struct irqaction {
irq_handler_t handler; // request_irq 初始化
void *dev_id;
void __percpu *percpu_dev_id;
struct irqaction *next;
irq_handler_t thread_fn;
struct task_struct *thread;
struct irqaction *secondary;
unsigned int irq;
unsigned int flags;
unsigned long thread_flags;
unsigned long thread_mask;
const char *name;
struct proc_dir_entry *dir;
} ____cacheline_internodealigned_in_smp;
struct irq_desc {
struct irq_common_data irq_common_data;
struct irq_data irq_data;
unsigned int __percpu *kstat_irqs;
irq_flow_handler_t handle_irq;
#ifdef CONFIG_IRQ_PREFLOW_FASTEOI
irq_preflow_handler_t preflow_handler;
#endif
struct irqaction *action; /* IRQ action list */
unsigned int status_use_accessors;
unsigned int core_internal_state__do_not_mess_with_it;
unsigned int depth; /* nested irq disables */
unsigned int wake_depth; /* nested wake enables */
unsigned int irq_count; /* For detecting broken IRQs */
unsigned long last_unhandled; /* Aging timer for unhandled count */
unsigned int irqs_unhandled;
atomic_t threads_handled;
int threads_handled_last;
raw_spinlock_t lock;
struct cpumask *percpu_enabled;
#ifdef CONFIG_SMP
const struct cpumask *affinity_hint;
struct irq_affinity_notify *affinity_notify;
#ifdef CONFIG_GENERIC_PENDING_IRQ
cpumask_var_t pending_mask;
#endif
#endif
unsigned long threads_oneshot;
atomic_t threads_active;
wait_queue_head_t wait_for_threads;
#ifdef CONFIG_PM_SLEEP
unsigned int nr_actions;
unsigned int no_suspend_depth;
unsigned int cond_suspend_depth;
unsigned int force_resume_depth;
#endif
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *dir;
#endif
int parent_irq;
struct module *owner;
const char *name;
} ____cacheline_internodealigned_in_smp;
struct irq_chip {
const char *name;
unsigned int (*irq_startup)(struct irq_data *data);
void (*irq_shutdown)(struct irq_data *data);
void (*irq_enable)(struct irq_data *data);
void (*irq_disable)(struct irq_data *data);
void (*irq_ack)(struct irq_data *data);
void (*irq_mask)(struct irq_data *data);
void (*irq_mask_ack)(struct irq_data *data);
void (*irq_unmask)(struct irq_data *data);
void (*irq_eoi)(struct irq_data *data);
int (*irq_set_affinity)(struct irq_data *data, const struct cpumask *dest, bool force);
int (*irq_retrigger)(struct irq_data *data);
int (*irq_set_type)(struct irq_data *data, unsigned int flow_type);
int (*irq_set_wake)(struct irq_data *data, unsigned int on);
void (*irq_bus_lock)(struct irq_data *data);
void (*irq_bus_sync_unlock)(struct irq_data *data);
void (*irq_cpu_online)(struct irq_data *data);
void (*irq_cpu_offline)(struct irq_data *data);
void (*irq_suspend)(struct irq_data *data);
void (*irq_resume)(struct irq_data *data);
void (*irq_pm_shutdown)(struct irq_data *data);
void (*irq_calc_mask)(struct irq_data *data);
void (*irq_print_chip)(struct irq_data *data, struct seq_file *p);
int (*irq_request_resources)(struct irq_data *data);
void (*irq_release_resources)(struct irq_data *data);
void (*irq_compose_msi_msg)(struct irq_data *data, struct msi_msg *msg);
void (*irq_write_msi_msg)(struct irq_data *data, struct msi_msg *msg);
int (*irq_get_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool *state);
int (*irq_set_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool state);
int (*irq_set_vcpu_affinity)(struct irq_data *data, void *vcpu_info);
unsigned long flags;
};
/**
* struct irq_domain_ops - Methods for irq_domain objects
* @match: Match an interrupt controller device node to a host, returns
* 1 on a match
* match是判断一个指定的 interrupt controller(node 参数)是否和一个irq domain 匹配(d 参数),
* 如果匹配的话, 返回 1. 实际上, 内核中很少定义这个 callback 函数(！！！),
* 实际上struct irq_domain中有一个of_node指向了对应的 interrupt controller的device node,
* 因此, 如果不提供该函数, 那么default 的匹配函数其实就是判断 irq domain的of_node 成员是否等于传入的node 参数.
*
* @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().
*
*在 __irq_domain_add 中将ops 传递给domain
*/
struct irq_domain_ops {
int (*match)(struct irq_domain *d, struct device_node *node,
enum irq_domain_bus_token bus_token);
int (*select)(struct irq_domain *d, struct irq_fwspec *fwspec,
enum irq_domain_bus_token bus_token);
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);
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
/* extended V2 interfaces to support hierarchy irq_domains */
int (*alloc)(struct irq_domain *d, unsigned int virq,
unsigned int nr_irqs, void *arg);
void (*free)(struct irq_domain *d, unsigned int virq,
unsigned int nr_irqs);
int (*activate)(struct irq_domain *d, struct irq_data *irqd, bool reserve);
void (*deactivate)(struct irq_domain *d, struct irq_data *irq_data);
int (*translate)(struct irq_domain *d, struct irq_fwspec *fwspec,
unsigned long *out_hwirq, unsigned int *out_type);
#endif
#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
void (*debug_show)(struct seq_file *m, struct irq_domain *d,
struct irq_data *irqd, int ind);
#endif
};
struct irq_domain {
struct list_head link; // 常规操作，所有的 irq_domain 连接到全局链表上
const char *name;
const struct irq_domain_ops *ops; // 这个应该是不同的控制器操作函数不同
void *host_data;
unsigned int flags;
unsigned int mapcount; // 管理的中断源数量
/* Optional data */
struct fwnode_handle *fwnode; // 从 DTS 或 ACPI 获取的
enum irq_domain_bus_token bus_token;
struct irq_domain_chip_generic *gc;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
struct irq_domain *parent; // 这个应该就是多个中断控制器级联成树状结构
#endif
/* reverse map data. The linear map gets appended to the irq_domain */
irq_hw_number_t hwirq_max; // 最大支持的中断数量
unsigned int revmap_size; // 线性映射的大小
struct radix_tree_root revmap_tree; // 基数树映射的根节点
struct mutex revmap_mutex;
struct irq_data __rcu *revmap[]; // 线性映射用到的查找表
};
图的左侧紫色部分，主要在中断控制器驱动中进行初始化设置，包括各个结构中函数指针的指向等，其中 struct irq_chip 用于对中断控制器的硬件操作，struct irq_domain 与中断控制器对应，完成的工作是硬件中断号到 irq 的映射；