[PATCH v1 2/2] iommu/tegra-smmu: Revert workaround that was needed for Nyan Big Chromebook

Dmitry Osipenko
2021-03-28T23:34:44Z

The previous commit fixes problem where display client was attaching too
early to IOMMU during kernel boot in a multi-platform kernel configuration
which enables CONFIG_ARM_DMA_USE_IOMMU=y. The workaround that helped to
defer the IOMMU attachment for Nyan Big Chromebook isn't needed anymore,
revert it.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/iommu/tegra-smmu.c | 71 +-------------------------------------
1 file changed, 1 insertion(+), 70 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index af1e4b5adb27..572a4544ae88 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -869,69 +869,10 @@ static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
return SMMU_PFN_PHYS(pfn) + SMMU_OFFSET_IN_PAGE(iova);
}

-static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
-{
- struct platform_device *pdev;
- struct tegra_mc *mc;
-
- pdev = of_find_device_by_node(np);
- if (!pdev)
- return NULL;
-
- mc = platform_get_drvdata(pdev);
- if (!mc)
- return NULL;
-
- 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 struct iommu_device *tegra_smmu_probe_device(struct device *dev)
{
- struct device_node *np = dev->of_node;
- struct tegra_smmu *smmu = NULL;
- struct of_phandle_args args;
- unsigned int index = 0;
- int err;
-
- while (of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
- &args) == 0) {
- smmu = tegra_smmu_find(args.np);
- if (smmu) {
- err = tegra_smmu_configure(smmu, dev, &args);
-
- if (err < 0) {
- of_node_put(args.np);
- return ERR_PTR(err);
- }
- }
-
- of_node_put(args.np);
- index++;
- }
+ struct tegra_smmu *smmu = dev_iommu_priv_get(dev);

- smmu = dev_iommu_priv_get(dev);
if (!smmu)
return ERR_PTR(-ENODEV);

@@ -1158,16 +1099,6 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
if (!smmu)
return ERR_PTR(-ENOMEM);

- /*
- * This is a bit of a hack. Ideally we'd want to simply return this
- * value. However the IOMMU registration process will attempt to add
- * all devices to the IOMMU when bus_set_iommu() is called. In order
- * not to rely on global variables to track the IOMMU instance, we
- * set it here so that it can be looked up from the .probe_device()
- * callback via the IOMMU device's .drvdata field.
- */
- mc->smmu = smmu;
-
size = BITS_TO_LONGS(soc->num_asids) * sizeof(long);

smmu->asids = devm_kzalloc(dev, size, GFP_KERNEL);
--
2.30.2