International Business Machines Corporation

Lenovo (singapore) Pte. Ltd.

Sandra Rhodes

William Edward Atherton

Laurence Victor Marks

Dustin Patterson

Charles Bruce Dillon

Sreekanth Konireddygari

Frank Westbrook Dain

For optimizing expansion devices on a computer expansion bus based on real-time flow control data, a system, apparatus, method, and computer program product are disclosed. The apparatus includes a configuration module that initializes a plurality of expansion bus registers, each expansion bus register associated with one of the plurality of expansion bus slots, a packet module that monitors flow control packets on the expansion bus, a flow control module that calculates flow control data from the flow control packets, the flow control data relating to the plurality of expansion devices, and a register module that writes flow control data to the plurality of expansion bus registers. The apparatus may further includes an optimization module that calculates an arrangement of the plurality of expansion devices, based on the flow control data, to maximize expansion bus throughput.

PCI-E real-time flow control optimization

Encryption of interrupt vectors and authentication of device drivers prevents unauthorized modules from interfering with an interrupt handler. An operating system may encrypt an interrupt vector for a PCI device, initializing a Local Interrupt Controller of a CPU with the key to enable decryption of the interrupt vector, initializing a redirection table on an I/O Interrupt Controller of the CPU with the encrypted interrupt vector, and initializing the PCI device with an encrypted MSI vector for subsequent use in an interrupt request. The PCI device may raise an interrupt that can only be decrypted by the Local Interrupt Controller and used be used by the processor to handle the interrupt. The operating system may also authenticate a driver before executing a request to register, deregister or change an interrupt handler. An authentication code is sent from the OS to the device driver for use in any request. The request is executed only if the operating system determines that the authentication code in the request matches the authentication code stored by the operating system for that device driver.

Secure handling and routing of message-signaled interrupts

When two 56K server modems communicate with one another over the public switched telephone network, they signal each other so that they communicate data to each other in a digital pass-through mode whereby essentially there is a direct digital connection between the two modems. This is accomplished by using extended ITU-T Recommendation V.8 protocols.

Modem protocol

Growing community of inventors

Wake Forest, NC, United States of America

Sandra Rhodes