[IA64] update memory attribute aliasing documentation & test cases
Updates documentation and adds some test cases. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Bjorn Helgaas
Tony Luck
247
Documentation/ia64/aliasing-test.c
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247
Documentation/ia64/aliasing-test.c
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/*
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* Exercise /dev/mem mmap cases that have been troublesome in the past
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*
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* (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
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* Bjorn Helgaas <bjorn.helgaas@hp.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <sys/types.h>
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#include <dirent.h>
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#include <fcntl.h>
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#include <fnmatch.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <unistd.h>
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int sum;
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int map_mem(char *path, off_t offset, size_t length, int touch)
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{
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int fd, rc;
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void *addr;
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int *c;
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fd = open(path, O_RDWR);
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if (fd == -1) {
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perror(path);
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return -1;
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}
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addr = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_SHARED, fd, offset);
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if (addr == MAP_FAILED)
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return 1;
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if (touch) {
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c = (int *) addr;
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while (c < (int *) (offset + length))
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sum += *c++;
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}
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rc = munmap(addr, length);
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if (rc == -1) {
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perror("munmap");
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return -1;
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}
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close(fd);
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return 0;
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}
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int scan_sysfs(char *path, char *file, off_t offset, size_t length, int touch)
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{
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struct dirent **namelist;
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char *name, *path2;
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int i, n, r, rc, result = 0;
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struct stat buf;
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n = scandir(path, &namelist, 0, alphasort);
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if (n < 0) {
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perror("scandir");
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return -1;
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}
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for (i = 0; i < n; i++) {
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name = namelist[i]->d_name;
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if (fnmatch(".", name, 0) == 0)
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goto skip;
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if (fnmatch("..", name, 0) == 0)
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goto skip;
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path2 = malloc(strlen(path) + strlen(name) + 3);
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strcpy(path2, path);
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strcat(path2, "/");
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strcat(path2, name);
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if (fnmatch(file, name, 0) == 0) {
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rc = map_mem(path2, offset, length, touch);
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if (rc == 0)
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fprintf(stderr, "PASS: %s 0x%lx-0x%lx is %s\n", path2, offset, offset + length, touch ? "readable" : "mappable");
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else if (rc > 0)
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fprintf(stderr, "PASS: %s 0x%lx-0x%lx not mappable\n", path2, offset, offset + length);
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else {
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fprintf(stderr, "FAIL: %s 0x%lx-0x%lx not accessible\n", path2, offset, offset + length);
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return rc;
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}
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} else {
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r = lstat(path2, &buf);
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if (r == 0 && S_ISDIR(buf.st_mode)) {
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rc = scan_sysfs(path2, file, offset, length, touch);
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if (rc < 0)
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return rc;
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}
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}
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result |= rc;
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free(path2);
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skip:
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free(namelist[i]);
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}
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free(namelist);
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return rc;
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}
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char buf[1024];
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int read_rom(char *path)
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{
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int fd, rc;
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size_t size = 0;
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fd = open(path, O_RDWR);
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if (fd == -1) {
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perror(path);
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return -1;
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}
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rc = write(fd, "1", 2);
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if (rc <= 0) {
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perror("write");
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return -1;
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}
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do {
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rc = read(fd, buf, sizeof(buf));
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if (rc > 0)
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size += rc;
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} while (rc > 0);
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close(fd);
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return size;
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}
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int scan_rom(char *path, char *file)
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{
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struct dirent **namelist;
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char *name, *path2;
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int i, n, r, rc, result = 0;
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struct stat buf;
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n = scandir(path, &namelist, 0, alphasort);
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if (n < 0) {
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perror("scandir");
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return -1;
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}
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for (i = 0; i < n; i++) {
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name = namelist[i]->d_name;
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if (fnmatch(".", name, 0) == 0)
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goto skip;
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if (fnmatch("..", name, 0) == 0)
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goto skip;
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path2 = malloc(strlen(path) + strlen(name) + 3);
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strcpy(path2, path);
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strcat(path2, "/");
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strcat(path2, name);
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if (fnmatch(file, name, 0) == 0) {
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rc = read_rom(path2);
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/*
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* It's OK if the ROM is unreadable. Maybe there
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* is no ROM, or some other error ocurred. The
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* important thing is that no MCA happened.
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*/
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if (rc > 0)
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fprintf(stderr, "PASS: %s read %ld bytes\n", path2, rc);
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else {
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fprintf(stderr, "PASS: %s not readable\n", path2);
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return rc;
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}
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} else {
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r = lstat(path2, &buf);
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if (r == 0 && S_ISDIR(buf.st_mode)) {
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rc = scan_rom(path2, file);
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if (rc < 0)
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return rc;
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}
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}
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result |= rc;
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free(path2);
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skip:
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free(namelist[i]);
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}
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free(namelist);
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return rc;
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}
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main()
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{
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int rc;
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if (map_mem("/dev/mem", 0, 0xA0000, 1) == 0)
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fprintf(stderr, "PASS: /dev/mem 0x0-0xa0000 is readable\n");
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else
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fprintf(stderr, "FAIL: /dev/mem 0x0-0xa0000 not accessible\n");
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/*
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* It's not safe to blindly read the VGA frame buffer. If you know
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* how to poke the card the right way, it should respond, but it's
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* not safe in general. Many machines, e.g., Intel chipsets, cover
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* up a non-responding card by just returning -1, but others will
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* report the failure as a machine check.
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*/
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if (map_mem("/dev/mem", 0xA0000, 0x20000, 0) == 0)
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fprintf(stderr, "PASS: /dev/mem 0xa0000-0xc0000 is mappable\n");
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else
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fprintf(stderr, "FAIL: /dev/mem 0xa0000-0xc0000 not accessible\n");
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if (map_mem("/dev/mem", 0xC0000, 0x40000, 1) == 0)
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fprintf(stderr, "PASS: /dev/mem 0xc0000-0x100000 is readable\n");
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else
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fprintf(stderr, "FAIL: /dev/mem 0xc0000-0x100000 not accessible\n");
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/*
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* Often you can map all the individual pieces above (0-0xA0000,
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* 0xA0000-0xC0000, and 0xC0000-0x100000), but can't map the whole
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* thing at once. This is because the individual pieces use different
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* attributes, and there's no single attribute supported over the
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* whole region.
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*/
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rc = map_mem("/dev/mem", 0, 1024*1024, 0);
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if (rc == 0)
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fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 is mappable\n");
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else if (rc > 0)
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fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 not mappable\n");
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else
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fprintf(stderr, "FAIL: /dev/mem 0x0-0x100000 not accessible\n");
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scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0, 0xA0000, 1);
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scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0xA0000, 0x20000, 0);
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scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0xC0000, 0x40000, 1);
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scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0, 1024*1024, 0);
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scan_rom("/sys/devices", "rom");
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}
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