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PCI-Express Hot-Plug Event Tri-Modal Interrupt Escalation

IP.com Disclosure Number: IPCOM000019526D
Publication Date: 2003-Sep-17
Document File: 2 page(s) / 315K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that uses control logic to selectively steer detected PCI-Express hot-plug events to one of three interrupt types. Benefits include support of standard PCI interrupts, low overhead by service routines, and firmware-based system specific event signaling mechanisms in the absence of OS PCI interrupt support.

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PCI-Express Hot-Plug Event Tri-Modal Interrupt Escalation

Disclosed is a method that uses control logic to selectively steer detected PCI-Express hot-plug events to one of three interrupt types. Benefits include support of standard PCI interrupts, low overhead by service routines, and firmware-based system specific event signaling mechanisms in the absence of OS PCI interrupt support.

Background

Typically, software is made aware of hot-plug events either by polling status registers or by interrupt notifications. Polling wastes processing power, while interrupts allow processing until the moment the interrupt occurs.

General Description

The disclosed method (see Figure 1) supports three different types of interrupts: standard PCI Interrupts, Message signaled interrupts (MSI), and a dedicated general purpose event interrupt (GPEI).

The method of traversing hierarchy to service PCI interrupts uses the interrupt status bit of the PCI status register. The MSI must be understood by the OS, (and are not supported by current OSs), but have the advantage that the message number informs the processor exactly what area of logic caused the interrupt. The GPEI is dedicated to hot-plug events in the disclosed method. This GPEI has the advantage that it does not require traversing the hierarchy to determine what caused the interrupt, unlike the standard PCI interrupt, which is not supported by current OSs with hot-plug support.

Advantages

Some implementations of the disclosed structure and...