[PATCH 2/2] arm-smmu: Add possibillity to mask streamIDs

[thommyj@gmail.com (Thommy Jakobsson)]

Use DT bindings to allow masks to be added for a masters streamIDs. This
is necessary for devices that have multiple IDs, or use dynamic signals to
build up the ID. For example the ZynqMPSoC that mirrors 6bits from the
AXI ID into the streamid.

Signed-off-by: Thommy Jakobsson <thommyj@gmail.com>
---
 drivers/iommu/arm-smmu.c | 46 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 9345a3f..14438f8 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -305,6 +305,7 @@ struct arm_smmu_smr {
 struct arm_smmu_master_cfg {
 	int				num_streamids;
 	u16				streamids[MAX_MASTER_STREAMIDS];
+	u16				streammasks[MAX_MASTER_STREAMIDS];
 	struct arm_smmu_smr		*smrs;
 };
 
@@ -554,6 +555,38 @@ static int register_smmu_master(struct arm_smmu_device *smmu,
 	return insert_smmu_master(smmu, master);
 }
 
+static int register_smmu_master_mask(struct arm_smmu_device *smmu,
+				     struct device *dev,
+				     struct of_phandle_args *masterspec)
+{
+	int i;
+	struct arm_smmu_master *master;
+
+	master = find_smmu_master(smmu, masterspec->np);
+	if (!master) {
+		dev_err(dev,
+			"mask phandle to %s, but no ID registred\n",
+			masterspec->np->name);
+		return -EINVAL;
+	}
+
+	if (masterspec->args_count != master->cfg.num_streamids) {
+		dev_err(dev,
+			"Different number of ids %d and masks %d not supported for master device %s\n",
+			master->cfg.num_streamids,
+			masterspec->args_count,
+			masterspec->np->name);
+		return -ENOSPC;
+	}
+
+	for (i = 0; i < master->cfg.num_streamids; ++i) {
+		u16 streammask = masterspec->args[i];
+
+		master->cfg.streamids[i] = streammask;
+	}
+	return 0;
+}
+
 static struct arm_smmu_device *find_smmu_for_device(struct device *dev)
 {
 	struct arm_smmu_device *smmu;
@@ -1106,7 +1139,7 @@ static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu,
 
 		smrs[i] = (struct arm_smmu_smr) {
 			.idx	= idx,
-			.mask	= 0, /* We don't currently share SMRs */
+			.mask	= cfg->streammasks[i],
 			.id	= cfg->streamids[i],
 		};
 	}
@@ -1972,6 +2005,17 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 
 	dev_notice(dev, "registered %d master devices\n", i);
 
+	while (!of_parse_phandle_with_args(dev->of_node, "mmu-masters-mask",
+					   "#stream-id-cells", i,
+					   &masterspec)) {
+		err = register_smmu_master_mask(smmu, dev, &masterspec);
+		if (err) {
+			dev_err(dev, "failed to add mask for%s\n",
+				masterspec.np->name);
+			goto out_put_masters;
+		}
+
+	}
 	kfree(masterspec);
 
 	parse_driver_options(smmu);
-- 
1.9.1