Messages in this thread | | | Subject | Re: [PATCH 0/2] Let pci_fixup_final access iommu_fwnode | From | Zhangfei Gao <> | Date | Fri, 22 May 2020 10:13:11 +0800 |
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Hi, Joerg
On 2020/5/12 下午12:08, 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); > > > Zhangfei Gao (2): > iommu/of: Let pci_fixup_final access iommu_fwnode > ACPI/IORT: Let pci_fixup_final access iommu_fwnode > > drivers/acpi/arm64/iort.c | 1 + > drivers/iommu/of_iommu.c | 1 + > 2 files changed, 2 insertions(+) > Would you mind give any suggestion?
We need access fwspec->can_stall describing the platform device (a fake pcie) can support stall feature. can_stall will be used arm_smmu_add_device [1]. And stall is not a pci feature, so no such member in struct pci_dev.
iommu_fwnode is allocated in iommu_fwspec_init, from of_pci_iommu_init or iort_pci_iommu_init. The pci_fixup_device(pci_fixup_final, dev) in pci_bus_add_device is too early that iommu_fwnode is not allocated. The pci_fixup_device(pci_fixup_enable, dev) in do_pci_enable_device is too late after
arm_smmu_add_device.
So the idea here is calling pci_fixup_device(pci_fixup_final) after of_pci_iommu_init and iort_pci_iommu_init, where iommu_fwnode is allocated.
[1] https://www.spinics.net/lists/linux-pci/msg94559.html
Thanks
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