Re: [PATCH 0/2] Let pci_fixup_final access iommu_fwnode

[Zhangfei Gao]

On 2020/5/25 äå9:43, Joerg Roedel wrote:
> On Tue, May 12, 2020 at 12:08:29PM +0800, Zhangfei Gao wrote:
> > Some platform devices appear as PCI but are
> > actually on the AMBA bus, and they need fixup in
> > drivers/pci/quirks.c handling iommu_fwnode.
> > So calling pci_fixup_final after iommu_fwnode is allocated.
> >
> > For example:
> > Hisilicon platform device need fixup in
> > drivers/pci/quirks.c
> >
> > +static void quirk_huawei_pcie_sva(struct pci_dev *pdev)
> > +{
> > +	struct iommu_fwspec *fwspec;
> > +
> > +	pdev->eetlp_prefix_path = 1;
> > +	fwspec = dev_iommu_fwspec_get(&pdev->dev);
> > +	if (fwspec)
> > +		fwspec->can_stall = 1;
> > +}
> > +
> > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa250, quirk_huawei_pcie_sva);
> > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa251, quirk_huawei_pcie_sva);
> I don't think it is a great idea to hook this into PCI_FIXUP_FINAL. The
> fixup list needs to be processed for every device, which will slow down
> probing.
>
> So either we introduce something like PCI_FIXUP_IOMMU, if this is
> entirely PCI specific. If it needs to be generic we need some fixup
> infrastructure in the IOMMU code itself.

Thanks Joerg for the good suggestion.
I am trying to introduce PCI_FIXUP_IOMMU in
https://lkml.org/lkml/2020/5/26/366

Thanks