#include <linux/slab.h>#include <asm/types.h>#include <asm/uaccess.h>#include "circular_buf.h"#ifdef DEBUG	#define	mydebug(fmt,args...)	printk(fmt,##args)#else	#define	mydebug(fmt,args...)#endifvoid clear_circular_buf(struct circular_buffer *buf)//yangxing modify{	buf->in=buf->out=0;}//circular_buffer operationsvoid init_circular_buf(struct circular_buffer *buf, int size)//yangxing modify{	buf->size=size;//512;	buf->in=buf->out=0;	buf->buffer=kmalloc(buf->size,GFP_KERNEL);}void free_circular_buf(struct circular_buffer *buf){	kfree(buf->buffer);}int write_to_circular_buf(struct circular_buffer *buf, char __user *pdata,int count){	unsigned int l;	unsigned int mask;	int count_t = count;	mask=buf->size-1;	count_t	= min( count_t, mask& (mask - buf->in + buf->out ) );	l	= min( count_t, buf->size - (buf->in & mask) );	copy_from_user(buf->buffer + (buf->in & mask), pdata, l);	copy_from_user(buf->buffer, pdata+l, count_t-l);	buf->in +=count_t;	return count_t;}int read_circular_buf_1(struct circular_buffer *buf, char *pdata){	unsigned int mask=buf->size-1;	if(buf->out!=buf->in){		*pdata=buf->buffer[buf->out&mask];		buf->out++;		return 1;	}	return 0;}int can_circular_buf_write(struct circular_buffer *buf){	if( (buf->in+1)==buf->out) return 0;	return 1;}int can_circular_buf_read(struct circular_buffer *buf){	if( buf->in==buf->out) return 0;	return 1;}int write_circular_buf_1(struct circular_buffer *buf, char data){	unsigned int mask=buf->size-1;	if((buf->in+1)!=buf->out){		buf->buffer[ buf->in&mask ]=data;		buf->in++;		return 1;	}	return 0;}int read_from_circular_buf(struct circular_buffer *buf, char __user *pdata, int count){	unsigned int l;	unsigned int mask;	int count_t = count;	mask =buf->size-1;	count_t	= min(count_t, buf->in - buf->out);	l	= min(count_t, buf->size - (buf->out &mask));		copy_to_user(pdata, buf->buffer+ (buf->out & mask), l);	copy_to_user(pdata+l, buf->buffer, count_t -l);	buf->out+=count_t;	return count_t;}//yangxingint write_circular_buf(struct circular_buffer *buf, char *pdata,int count){	unsigned int l;	unsigned int mask;	int count_t = count;	mask=buf->size-1;	count_t	= min( count_t, mask& (mask - buf->in + buf->out ) );	l	= min( count_t, buf->size - (buf->in & mask) );	memcpy(buf->buffer + (buf->in & mask), pdata, l);	memcpy(buf->buffer, pdata+l, count_t-l);	buf->in +=count_t;	return count_t;}int read_circular_buf(struct circular_buffer *buf, char *pdata, int count){	unsigned int l;	unsigned int mask;	uint count_t = count;	mask =buf->size-1;	count_t	= min(count_t, buf->in - buf->out);	l	= min(count_t, buf->size - (buf->out &mask));		memcpy(pdata, buf->buffer+ (buf->out & mask), l);	memcpy(pdata+l, buf->buffer, count_t -1);	buf->out+=count_t;	return count_t;}