在 2022/9/27 PM6:04, Jonathan Cameron 写道: > On Tue, 27 Sep 2022 13:13:29 +0800 > Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx> wrote: > >> 在 2022/9/27 AM1:18, Bjorn Helgaas 写道: >>> On Mon, Sep 26, 2022 at 09:31:34PM +0800, Shuai Xue wrote: >>>> 在 2022/9/23 PM11:54, Jonathan Cameron 写道: >>>>>> I found a similar definition in arch/ia64/pci/pci.c . >>>>>> >>>>>> #define PCI_SAL_ADDRESS(seg, bus, devfn, reg) \ >>>>>> (((u64) seg << 24) | (bus << 16) | (devfn << 8) | (reg)) >>>>>> >>>>>> Should we move it into a common header first? >>>>> >>>>> Maybe. The bus, devfn, reg part is standard bdf, but I don't think >>>>> the PCI 6.0 spec defined a version with the seg in the upper bits. >>>>> I'm not sure if we want to adopt that in LInux. >>>> >>>> I found lots of code use seg,bus,devfn,reg with format "%04x:%02x:%02x.%x", >>>> I am not quite familiar with PCIe spec. What do you think about it, Bjorn? >>> >>> The PCIe spec defines an address encoding for bus/device/function/reg >>> for the purposes of ECAM (PCIe r6.0, sec 7.2.2), but as far as I know, >>> it doesn't define anything similar that includes the segment. The >>> segment is really outside the scope of PCIe because each segment is a >>> completely separate PCIe hierarchy. >> >> Thank you for your explanation. >> >>> >>> So I probably wouldn't make this a generic definition. But if/when >>> you print things like this out, please do use the format spec you >>> mentioned above so it matches the style used elsewhere. >>> >> >> Agree. The print format of bus/device/function/reg is "%04x:%02x:%02x.%x", >> so I named the PMU as the same format. Then the usage flow would be: >> >> - lspci to get the device root port in format seg/bus/device/function/reg. >> 10:00.0 PCI bridge: Device 1ded:8000 (rev 01) >> - select its PMU name pcie_bdf_100000. >> - monitor with perf: >> perf stat -a -e pcie_bdf_100000/Rx_PCIe_TLP_Data_Payload/ > > I think you probably want something in there to indicate it's an RP > and the bdf part may be redundant... Yes, I realized that the prefix `pcie_bdf` is not appropriate. Let's discuss with Robin in his thread. Thank you. Best Regards, Shuai
