iommu/tegra-smmu: Use fwspec in tegra_smmu_(de)attach_dev

In tegra_smmu_(de)attach_dev() functions, we poll DTB for each
client's iommus property to get swgroup ID in order to prepare
"as" and enable smmu. Actually tegra_smmu_configure() prepared
an fwspec for each client, and added to the fwspec all swgroup
IDs of client DT node in DTB.

So this patch uses fwspec in tegra_smmu_(de)attach_dev() so as
to replace the redundant DT polling code.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20201125101013.14953-4-nicoleotsuka@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 6a3ecc3..297d49f 100644 (file)
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -484,60 +484,50 @@ static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu,
 static int tegra_smmu_attach_dev(struct iommu_domain *domain,
                                 struct device *dev)
 {
+       struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
        struct tegra_smmu *smmu = dev_iommu_priv_get(dev);
        struct tegra_smmu_as *as = to_smmu_as(domain);
-       struct device_node *np = dev->of_node;
-       struct of_phandle_args args;
-       unsigned int index = 0;
-       int err = 0;
-
-       while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
-                                          &args)) {
-               unsigned int swgroup = args.args[0];
-
-               if (args.np != smmu->dev->of_node) {
-                       of_node_put(args.np);
-                       continue;
-               }
+       unsigned int index;
+       int err;
 
-               of_node_put(args.np);
+       if (!fwspec)
+               return -ENOENT;
 
+       for (index = 0; index < fwspec->num_ids; index++) {
                err = tegra_smmu_as_prepare(smmu, as);
-               if (err < 0)
-                       return err;
+               if (err)
+                       goto disable;
 
-               tegra_smmu_enable(smmu, swgroup, as->id);
-               index++;
+               tegra_smmu_enable(smmu, fwspec->ids[index], as->id);
        }
 
        if (index == 0)
                return -ENODEV;
 
        return 0;
+
+disable:
+       while (index--) {
+               tegra_smmu_disable(smmu, fwspec->ids[index], as->id);
+               tegra_smmu_as_unprepare(smmu, as);
+       }
+
+       return err;
 }
 
 static void tegra_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
 {
+       struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
        struct tegra_smmu_as *as = to_smmu_as(domain);
-       struct device_node *np = dev->of_node;
        struct tegra_smmu *smmu = as->smmu;
-       struct of_phandle_args args;
-       unsigned int index = 0;
-
-       while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
-                                          &args)) {
-               unsigned int swgroup = args.args[0];
+       unsigned int index;
 
-               if (args.np != smmu->dev->of_node) {
-                       of_node_put(args.np);
-                       continue;
-               }
-
-               of_node_put(args.np);
+       if (!fwspec)
+               return;
 
-               tegra_smmu_disable(smmu, swgroup, as->id);
+       for (index = 0; index < fwspec->num_ids; index++) {
+               tegra_smmu_disable(smmu, fwspec->ids[index], as->id);
                tegra_smmu_as_unprepare(smmu, as);
-               index++;
        }
 }