Method and apparatus for initiating CPU data prefetches by an external agent

A method for initiating CPU data prefetches, comprising:

• executing a program by a target agent;
• obtaining new data by an external source agent, the new data needed for the target agent to run the program;
• creating and issuing a prefetch directive when the new data is obtained by the external source agent;
• and
• issuing a request to prefetch the new data into a target cache, when the prefetch directive is received.

An article comprising a machine readable medium having stored thereon a prefetch directive, the prefetch directive comprising:

• a first field including a message opcode to identify the prefetch directive;
• a second field including a source address to indicate where in the memory data is to be prefetched;
• and
• a third field including routing information to help route the prefetch directive to a target and data to at least one of a memory and a target cache, the target associated with the target cache.

A computing system, comprising:

• a target processor to execute a program;
• an external agent to supply at least a portion of data for the target agent to execute the program, and when having new data, to initiate data prefetch from a memory to a cache, the cache associated with the target processor;
• and
• a supporting platform to provide interfaces between the target processor and the external agent and to facilitate data move among the target processor, the external agent, the cache, and the memory;
• wherein the target processor has faster access to data in the cache than access to data in the memory.

An article comprising a machine readable medium having stored thereon data which, when accessed by a processor in conjunction with simulation routines, provides functionality of a model including:

• a target agent to execute a program;
• the external source agent to supply at least a portion of data for the target agent to execute the program, and when having new data, to create and issue a prefetch directive;
• and
• a hardware prefetcher associated with the target agent, when receiving and recognizing the prefetch directive, to issue a request to prefetch the new data from a memory to a target cache;
• wherein the target agent has more efficient access to data in the target cache than access to data in the memory.