/*
   * irq_domain - IRQ translation domains
   *
   * Translation infrastructure between hw and linux irq numbers.  This is
   * helpful for interrupt controllers to implement mapping between hardware
   * irq numbers and the Linux irq number space.
   *
   * irq_domains also have a hook for translating device tree interrupt
   * representation into a hardware irq number that can be mapped back to a
   * Linux irq number without any extra platform support code.
   *
   * Interrupt controller "domain" data structure. This could be defined as a
   * irq domain controller. That is, it handles the mapping between hardware
   * and virtual interrupt numbers for a given interrupt domain. The domain
   * structure is generally created by the PIC code for a given PIC instance
   * (though a domain can cover more than one PIC if they have a flat number
   * model). It's the domain callbacks that are responsible for setting the
   * irq_chip on a given irq_desc after it's been mapped.
   *
   * The host code and data structures are agnostic to whether or not
   * we use an open firmware device-tree. We do have references to struct
   * device_node in two places: in irq_find_host() to find the host matching
   * a given interrupt controller node, and of course as an argument to its
   * counterpart domain->ops->match() callback. However, those are treated as
   * generic pointers by the core and the fact that it's actually a device-node
   * pointer is purely a convention between callers and implementation. This
   * code could thus be used on other architectures by replacing those two
   * by some sort of arch-specific void * "token" used to identify interrupt
   * controllers.
   */
  
  #ifndef _LINUX_IRQDOMAIN_H
  #define _LINUX_IRQDOMAIN_H
  
  #include <linux/types.h>
  #include <linux/radix-tree.h>
  
  struct device_node;
  struct irq_domain;
  struct of_device_id;
  
  /* Number of irqs reserved for a legacy isa controller */
  #define NUM_ISA_INTERRUPTS	16
  
  /**
   * struct irq_domain_ops - Methods for irq_domain objects
   * @match: Match an interrupt controller device node to a host, returns
   *         1 on a match
   * @map: Create or update a mapping between a virtual irq number and a hw
   *       irq number. This is called only once for a given mapping.
   * @unmap: Dispose of such a mapping
   * @xlate: Given a device tree node and interrupt specifier, decode
   *         the hardware irq number and linux irq type value.
   *
   * Functions below are provided by the driver and called whenever a new mapping
   * is created or an old mapping is disposed. The driver can then proceed to
   * whatever internal data structures management is required. It also needs
   * to setup the irq_desc when returning from map().
   */
  struct irq_domain_ops {
  	int (*match)(struct irq_domain *d, struct device_node *node);
  	int (*map)(struct irq_domain *d, unsigned int virq, irq_hw_number_t hw);
  	void (*unmap)(struct irq_domain *d, unsigned int virq);
  	int (*xlate)(struct irq_domain *d, struct device_node *node,
  		     const u32 *intspec, unsigned int intsize,
  		     unsigned long *out_hwirq, unsigned int *out_type);
  };
  
  extern struct irq_domain_ops irq_generic_chip_ops;
  
  struct irq_domain_chip_generic;
  
  /**
   * struct irq_domain - Hardware interrupt number translation object
   * @link: Element in global irq_domain list.
   * @name: Name of interrupt domain
   * @ops: pointer to irq_domain methods
   * @host_data: private data pointer for use by owner.  Not touched by irq_domain
   *             core code.
   *
   * Optional elements
   * @of_node: Pointer to device tree nodes associated with the irq_domain. Used
   *           when decoding device tree interrupt specifiers.
   * @gc: Pointer to a list of generic chips. There is a helper function for
   *      setting up one or more generic chips for interrupt controllers
   *      drivers using the generic chip library which uses this pointer.
   *
   * Revmap data, used internally by irq_domain
   * @revmap_direct_max_irq: The largest hwirq that can be set for controllers that
   *                         support direct mapping
   * @revmap_size: Size of the linear map table @linear_revmap[]
   * @revmap_tree: Radix map tree for hwirqs that don't fit in the linear map
   * @linear_revmap: Linear table of hwirq->virq reverse mappings
   */
  struct irq_domain {
  	struct list_head link;
  	const char *name;
  	const struct irq_domain_ops *ops;
  	void *host_data;
  
  	/* Optional data */
  	struct device_node *of_node;
  	struct irq_domain_chip_generic *gc;
  
  	/* reverse map data. The linear map gets appended to the irq_domain */
  	irq_hw_number_t hwirq_max;
  	unsigned int revmap_direct_max_irq;
  	unsigned int revmap_size;
  	struct radix_tree_root revmap_tree;
  	unsigned int linear_revmap[];
  };
  
  #ifdef CONFIG_IRQ_DOMAIN
  struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
  				    irq_hw_number_t hwirq_max, int direct_max,
  				    const struct irq_domain_ops *ops,
  				    void *host_data);
  struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
  					 unsigned int size,
  					 unsigned int first_irq,
  					 const struct irq_domain_ops *ops,
  					 void *host_data);
  struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
  					 unsigned int size,
  					 unsigned int first_irq,
  					 irq_hw_number_t first_hwirq,
  					 const struct irq_domain_ops *ops,
  					 void *host_data);
  extern struct irq_domain *irq_find_host(struct device_node *node);
  extern void irq_set_default_host(struct irq_domain *host);
  
  /**
   * irq_domain_add_linear() - Allocate and register a linear revmap irq_domain.
   * @of_node: pointer to interrupt controller's device tree node.
   * @size: Number of interrupts in the domain.
   * @ops: map/unmap domain callbacks
   * @host_data: Controller private data pointer
   */
  static inline struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
  					 unsigned int size,
  					 const struct irq_domain_ops *ops,
  					 void *host_data)
  {
  	return __irq_domain_add(of_node, size, size, 0, ops, host_data);
  }
  static inline struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
  					 unsigned int max_irq,
  					 const struct irq_domain_ops *ops,
  					 void *host_data)
  {
  	return __irq_domain_add(of_node, 0, max_irq, max_irq, ops, host_data);
  }
  static inline struct irq_domain *irq_domain_add_legacy_isa(
  				struct device_node *of_node,
  				const struct irq_domain_ops *ops,
  				void *host_data)
  {
  	return irq_domain_add_legacy(of_node, NUM_ISA_INTERRUPTS, 0, 0, ops,
  				     host_data);
  }
  static inline struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
  					 const struct irq_domain_ops *ops,
  					 void *host_data)
  {
  	return __irq_domain_add(of_node, 0, ~0, 0, ops, host_data);
  }
  
  extern void irq_domain_remove(struct irq_domain *host);
  
  extern int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
  					irq_hw_number_t hwirq);
  extern void irq_domain_associate_many(struct irq_domain *domain,
  				      unsigned int irq_base,
  				      irq_hw_number_t hwirq_base, int count);
  
  extern unsigned int irq_create_mapping(struct irq_domain *host,
  				       irq_hw_number_t hwirq);
  extern void irq_dispose_mapping(unsigned int virq);
  
  /**
   * irq_linear_revmap() - Find a linux irq from a hw irq number.
   * @domain: domain owning this hardware interrupt
   * @hwirq: hardware irq number in that domain space
   *
   * This is a fast path alternative to irq_find_mapping() that can be
   * called directly by irq controller code to save a handful of
   * instructions. It is always safe to call, but won't find irqs mapped
   * using the radix tree.
   */
  static inline unsigned int irq_linear_revmap(struct irq_domain *domain,
  					     irq_hw_number_t hwirq)
  {
  	return hwirq < domain->revmap_size ? domain->linear_revmap[hwirq] : 0;
  }
  extern unsigned int irq_find_mapping(struct irq_domain *host,
  				     irq_hw_number_t hwirq);
  extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
  extern int irq_create_strict_mappings(struct irq_domain *domain,
  				      unsigned int irq_base,
  				      irq_hw_number_t hwirq_base, int count);
  
  static inline int irq_create_identity_mapping(struct irq_domain *host,
  					      irq_hw_number_t hwirq)
  {
  	return irq_create_strict_mappings(host, hwirq, hwirq, 1);
  }
  
  extern const struct irq_domain_ops irq_domain_simple_ops;
  
  /* stock xlate functions */
  int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
  			const u32 *intspec, unsigned int intsize,
  			irq_hw_number_t *out_hwirq, unsigned int *out_type);
  int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
  			const u32 *intspec, unsigned int intsize,
  			irq_hw_number_t *out_hwirq, unsigned int *out_type);
  int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr,
  			const u32 *intspec, unsigned int intsize,
  			irq_hw_number_t *out_hwirq, unsigned int *out_type);
  
  #else /* CONFIG_IRQ_DOMAIN */
  static inline void irq_dispose_mapping(unsigned int virq) { }
  #endif /* !CONFIG_IRQ_DOMAIN */
  
  #endif /* _LINUX_IRQDOMAIN_H */