[LinuxBIOS] The device number of PCIe

[Feng, Libo]

Hi, all,

In PCI, the IDSEL pin defines the device number. But in PCIe, there is no such pin, how is the device number defined?

Best Regards

丰立波 Feng Libo @ AMD  Ext: 20906
Mobile Phone: [phone]
Office Phone: [phone]

[Rudolf Marek]

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> In PCI, the IDSEL pin defines the device number. But in PCIe, there is
> no such pin, how is the device number defined?

Imho for each slot there is PCI-PCI bridge.

00:02.0 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller
00:03.0 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller
00:03.1 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller
00:03.2 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller
00:03.3 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller

You can turn on/off in the bridge if the bridge decodes just one address -
otherwise you will see it as all devices possible behind the bridge. xx:00-xx:31

Thats all I know. :) Maybe you can take a look to PCIe express specs.

Rudolf
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[Ed Swierk]

On 1/6/08, Feng, Libo  wrote:
> In PCI, the IDSEL pin defines the device number. But in PCIe, there is no
> such pin, how is the device number defined?

"Each PCI Express Link is equivalent to a logical PCI bus. In other
words, each Link is assigned a bus number by the bus enumerating
software. A PCI Express endpoint is device 0 on a PCI Express Link of
a given bus number. Only one device (device 0) exists per PCI Express
Link."

-- PCI Express System Architecture, p. 51

--Ed