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#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/config.h>
#include <linux/init.h>
#include <linux/fs.h>
#include "vhd.h"
#include "vhdheader.h"
#include <asm/semaphore.h>

struct file_operations *fileOp;
struct vhd_block *rBlock;
struct vhd_block *wBlock;
struct semaphore *sem0;
struct semaphore *sem1;

int ioctl_function(struct inode *ip, struct file *fp, unsigned int cmd, unsigned long param) {
	struct vhd_header *userSpace  = (struct vhd_header *)kmalloc(sizeof(struct vhd_header), GFP_KERNEL);
	
	printk("ioctl function called\n");
		
	copy_from_user(userSpace, (struct vhd_header *)param, sizeof(struct vhd_header));
	down(sem1);
	printk("copied ok\n");
	if (cmd == VHD_WRITE) {
		printk("WriteIOCTL\n");
		wBlock -> block_number = userSpace->block_number;
		wBlock -> operation = VHD_WRITE;
		memcpy(wBlock->data, userSpace->data, 64);	
		
	printk(">>>%s and %s\n", wBlock->data, userSpace->data);
		//down(sem0);
		vhd_request_operation(wBlock);
		//down(sem1);
		//up(sem0);
	}

	if (cmd == VHD_READ) {
		printk("ReadIOCTL\n");
		rBlock -> block_number = userSpace->block_number;
		rBlock -> operation = VHD_READ;
		vhd_request_operation(rBlock);
		down(sem0);
		printk("IOCTL read data: %s\n", rBlock->data);
		copy_to_user((struct vhd_header *)param, rBlock, sizeof(struct vhd_header));
		
	}

	printk("end of ioctl\n");

}

void callBack(struct vhd_block *block) {

	if (block->operation == VHD_READ) {
		printk("Data read: %s\n", block->data);
		up(sem0);
	}
	else if (block->operation == VHD_WRITE) {
		printk("Data: %s - Written to: %d\n", block->data, block->block_number);
		//up(sem1);

	}

	kfree(block);
	up(sem1);

}

int init(void)
{
	fileOp = (struct file_operations *)kmalloc(sizeof(struct file_operations), GFP_KERNEL);
	
	sem0 = (struct semaphore *)kmalloc(sizeof(struct semaphore), GFP_KERNEL);
	sem1 = (struct semaphore *)kmalloc(sizeof(struct semaphore), GFP_KERNEL);

	memset(fileOp, 0, sizeof (struct file_operations));

	sema_init(sem0, 0);
	sema_init(sem1, 1);

	fileOp->ioctl = ioctl_function;
	register_chrdev (241, "VHD", fileOp);

	rBlock = (struct vhd_block *)kmalloc(sizeof(struct vhd_block), GFP_KERNEL);
	wBlock = (struct vhd_block *)kmalloc(sizeof(struct vhd_block), GFP_KERNEL);
	vhd_init();

	vhd_register_interrupt(callBack);

	return 0;
}

void cleanup(void)
{
	unregister_chrdev(241, "VHD");
	vhd_cleanup();
}


module_init(init);
module_exit(cleanup);
MODULE_LICENSE("GPL");