[RFC 1/2] iommu: arm-smmu: Extract arm_smmu_of_parse()

[Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

This function will be subsequently used to extract stream ID information
early, before a struct device is available.

Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/iommu/arm-smmu.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index d1aef07bb784..5c5cf942077e 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1545,18 +1545,28 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
 	return ret;
 }
 
-static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
+static u32 arm_smmu_of_parse(struct device_node *np, const u32 *args,
+			     unsigned int count)
 {
-	u32 mask, fwid = 0;
+	u32 fwid = 0, mask;
 
-	if (args->args_count > 0)
-		fwid |= FIELD_PREP(SMR_ID, args->args[0]);
+	if (count > 0)
+		fwid |= FIELD_PREP(SMR_ID, args[0]);
 
-	if (args->args_count > 1)
-		fwid |= FIELD_PREP(SMR_MASK, args->args[1]);
-	else if (!of_property_read_u32(args->np, "stream-match-mask", &mask))
+	if (count > 1)
+		fwid |= FIELD_PREP(SMR_MASK, args[1]);
+	else if (!of_property_read_u32(np, "stream-match-mask", &mask))
 		fwid |= FIELD_PREP(SMR_MASK, mask);
 
+	return fwid;
+}
+
+static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
+{
+	u32 fwid;
+
+	fwid = arm_smmu_of_parse(args->np, args->args, args->args_count);
+
 	return iommu_fwspec_add_ids(dev, &fwid, 1);
 }
 
-- 
2.23.0