Re: [RESEND PATCH V2 5/6] perf/x86/intel/uncore: Generic support for the PCI sub driver

From: Bjorn Helgaas
Date: Mon Sep 21 2020 - 18:19:31 EST

On Mon, Sep 14, 2020 at 07:34:19AM -0700, kan.liang@xxxxxxxxxxxxxxx wrote:
> From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
> Some uncore counters may be located in the configuration space of a PCI
> device, which already has a bonded driver. Currently, the uncore driver
> cannot register a PCI uncore PMU for these counters, because, to
> register a PCI uncore PMU, the uncore driver must be bond to the device.
> However, one device can only have one bonded driver.
> Add an uncore PCI sub driver to support such kind of devices.
> The sub driver doesn't own the device. In initialization, the sub
> driver searches the device via pci_get_device(), and register the
> corresponding PMU for the device. In the meantime, the sub driver
> registeris a PCI bus notifier, which is used to notify the sub driver
> once the device is removed. The sub driver can unregister the PMU
> accordingly.


It looks like this only handles hot-remove of the device, not hot-add.
Maybe that's OK for your use case, I dunno, so just pointing it out.