Linux中断内核编程
前言
在前面分析了中断的基本原理后，就可以写一个内核中断程序来体验以下，也可以借此程序继续深入来了解内核中断的执行过程
一.内核中断程序：
我们还是来看一看成程序：
在看程序之前，要熟悉如何进行模块编程，和了解module_pararm()的用法。如果不熟悉的话请大家看，module_param()的学习和Linux内核模块编程，在此不作解释。
1.程序interrupt.c
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1
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:=http://www.3lian.com/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
#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
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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; 188 unsigned int status;
189 190 unsigned int depth;
191 unsigned int wake_depth; 192 unsigned int irq_count;
193 unsigned long last_unhandled; 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
135#ifdef CONFIG_IRQ_RELEASE_METHOD 136 void (*release)(unsigned int irq, void *dev_id);
137#endif 138 142 const char *typename;
143}; 144
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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 [c-sharp] view plaincopy
1049int request_threaded_irq(unsigned int irq, irq_handler_t handler, 1050 irq_handler_t thread_fn, unsigned long irqflags,
1051 const char *devname, void *dev_id) 1052{
1053 struct irqaction *action; 1054 struct irq_desc *desc;
1055 int retval; 1056
1057
1063 if ((irqflags & IRQF_SHARED) && !dev_id) 1064 return -EINVAL;
1065 1066 desc=irq_to_desc(irq);
1067 if (!desc) 1068 return -EINVAL;
1069 1070 if (desc->status & IRQ_NOREQUEST)
1071 return -EINVAL; 1072
1073 if (!handler) { 1074 if (!thread_fn)
1075 return -EINVAL; 1076 handler=irq_default_primary_handler;
1077 } 1078
1079 action=kzalloc(sizeof(struct irqaction), GFP_KERNEL); 1080 if (!action)
1081 return -ENOMEM; 1082
1083 action->handler=handler; 1084 action->thread_fn=thread_fn;
1085 action->flags=irqflags; 1086 action->name=devname;
1087 action->dev_id=dev_id; 1088
1089 chip_bus_lock(irq, desc); 1090 retval=__setup_irq(irq, desc, action);
1091 chip_bus_sync_unlock(irq, desc); 1092
1093 if (retval) 1094 kfree(action);
1095 1096#ifdef CONFIG_DEBUG_SHIRQ
1097 if (!retval && (irqflags & IRQF_SHARED)) { 1098 1104 unsigned long flags;
1105 1106 disable_irq(irq);
1107 local_irq_save(flags); 1108
1109 handler(irq, dev_id); 1110
1111 local_irq_restore(flags); 1112 enable_irq(irq);
1113 } 1114#endif
1115 return retval; 1116} [c-sharp] view plaincopy
993void free_irq(unsigned int irq, void *dev_id) 994{
995 struct irq_desc *desc=irq_to_desc(irq); 996
997 if (!desc) 998 return;
999 1000 chip_bus_lock(irq, desc);
1001 kfree(__free_irq(irq, dev_id)); 1002 chip_bus_sync_unlock(irq, desc);
