1 files changed, 292 insertions, 159 deletions

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index a296eaf52a5b..e3816819dbfe 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -16,6 +16,7 @@
 
 #define pr_fmt(fmt)	"OF: " fmt
 
+#include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/list.h>
@@ -25,6 +26,8 @@
 #include <linux/string.h>
 #include <linux/slab.h>
 
+#include "of_private.h"
+
 /**
  * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
  * @dev: Device node of the device whose interrupt is to be mapped
@@ -36,11 +39,15 @@
 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 {
 	struct of_phandle_args oirq;
+	unsigned int ret;
 
 	if (of_irq_parse_one(dev, index, &oirq))
 		return 0;
 
-	return irq_create_of_mapping(&oirq);
+	ret = irq_create_of_mapping(&oirq);
+	of_node_put(oirq.np);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 
@@ -48,8 +55,8 @@ EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
  * of_irq_find_parent - Given a device node, find its interrupt parent node
  * @child: pointer to device node
  *
- * Returns a pointer to the interrupt parent node, or NULL if the interrupt
- * parent could not be determined.
+ * Return: A pointer to the interrupt parent node with refcount increased
+ * or NULL if the interrupt parent could not be determined.
  */
 struct device_node *of_irq_find_parent(struct device_node *child)
 {
@@ -76,28 +83,104 @@ struct device_node *of_irq_find_parent(struct device_node *child)
 }
 EXPORT_SYMBOL_GPL(of_irq_find_parent);
 
+/*
+ * These interrupt controllers abuse interrupt-map for unspeakable
+ * reasons and rely on the core code to *ignore* it (the drivers do
+ * their own parsing of the property). The PAsemi entry covers a
+ * non-sensical interrupt-map that is better left ignored.
+ *
+ * If you think of adding to the list for something *new*, think
+ * again. There is a high chance that you will be sent back to the
+ * drawing board.
+ */
+static const char * const of_irq_imap_abusers[] = {
+	"CBEA,platform-spider-pic",
+	"sti,platform-spider-pic",
+	"realtek,rtl-intc",
+	"fsl,ls1021a-extirq",
+	"fsl,ls1043a-extirq",
+	"fsl,ls1088a-extirq",
+	"renesas,rza1-irqc",
+	"pasemi,rootbus",
+	NULL,
+};
+
+const __be32 *of_irq_parse_imap_parent(const __be32 *imap, int len, struct of_phandle_args *out_irq)
+{
+	u32 intsize, addrsize;
+	struct device_node *np;
+
+	/* Get the interrupt parent */
+	if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+		np = of_node_get(of_irq_dflt_pic);
+	else
+		np = of_find_node_by_phandle(be32_to_cpup(imap));
+	imap++;
+	len--;
+
+	/* Check if not found */
+	if (!np) {
+		pr_debug(" -> imap parent not found !\n");
+		return NULL;
+	}
+
+	/* Get #interrupt-cells and #address-cells of new parent */
+	if (of_property_read_u32(np, "#interrupt-cells",
+					&intsize)) {
+		pr_debug(" -> parent lacks #interrupt-cells!\n");
+		of_node_put(np);
+		return NULL;
+	}
+	if (of_property_read_u32(np, "#address-cells",
+					&addrsize))
+		addrsize = 0;
+
+	pr_debug(" -> intsize=%d, addrsize=%d\n",
+		intsize, addrsize);
+
+	/* Check for malformed properties */
+	if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)
+		|| (len < (addrsize + intsize))) {
+		of_node_put(np);
+		return NULL;
+	}
+
+	pr_debug(" -> imaplen=%d\n", len);
+
+	imap += addrsize + intsize;
+
+	out_irq->np = np;
+	for (int i = 0; i < intsize; i++)
+		out_irq->args[i] = be32_to_cpup(imap - intsize + i);
+	out_irq->args_count = intsize;
+
+	return imap;
+}
+
 /**
  * of_irq_parse_raw - Low level interrupt tree parsing
  * @addr:	address specifier (start of "reg" property of the device) in be32 format
  * @out_irq:	structure of_phandle_args updated by this function
  *
- * Returns 0 on success and a negative number on error
- *
  * This function is a low-level interrupt tree walking function. It
- * can be used to do a partial walk with synthetized reg and interrupts
+ * can be used to do a partial walk with synthesized reg and interrupts
  * properties, for example when resolving PCI interrupts when no device
  * node exist for the parent. It takes an interrupt specifier structure as
  * input, walks the tree looking for any interrupt-map properties, translates
  * the specifier for each map, and then returns the translated map.
+ *
+ * Return: 0 on success and a negative number on error
+ *
+ * Note: refcount of node @out_irq->np is increased by 1 on success.
  */
 int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 {
-	struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
+	struct device_node *ipar, *tnode, *old = NULL;
 	__be32 initial_match_array[MAX_PHANDLE_ARGS];
 	const __be32 *match_array = initial_match_array;
-	const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
-	u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
-	int imaplen, match, i, rc = -EINVAL;
+	const __be32 *tmp, dummy_imask[] = { [0 ... (MAX_PHANDLE_ARGS - 1)] = cpu_to_be32(~0) };
+	u32 intsize = 1, addrsize;
+	int i, rc = -EINVAL;
 
 #ifdef DEBUG
 	of_print_phandle_args("of_irq_parse_raw: ", out_irq);
@@ -156,10 +239,21 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 
 	/* Now start the actual "proper" walk of the interrupt tree */
 	while (ipar != NULL) {
-		/* Now check if cursor is an interrupt-controller and if it is
-		 * then we are done
+		int imaplen, match;
+		const __be32 *imap, *oldimap, *imask;
+		struct device_node *newpar;
+		/*
+		 * Now check if cursor is an interrupt-controller and
+		 * if it is then we are done, unless there is an
+		 * interrupt-map which takes precedence except on one
+		 * of these broken platforms that want to parse
+		 * interrupt-map themselves for $reason.
 		 */
-		if (of_property_read_bool(ipar, "interrupt-controller")) {
+		bool intc = of_property_read_bool(ipar, "interrupt-controller");
+
+		imap = of_get_property(ipar, "interrupt-map", &imaplen);
+		if (intc &&
+		    (!imap || of_device_compatible_match(ipar, of_irq_imap_abusers))) {
 			pr_debug(" -> got it !\n");
 			return 0;
 		}
@@ -173,8 +267,6 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 			goto fail;
 		}
 
-		/* Now look for an interrupt-map */
-		imap = of_get_property(ipar, "interrupt-map", &imaplen);
 		/* No interrupt map, check for an interrupt parent */
 		if (imap == NULL) {
 			pr_debug(" -> no map, getting parent\n");
@@ -190,7 +282,7 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 
 		/* Parse interrupt-map */
 		match = 0;
-		while (imaplen > (addrsize + intsize + 1) && !match) {
+		while (imaplen > (addrsize + intsize + 1)) {
 			/* Compare specifiers */
 			match = 1;
 			for (i = 0; i < (addrsize + intsize); i++, imaplen--)
@@ -198,66 +290,45 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 
 			pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
 
-			/* Get the interrupt parent */
-			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
-				newpar = of_node_get(of_irq_dflt_pic);
-			else
-				newpar = of_find_node_by_phandle(be32_to_cpup(imap));
-			imap++;
-			--imaplen;
-
-			/* Check if not found */
-			if (newpar == NULL) {
-				pr_debug(" -> imap parent not found !\n");
-				goto fail;
-			}
-
-			if (!of_device_is_available(newpar))
-				match = 0;
-
-			/* Get #interrupt-cells and #address-cells of new
-			 * parent
-			 */
-			if (of_property_read_u32(newpar, "#interrupt-cells",
-						 &newintsize)) {
-				pr_debug(" -> parent lacks #interrupt-cells!\n");
-				goto fail;
-			}
-			if (of_property_read_u32(newpar, "#address-cells",
-						 &newaddrsize))
-				newaddrsize = 0;
-
-			pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
-			    newintsize, newaddrsize);
-
-			/* Check for malformed properties */
-			if (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS)
-			    || (imaplen < (newaddrsize + newintsize))) {
-				rc = -EFAULT;
+			oldimap = imap;
+			imap = of_irq_parse_imap_parent(oldimap, imaplen, out_irq);
+			if (!imap)
 				goto fail;
-			}
 
-			imap += newaddrsize + newintsize;
-			imaplen -= newaddrsize + newintsize;
+			match &= of_device_is_available(out_irq->np);
+			if (match)
+				break;
 
+			of_node_put(out_irq->np);
+			imaplen -= imap - oldimap;
 			pr_debug(" -> imaplen=%d\n", imaplen);
 		}
 		if (!match)
 			goto fail;
 
 		/*
-		 * Successfully parsed an interrrupt-map translation; copy new
+		 * Successfully parsed an interrupt-map translation; copy new
 		 * interrupt specifier into the out_irq structure
 		 */
-		match_array = imap - newaddrsize - newintsize;
-		for (i = 0; i < newintsize; i++)
-			out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
-		out_irq->args_count = intsize = newintsize;
-		addrsize = newaddrsize;
+		match_array = oldimap + 1;
+
+		newpar = out_irq->np;
+		intsize = out_irq->args_count;
+		addrsize = (imap - match_array) - intsize;
+
+		if (ipar == newpar) {
+			/*
+			 * We got @ipar's refcount, but the refcount was
+			 * gotten again by of_irq_parse_imap_parent() via its
+			 * alias @newpar.
+			 */
+			of_node_put(ipar);
+			pr_debug("%pOF interrupt-map entry to self\n", ipar);
+			return 0;
+		}
 
 	skiplevel:
 		/* Iterate again with new parent */
-		out_irq->np = newpar;
 		pr_debug(" -> new parent: %pOF\n", newpar);
 		of_node_put(ipar);
 		ipar = newpar;
@@ -267,7 +338,6 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 
  fail:
 	of_node_put(ipar);
-	of_node_put(newpar);
 
 	return rc;
 }
@@ -282,13 +352,16 @@ EXPORT_SYMBOL_GPL(of_irq_parse_raw);
  * This function resolves an interrupt for a node by walking the interrupt tree,
  * finding which interrupt controller node it is attached to, and returning the
  * interrupt specifier that can be used to retrieve a Linux IRQ number.
+ *
+ * Note: refcount of node @out_irq->np is increased by 1 on success.
  */
 int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
 {
-	struct device_node *p;
+	struct device_node __free(device_node) *p = NULL;
 	const __be32 *addr;
 	u32 intsize;
-	int i, res;
+	int i, res, addr_len;
+	__be32 addr_buf[3] = { 0 };
 
 	pr_debug("of_irq_parse_one: dev=%pOF, index=%d\n", device, index);
 
@@ -297,46 +370,45 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar
 		return of_irq_parse_oldworld(device, index, out_irq);
 
 	/* Get the reg property (if any) */
-	addr = of_get_property(device, "reg", NULL);
+	addr_len = 0;
+	addr = of_get_property(device, "reg", &addr_len);
+
+	/* Prevent out-of-bounds read in case of longer interrupt parent address size */
+	if (addr_len > sizeof(addr_buf))
+		addr_len = sizeof(addr_buf);
+	if (addr)
+		memcpy(addr_buf, addr, addr_len);
 
 	/* Try the new-style interrupts-extended first */
 	res = of_parse_phandle_with_args(device, "interrupts-extended",
 					"#interrupt-cells", index, out_irq);
-	if (!res)
-		return of_irq_parse_raw(addr, out_irq);
-
-	/* Look for the interrupt parent. */
-	p = of_irq_find_parent(device);
-	if (p == NULL)
-		return -EINVAL;
-
-	/* Get size of interrupt specifier */
-	if (of_property_read_u32(p, "#interrupt-cells", &intsize)) {
-		res = -EINVAL;
-		goto out;
-	}
-
-	pr_debug(" parent=%pOF, intsize=%d\n", p, intsize);
+	if (!res) {
+		p = out_irq->np;
+	} else {
+		/* Look for the interrupt parent. */
+		p = of_irq_find_parent(device);
+		/* Get size of interrupt specifier */
+		if (!p || of_property_read_u32(p, "#interrupt-cells", &intsize))
+			return -EINVAL;
+
+		pr_debug(" parent=%pOF, intsize=%d\n", p, intsize);
+
+		/* Copy intspec into irq structure */
+		out_irq->np = p;
+		out_irq->args_count = intsize;
+		for (i = 0; i < intsize; i++) {
+			res = of_property_read_u32_index(device, "interrupts",
+							(index * intsize) + i,
+							out_irq->args + i);
+			if (res)
+				return res;
+		}
 
-	/* Copy intspec into irq structure */
-	out_irq->np = p;
-	out_irq->args_count = intsize;
-	for (i = 0; i < intsize; i++) {
-		res = of_property_read_u32_index(device, "interrupts",
-						 (index * intsize) + i,
-						 out_irq->args + i);
-		if (res)
-			goto out;
+		pr_debug(" intspec=%d\n", *out_irq->args);
 	}
 
-	pr_debug(" intspec=%d\n", *out_irq->args);
-
-
 	/* Check if there are any interrupt-map translations to process */
-	res = of_irq_parse_raw(addr, out_irq);
- out:
-	of_node_put(p);
-	return res;
+	return of_irq_parse_raw(addr_buf, out_irq);
 }
 EXPORT_SYMBOL_GPL(of_irq_parse_one);
 
@@ -366,9 +438,8 @@ int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
 		of_property_read_string_index(dev, "interrupt-names", index,
 					      &name);
 
-		r->start = r->end = irq;
-		r->flags = IORESOURCE_IRQ | irqd_get_trigger_type(irq_get_irq_data(irq));
-		r->name = name ? name : of_node_full_name(dev);
+		*r = DEFINE_RES_IRQ_NAMED(irq, name ?: of_node_full_name(dev));
+		r->flags |= irq_get_trigger_type(irq);
 	}
 
 	return irq;
@@ -380,7 +451,7 @@ EXPORT_SYMBOL_GPL(of_irq_to_resource);
  * @dev: pointer to device tree node
  * @index: zero-based index of the IRQ
  *
- * Returns Linux IRQ number on success, or 0 on the IRQ mapping failure, or
+ * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
  * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
  * of any other failure.
  */
@@ -395,19 +466,45 @@ int of_irq_get(struct device_node *dev, int index)
 		return rc;
 
 	domain = irq_find_host(oirq.np);
-	if (!domain)
-		return -EPROBE_DEFER;
+	if (!domain) {
+		rc = -EPROBE_DEFER;
+		goto out;
+	}
 
-	return irq_create_of_mapping(&oirq);
+	rc = irq_create_of_mapping(&oirq);
+out:
+	of_node_put(oirq.np);
+
+	return rc;
 }
 EXPORT_SYMBOL_GPL(of_irq_get);
 
+const struct cpumask *of_irq_get_affinity(struct device_node *dev, int index)
+{
+	struct of_phandle_args oirq;
+	struct irq_fwspec_info info;
+	struct irq_fwspec fwspec;
+	int rc;
+
+	rc = of_irq_parse_one(dev, index, &oirq);
+	if (rc)
+		return NULL;
+
+	of_phandle_args_to_fwspec(oirq.np, oirq.args, oirq.args_count,
+				  &fwspec);
+
+	if (irq_populate_fwspec_info(&fwspec, &info))
+		return NULL;
+
+	return info.affinity;
+}
+
 /**
  * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
  * @dev: pointer to device tree node
  * @name: IRQ name
  *
- * Returns Linux IRQ number on success, or 0 on the IRQ mapping failure, or
+ * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
  * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
  * of any other failure.
  */
@@ -435,11 +532,14 @@ int of_irq_count(struct device_node *dev)
 	struct of_phandle_args irq;
 	int nr = 0;
 
-	while (of_irq_parse_one(dev, nr, &irq) == 0)
+	while (of_irq_parse_one(dev, nr, &irq) == 0) {
+		of_node_put(irq.np);
 		nr++;
+	}
 
 	return nr;
 }
+EXPORT_SYMBOL_GPL(of_irq_count);
 
 /**
  * of_irq_to_resource_table - Fill in resource table with node's IRQ info
@@ -447,7 +547,7 @@ int of_irq_count(struct device_node *dev)
  * @res: array of resources to fill in
  * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
  *
- * Returns the size of the filled in table (up to @nr_irqs).
+ * Return: The size of the filled in table (up to @nr_irqs).
  */
 int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
 		int nr_irqs)
@@ -507,9 +607,20 @@ void __init of_irq_init(const struct of_device_id *matches)
 
 		desc->irq_init_cb = match->data;
 		desc->dev = of_node_get(np);
-		desc->interrupt_parent = of_irq_find_parent(np);
-		if (desc->interrupt_parent == np)
+		/*
+		 * interrupts-extended can reference multiple parent domains.
+		 * Arbitrarily pick the first one; assume any other parents
+		 * are the same distance away from the root irq controller.
+		 */
+		desc->interrupt_parent = of_parse_phandle(np, "interrupts-extended", 0);
+		if (!desc->interrupt_parent && of_property_present(np, "interrupts"))
+			desc->interrupt_parent = of_irq_find_parent(np);
+		else if (!desc->interrupt_parent)
+			desc->interrupt_parent = of_parse_phandle(np, "interrupt-parent", 0);
+		if (desc->interrupt_parent == np) {
+			of_node_put(desc->interrupt_parent);
 			desc->interrupt_parent = NULL;
+		}
 		list_add_tail(&desc->list, &intc_desc_list);
 	}
 
@@ -540,7 +651,12 @@ void __init of_irq_init(const struct of_device_id *matches)
 			ret = desc->irq_init_cb(desc->dev,
 						desc->interrupt_parent);
 			if (ret) {
+				pr_err("%s: Failed to init %pOF (%p), parent %p\n",
+				       __func__, desc->dev, desc->dev,
+				       desc->interrupt_parent);
 				of_node_clear_flag(desc->dev, OF_POPULATED);
+				of_node_put(desc->interrupt_parent);
+				of_node_put(desc->dev);
 				kfree(desc);
 				continue;
 			}
@@ -571,60 +687,94 @@ void __init of_irq_init(const struct of_device_id *matches)
 err:
 	list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
 		list_del(&desc->list);
+		of_node_put(desc->interrupt_parent);
 		of_node_put(desc->dev);
 		kfree(desc);
 	}
 }
 
-static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
-			    u32 rid_in)
+static int of_check_msi_parent(struct device_node *dev_node, struct device_node **msi_node)
 {
-	struct device *parent_dev;
-	u32 rid_out = rid_in;
+	struct of_phandle_args msi_spec;
+	int ret;
 
 	/*
-	 * Walk up the device parent links looking for one with a
-	 * "msi-map" property.
+	 * An msi-parent phandle with a missing or == 0 #msi-cells
+	 * property identifies a 1:1 ID translation mapping.
+	 *
+	 * Set the msi controller node if the firmware matches this
+	 * condition.
 	 */
-	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent)
-		if (!of_map_rid(parent_dev->of_node, rid_in, "msi-map",
-				"msi-map-mask", np, &rid_out))
-			break;
-	return rid_out;
+	ret = of_parse_phandle_with_optional_args(dev_node, "msi-parent", "#msi-cells",
+						  0, &msi_spec);
+	if (ret)
+		return ret;
+
+	if ((*msi_node && *msi_node != msi_spec.np) || msi_spec.args_count != 0)
+		ret = -EINVAL;
+
+	if (!ret) {
+		/* Return with a node reference held */
+		*msi_node = msi_spec.np;
+		return 0;
+	}
+	of_node_put(msi_spec.np);
+
+	return ret;
 }
 
 /**
- * of_msi_map_rid - Map a MSI requester ID for a device.
+ * 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: device node of the expected msi controller.
- * @rid_in: unmapped MSI requester ID for the device.
+ * @msi_np: Pointer to target MSI controller node
+ * @id_in: Device ID.
  *
  * Walk up the device hierarchy looking for devices with a "msi-map"
- * property.  If found, apply the mapping to @rid_in.
+ * 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 requester ID.
+ * Returns: The mapped MSI id.
  */
-u32 of_msi_map_rid(struct device *dev, struct device_node *msi_np, u32 rid_in)
+u32 of_msi_xlate(struct device *dev, struct device_node **msi_np, u32 id_in)
 {
-	return __of_msi_map_rid(dev, &msi_np, rid_in);
+	struct device *parent_dev;
+	u32 id_out = id_in;
+
+	/*
+	 * Walk up the device parent links looking for one with a
+	 * "msi-map" or an "msi-parent" property.
+	 */
+	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
+		if (!of_map_id(parent_dev->of_node, id_in, "msi-map",
+				"msi-map-mask", msi_np, &id_out))
+			break;
+		if (!of_check_msi_parent(parent_dev->of_node, msi_np))
+			break;
+	}
+	return id_out;
 }
+EXPORT_SYMBOL_GPL(of_msi_xlate);
 
 /**
  * of_msi_map_get_device_domain - Use msi-map to find the relevant MSI domain
  * @dev: device for which the mapping is to be done.
- * @rid: Requester ID for the device.
+ * @id: Device ID.
+ * @bus_token: Bus token
  *
  * Walk up the device hierarchy looking for devices with a "msi-map"
  * property.
  *
  * Returns: the MSI domain for this device (or NULL on failure)
  */
-struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 rid)
+struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 id,
+						u32 bus_token)
 {
 	struct device_node *np = NULL;
 
-	__of_msi_map_rid(dev, &np, rid);
-	return irq_find_matching_host(np, DOMAIN_BUS_PCI_MSI);
+	of_msi_xlate(dev, &np, id);
+	return irq_find_matching_host(np, bus_token);
 }
 
 /**
@@ -633,53 +783,36 @@ struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 rid)
  * @np: device node for @dev
  * @token: bus type for this domain
  *
- * Parse the msi-parent property (both the simple and the complex
- * versions), and returns the corresponding MSI domain.
+ * Parse the msi-parent property and returns the corresponding MSI domain.
  *
  * Returns: the MSI domain for this device (or NULL on failure).
  */
 struct irq_domain *of_msi_get_domain(struct device *dev,
-				     struct device_node *np,
+				     const struct device_node *np,
 				     enum irq_domain_bus_token token)
 {
-	struct device_node *msi_np;
+	struct of_phandle_iterator it;
 	struct irq_domain *d;
+	int err;
 
-	/* Check for a single msi-parent property */
-	msi_np = of_parse_phandle(np, "msi-parent", 0);
-	if (msi_np && !of_property_read_bool(msi_np, "#msi-cells")) {
-		d = irq_find_matching_host(msi_np, token);
-		if (!d)
-			of_node_put(msi_np);
-		return d;
-	}
-
-	if (token == DOMAIN_BUS_PLATFORM_MSI) {
-		/* Check for the complex msi-parent version */
-		struct of_phandle_args args;
-		int index = 0;
-
-		while (!of_parse_phandle_with_args(np, "msi-parent",
-						   "#msi-cells",
-						   index, &args)) {
-			d = irq_find_matching_host(args.np, token);
-			if (d)
-				return d;
-
-			of_node_put(args.np);
-			index++;
+	of_for_each_phandle(&it, err, np, "msi-parent", "#msi-cells", 0) {
+		d = irq_find_matching_host(it.node, token);
+		if (d) {
+			of_node_put(it.node);
+			return d;
 		}
 	}
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(of_msi_get_domain);
 
 /**
  * of_msi_configure - Set the msi_domain field of a device
  * @dev: device structure to associate with an MSI irq domain
  * @np: device node for that device
  */
-void of_msi_configure(struct device *dev, struct device_node *np)
+void of_msi_configure(struct device *dev, const struct device_node *np)
 {
 	dev_set_msi_domain(dev,
 			   of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));