said HAL interface.

23. The program product of claim 13 wherein an instance of said HAL interface comprises peeking at a specified number of specified bytes in a packet associated with one of said ports of said instance, and providing said peeked at bytes to the process associated with said instance.

24. The program product of claim 13 further comprising:

creating a second instance of said HAL interface in the node;

additionally obtaining device specific characteristics from a second communications device and a second pointer pointing to access functions in said functions for accessing said second communications device;

opening multiple ports on the second communications device through said functions of said second instance; and

sending messages between the node and said second communications device using said access functions pointed to by said second pointer, wherein the messages are optimized with respect to the second communications device as determined by the additionally obtained device specific characteristics.

38. The program product of claim 13 further comprising:

directly assembling protocol headers in network buffers, thereby avoiding copy operations during sending of messages.

41. The program product of claim 13 wherein said HAL may further receive messages via said communications device from said multinode network, said method further comprising:

handling network messages received from said communications device in said communications layer without involvement of said communications protocol layer.

25. An apparatus comprising:

a multinode network, one node in said multinode network having a user space and a Kernel space, and further having a communications protocol layer;

a communications device below said communications protocol layer for communicating with said one node in said multinode network;

a hardware abstraction layer (HAL) in said one node between said communications device and said communications protocol layer, said HAL creating an instance of an interface in said node, said interface comprising a communications layer and providing for functions that control access to said communications device from said user space in said one node;

an initiation function in said instance of HAL obtaining device specific characteristics from the communications device and a pointer pointing to access functions in said functions for accessing said communications device;

a port opening function in said instance of HAL opening multiple ports on the communications device through the instance of said interface using said functions; and

message sending function in said instance of HAL sending messages between said one node and the communications device using said access functions pointed to by said pointer, wherein the messages are optimized with respect to the communications device as determined by the obtained device specific characteristics, and said messages are communicated directly to said communications layer below said communications protocol layer thereby bypassing said Kernel space.

26. The apparatus of claim 25 further comprising:

a protocol stack in said one node to be used in sending messages between said one node and the communications device;

a set of other nodes in the multinode network assigned to said protocol stack;

a partition in said one node encapsulating said set of other nodes; and

a port on the communications device associated with said partition through said functions such that a single protocol stack is associated with a single port.

27. The apparatus of claim 25 wherein said messages are packetized, and further comprising:

a send function in said instance of HAL sending one packet of a message with a single function call of said instance of said interface.

28. The apparatus of claim 25 further comprising:

multiple processes on said one node; and

multiple instances of the interface established in a single node, each instance having a separate set of ports to said communications device, each instance associated with a separate one of said processes on said one node.

29. The apparatus of claim 28 further comprising multiple ports associated with a single process on said one node.

30. The apparatus of claim 28 further comprising multiple virtual ports associated with a separate one of said ports in a single process.

31. The apparatus of claim 30 further comprising a separate protocol stack associated with each virtual port such that multiple protocol stacks are associated with a single port.

32. The apparatus of claim 28 further comprising:

a function in said instance of HAL sending a notification from an instance of the interface to its associated process for both send and receive events in the communication of messages between said one node and said communications device.

33. The apparatus of claim 32 wherein said instance of HAL has a function sending messages in multiple packets and said receive notification is delivered after some specified number of packets have been received from the network.

34. The apparatus of claim 25 wherein said instance of said interface comprises caching packets in a cache at said one node until some specified number of packets from a message being sent have been accumulated by said instance to said communications device, and said instance of HAL includes a function thereafter injecting packets from said cache into said network from said communications device.

35. The apparatus of claim 25 wherein said instance of said HAL includes a peek function peeking at a specified number of specified bytes in a packet associated with one of said ports, said peek function providing said peeked at bytes to said process associated with said instance.

36. The apparatus of claim 25 further comprising:

a second communications device;

a second instance of said interface created by said HAL in said one node;

an initiation function in said second instance additionally obtaining device specific characteristics from said second communications device and a second pointer pointing to access functions in said functions for accessing said second communications device;

an port opening function in said second instance opening multiple ports on the second communications device; and

a message sending function in said second instance sending messages between said one node and said second communications device using said access functions pointed to by said second pointer, wherein the messages are optimized with respect to said second communications device as determined by the additionally obtained device specific characteristics.

39. The apparatus of claim 25 further comprising:

network buffers in said one node, and

a function in said instance of HAL directly assembling protocol headers in said network buffers, thereby avoiding copy operations during sending of messages.

42. The apparatus of claim 25 wherein said HAL may further receive messages via said communications device from said multinode network, said apparatus further comprising:

a function is said instance of HAL handling network messages received from said communications device in said communications layer without involvement of said communications protocol layer.