iommu/arm-smmu: Make use of phandle iterators in device-tree parsing

Remove the usage of of_parse_phandle_with_args() and replace
it by the phandle-iterator implementation so that we can
parse out all of the potentially present 128 stream-ids.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>

1 files changed, 30 insertions, 8 deletions

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 2409e3bd3df2..a1c965cdcfad 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -49,7 +49,7 @@
 #include "io-pgtable.h"
 
 /* Maximum number of stream IDs assigned to a single device */
-#define MAX_MASTER_STREAMIDS            MAX_PHANDLE_ARGS
+#define MAX_MASTER_STREAMIDS            128
 
 /* Maximum number of context banks per SMMU */
 #define ARM_SMMU_MAX_CBS                128
@@ -357,6 +357,12 @@ struct arm_smmu_domain {
         struct iommu_domain             domain;
 };
 
+struct arm_smmu_phandle_args {
+        struct device_node *np;
+        int args_count;
+        uint32_t args[MAX_MASTER_STREAMIDS];
+};
+
 static struct iommu_ops arm_smmu_ops;
 
 static DEFINE_SPINLOCK(arm_smmu_devices_lock);
@@ -466,7 +472,7 @@ static int insert_smmu_master(struct arm_smmu_device *smmu,
 
 static int register_smmu_master(struct arm_smmu_device *smmu,
                                 struct device *dev,
-                                struct of_phandle_args *masterspec)
+                                struct arm_smmu_phandle_args *masterspec)
 {
         int i;
         struct arm_smmu_master *master;
@@ -1737,7 +1743,8 @@ 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;
+        struct of_phandle_iterator it;
+        struct arm_smmu_phandle_args *masterspec;
         int num_irqs, i, err;
 
         smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
@@ -1798,20 +1805,35 @@ 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);
+
+        err = -ENOMEM;
+        /* No need to zero the memory for masterspec */
+        masterspec = kmalloc(sizeof(*masterspec), GFP_KERNEL);
+        if (!masterspec)
+                goto out_put_masters;
+
+        of_for_each_phandle(&it, err, dev->of_node,
+                            "mmu-masters", "#stream-id-cells", 0) {
+                int count = of_phandle_iterator_args(&it, masterspec->args,
+                                                     MAX_MASTER_STREAMIDS);
+                masterspec->np          = of_node_get(it.node);
+                masterspec->args_count  = count;
+
+                err = register_smmu_master(smmu, dev, masterspec);
                 if (err) {
                         dev_err(dev, "failed to add master %s\n",
-                                masterspec.np->name);
+                                masterspec->np->name);
+                        kfree(masterspec);
                         goto out_put_masters;
                 }
 
                 i++;
         }
+
         dev_notice(dev, "registered %d master devices\n", i);
 
+        kfree(masterspec);
+
         parse_driver_options(smmu);
 
         if (smmu->version > ARM_SMMU_V1 &&