PCIe switch and endpoint address space distribution method

Abstract

The invention relates to a PCIe switch and an end point address space distribution method. In the virtual PCI bridge traversal process, virtual end points are set under the downstream virtual PCI bridges where a connection end point device is not found, the virtual end points are added to the link of the downstream virtual PCI bridges to form the system topology structure including the virtual endpoints, fixed-interval subordinate peripheral address spaces are set for all the virtual PCI bridges under the system extension link so that the distributed address spaces of the effective end pointsaccessed to the downstream virtual PCI bridges are fixed regardless of change of the number, the type and the position of the system end points, and problems of unified programming difficulty causedby automatic distribution of the PCIe peripheral address and hidden troubles such as the system peripheral address access error and memory tampering are solved.

Description

technical field [0001] The invention belongs to the technical field of PCIe switch interface expansion, and in particular relates to a PCIe switch and an endpoint address space allocation method thereof. Background technique [0002] The PCIe bus is based on a point-to-point topology. Only a switch can be used to expand the PCIe link. The PCIe link extended through the switch can continue to be connected to EP (external equipment) or other switches. And each expansion of a PCIe link will generate a new PCIe bus number. Each PCIe device / bridge is numbered with a combination of bus number, device number, and function number, which is called endpoint ID information. Such as figure 1 As shown, the switch (Switch) in the system based on PCIe switch link extension can be regarded as a collection of virtual PCI bridge and virtual Bus, and the device is composed of one upstream port and multiple downstream ports. [0003] In a system with this architecture, if all devices use the...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a PCIe switch and its endpoint address space allocation method, which is used to solve the problems of unified programming difficulties caused by automatic allocation of PCIe peripheral addresses and hidden dangers such as system peripheral address access errors and memory tampering.

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