include/linux/irqdomain.h

/*
 * 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 */