Minimizing cache overhead by storing data for communications between a peripheral device and a host system into separate locations in memory

摘要

A method and apparatus for storing, in a data storage device, status data and control data used for communications between a peripheral device and a host system with a mechanism for minimizing cache data processing overhead. The data storage device of the present invention includes a status portion, at a first location within the data storage device, for storing status data corresponding to a buffer. The first location of the data storage device corresponds to a first cache line, and the peripheral device generates the status data for providing status information to the host system. The data storage device further includes a control portion, at a second location within the data storage device, for storing control data corresponding to the descriptor. The second location of the data storage device corresponds to a second cache line, and the host system generates the control data for providing control information to the peripheral device. The host system reads the status information from cache and a cache controller transfers the status data from the data storage device to the cache for reading of the status data by the host system from the cache. With the present invention, the first cache line is different from the second cache line such that cache data processing overhead is minimized when coordinating access to the control data and the status data by the peripheral device and by the host system.