On 08/03/17 18:58, Jean-Philippe Brucker wrote:
[...]
>> static const struct iommu_ops
>> -*of_pci_iommu_configure(struct pci_dev *pdev, struct device_node *bridge_np)
>> +*of_pci_iommu_init(struct pci_dev *pdev, struct device_node *bridge_np)
>> {
>> const struct iommu_ops *ops;
>> struct of_phandle_args iommu_spec;
>> + int err;
>>
>> /*
>> * Start by tracing the RID alias down the PCI topology as
>> @@ -123,56 +146,56 @@ static int __get_pci_rid(struct pci_dev *pdev, u16
>> alias, void *data)
>> * bus into the system beyond, and which IOMMU it ends up at.
>> */
>> iommu_spec.np = NULL;
>> - if (of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
>> - "iommu-map-mask", &iommu_spec.np, iommu_spec.args))
>> - return NULL;
>> + err = of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
>> + "iommu-map-mask", &iommu_spec.np,
>> + iommu_spec.args);
>> + if (err)
>> + return ERR_PTR(err);
>
> This change doesn't work with of_pci_map_rid when the PCI RC isn't behind
> an IOMMU:
>
> map = of_get_property(np, map_name, &map_len);
> if (!map) {
> if (target)
> return -ENODEV;
> /* Otherwise, no map implies no translation */
> *id_out = rid;
> return 0;
> }
>
> Previously with no iommu-map, we returned -ENODEV but it was discarded by
> of_pci_iommu_configure. Now it is propagated and the whole device probing
> fails. Instead, maybe of_pci_map_rid should always return 0 if no
> iommu-map, and the caller should check if *target is still NULL?
Ah yes, Tomasz had found breakages with the "mmu-masters" binding
before, and I'd already pushed out a fixup for this one[1], but I forgot
that that discussion was all off-list (out of diplomatic concern that
the breakage might have been intentional - it wasn't, honest!)
Now that rc1 is out I should re-do that branch with v8 of this series
plus the fixups folded in, unless Sricharan beats me to it.
Thanks for the reminder,
Robin.
[1]:http://www.linux-arm.org/git?p=linux-rm.git;a=commitdiff;h=0049a34e523506813995c05766f5e2c16d616354
>
> Thanks,
> Jean-Philippe
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