linux - 来自 lspci -xxxx 的 BAR 值

Question

我需要从 lspci -xxxx 的输出中提取 BAR 值。这是我的输出:

00:0d.0 SATA controller: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) SATA Controller [AHCI mode] (rev 02)
00: 86 80 29 28 07 00 10 00 02 01 06 01 00 40 00 00
10: 41 d2 00 00 49 d2 00 00 51 d2 00 00 59 d2 00 00
20: 61 d2 00 00 00 60 80 f0 00 00 00 00 00 00 00 00
30: 00 00 00 00 70 00 00 00 00 00 00 00 0b 01 00 00
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
70: 01 a8 03 00 00 00 00 00 00 00 00 00 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 40 00 3f 01 80 01 00 78 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 12 00 10 00 28 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

如果我理解PCI spec正确地，我的 BAR 值位于地址 0x10、0x14、0x18、0x1C、0x20 和 0x24。

然而，当我查看 lspci -vvvv

的输出时

00:0d.0 SATA controller: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) SATA Controller [AHCI mode] (rev 02) (prog-if 01 [AHCI 1.0])
    Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
    Latency: 64
    Interrupt: pin A routed to IRQ 21
    Region 0: I/O ports at d240 [size=8]
    Region 1: I/O ports at 0000
    Region 2: I/O ports at d250 [size=8]
    Region 3: I/O ports at 0000
    Region 4: I/O ports at d260 [size=16]
    Region 5: Memory at f0806000 (32-bit, non-prefetchable) [size=8K]
    Capabilities: [70] Power Management version 3
        Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
        Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
    Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000002
    Kernel driver in use: ahci

区域 5 与 lspci -xxxx 的输出中显示的值匹配。例如，地址 0x24 的值匹配 Region 5: Memory at f0806000。为什么区域 0 到区域 4 不匹配？ d240 [size=8] 处的 I/O 端口是什么意思

Answer 1

区域 0、2 和 4 实际上匹配。 I/O BAR 的低 2 位是标志位。特别是最低位，指定这些是 I/O 区域而不是内存区域。参见 http://wiki.osdev.org/PCI#Base_Address_Registers .

我无法解释区域 1 和区域 3 发生了什么。在我看来，它们应该显示为:

Region 1: I/O ports at d248
Region 3: I/O ports at d258

几乎可以肯定每个大小也是 8，但这实际上是动态确定的——通过将全 1 写入寄存器然后读回结果，所以不尝试就无法确定。

我想设备可能无法正确处理所有 1 都写入寄存器的情况，但这似乎有些牵强(如果那不起作用，地址已经分配给它们了) .

所以我不知道...可能是 lspci 中的错误？

I/O ports at d240 [size=8] 的含义是设备在“I/O 空间”(与内存空间相对)中支持长度为 8 的区域，并且该区域已分配基地址 0xd240。对于 I/O 空间，您使用“IN”和“OUT”指令而不是普通的内存加载/存储指令通过这些寄存器与设备通信。