Non-disruptive code update of a single processor in a multi-processor computing system

A computing system having at least a first multi-processor controller, the first multi-processor controller comprising:

• a first server processor operable to execute operating system code for the first controller;
• a first host adapter processor operable to execute code providing an interface with attached hosts;
• a first bus to which first system resources are coupled;
• a plurality of resources, each resource usable exclusively by either of the processors and each resource sharable by both of the processors, the resources including:
• a first memory;
• a first bridge coupled to the first server processor, the first host adapter processor, the first bus and the first memory, the first bridge comprising:
• a first interrupt control module;
• and
• a first memory control module;
• and
• first logic associated with the first server processor configured to:
• halt transactions processed by the first server processor without affecting processing of transactions by the first host adapter processor;
• receive new code;
• terminate the operating system code whereby all processes and threads being executed by the first server processor are terminated;
• after terminating the operating system, check the state of a first bit settable in memory after receiving the new code in the first server processor to determine if a self-reset is to be performed by the first server processor;
• perform a hardware reset of the multi-processor system if the first bit is not set;
• and
• if the first bit is set:
• commence execution of a self-reset of the first server processor;
• disable interrupts associated with the first server processor;
• reset only those first system resources being exclusively used by the first server processor without resetting those system resources being used exclusively by the first host adapter processor and without resetting those system resources, including the bridge, being shared with the first host adapter processor;
• disable memory transactions associated with the first server processor;
• copy an image of the new code into memory associated with the first server processor, after commencing execution of the self-reset, disabling interrupts, resetting, and disabling the memory transactions;
• reset registers over which the first server processor has control as if a hardware reset had occurred;
• and
• boot the new code for the first server processor as if a hardware reset had occurred.

A computer program product stored in a non-transitory computer readable medium usable with a programmable computer, the computer program product having computer-readable code embodied therein for updating code of a single processor in a multiprocessor system having resources that are coupled through a bridge to all of the processors in the system, each resource usable exclusively by anyone of the processors and each resource sharable by more than one of the processors, the computer-readable code comprising instructions for:

• halting transactions processed by a first processor in the system and maintaining processing of transactions by a second processor in the system;
• receiving new code in the first processor;
• terminating an operating system running on the first processor whereby all processes and threads being executed by the first processor are terminated;
• after terminating the operating system, checking the state of a bit settable in memory after receiving the new code in the first processor to determine if a self-reset is to be performed by the first processor;
• performing a hardware reset of the multi-processor system if the bit is not set;
• and
• if the bit is set:
• commencing execution of a self-reset of the first processor;
• disabling interrupts associated with the first processor;
• resetting only those system resources being exclusively used by the first processor without resetting those system resources being used exclusively by the second processor and without resetting those system resources, including the bridge, being shared with the second processor;
• disabling memory transactions associated with the first processor;
• copying an image of the new code into memory associated with the first processor, after the commencing execution of the self-reset, disabling interrupts, resetting, and disabling the memory transactions;
• resetting registers over which the first processor has control as if a hardware reset had occurred;
• and
• executing the new code by the first processor as if a hardware reset had occurred.