Processor reset generated via memory access interrupt

• US 6,467,007 B1
• Filed: 05/19/1999
• Issued: 10/15/2002
• Est. Priority Date: 05/19/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Armstrong, William Joseph, Nayar, Naresh, Vossen, Kenneth Charles, Armstrong, Troy David
• Primary Examiner(s): THAI, XUAN MARIAN
• Application Number:
  US09/314,769
• Time in Patent Office: 1,245 Days
• Field of Search: 710/260, 710/261, 710/266, 709/215, 709/216, 712/216, 712/226, 712/244, 713/1, 713/100, 714/23, 714/701, 714/702, 714/763, 711/100, 711/147, 711/153, 711/166
• US Class Current: 710/260
• CPC Class Codes: G06F 1/24 Resetting means
• CPC Class Codes: G06F 11/0712 in a virtual computing platform, e.g. logically partitioned systems
• CPC Class Codes: G06F 11/073 in a memory management context, e.g. virtual memory or cache management memory management G06F12/00; testing of static memory units G11C29/00
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40

Abstract

An apparatus, program product, and method utilize a memory access interrupt to effect a reset of a processor in a multi-processor environment. Specifically, a source processor is permitted to initiate a reset of a target processor simply by generating both a reset request and a memory access interrupt for the target processor. The target processor is then specifically configured to detect the presence of a pending reset request during handing of the memory access interrupt, such that the target processor will perform a reset operation responsive to detection of such a request.

Claims

1. A method of resetting a processor, comprising:

(a) generating a reset request for the processor;

(b) generating a memory access interrupt on the processor; and

(c) resetting the processor during handling of the memory access interrupt by the processor responsive to detection of the reset request.

2. The method of claim 1, further comprising accessing data with the processor using a virtual memory system accessible through an address translation table associated with the processor, and wherein generating the memory access interrupt includes invalidating at least one entry in the address translation table.

3. The method of claim 2, wherein invalidating at least one entry in the address translation table includes invalidating every entry in the address translation table.

4. The method of claim 3, wherein generating the memory access interrupt further includes invalidating a corresponding entry in a translation table cache associated with the processor.

5. The method of claim 4, wherein generating the memory access interrupt further includes invalidating a cache entry, associated with a cache line referenced by an invalidated entry in the address translation table, and located in a cache associated with the processor.

6. The method of claim 1, wherein the address translation table includes a plurality of entries, with each entry identifying a virtual memory address used by the processor and a real memory address mapped to the virtual memory address.

7. The method of claim 1, wherein generating the reset request includes setting a reset flag.

8. The method of claim 7, wherein the reset flag is stored in a local storage area for the processor.

9. The method of claim 7, further comprising detecting the reset request in the processor by accessing the reset flag.

10. The method of claim 1, wherein the memory access interrupt includes at least one of a data storage interrupt and an instruction storage interrupt.

11. The method of claim 1, wherein resetting the processor during handling of the memory access interrupt responsive to detection of the reset request is performed by a memory access interrupt routine executed by the processor responsive to a memory access interrupt.

12. The method of claim 11, wherein generating the reset request and generating the memory access interrupt are performed on a second processor coupled to the first processor.

13. The method of claim 12, wherein the first and second processors are among a plurality of processors in a multi-processor computer system.

14. The method of claim 13, wherein the multi-processor computer system defines a plurality of partitions, each partition including an operating system executing on at least one of the plurality of processors, the multi-processor computer system further including a partition manager executing on at least one of the plurality of processors, wherein generating the reset request and generating the memory access interrupt are performed by the partition manager.

15. The method of claim 1, further comprising detecting whether the processor may be locked up with external interrupts disabled, wherein generating the reset request and generating the memory access interrupt are performed responsive to detecting that the processor may be locked up with external interrupts disabled.

16. The method of claim 1, wherein generating the reset request and generating the memory access interrupt are performed responsive to determining that an attempt to reset the processor using an inter-processor interrupt was unsuccessful after determining that the processor is locked up.

17. A method of resetting a first processor among a plurality of processors in a multi-processor computer system, comprising:

(a) detecting with a processor other than the first processor a likely lockup condition in the first processor while external interrupts on the first processor are disabled;

(b) generating with a processor other than the first processor a reset request for the first processor;

(c) generating with a processor other than the first processor a memory access interrupt on the first processor; and

(d) handling the memory access interrupt in the first processor, including detecting the reset request with the first processor and performing a reset on the first processor responsive thereto.

18. An apparatus comprising first and second processors, wherein:

(a) the second processor is configured to initiate a reset of the first processor by generating a reset request and a memory access interrupt for the first processor; and

(b) the first processor is configured to handle the memory access interrupt and to perform a reset responsive to detection of the reset request during handling of the memory access interrupt.

19. The apparatus of claim 18, wherein the first processor is further configured to access data from a memory using an address translation table associated with the first processor, and wherein the second processor is configured to generate the memory access interrupt by invalidating at least one entry in the address translation table.

20. The apparatus of claim 19, the second processor is configured to generate the memory access interrupt by invalidating every entry in the address translation table.

21. The apparatus of claim 20, further comprising a translation table cache associated with the first processor, wherein the second processor is further configured to invalidate a corresponding entry in the translation table cache.

22. The apparatus of claim 21, further comprising a cache associated with the first processor, wherein the second processor is further configured to invalidate a cache entry in the cache that is associated with a cache line referenced by an invalidated entry in the address translation table.

23. The apparatus of claim 22, wherein the cache is a level one instruction cache.

24. The apparatus of claim 18, wherein the second processor is configured to generate the reset request by setting a reset flag, and wherein the first processor is configured to detect the reset request by determining whether the reset flag is set.

25. The apparatus of claim 18, wherein the memory access interrupt includes at least one of a data storage interrupt and an instruction storage interrupt.

26. The apparatus of claim 18, wherein the first processor is configured to execute a memory access interrupt routine responsive to the memory access interrupt, and to detect the reset request during execution of the memory access interrupt routine.

27. The apparatus of claim 18, wherein the first and second processors are among a plurality of processors in a multi-processor computer system, wherein the multi-processor computer system defines a plurality of partitions, each partition including an operating system executing on at least one of the plurality of processors, the multi-processor computer system further including a partition manager executing on at least the second processor.

28. The apparatus of claim 18, wherein the second processor is configured to detect whether the first processor may be locked up with external interrupts disabled, and to generate the reset request and the memory access interrupt responsive to detecting that the first processor may be locked up with external interrupts disabled.

29. The apparatus of claim 18, wherein the second processor is configured to generate the reset request and the memory access interrupt responsive to determining that an attempt to reset the first processor using an inter-processor interrupt was unsuccessful.

30. An apparatus, comprising:

(a) a memory defining a real address space with a plurality of real memory addresses;

(b) a first processor configured to access the memory using a virtual address space including a plurality of virtual memory addresses;

(c) an address translation table accessible by the first processor and including a plurality of entries, each entry configured to map a virtual memory address in the virtual address space to a real memory address in the real address space;

(d) a memory access interrupt handler configured to be executed by the first processor in response to an attempt by the first processor to access an unmapped virtual memory address in the address translation table, the memory access interrupt handler further configured to reset the first processor responsive to a pending reset request; and

(e) a second processor coupled to the first processor, the second processor configured to initiate a reset of the first processor by generating a reset request and invalidating at least one entry in the address translation table.

31. The apparatus of claim 30, wherein the plurality of processors are configured to implement a partitioned environment including a plurality of logical partitions.

32. A program product, comprising:

(a) first and second programs respectively configured to execute on first and second processors, the second program configured to initiate a reset of the first processor by generating a reset request and a memory access interrupt for the first processor, and the first program configured to handle the memory access interrupt and to perform a reset responsive to detection of the reset request during handling of the memory access interrupt; and

(b) a signal bearing medium bearing the first and second programs.

33. The program product of claim 32, wherein the signal bearing medium includes at least one of a recordable medium and a transmission-type medium.