#include <sys/ioctl.h>
#include <stdio.h>
#include <linux/pci.h>
#include <errno.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>

int main(int argc, char **argv)
{
	unsigned long iobar;
	void *maddr;
	char buf[256];
	int fd;
	int i,j;
	struct timespec start, end;
	int pagesize = getpagesize();
	if (argc != 3) {
		fprintf(stderr, "Usage: %s <bb/dd.f> <addr>\n", argv[0]);
		exit(1);
	}
	if (argv[1][0] != '/') {
		snprintf(buf, sizeof(buf), "/proc/bus/pci/%s", argv[1]);
	} else
		strncpy(buf, argv[1], sizeof(buf));

	iobar = strtoul(argv[2], NULL, 0);

	fd = open(buf, O_RDWR);
	if (fd < 0) {
		fprintf(stderr, "Open %s: %s\n", buf, strerror(errno));
		exit(1);
	}
	if (!strncmp(buf, "/proc", 5) && ioctl(fd, PCIIOC_MMAP_IS_MEM, NULL)) {
                perror("ioctl");
        }

	maddr = mmap(NULL, pagesize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, iobar);
	if (maddr == MAP_FAILED) {
		perror("mmap");
		exit(1);
	}

	clock_gettime(CLOCK_MONOTONIC, &start);
	for (j=0;j<1000;j++) {
		for (i=0; i < pagesize; i++) {
			*(volatile char *)(maddr + i) = j;
		}
	}
	clock_gettime(CLOCK_MONOTONIC, &end);

	end.tv_sec -= start.tv_sec;
	if ((end.tv_nsec -= start.tv_nsec) < 0) {
		end.tv_nsec += 1000000000L;
		end.tv_sec--;
	}
	printf("Copied %d loops in %ld.%09lds\n", j, end.tv_sec, end.tv_nsec);
	return 0;
}