在Linux内核驱动中,构建一个存放如下结构体指针的队列: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msg所有成员设置为常数(其中msg的complete成员设置为0),向msg的data数组内放置两个unsigned int 类型数据a和b,之后将msg结构体放入队列中,触发函数二,使用usleep_range()函数等待函数二将msg的complete成员设置为1后,获取函数二放入的c并还原成unsigned int 类型;函数二需要从队列中取出msg,并进行解析:判断msg的module_id是否为0x1,如果不是,报错,如果是0x1,使用switch函数解析msg的cmd_id,再根据不同的cmd_id解析cmd_subid,具体解析内容为,取出在函数一向msg的data数组中放入的a和b,还原成unsigned int 类型数据,再将一个unsigned int 类型数据c放到msg的data数组内,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,使用移位的方式放置和还原unsigned int类型数据
时间: 2024-03-17 09:42:08 浏览: 54
浅谈Linux内核创建新进程的全过程
初始化队列函数:
```c
void init_ring_buffer(struct ring_buffer *ring, unsigned int capacity)
{
ring->head = 0;
ring->tail = 0;
ring->size = 0;
ring->capacity = capacity;
ring->data = kmalloc(capacity * sizeof(struct msg), GFP_KERNEL);
}
```
入队操作函数:
```c
int enqueue_msg(struct ring_buffer *ring, struct msg *msg)
{
if (ring->size >= ring->capacity) {
return -1; // 队列已满
}
ring->data[ring->tail] = *msg;
ring->tail = (ring->tail + 1) % ring->capacity;
ring->size++;
return 0;
}
```
出队操作函数:
```c
int dequeue_msg(struct ring_buffer *ring, struct msg *msg)
{
if (ring->size == 0) {
return -1; // 队列为空
}
*msg = ring->data[ring->head];
ring->head = (ring->head + 1) % ring->capacity;
ring->size--;
return 0;
}
```
注销队列函数:
```c
void destroy_ring_buffer(struct ring_buffer *ring)
{
kfree(ring->data);
ring->data = NULL;
ring->capacity = 0;
}
```
函数一:
```c
void init_msg(struct msg *msg, unsigned int a, unsigned int b)
{
msg->module_id = 0x1;
msg->cmd_id = 0x1;
msg->cmd_subid = 0x1;
msg->complete = 0;
*(unsigned int*)(&msg->data[0]) = a;
*(unsigned int*)(&msg->data[4]) = b;
enqueue_msg(ring, msg);
while (msg->complete == 0) {
usleep_range(1000, 2000); // 等待函数二将complete置1
}
unsigned int c = *(unsigned int*)(&msg->data[0]);
dequeue_msg(ring, msg);
}
```
函数二:
```c
void process_msg(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:
unsigned int a = *(unsigned int*)(&msg->data[0]);
unsigned int b = *(unsigned int*)(&msg->data[4]);
*(unsigned int*)(&msg->data[0]) = a << 1;
*(unsigned int*)(&msg->data[4]) = b << 1;
*(unsigned int*)(&msg->data[8]) = a + b;
msg->complete = 1;
break;
default:
printk(KERN_ERR "Invalid cmd subid\n");
break;
}
break;
default:
printk(KERN_ERR "Invalid cmd id\n");
break;
}
}
```
在probe函数中注册队列:
```c
struct ring_buffer *ring;
static int my_driver_probe(struct platform_device *pdev)
{
ring = kmalloc(sizeof(struct ring_buffer), GFP_KERNEL);
init_ring_buffer(ring, 10);
// 其他初始化操作
return 0;
}
static int my_driver_remove(struct platform_device *pdev)
{
// 其他清理操作
destroy_ring_buffer(ring);
kfree(ring);
return 0;
}
```
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