Matthew Wilcox - Hewlett Packard

PCI: Past, Present and Future

PCI is probably the most successful I/O architecture in history. Introduced in 1992, it has enjoyed great success over the last 12 years. Incremental changes have brought it from a theoretical bandwidth of 132MB/s to over 1GB/s. It has replaced many proprietary I/O architectures and is supported by almost every system architecture. It has spawned a number of related technologies including PCI-X, AGP and CompactPCI, and several formfactors including MiniPCI, Low Profile PCI and Cardbus. It has been flexible enough to meet the needs of everyone from low-margin sound cards to high-end Ultra 320 SCSI cards.

While PCI continues to be important in current systems, the industry is rapidly moving towards its designated successor, PCI Express. PCI Express is a radical change in hardware, bus protocol and design, but continues to be largely compatible at the software level. Some changes have been necessary to Linux to accommodate Express. Examples include the use of a new configuration space access method (MMConfig), the expanded configuration address space and the new functionality offered by all Express devices.

This talk covers the evolution of PCI and discusses its implementation within Linux. Special attention will be paid to how this move is going to affect users and sysadmins; this is a general-interest talk, not aimed specifically at programmers.

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