APPARATUS AND METHOD FOR HANDLING CACHE MAINTENANCE OPERATIONS

• Main Authors: MATHEWSON, Bruce James, MANNAVA, Phanindra Kumar, JALAL, Jamshed
• Format: Patent
• Language: English
• Published: 08.04.2021
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; PHYSICS

An apparatus and method are provided for handling cache maintenance operations. The apparatus has a plurality of requester elements for issuing requests and at least one completer element for processing such requests. A cache hierarchy is provided having a plurality of levels of cache to store cached copies of data associated with addresses in memory. A requester element may be arranged to issue a cache maintenance operation request specifying a memory address range in order to cause a block of data associated with the specified memory address range to be pushed through at least one level of the cache hierarchy to a determined visibility point in order to make that block of data visible to one or more other requester elements. The given requester element may be arranged to detect when there is a need to issue a write request prior to the cache maintenance operation request in order to cause a write operation to be performed in respect of data within the specified memory address range, and in that event to generate a combined write and cache maintenance operation request to be issued instead of the write request and a subsequent cache maintenance operation request. A recipient completer element that receives the combined write and cache maintenance operation request may then be arranged to initiate processing of the cache maintenance operation required by the combined write and cache maintenance operation request without waiting for the write operation to complete. This can significantly reduce latency in the handling of cache maintenance operations, and can provide for reduced bandwidth utilisation.