linux中斷--內核中斷編程

　　Linux中斷內核編程

　　前言

　　在前面分析了中斷的基本原理後，就可以寫一個內核中斷程序來體驗以下，也可以借此程序繼續深入來了解內核中斷的執行過程

　　一.內核中斷程序：

　　我們還是來看一看成程序：

　　在看程序之前，要熟悉如何進行模塊編程，和了解module_pararm()的用法。如果不熟悉的話請大家看，module_param()的學習和Linux內核模塊編程，在此不作解釋。

　　1.程序interrupt.c

　　[c-sharp] view plaincopy

　　1 /* 2 *file name :interrupt.c

　　3 *atuthor : john 4 */

　　5 #include 6 #include

　　7 #include 8 #include

　　9 10 MODULE_LICENSE("GPL");

　　11 static int irq; 12 char *interface;

　　13 static irqreturn_t myirq_handler(int irq,void *dev); 14

　　15 static int __init myirq_init(void) 16 {

　　17 printk("the module is working!/n"); 18 printk("the irq is ready for working!/n");

　　19 if(request_irq(irq,myirq_handler,IRQF_SHARED,interface,&irq)){ 20 printk(KERN_ERR "%s interrrupt can't register %d IRQ /n",interface,irq);

　　21 return -EIO; 22 }

　　23 printk("%s request %d IRQ/n",interface,irq); 24 return 0;

　　25 } 26 static irqreturn_t myirq_handler(int irq,void *dev)

　　27 { 28 printk("%d IRQ is working/n",irq);

　　29 return IRQ_NONE; 30 }

　　31 static void __exit myirq_exit(void) 32 {

　　33 printk("the module is leaving!/n"); 34 printk("the irq is bye bye!/n");

　　35 free_irq(irq,&irq); 36 printk("%s interrupt free %d IRQ/n",interface,irq);

　　37 38 }

　　39 module_init(myirq_init); 0 module_exit(myirq_exit);

　　41 module_param(interface,charp,0644); 42 module_param(irq,int,0644);

　　43 [c-sharp] view plaincopy

　　1 obj-m:=tiger.o 2

　　3 CURRENT_PATH:=$(shell pwd) 4 VERSION_NUM:=$(shell uname -r)

　　5 LINUX_PATH:=/usr/src/linux-headers-$(VERSION_NUM) 6

　　7 8 all :

　　9 make -C $(LINUX_PATH) M=$(CURRENT_PATH) modules 10 clean:

　　11 make -C $(LINUX_PATH) M=$(CURRENT_PATH) clean [c-sharp] view plaincopy

　　/* * These flags used only by the kernel as part of the

　　* irq handling routines. *

　　* IRQF_DISABLED - keep irqs disabled when calling the action handler * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator

　　* IRQF_SHARED - allow sharing the irq among several devices * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur

　　* IRQF_TIMER - Flag to mark this interrupt as timer interrupt * IRQF_PERCPU - Interrupt is per cpu

　　* IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is

　　* registered first in an shared interrupt is considered for * performance reasons)

　　*/ #define IRQF_DISABLED 0x00000020

　　#define IRQF_SAMPLE_RANDOM 0x00000040 #define IRQF_SHARED 0x00000080

　　#define IRQF_PROBE_SHARED 0x00000100 #define IRQF_TIMER 0x00000200

　　#define IRQF_PERCPU 0x00000400 #define IRQF_NOBALANCING 0x00000800

　　#define IRQF_IRQPOLL 0x00001000

　　[c-sharp] view plaincopy

　　113struct irqaction { 114 irq_handler_t handler;

　　115 unsigned long flags; 116 const char *name;

　　117 void *dev_id; 118 struct irqaction *next;

　　119 int irq; 120 struct proc_dir_entry *dir;

　　121 irq_handler_t thread_fn; 122 struct task_struct *thread;

　　123 unsigned long thread_flags; 124};

　　125 [c-sharp] view plaincopy

　　175struct irq_desc { 176 unsigned int irq;

　　177 struct timer_rand_state *timer_rand_state; 178 unsigned int *kstat_irqs;

　　179#ifdef CONFIG_INTR_REMAP 180 struct irq_2_iommu *irq_2_iommu;

　　181#endif 182 irq_flow_handler_t handle_irq;

　　183 struct irq_chip *chip; 184 struct msi_desc *msi_desc;

　　185 void *handler_data; 186 void *chip_data;

　　187 struct irqaction *action; /* IRQ action list */ 188 unsigned int status; /* IRQ status */

　　189 190 unsigned int depth; /* nested irq disables */

　　191 unsigned int wake_depth; /* nested wake enables */ 192 unsigned int irq_count; /* For detecting broken IRQs */

　　193 unsigned long last_unhandled; /* Aging timer for unhandled count */ 194 unsigned int irqs_unhandled;

　　195 raw_spinlock_t lock; 196#ifdef CONFIG_SMP

　　197 cpumask_var_t affinity; 198 const struct cpumask *affinity_hint;

　　199 unsigned int node; 200#ifdef CONFIG_GENERIC_PENDING_IRQ

　　201 cpumask_var_t pending_mask; 202#endif

　　203#endif 204 atomic_t threads_active;

　　205 wait_queue_head_t wait_for_threads; 206#ifdef CONFIG_PROC_FS

　　207 struct proc_dir_entry *dir; 208#endif

　　209 const char *name; 210} ____cacheline_internodealigned_in_smp;

　　211 212extern void arch_init_copy_chip_data(struct irq_desc *old_desc,

　　213 struct irq_desc *desc, int node); 214extern void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc);

　　215 216#ifndef CONFIG_SPARSE_IRQ

　　217extern struct irq_desc irq_desc[NR_IRQS]; [c-sharp] view plaincopy

　　111struct irq_chip { 112 const char *name;

　　113 unsigned int (*startup)(unsigned int irq); 114 void (*shutdown)(unsigned int irq);

　　115 void (*enable)(unsigned int irq); 116 void (*disable)(unsigned int irq);

　　117 118 void (*ack)(unsigned int irq);

　　119 void (*mask)(unsigned int irq); 120 void (*mask_ack)(unsigned int irq);

　　121 void (*unmask)(unsigned int irq); 122 void (*eoi)(unsigned int irq);

　　123 124 void (*end)(unsigned int irq);

　　125 int (*set_affinity)(unsigned int irq, 126 const struct cpumask *dest);

　　127 int (*retrigger)(unsigned int irq); 128 int (*set_type)(unsigned int irq, unsigned int flow_type);

　　129 int (*set_wake)(unsigned int irq, unsigned int on); 130

　　131 void (*bus_lock)(unsigned int irq); 132 void (*bus_sync_unlock)(unsigned int irq);

　　133 134 /* Currently used only by UML, might disappear one day.*/

　　135#ifdef CONFIG_IRQ_RELEASE_METHOD 136 void (*release)(unsigned int irq, void *dev_id);

　　137#endif 138 /*

　　139 * For compatibility, ->typename is copied into ->name. 140 * Will disappear.

　　141 */ 142 const char *typename;

　　143}; 144

　　[c-sharp] view plaincopy

　　135request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, 136 const char *name, void *dev)

　　137{ 138 return request_threaded_irq(irq, handler, NULL, flags, name, dev);

　　139} 140 [c-sharp] view plaincopy

　　1006/** 1007 * request_threaded_irq - allocate an interrupt line

　　1008 * @irq: Interrupt line to allocate 1009 * @handler: Function to be called when the IRQ occurs.

　　1010 * Primary handler for threaded interrupts 1011 * If NULL and thread_fn != NULL the default

　　1012 * primary handler is installed 1013 * @thread_fn: Function called from the irq handler thread

　　1014 * If NULL, no irq thread is created 1015 * @irqflags: Interrupt type flags

　　1016 * @devname: An ascii name for the claiming device 1017 * @dev_id: A cookie passed back to the handler function

　　1018 * 1019 * This call allocates interrupt resources and enables the

　　1020 * interrupt line and IRQ handling. From the point this 1021 * call is made your handler function may be invoked. Since

　　1022 * your handler function must clear any interrupt the board 1023 * raises, you mus