从SMBIOS了解段组、总线、设备和功能编号

Question

目标

我正在尝试以编程方式找出特定PCIe设备连接在哪个物理插槽上。前提是我有一张卡的PCI-ID，该卡肯定正在占用一个插槽，解决方案是找出哪个卡。

请注意，我只对PCI Express总线上的工作感兴趣，尽管我认为设备标识/枚举过程与旧的PCI相同。

尝试

SMBIOS包含有关可用主板插槽的信息。可以从linux命令行检查此信息：

$ sudo dmidecode -t slot
# dmidecode 2.11
SMBIOS 2.7 present.

Handle 0x003A, DMI type 9, 17 bytes
System Slot Information
    Designation: PCIEX16_1
    Type: x16 PCI Express x16
    Current Usage: In Use
    Length: Short
    ID: 1
    Characteristics:
        3.3 V is provided
        Opening is shared
        PME signal is supported
    Bus Address: 0000:03:02.0

Handle 0x003B, DMI type 9, 17 bytes
System Slot Information
    Designation: PCIEX16_2
    Type: x8 PCI Express x8
    Current Usage: In Use
    Length: Short
    ID: 2
    Characteristics:
        3.3 V is provided
        Opening is shared
        PME signal is supported
    Bus Address: 0000:04:02.2

Handle 0x003C, DMI type 9, 17 bytes
System Slot Information
    Designation: PCIEX16_3
    Type: x16 PCI Express x16
    Current Usage: In Use
    Length: Short
    ID: 3
    Characteristics:
        3.3 V is provided
        Opening is shared
        PME signal is supported
    Bus Address: 0000:05:03.0

但是，我在PCI bus (lspci)中找不到任何PCI为0000:03:02.0、0000:04:02.2或0000:05:03.0的设备。我通过人工检查了解到的情况如下：

1. 卡0000:03:00.0位于第一个插槽中。PCI桥似乎位于第二个插槽中的0000:00:02.0
2. Card 0000:04:00.0。PCI桥似乎位于第三个插槽中的0000:00:02.2
3. Card 0000:05:00.0。PCI网桥显示为0000:00:03.0

。

所以这里出现了一种模式。从SMBIOS结构来看，总线编号是提供给插入的卡的总线编号，但设备/功能编号与相应的PCI网桥相同。

这种模式在我的主板上只是一个巧合，还是有其背后的原因？它是一块华硕主板，带有AMI BIOS。我读到过一些BIOSes不能提供关于它们插槽的准确信息，所以我想知道我能实现多大的通用性。

任何指向参考文档的提示或指针也是非常受欢迎的。

Answer 1

您可能会发现lspci命令很有帮助。以下是示例输出：

# lspci -v -t
-[0000:00]-+-00.0  Intel Corporation 5500 I/O Hub to ESI Port
           +-01.0-[01]--+-00.0  Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet
           |            \-00.1  Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet
           +-03.0-[02]--+-00.0  Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet
           |            \-00.1  Broadcom Corporation NetXtreme II BCM5709 Gigabit Ethernet
           +-07.0-[04]----00.0  LSI Logic / Symbios Logic MegaRAID SAS 2108 [Liberator]
           +-09.0-[05]----00.0  LSI Logic / Symbios Logic MegaRAID SAS 2108 [Liberator]
           +-14.0  Intel Corporation 7500/5520/5500/X58 I/O Hub System Management Registers
           +-14.1  Intel Corporation 7500/5520/5500/X58 I/O Hub GPIO and Scratch Pad Registers
           +-14.2  Intel Corporation 7500/5520/5500/X58 I/O Hub Control Status and RAS Registers
           +-1a.0  Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4
           +-1a.1  Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5
           +-1a.7  Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2
           +-1c.0-[03]----00.0  LSI Logic / Symbios Logic MegaRAID SAS 2108 [Liberator]
           +-1d.0  Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1
           +-1d.1  Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2
           +-1d.7  Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1
           +-1e.0-[06]----03.0  Matrox Electronics Systems Ltd. MGA G200eW WPCM450
           +-1f.0  Intel Corporation 82801IB (ICH9) LPC Interface Controller
           \-1f.2  Intel Corporation 82801IB (ICH9) 2 port SATA Controller [IDE mode]