[PATCH v4 1/3] iommu/tegra-smmu: Use fwspec in tegra_smmu_(de)attach_dev

From: Nicolin Chen
Date: Fri Oct 02 2020 - 02:15:12 EST


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@xxxxxxxxx>
---

Changelog
v3->v4:
* Seperated the change, as a cleanup, from the rework patch
v1->v3:
* N/A

drivers/iommu/tegra-smmu.c | 50 +++++++++++++++-----------------------
1 file changed, 20 insertions(+), 30 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 6a3ecc334481..a573a5151c69 100644
--- 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;
- }
-
- 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];
-
- 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++;
}
}

--
2.17.1