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

[Zhangfei Gao <zhangfei.gao@linaro.org>]

On 2020/5/25 下午9:43, 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