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

From: Zhangfei Gao
Date: Tue May 26 2020 - 08:07:35 EST

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

+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

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