On Mon, 27 Nov 2017 10:50:54 +0100
Thierry Reding <thierry.reding@xxxxxxxxx> wrote:
> From: Thierry Reding <treding@xxxxxxxxxx>
>
> Implement the ->device_group() and ->of_xlate() callbacks which are used
> in order to group devices. Each group can then share a single domain.
>
> This is implemented primarily in order to achieve the same semantics on
> Tegra210 and earlier as on Tegra186 where the Tegra SMMU was replaced by
> an ARM SMMU. Users of the IOMMU API can now use the same code to share
> domains between devices, whereas previously they used to attach each
> device individually.
>
> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> ---
> drivers/iommu/tegra-smmu.c | 124 +++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 120 insertions(+), 4 deletions(-)
Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
>
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index 3b6449e2cbf1..8885635d0a3b 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -20,6 +20,12 @@
> #include <soc/tegra/ahb.h>
> #include <soc/tegra/mc.h>
>
> +struct tegra_smmu_group {
> + struct list_head list;
> + const struct tegra_smmu_group_soc *soc;
> + struct iommu_group *group;
> +};
> +
> struct tegra_smmu {
> void __iomem *regs;
> struct device *dev;
> @@ -27,6 +33,8 @@ struct tegra_smmu {
> struct tegra_mc *mc;
> const struct tegra_smmu_soc *soc;
>
> + struct list_head groups;
> +
> unsigned long pfn_mask;
> unsigned long tlb_mask;
>
> @@ -703,19 +711,47 @@ static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
> return mc->smmu;
> }
>
> +static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
> + struct of_phandle_args *args)
> +{
> + const struct iommu_ops *ops = smmu->iommu.ops;
> + int err;
> +
> + err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
> + if (err < 0) {
> + dev_err(dev, "failed to initialize fwspec: %d\n", err);
> + return err;
> + }
> +
> + err = ops->of_xlate(dev, args);
> + if (err < 0) {
> + dev_err(dev, "failed to parse SW group ID: %d\n", err);
> + iommu_fwspec_free(dev);
> + return err;
> + }
> +
> + return 0;
> +}
> +
> static int tegra_smmu_add_device(struct device *dev)
> {
> struct device_node *np = dev->of_node;
> + struct tegra_smmu *smmu = NULL;
> struct iommu_group *group;
> struct of_phandle_args args;
> unsigned int index = 0;
> + int err;
>
> while (of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
> &args) == 0) {
> - struct tegra_smmu *smmu;
> -
> smmu = tegra_smmu_find(args.np);
> if (smmu) {
> + err = tegra_smmu_configure(smmu, dev, &args);
> + of_node_put(args.np);
> +
> + if (err < 0)
> + return err;
> +
> /*
> * Only a single IOMMU master interface is currently
> * supported by the Linux kernel, so abort after the
> @@ -728,9 +764,13 @@ static int tegra_smmu_add_device(struct device *dev)
> break;
> }
>
> + of_node_put(args.np);
> index++;
> }
>
> + if (!smmu)
> + return -ENODEV;
> +
> group = iommu_group_get_for_dev(dev);
> if (IS_ERR(group))
> return PTR_ERR(group);
> @@ -751,6 +791,80 @@ static void tegra_smmu_remove_device(struct device *dev)
> iommu_group_remove_device(dev);
> }
>
> +static const struct tegra_smmu_group_soc *
> +tegra_smmu_find_group(struct tegra_smmu *smmu, unsigned int swgroup)
> +{
> + unsigned int i, j;
> +
> + for (i = 0; i < smmu->soc->num_groups; i++)
> + for (j = 0; j < smmu->soc->groups[i].num_swgroups; j++)
> + if (smmu->soc->groups[i].swgroups[j] == swgroup)
> + return &smmu->soc->groups[i];
> +
> + return NULL;
> +}
> +
> +static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu,
> + unsigned int swgroup)
> +{
> + const struct tegra_smmu_group_soc *soc;
> + struct tegra_smmu_group *group;
> +
> + soc = tegra_smmu_find_group(smmu, swgroup);
> + if (!soc)
> + return NULL;
> +
> + mutex_lock(&smmu->lock);
> +
> + list_for_each_entry(group, &smmu->groups, list)
> + if (group->soc == soc) {
> + mutex_unlock(&smmu->lock);
> + return group->group;
> + }
> +
> + group = devm_kzalloc(smmu->dev, sizeof(*group), GFP_KERNEL);
> + if (!group) {
> + mutex_unlock(&smmu->lock);
> + return NULL;
> + }
> +
> + INIT_LIST_HEAD(&group->list);
> + group->soc = soc;
> +
> + group->group = iommu_group_alloc();
> + if (!group->group) {
> + devm_kfree(smmu->dev, group);
> + mutex_unlock(&smmu->lock);
> + return NULL;
> + }
> +
> + list_add_tail(&group->list, &smmu->groups);
> + mutex_unlock(&smmu->lock);
> +
> + return group->group;
> +}
> +
> +static struct iommu_group *tegra_smmu_device_group(struct device *dev)
> +{
> + struct iommu_fwspec *fwspec = dev->iommu_fwspec;
> + struct tegra_smmu *smmu = dev->archdata.iommu;
> + struct iommu_group *group;
> +
> + group = tegra_smmu_group_get(smmu, fwspec->ids[0]);
> + if (!group)
> + group = generic_device_group(dev);
> +
> + return group;
> +}
> +
> +static int tegra_smmu_of_xlate(struct device *dev,
> + struct of_phandle_args *args)
> +{
> + u32 id = args->args[0];
> +
> + return iommu_fwspec_add_ids(dev, &id, 1);
> +}
> +
> static const struct iommu_ops tegra_smmu_ops = {
> .capable = tegra_smmu_capable,
> .domain_alloc = tegra_smmu_domain_alloc,
> @@ -759,12 +873,12 @@ static const struct iommu_ops tegra_smmu_ops = {
> .detach_dev = tegra_smmu_detach_dev,
> .add_device = tegra_smmu_add_device,
> .remove_device = tegra_smmu_remove_device,
> - .device_group = generic_device_group,
> + .device_group = tegra_smmu_device_group,
> .map = tegra_smmu_map,
> .unmap = tegra_smmu_unmap,
> .map_sg = default_iommu_map_sg,
> .iova_to_phys = tegra_smmu_iova_to_phys,
> -
> + .of_xlate = tegra_smmu_of_xlate,
> .pgsize_bitmap = SZ_4K,
> };
>
> @@ -913,6 +1027,7 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
> if (!smmu->asids)
> return ERR_PTR(-ENOMEM);
>
> + INIT_LIST_HEAD(&smmu->groups);
> mutex_init(&smmu->lock);
>
> smmu->regs = mc->regs;
> @@ -954,6 +1069,7 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
> return ERR_PTR(err);
>
> iommu_device_set_ops(&smmu->iommu, &tegra_smmu_ops);
> + iommu_device_set_fwnode(&smmu->iommu, dev->fwnode);
>
> err = iommu_device_register(&smmu->iommu);
> if (err) {
--
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