From 7f4c9176f760f4006af9f0863403f977a0bb3c52 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Thu, 12 Oct 2017 16:19:16 +0200 Subject: iommu/tegra: Allow devices to be grouped 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. Acked-by: Alex Williamson Signed-off-by: Thierry Reding --- drivers/iommu/tegra-smmu.c | 124 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 120 insertions(+), 4 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c index 3b6449e..8885635 100644 --- a/drivers/iommu/tegra-smmu.c +++ b/drivers/iommu/tegra-smmu.c @@ -20,6 +20,12 @@ #include #include +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) { -- cgit v1.1 From 83476bfaf6ac1cebf0cc5a3bdcf5031ef875cf42 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Wed, 20 Dec 2017 03:06:09 +0000 Subject: iommu/tegra-smmu: Fix return value check in tegra_smmu_group_get() In case of error, the function iommu_group_alloc() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR(). Fixes: 7f4c9176f760 ("iommu/tegra: Allow devices to be grouped") Signed-off-by: Wei Yongjun Acked-by: Alex Williamson Signed-off-by: Thierry Reding --- drivers/iommu/tegra-smmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c index 8885635..44d40bc 100644 --- a/drivers/iommu/tegra-smmu.c +++ b/drivers/iommu/tegra-smmu.c @@ -832,7 +832,7 @@ static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu, group->soc = soc; group->group = iommu_group_alloc(); - if (!group->group) { + if (IS_ERR(group->group)) { devm_kfree(smmu->dev, group); mutex_unlock(&smmu->lock); return NULL; -- cgit v1.1