of: Factor arguments passed to of_map_id() into a struct

Change of_map_id() to take a pointer to struct of_phandle_args
instead of passing target device node and translated IDs separately.
Update all callers accordingly.

Add an explicit filter_np parameter to of_map_id() and of_map_msi_id()
to separate the filter input from the output. Previously, the target
parameter served dual purpose: as an input filter (if non-NULL, only
match entries targeting that node) and as an output (receiving the
matched node with a reference held). Now filter_np is the explicit
input filter and arg->np is the pure output.

Previously, of_map_id() would call of_node_put() on the matched node
when a filter was provided, making reference ownership inconsistent.
Remove this internal of_node_put() call so that of_map_id() now always
transfers ownership of the matched node reference to the caller via
arg->np. Callers are now consistently responsible for releasing this
reference with of_node_put(arg->np) when done.

Acked-by: Frank Li <Frank.Li@nxp.com>
Suggested-by: Rob Herring (Arm) <robh@kernel.org>
Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
Link: https://patch.msgid.link/20260603-parse_iommu_cells-v16-2-dc509dacb19a@oss.qualcomm.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

2 files changed, 63 insertions, 39 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index d936829ff2d2..69aa023399d2 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2131,36 +2131,40 @@ int of_find_last_cache_level(unsigned int cpu)
  * @id: device ID to map.
  * @map_name: property name of the map to use.
  * @map_mask_name: optional property name of the mask to use.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
+ * @filter_np: pointer to an optional filter node, or NULL to allow bypass.
+ *	If non-NULL, the map property must exist (-ENODEV if absent). If
+ *	*filter_np is also non-NULL, only entries targeting that node match.
+ * @arg: pointer to a &struct of_phandle_args for the result. On success,
+ *	@arg->args[0] will contain the translated ID. If a map entry was
+ *	matched, @arg->np will be set to the target node with a reference
+ *	held that the caller must release with of_node_put().
  *
  * Given a device ID, look up the appropriate implementation-defined
  * platform ID and/or the target device which receives transactions on that
- * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
- * @id_out may be NULL if only the other is required. If @target points to
- * a non-NULL device node pointer, only entries targeting that node will be
- * matched; if it points to a NULL value, it will receive the device node of
- * the first matching target phandle, with a reference held.
+ * ID, as per the "iommu-map" and "msi-map" bindings.
  *
  * Return: 0 on success or a standard error code on failure.
  */
 int of_map_id(const struct device_node *np, u32 id,
 	       const char *map_name, const char *map_mask_name,
-	       struct device_node **target, u32 *id_out)
+	       struct device_node * const *filter_np, struct of_phandle_args *arg)
 {
 	u32 map_mask, masked_id;
 	int map_len;
 	const __be32 *map = NULL;
 
-	if (!np || !map_name || (!target && !id_out))
+	if (!np || !map_name || !arg)
 		return -EINVAL;
+	/* Ensure bypass/no-match success never returns a stale target node. */
+	arg->np = NULL;
 
 	map = of_get_property(np, map_name, &map_len);
 	if (!map) {
-		if (target)
+		if (filter_np)
 			return -ENODEV;
 		/* Otherwise, no map implies no translation */
-		*id_out = id;
+		arg->args[0] = id;
+		arg->args_count = 1;
 		return 0;
 	}
 
@@ -2202,18 +2206,14 @@ int of_map_id(const struct device_node *np, u32 id,
 		if (!phandle_node)
 			return -ENODEV;
 
-		if (target) {
-			if (*target)
-				of_node_put(phandle_node);
-			else
-				*target = phandle_node;
-
-			if (*target != phandle_node)
-				continue;
+		if (filter_np && *filter_np && *filter_np != phandle_node) {
+			of_node_put(phandle_node);
+			continue;
 		}
 
-		if (id_out)
-			*id_out = masked_id - id_base + out_base;
+		arg->np = phandle_node;
+		arg->args[0] = masked_id - id_base + out_base;
+		arg->args_count = 1;
 
 		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
 			np, map_name, map_mask, id_base, out_base,
@@ -2222,11 +2222,11 @@ int of_map_id(const struct device_node *np, u32 id,
 	}
 
 	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
-		id, target && *target ? *target : NULL);
+		id, filter_np && *filter_np ? *filter_np : NULL);
 
 	/* Bypasses translation */
-	if (id_out)
-		*id_out = id;
+	arg->args[0] = id;
+	arg->args_count = 1;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_map_id);
@@ -2236,17 +2236,19 @@ EXPORT_SYMBOL_GPL(of_map_id);
  * @np: root complex device node.
  * @id: Requester ID of the device (e.g. PCI RID/BDF or a platform
  *      stream/device ID) used as the lookup key in the iommu-map table.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
+ * @arg: pointer to a &struct of_phandle_args for the result. On success,
+ *	@arg->args[0] contains the translated ID. If a map entry was matched,
+ *	@arg->np holds a reference to the target node that the caller must
+ *	release with of_node_put().
  *
  * Convenience wrapper around of_map_id() using "iommu-map" and "iommu-map-mask".
  *
  * Return: 0 on success or a standard error code on failure.
  */
 int of_map_iommu_id(const struct device_node *np, u32 id,
-		    struct device_node **target, u32 *id_out)
+		    struct of_phandle_args *arg)
 {
-	return of_map_id(np, id, "iommu-map", "iommu-map-mask", target, id_out);
+	return of_map_id(np, id, "iommu-map", "iommu-map-mask", NULL, arg);
 }
 EXPORT_SYMBOL_GPL(of_map_iommu_id);
 
@@ -2255,16 +2257,21 @@ EXPORT_SYMBOL_GPL(of_map_iommu_id);
  * @np: root complex device node.
  * @id: Requester ID of the device (e.g. PCI RID/BDF or a platform
  *      stream/device ID) used as the lookup key in the msi-map table.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
+ * @filter_np: pointer to an optional filter node, or NULL to allow bypass.
+ *	If non-NULL, the map property must exist (-ENODEV if absent). If
+ *	*filter_np is also non-NULL, only entries targeting that node match.
+ * @arg: pointer to a &struct of_phandle_args for the result. On success,
+ *	@arg->args[0] contains the translated ID. If a map entry was matched,
+ *	@arg->np holds a reference to the target node that the caller must
+ *	release with of_node_put().
  *
  * Convenience wrapper around of_map_id() using "msi-map" and "msi-map-mask".
  *
  * Return: 0 on success or a standard error code on failure.
  */
 int of_map_msi_id(const struct device_node *np, u32 id,
-		  struct device_node **target, u32 *id_out)
+		  struct device_node * const *filter_np, struct of_phandle_args *arg)
 {
-	return of_map_id(np, id, "msi-map", "msi-map-mask", target, id_out);
+	return of_map_id(np, id, "msi-map", "msi-map-mask", filter_np, arg);
 }
 EXPORT_SYMBOL_GPL(of_map_msi_id);
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index e37c1b3f8736..967c19100879 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -796,14 +796,15 @@ static int of_check_msi_parent(struct device_node *dev_node, struct device_node
 /**
  * of_msi_xlate - map a MSI ID and find relevant MSI controller node
  * @dev: device for which the mapping is to be done.
- * @msi_np: Pointer to target MSI controller node
+ * @msi_np: Pointer to target MSI controller node, or NULL if the caller
+ *           only needs the translated ID without receiving the controller node.
+ *           If non-NULL and pointing to a non-NULL node, only entries targeting
+ *           that node will be matched. If non-NULL and pointing to NULL, it will
+ *           receive the first matching target node with a reference held.
  * @id_in: Device ID.
  *
  * Walk up the device hierarchy looking for devices with a "msi-map"
  * or "msi-parent" property. If found, apply the mapping to @id_in.
- * If @msi_np points to a non-NULL device node pointer, only entries targeting
- * that node will be matched; if it points to a NULL value, it will receive the
- * device node of the first matching target phandle, with a reference held.
  *
  * Returns: The mapped MSI id.
  */
@@ -817,9 +818,22 @@ u32 of_msi_xlate(struct device *dev, struct device_node **msi_np, u32 id_in)
 	 * "msi-map" or an "msi-parent" property.
 	 */
 	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
-		if (!of_map_msi_id(parent_dev->of_node, id_in, msi_np, &id_out))
+		struct of_phandle_args msi_spec = {};
+
+		if (!of_map_msi_id(parent_dev->of_node, id_in, msi_np, &msi_spec)) {
+			if (msi_spec.np) {
+				/* msi-map matched: use the translated ID and target node */
+				if (msi_spec.args_count > 0)
+					id_out = msi_spec.args[0];
+				if (msi_np && !*msi_np)
+					*msi_np = of_node_get(msi_spec.np);
+				of_node_put(msi_spec.np);
+			}
+			/* msi-map present but no match → stop walking */
 			break;
-		if (!of_check_msi_parent(parent_dev->of_node, msi_np))
+		}
+		/* -ENODEV: msi-map absent → check for msi-parent */
+		if (msi_np && !of_check_msi_parent(parent_dev->of_node, msi_np))
 			break;
 	}
 	return id_out;
@@ -841,9 +855,12 @@ struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 id,
 						u32 bus_token)
 {
 	struct device_node *np = NULL;
+	struct irq_domain *d;
 
 	of_msi_xlate(dev, &np, id);
-	return irq_find_matching_host(np, bus_token);
+	d = irq_find_matching_host(np, bus_token);
+	of_node_put(np);
+	return d;
 }
 
 /**