Method and system for maintaining translation lookaside buffer coherency in a multiprocessor data processing system

摘要

Translation lookaside buffers (TLB) are often utilized in the data processing system to efficiently translate an effective or virtual address to a real address within system memory. In systems which include multiple processors which may all access system memory, each processor may include a translation lookaside buffer (TLB) for translating effective addresses to real addresses and coherency between all translation lookaside buffers (TLB) must therefore be maintained. The method and system disclosed herein may be utilized to broadcast a unique bus structure in response to an execution of a translation lookaside buffer invalidate (TLBI) instruction by any processor within a multiprocessor system. The bus structure is accepted by other processors along the bus only in response to an absence of a pending translation lookaside buffer invalidate (TLBI) instruction within each processor. Thus, a broadcast translation lookaside buffer invalidate (TLBI) instruction may only be executed by the other processors within a multiprocessor system if it has been accepted by all processors within the system. After initiating execution of a translation lookaside buffer invalidate (TLBI) instruction at all processors within the system, the execution of pending instructions is temporarily terminated until after the translation lookaside buffer invalidate (TLBI) instruction has been executed. Thereafter, the execution of instructions is suspended until all read and write operations within the memory queue have achieved coherency. Next, all suspended and/or prefetched instructions are refetched utilizing the modified translation lookaside buffer (TLB) to ensure that the address utilized is still valid.