Linux module to convert virtual to physical and vice versa

virt_to_phys: Function converts kernel virtual address to physical address.
phys_to_virt: Function converts physical address to kernel virtual address.

Code:

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/mm.h>
	#include <linux/moduleparam.h>
	#include <asm/io.h>
	static void *virtual_addr;
	static phys_addr_t physical_addr;
	int size = 1024; /* allocate 1024 bytes */
	static int alloc_init(void)
	{
	virtual_addr = kmalloc(size,GFP_ATOMIC);
	if(!virtual_addr) {
	/* handle error */
	pr_err("memory allocation failed\n");
	return -ENOMEM;
	} else {
	pr_info("Memory allocated successfully Virtual address:%p\n", virtual_addr);
	physical_addr = virt_to_phys(virtual_addr);
	pr_info("Physical address:%llx\n", physical_addr);
	pr_info("Virtual address:%p\n", phys_to_virt(physical_addr));
	}
	return 0;
	}
	static void alloc_exit(void)
	{
	kfree(virtual_addr);
	pr_info("Memory freed\n");
	}
	module_init(alloc_init);
	module_exit(alloc_exit);
	MODULE_LICENSE("GPL");

view raw kmalloc_test.c hosted with ❤ by GitHub

Output: