#include <stdio.h>
#include <stdlib.h>
#include <sys/io.h>

#if defined(__i386__)
typedef unsigned long long u64;
#  define __PRI64_PREFIX        "ll"
#define rdtscll(val) \
     __asm__ __volatile__("rdtsc" : "=A" (val))

#elif defined(__x86_64__)
typedef unsigned long u64;
#  define __PRI64_PREFIX        "l"

#define rdtscll(val) do { \
     unsigned int a,d; \
     asm volatile("rdtsc" : "=a" (a), "=d" (d)); \
     (val) = ((unsigned long)a) | (((unsigned long)d)<<32); \
} while(0)
#endif

# define PRId64         __PRI64_PREFIX "d"

u64 diff[1000000];
int count;
static void pio_inb(unsigned port)
{
	int i;
	u64 t1, t2;
	iopl(3);
	//ioperm(0x512, 1, 1);
	for (i = 0; i < count; i++) 
	{
	        rdtscll(t1);
		inb(port);
        	rdtscll(t2);
		diff[i] = t2-t1;
	}
	for (i = 0; i < count; i++) 
		printf("port:0x%x, tsc diff: %"PRId64"\n", port, diff[i]);
}

int main(int argc, char** argv)
{
	if (argc != 3) {
		printf("usage: app 0xport_num count\n");
		return -1;
	}

	count = atoi(argv[2]);
	pio_inb((unsigned)strtoul(argv[1], NULL, 16));

	return 0;

}