On Tue, Jun 28, 2016 at 04:48:26PM +0100, Robin Murphy wrote:
> Now that we can properly describe the mapping between PCI RIDs and
> stream IDs via "iommu-map", and have it fed it to the driver
> automatically via of_xlate(), rework the SMMUv3 driver to benefit from
> that, and get rid of the current misuse of the "iommus" binding.
>
> Since having of_xlate wired up means that masters will now be given the
> appropriate DMA ops, we also need to make sure that default domains work
> properly. This necessitates dispensing with the "whole group at a time"
> notion for attaching to a domain, as devices which share a group get
> attached to the group's default domain one by one as they are initially
> probed.
>
> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
> ---
[...]
> static int arm_smmu_add_device(struct device *dev)
> {
> int i, ret;
> - u32 sid, *sids;
> - struct pci_dev *pdev;
> - struct iommu_group *group;
> - struct arm_smmu_group *smmu_group;
> struct arm_smmu_device *smmu;
> + struct arm_smmu_master_data *master;
> + struct iommu_fwspec *fwspec = dev_iommu_fwspec(dev);
> + struct iommu_group *group;
>
> - /* We only support PCI, for now */
> - if (!dev_is_pci(dev))
> + if (!fwspec || fwspec->iommu_ops != &arm_smmu_ops)
> return -ENODEV;
> -
> - pdev = to_pci_dev(dev);
> - group = iommu_group_get_for_dev(dev);
> - if (IS_ERR(group))
> - return PTR_ERR(group);
> -
> - smmu_group = iommu_group_get_iommudata(group);
> - if (!smmu_group) {
> - smmu = arm_smmu_get_for_pci_dev(pdev);
> - if (!smmu) {
> - ret = -ENOENT;
> - goto out_remove_dev;
> - }
> -
> - smmu_group = kzalloc(sizeof(*smmu_group), GFP_KERNEL);
> - if (!smmu_group) {
> - ret = -ENOMEM;
> - goto out_remove_dev;
> - }
> -
> - smmu_group->ste.valid = true;
> - smmu_group->smmu = smmu;
> - iommu_group_set_iommudata(group, smmu_group,
> - __arm_smmu_release_pci_iommudata);
> + /*
> + * We _can_ actually withstand dodgy bus code re-calling add_device()
> + * without an intervening remove_device()/of_xlate() sequence, but
> + * we're not going to do so quietly...
> + */
> + if (WARN_ON_ONCE(fwspec->iommu_priv)) {
> + master = fwspec->iommu_priv;
> + smmu = master->smmu;
> } else {
> - smmu = smmu_group->smmu;
> + smmu = arm_smmu_get_by_node(fwspec->iommu_np);
> + if (!smmu)
> + return -ENODEV;
> + master = kzalloc(sizeof(*master), GFP_KERNEL);
> + if (!master)
> + return -ENOMEM;
> +
> + master->smmu = smmu;
> + fwspec->iommu_priv = master;
> }
>
> - /* Assume SID == RID until firmware tells us otherwise */
> - pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid, &sid);
> - for (i = 0; i < smmu_group->num_sids; ++i) {
> - /* If we already know about this SID, then we're done */
> - if (smmu_group->sids[i] == sid)
> - goto out_put_group;
> + /* Check the SIDs are in range of the SMMU and our stream table */
> + for (i = 0; i < fwspec->num_ids; i++) {
> + u32 sid = fwspec->ids[i];
> +
> + if (!arm_smmu_sid_in_range(smmu, sid))
> + return -ERANGE;
> +
> + /* Ensure l2 strtab is initialised */
> + if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
> + ret = arm_smmu_init_l2_strtab(smmu, sid);
> + if (ret)
> + return ret;
> + }
> }
Do you not need to do some cleanup here, rather than just returning (same
for the -ERANGE above)? For example, freeing the master?
Will
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