irqdomain.h

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/*
 * 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 {
    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);
};

struct irq_domain {
    struct list_head link;

    /* type of reverse mapping_technique */
    unsigned int revmap_type;
    union {
        struct {
            unsigned int size;
            unsigned int first_irq;
            irq_hw_number_t first_hwirq;
        } legacy;
        struct {
            unsigned int size;
            unsigned int *revmap;
        } linear;
        struct {
            unsigned int max_irq;
        } nomap;
        struct radix_tree_root tree;
    } revmap_data;
    const struct irq_domain_ops *ops;
    void *host_data;
    irq_hw_number_t inval_irq;

    /* Optional device node pointer */
    struct device_node *of_node;
};

#ifdef CONFIG_IRQ_DOMAIN
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);
struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
                     unsigned int size,
                     const struct irq_domain_ops *ops,
                     void *host_data);
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);
struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
                     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);

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);
}

extern void irq_domain_remove(struct irq_domain *host);

extern int irq_domain_associate_many(struct irq_domain *domain,
                     unsigned int irq_base,
                     irq_hw_number_t hwirq_base, int count);
static inline int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
                    irq_hw_number_t hwirq)
{
    return irq_domain_associate_many(domain, irq, hwirq, 1);
}

extern unsigned int irq_create_mapping(struct irq_domain *host,
                       irq_hw_number_t hwirq);
extern void irq_dispose_mapping(unsigned int virq);
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 unsigned int irq_linear_revmap(struct irq_domain *host,
                      irq_hw_number_t hwirq);

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);

#if defined(CONFIG_OF_IRQ)
extern void irq_domain_generate_simple(const struct of_device_id *match,
                    u64 phys_base, unsigned int irq_start);
#else /* CONFIG_OF_IRQ */
static inline void irq_domain_generate_simple(const struct of_device_id *match,
                    u64 phys_base, unsigned int irq_start) { }
#endif /* !CONFIG_OF_IRQ */

#else /* CONFIG_IRQ_DOMAIN */
static inline void irq_dispose_mapping(unsigned int virq) { }
#endif /* !CONFIG_IRQ_DOMAIN */

#endif /* _LINUX_IRQDOMAIN_H */