text: // SPDX-License-Identifier: GPL-2.0+
  /*
   *  Derived from arch/i386/kernel/irq.c
   *    Copyright (C) 1992 Linus Torvalds
   *  Adapted from arch/i386 by Gary Thomas
   *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   *    Copyright (C) 1996-2001 Cort Dougan
   *  Adapted for Power Macintosh by Paul Mackerras
   *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
   *
   * This file contains the code used to make IRQ descriptions in the
   * device tree to actual irq numbers on an interrupt controller
   * driver.
   */
  
  #define pr_fmt(fmt)	"OF: " fmt
  
  #include <linux/device.h>
  #include <linux/errno.h>
  #include <linux/list.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_irq.h>
  #include <linux/string.h>
  #include <linux/slab.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
   * @index: Index of the interrupt to map
   *
   * This function is a wrapper that chains of_irq_parse_one() and
   * irq_create_of_mapping() to make things easier to callers
   */
  unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
  {
  	struct of_phandle_args oirq;
  
  	if (of_irq_parse_one(dev, index, &oirq))
  		return 0;
  
  	return irq_create_of_mapping(&oirq);
  }
  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
   *
   * Return: A pointer to the interrupt parent node, or NULL if the interrupt
   * parent could not be determined.
   */
  struct device_node *of_irq_find_parent(struct device_node *child)
  {
  	struct device_node *p;
  	phandle parent;
  
  	if (!of_node_get(child))
  		return NULL;
  
  	do {
  		if (of_property_read_u32(child, "interrupt-parent", &parent)) {
  			p = of_get_parent(child);
  		} else	{
  			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
  				p = of_node_get(of_irq_dflt_pic);
  			else
  				p = of_find_node_by_phandle(parent);
  		}
  		of_node_put(child);
  		child = p;
  	} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
  
  	return p;
  }
  EXPORT_SYMBOL_GPL(of_irq_find_parent);
  
  /**
   * 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
   *
   * This function is a low-level interrupt tree walking function. It
   * can be used to do a partial walk with synthetized 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
   */
  int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
  {
  	struct device_node *ipar, *tnode, *old = NULL, *newpar = 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;
  
  #ifdef DEBUG
  	of_print_phandle_args("of_irq_parse_raw: ", out_irq);
  #endif
  
  	ipar = of_node_get(out_irq->np);
  
  	/* First get the #interrupt-cells property of the current cursor
  	 * that tells us how to interpret the passed-in intspec. If there
  	 * is none, we are nice and just walk up the tree
  	 */
  	do {
  		if (!of_property_read_u32(ipar, "#interrupt-cells", &intsize))
  			break;
  		tnode = ipar;
  		ipar = of_irq_find_parent(ipar);
  		of_node_put(tnode);
  	} while (ipar);
  	if (ipar == NULL) {
  		pr_debug(" -> no parent found !\n");
  		goto fail;
  	}
  
  	pr_debug("of_irq_parse_raw: ipar=%pOF, size=%d\n", ipar, intsize);
  
  	if (out_irq->args_count != intsize)
  		goto fail;
  
  	/* Look for this #address-cells. We have to implement the old linux
  	 * trick of looking for the parent here as some device-trees rely on it
  	 */
  	old = of_node_get(ipar);
  	do {
  		tmp = of_get_property(old, "#address-cells", NULL);
  		tnode = of_get_parent(old);
  		of_node_put(old);
  		old = tnode;
  	} while (old && tmp == NULL);
  	of_node_put(old);
  	old = NULL;
  	addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
  
  	pr_debug(" -> addrsize=%d\n", addrsize);
  
  	/* Range check so that the temporary buffer doesn't overflow */
  	if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) {
  		rc = -EFAULT;
  		goto fail;
  	}
  
  	/* Precalculate the match array - this simplifies match loop */
  	for (i = 0; i < addrsize; i++)
  		initial_match_array[i] = addr ? addr[i] : 0;
  	for (i = 0; i < intsize; i++)
  		initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
  
  	/* 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
  		 */
  		if (of_property_read_bool(ipar, "interrupt-controller")) {
  			pr_debug(" -> got it !\n");
  			return 0;
  		}
  
  		/*
  		 * interrupt-map parsing does not work without a reg
  		 * property when #address-cells != 0
  		 */
  		if (addrsize && !addr) {
  			pr_debug(" -> no reg passed in when needed !\n");
  			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");
  			newpar = of_irq_find_parent(ipar);
  			goto skiplevel;
  		}
  		imaplen /= sizeof(u32);
  
  		/* Look for a mask */
  		imask = of_get_property(ipar, "interrupt-map-mask", NULL);
  		if (!imask)
  			imask = dummy_imask;
  
  		/* Parse interrupt-map */
  		match = 0;
  		while (imaplen > (addrsize + intsize + 1) && !match) {
  			/* Compare specifiers */
  			match = 1;
  			for (i = 0; i < (addrsize + intsize); i++, imaplen--)
  				match &= !((match_array[i] ^ *imap++) & imask[i]);
  
  			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;
  				goto fail;
  			}
  
  			imap += newaddrsize + newintsize;
  			imaplen -= newaddrsize + newintsize;
  
  			pr_debug(" -> imaplen=%d\n", imaplen);
  		}
  		if (!match)
  			goto fail;
  
  		/*
  		 * Successfully parsed an interrrupt-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;
  
  	skiplevel:
  		/* Iterate again with new parent */
  		out_irq->np = newpar;
  		pr_debug(" -> new parent: %pOF\n", newpar);
  		of_node_put(ipar);
  		ipar = newpar;
  		newpar = NULL;
  	}
  	rc = -ENOENT; /* No interrupt-map found */
  
   fail:
  	of_node_put(ipar);
  	of_node_put(newpar);
  
  	return rc;
  }
  EXPORT_SYMBOL_GPL(of_irq_parse_raw);
  
  /**
   * of_irq_parse_one - Resolve an interrupt for a device
   * @device: the device whose interrupt is to be resolved
   * @index: index of the interrupt to resolve
   * @out_irq: structure of_phandle_args filled by this function
   *
   * 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.
   */
  int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
  {
  	struct device_node *p;
  	const __be32 *addr;
  	u32 intsize;
  	int i, res;
  
  	pr_debug("of_irq_parse_one: dev=%pOF, index=%d\n", device, index);
  
  	/* OldWorld mac stuff is "special", handle out of line */
  	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
  		return of_irq_parse_oldworld(device, index, out_irq);
  
  	/* Get the reg property (if any) */
  	addr = of_get_property(device, "reg", NULL);
  
  	/* 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);
  
  	/* 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);
  
  
  	/* 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;
  }
  EXPORT_SYMBOL_GPL(of_irq_parse_one);
  
  /**
   * of_irq_to_resource - Decode a node's IRQ and return it as a resource
   * @dev: pointer to device tree node
   * @index: zero-based index of the irq
   * @r: pointer to resource structure to return result into.
   */
  int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
  {
  	int irq = of_irq_get(dev, index);
  
  	if (irq < 0)
  		return irq;
  
  	/* Only dereference the resource if both the
  	 * resource and the irq are valid. */
  	if (r && irq) {
  		const char *name = NULL;
  
  		memset(r, 0, sizeof(*r));
  		/*
  		 * Get optional "interrupt-names" property to add a name
  		 * to the resource.
  		 */
  		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);
  	}
  
  	return irq;
  }
  EXPORT_SYMBOL_GPL(of_irq_to_resource);
  
  /**
   * of_irq_get - Decode a node's IRQ and return it as a Linux IRQ number
   * @dev: pointer to device tree node
   * @index: zero-based index of the IRQ
   *
   * 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.
   */
  int of_irq_get(struct device_node *dev, int index)
  {
  	int rc;
  	struct of_phandle_args oirq;
  	struct irq_domain *domain;
  
  	rc = of_irq_parse_one(dev, index, &oirq);
  	if (rc)
  		return rc;
  
  	domain = irq_find_host(oirq.np);
  	if (!domain)
  		return -EPROBE_DEFER;
  
  	return irq_create_of_mapping(&oirq);
  }
  EXPORT_SYMBOL_GPL(of_irq_get);
  
  /**
   * 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
   *
   * 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.
   */
  int of_irq_get_byname(struct device_node *dev, const char *name)
  {
  	int index;
  
  	if (unlikely(!name))
  		return -EINVAL;
  
  	index = of_property_match_string(dev, "interrupt-names", name);
  	if (index < 0)
  		return index;
  
  	return of_irq_get(dev, index);
  }
  EXPORT_SYMBOL_GPL(of_irq_get_byname);
  
  /**
   * of_irq_count - Count the number of IRQs a node uses
   * @dev: pointer to device tree node
   */
  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)
  		nr++;
  
  	return nr;
  }
  
  /**
   * of_irq_to_resource_table - Fill in resource table with node's IRQ info
   * @dev: pointer to device tree node
   * @res: array of resources to fill in
   * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
   *
   * 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)
  {
  	int i;
  
  	for (i = 0; i < nr_irqs; i++, res++)
  		if (of_irq_to_resource(dev, i, res) <= 0)
  			break;
  
  	return i;
  }
  EXPORT_SYMBOL_GPL(of_irq_to_resource_table);
  
  struct of_intc_desc {
  	struct list_head	list;
  	of_irq_init_cb_t	irq_init_cb;
  	struct device_node	*dev;
  	struct device_node	*interrupt_parent;
  };
  
  /**
   * of_irq_init - Scan and init matching interrupt controllers in DT
   * @matches: 0 terminated array of nodes to match and init function to call
   *
   * This function scans the device tree for matching interrupt controller nodes,
   * and calls their initialization functions in order with parents first.
   */
  void __init of_irq_init(const struct of_device_id *matches)
  {
  	const struct of_device_id *match;
  	struct device_node *np, *parent = NULL;
  	struct of_intc_desc *desc, *temp_desc;
  	struct list_head intc_desc_list, intc_parent_list;
  
  	INIT_LIST_HEAD(&intc_desc_list);
  	INIT_LIST_HEAD(&intc_parent_list);
  
  	for_each_matching_node_and_match(np, matches, &match) {
  		if (!of_property_read_bool(np, "interrupt-controller") ||
  				!of_device_is_available(np))
  			continue;
  
  		if (WARN(!match->data, "of_irq_init: no init function for %s\n",
  			 match->compatible))
  			continue;
  
  		/*
  		 * Here, we allocate and populate an of_intc_desc with the node
  		 * pointer, interrupt-parent device_node etc.
  		 */
  		desc = kzalloc(sizeof(*desc), GFP_KERNEL);
  		if (!desc) {
  			of_node_put(np);
  			goto err;
  		}
  
  		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)
  			desc->interrupt_parent = NULL;
  		list_add_tail(&desc->list, &intc_desc_list);
  	}
  
  	/*
  	 * The root irq controller is the one without an interrupt-parent.
  	 * That one goes first, followed by the controllers that reference it,
  	 * followed by the ones that reference the 2nd level controllers, etc.
  	 */
  	while (!list_empty(&intc_desc_list)) {
  		/*
  		 * Process all controllers with the current 'parent'.
  		 * First pass will be looking for NULL as the parent.
  		 * The assumption is that NULL parent means a root controller.
  		 */
  		list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
  			int ret;
  
  			if (desc->interrupt_parent != parent)
  				continue;
  
  			list_del(&desc->list);
  
  			of_node_set_flag(desc->dev, OF_POPULATED);
  
  			pr_debug("of_irq_init: init %pOF (%p), parent %p\n",
  				 desc->dev,
  				 desc->dev, desc->interrupt_parent);
  			ret = desc->irq_init_cb(desc->dev,
  						desc->interrupt_parent);
  			if (ret) {
  				of_node_clear_flag(desc->dev, OF_POPULATED);
  				kfree(desc);
  				continue;
  			}
  
  			/*
  			 * This one is now set up; add it to the parent list so
  			 * its children can get processed in a subsequent pass.
  			 */
  			list_add_tail(&desc->list, &intc_parent_list);
  		}
  
  		/* Get the next pending parent that might have children */
  		desc = list_first_entry_or_null(&intc_parent_list,
  						typeof(*desc), list);
  		if (!desc) {
  			pr_err("of_irq_init: children remain, but no parents\n");
  			break;
  		}
  		list_del(&desc->list);
  		parent = desc->dev;
  		kfree(desc);
  	}
  
  	list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
  		list_del(&desc->list);
  		kfree(desc);
  	}
  err:
  	list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
  		list_del(&desc->list);
  		of_node_put(desc->dev);
  		kfree(desc);
  	}
  }
  
  static u32 __of_msi_map_id(struct device *dev, struct device_node **np,
  			    u32 id_in)
  {
  	struct device *parent_dev;
  	u32 id_out = id_in;
  
  	/*
  	 * Walk up the device parent links looking for one with a
  	 * "msi-map" 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", np, &id_out))
  			break;
  	return id_out;
  }
  
  /**
   * of_msi_map_id - Map a MSI ID for a device.
   * @dev: device for which the mapping is to be done.
   * @msi_np: device node of the expected msi controller.
   * @id_in: unmapped MSI ID for the device.
   *
   * Walk up the device hierarchy looking for devices with a "msi-map"
   * property.  If found, apply the mapping to @id_in.
   *
   * Return: The mapped MSI ID.
   */
  u32 of_msi_map_id(struct device *dev, struct device_node *msi_np, u32 id_in)
  {
  	return __of_msi_map_id(dev, &msi_np, id_in);
  }
  
  /**
   * 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.
   * @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 id,
  						u32 bus_token)
  {
  	struct device_node *np = NULL;
  
  	__of_msi_map_id(dev, &np, id);
  	return irq_find_matching_host(np, bus_token);
  }
  
  /**
   * of_msi_get_domain - Use msi-parent to find the relevant MSI domain
   * @dev: device for which the domain is requested
   * @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.
   *
   * 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,
  				     enum irq_domain_bus_token token)
  {
  	struct device_node *msi_np;
  	struct irq_domain *d;
  
  	/* 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++;
  		}
  	}
  
  	return NULL;
  }
  
  /**
   * 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)
  {
  	dev_set_msi_domain(dev,
  			   of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
  }
  EXPORT_SYMBOL_GPL(of_msi_configure);
  