在Linux内核驱动中,构建一个存放如下结构体的队列:struct msg { u16 module_id; u16 cmd_id; u16 cmd_subid; u16 complete; u8 data[128]; };队列结构体如下:struct ring_buffer { int head; int tail; struct msg *data; int size; unsigned int capacity; };请给出操作这个队列的函数,包括初始化,入队,出队,注销等;再构建两个函数,函数一初始化msg结构体,将除了data数组外的所有成员设置为常数(其中complete设置为0),向data数组内放置两个unsigned int 类型数据,之后将msg结构体放入队列中,触发函数二,等待函数二将msg的complete成员设置为1后,获取函数二更新的msg的data成员;函数二需要从队列中取出msg,并进行解析:判断module_id是否为0x1,如果不是,报错,之后使用switch函数解析cmd_id,再根据不同的cmd_id解析cmd_subid,将一个unsigned int 类型数据放到函数一放置的两个数据之后,再将msg中的complete置1;请在驱动的probe函数中注册这个队列,在remove函数中注销队列
时间: 2024-03-17 09:41:26 浏览: 47
LINUX内核和驱动编程
初始化操作:
```
void init_ring_buffer(struct ring_buffer *rb, int size)
{
rb->head = 0;
rb->tail = 0;
rb->data = kmalloc(size * sizeof(struct msg), GFP_KERNEL);
if (!rb->data) {
printk(KERN_ERR "Failed to allocate buffer\n");
return;
}
rb->size = size;
rb->capacity = size - 1;
}
```
入队操作:
```
int enqueue(struct ring_buffer *rb, struct msg msg)
{
int next_tail = (rb->tail + 1) % rb->size;
if (next_tail == rb->head) {
printk(KERN_ERR "Buffer is full\n");
return -1;
}
memcpy(&rb->data[rb->tail], &msg, sizeof(struct msg));
rb->tail = next_tail;
return 0;
}
```
出队操作:
```
int dequeue(struct ring_buffer *rb, struct msg *msg)
{
if (rb->head == rb->tail) {
printk(KERN_ERR "Buffer is empty\n");
return -1;
}
memcpy(msg, &rb->data[rb->head], sizeof(struct msg));
rb->head = (rb->head + 1) % rb->size;
return 0;
}
```
注销操作:
```
void free_ring_buffer(struct ring_buffer *rb)
{
kfree(rb->data);
rb->data = NULL;
rb->head = 0;
rb->tail = 0;
rb->size = 0;
}
```
初始化msg结构体并入队:
```
void init_msg_and_enqueue(struct ring_buffer *rb, u16 module_id, u16 cmd_id, u16 cmd_subid, u8 data[128])
{
struct msg msg;
msg.module_id = module_id;
msg.cmd_id = cmd_id;
msg.cmd_subid = cmd_subid;
msg.complete = 0;
memcpy(msg.data, data, sizeof(u32) * 2);
enqueue(rb, msg);
// Wait for completion
wait_for_completion(&msg.completion);
// Get updated data
memcpy(data, msg.data, sizeof(u32) * 2);
}
```
解析msg结构体并更新:
```
void parse_and_update(struct ring_buffer *rb, struct msg *msg)
{
if (msg->module_id != 0x1) {
printk(KERN_ERR "Invalid module ID\n");
return;
}
switch (msg->cmd_id) {
case 0x1:
switch (msg->cmd_subid) {
case 0x1:
// Update data
*(u32 *)msg->data[8] = 0x12345678;
*(u32 *)msg->data[12] = 0x87654321;
break;
default:
printk(KERN_ERR "Invalid command sub ID\n");
break;
}
break;
default:
printk(KERN_ERR "Invalid command ID\n");
break;
}
msg->complete = 1;
complete(&msg->completion);
}
```
在probe函数中注册队列:
```
struct ring_buffer rb;
init_ring_buffer(&rb, 16);
// Register queue
if (misc_register(&my_dev) < 0) {
printk(KERN_ERR "Failed to register device\n");
free_ring_buffer(&rb);
return -1;
}
```
在remove函数中注销队列:
```
misc_deregister(&my_dev);
free_ring_buffer(&rb);
```
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