Methods and apparatus for efficient communication between caches in hierarchical caching design

Abstract

In accordance with embodiments disclosed herein, there are provided methods, systems, mechanisms, techniques, and apparatuses for implementing efficient communication between caches in hierarchical caching design. For example, in one embodiment, such means may include an integrated circuit having a data bus; a lower level cache communicably interfaced with the data bus; a higher level cache communicably interfaced with the data bus; one or more data buffers and one or more dataless buffers. The data buffers in such an embodiment being communicably interfaced with the data bus, and each of the one or more data buffers having a buffer memory to buffer a full cache line, one or more control bits to indicate state of the respective data buffer, and an address associated with the full cache line. The dataless buffers in such an embodiment being incapable of storing a full cache line and having one or more control bits to indicate state of the respective dataless buffer and an address for an inter-cache transfer line associated with the respective dataless buffer. In such an embodiment, inter-cache transfer logic is to request the inter-cache transfer line from the higher level cache via the data bus and is to further write the inter-cache transfer line into the lower level cache from the data bus.