Re: [PATCH 00/14] iommu: Move iommu_fwspec out of 'struct device'

From: Joerg Roedel
Date: Mon Mar 09 2020 - 12:32:07 EST


Hi Jean-Philippe,

On Fri, Mar 06, 2020 at 11:09:55AM +0100, Jean-Philippe Brucker wrote:
> I think that's because patch 01/14 move the fwspec access too early. In
>
> err = pci_for_each_dma_alias(to_pci_dev(dev),
> iort_pci_iommu_init, &info);
>
> if (!err && iort_pci_rc_supports_ats(node))
> dev->iommu_fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
>
> the iommu_fwspec is only valid if iort_pci_iommu_init() initialized it
> successfully, if err == 0. The following might fix it:
>
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 0e981d7f3c7d..7d04424189df 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -1015,7 +1015,7 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
> return ops;
>
> if (dev_is_pci(dev)) {
> - struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> + struct iommu_fwspec *fwspec;
> struct pci_bus *bus = to_pci_dev(dev)->bus;
> struct iort_pci_alias_info info = { .dev = dev };
>
> @@ -1028,7 +1028,8 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
> err = pci_for_each_dma_alias(to_pci_dev(dev),
> iort_pci_iommu_init, &info);
>
> - if (!err && iort_pci_rc_supports_ats(node))
> + fwspec = dev_iommu_fwspec_get(dev);
> + if (fwspec && iort_pci_rc_supports_ats(node))
> fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
> } else {
> int i = 0;

Thanks a lot for the fix! I added it to patch 1/14.

Regards,

Joerg