Hi Robin,
Very sorry about the delay, I forgot about this minor comment, below
On Fri, Jul 01, 2016 at 05:50:15PM +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>
> ---
>
> v4: Add explicit device probe in of_init callback.
>
> drivers/iommu/arm-smmu-v3.c | 278 +++++++++++++++++++-------------------------
> 1 file changed, 121 insertions(+), 157 deletions(-)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 94b68213c50d..fb438664b9f0 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
[...]
> @@ -1800,94 +1752,74 @@ static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
> return sid < limit;
> }
>
> +static struct iommu_ops arm_smmu_ops;
> +
> 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;
It's probably best to initialise master->ste.bypass = true here, to
reflect the initial state of STEs. Otherwise attach_dev always calls
detach_dev first for nothing.
Apart from that, this version works fine with my twisted setup. Note
that we might have to add a master->fwspec reference in the future, to
access those SIDs from various places. If I understood correctly, it
should be fine as those objects have the same lifetime after the
add_device call.
Thanks,
Jean-Philippe
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