Bypass method for efficient DMA disk I/O

A computer readable media having computer readable code which when executed by a processor of a computer system cause the computer system to implement a bypass method for efficient disk I/O (input output), comprising:

• upon receiving a request for said disk I/O from an application executing on the computer system, transferring a command to a disk controller, the command causing a start up of a disk drive coupled to the disk controller;
• subsequent to transferring the command causing the start up and before the completion of said start up, preparing disk transaction information by packaging a plurality of PRD (physical region descriptor) data structures and a plurality of CPB (command parameter block) data structures comprising a disk transaction in response to said command;
• accessing a bridge component controlling a bus coupled to the disk controller;
• in response to said preparing said disk transaction information, transferring the disk transaction information to a plurality of bypass registers of the disk controller via the bridge component;
• and
• in response to said transferring said disk transaction information to said disk controller, implementing said disk I/O, wherein the disk controller processes the disk transaction information to control the disk drive.

A computer system for implementing a bypass method for efficient disk I/O (input output), comprising:

• a processor;
• a system memory coupled to the processor;
• a bridge component coupled to the processor;
• and
• a disk controller coupled to the bridge component, the disk controller including a plurality of bypass registers, wherein the processor executes software code stored in the system memory, the software code causing the computer system to implement a method comprising:
• upon receiving a request for said disk I/O from an application executing on the computer system, transferring a command from the processor to the disk controller, the command causing a start up of a disk drive coupled to the disk controller;
• subsequent to transferring the command causing the start up and before the completion of said start up, preparing disk transaction information by packaging a plurality of data structures comprising a disk transaction in response to said command;
• in response to said preparing said disk transaction information, transferring the disk transaction information to the bypass registers of the disk controller;
• and
• in response to said transferring said disk transaction information to said disk controller, implementing said disk I/O, wherein the disk controller processes the disk transaction information to control the disk drive.