[PATCH 4/6] iommu/arm-smmu: implement generic DT bindings

Mitchel Humpherys
2014-08-13T00:51:37Z

Generic IOMMU device tree bindings were recently added in
["devicetree: Add generic IOMMU device tree bindings"]. Implement the
bindings in the ARM SMMU driver.

See Documentation/devicetree/bindings/iommu/iommu.txt for the bindings
themselves.

Signed-off-by: Mitchel Humpherys <mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
drivers/iommu/arm-smmu.c | 87 +++++++++++++++++++++++++++++++++++-------------
1 file changed, 64 insertions(+), 23 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 63c6707fad..22e25f3172 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -538,25 +538,32 @@ static int insert_smmu_master(struct arm_smmu_device *smmu,
return 0;
}

+struct iommus_entry {
+ struct list_head list;
+ struct device_node *node;
+ u16 streamids[MAX_MASTER_STREAMIDS];
+ int num_sids;
+};
+
static int register_smmu_master(struct arm_smmu_device *smmu,
- struct device *dev,
- struct of_phandle_args *masterspec)
+ struct iommus_entry *entry)
{
int i;
struct arm_smmu_master *master;
+ struct device *dev = smmu->dev;

- master = find_smmu_master(smmu, masterspec->np);
+ master = find_smmu_master(smmu, entry->node);
if (master) {
dev_err(dev,
"rejecting multiple registrations for master device %s\n",
- masterspec->np->name);
+ entry->node->name);
return -EBUSY;
}

- if (masterspec->args_count > MAX_MASTER_STREAMIDS) {
+ if (entry->num_sids > MAX_MASTER_STREAMIDS) {
dev_err(dev,
"reached maximum number (%d) of stream IDs for master device %s\n",
- MAX_MASTER_STREAMIDS, masterspec->np->name);
+ MAX_MASTER_STREAMIDS, entry->node->name);
return -ENOSPC;
}

@@ -564,15 +571,58 @@ static int register_smmu_master(struct arm_smmu_device *smmu,
if (!master)
return -ENOMEM;

- master->of_node = masterspec->np;
- master->cfg.num_streamids = masterspec->args_count;
+ master->of_node = entry->node;
+ master->cfg.num_streamids = entry->num_sids;

for (i = 0; i < master->cfg.num_streamids; ++i)
- master->cfg.streamids[i] = masterspec->args[i];
+ master->cfg.streamids[i] = entry->streamids[i];

return insert_smmu_master(smmu, master);
}

+static int arm_smmu_parse_iommus_properties(struct arm_smmu_device *smmu,
+ int *num_masters)
+{
+ struct of_phandle_args iommuspec;
+ struct device_node *dn;
+
+ for_each_node_with_property(dn, "iommus") {
+ int arg_ind = 0;
+ struct iommus_entry *entry, *n;
+ LIST_HEAD(iommus);
+
+ while (!of_parse_phandle_with_args(dn, "iommus", "#iommu-cells",
+ arg_ind, &iommuspec)) {
+ int i;
+
+ list_for_each_entry(entry, &iommus, list)
+ if (entry->node == dn)
+ break;
+ if (&entry->list == &iommus) {
+ entry = devm_kzalloc(smmu->dev, sizeof(*entry),
+ GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+ entry->node = dn;
+ list_add(&entry->list, &iommus);
+ }
+ entry->num_sids = iommuspec.args_count;
+ for (i = 0; i < entry->num_sids; ++i)
+ entry->streamids[i] = iommuspec.args[i];
+ arg_ind++;
+ }
+
+ list_for_each_entry_safe(entry, n, &iommus, list) {
+ register_smmu_master(smmu, entry);
+ (*num_masters)++;
+ list_del(&entry->list);
+ devm_kfree(smmu->dev, entry);
+ }
+ }
+
+ return 0;
+}
+
static struct arm_smmu_device *find_smmu_for_device(struct device *dev)
{
struct arm_smmu_device *smmu;
@@ -2196,8 +2246,7 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
struct arm_smmu_device *smmu;
struct device *dev = &pdev->dev;
struct rb_node *node;
- struct of_phandle_args masterspec;
- int num_irqs, i, err;
+ int num_irqs, i, err, num_masters;

smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
if (!smmu) {
@@ -2251,19 +2300,11 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)

i = 0;
smmu->masters = RB_ROOT;
- while (!of_parse_phandle_with_args(dev->of_node, "mmu-masters",
- "#stream-id-cells", i,
- &masterspec)) {
- err = register_smmu_master(smmu, dev, &masterspec);
- if (err) {
- dev_err(dev, "failed to add master %s\n",
- masterspec.np->name);
- goto out_put_masters;
- }
+ err = arm_smmu_parse_iommus_properties(smmu, &num_masters);
+ if (err)
+ goto out_put_masters;

- i++;
- }
- dev_notice(dev, "registered %d master devices\n", i);
+ dev_notice(dev, "registered %d master devices\n", num_masters);

err = arm_smmu_init_regulators(smmu);
if (err)