[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>
diff --git a/Documentation/ia64/aliasing-test.c b/Documentation/ia64/aliasing-test.c
new file mode 100644
index 0000000..3153167
--- /dev/null
+++ b/Documentation/ia64/aliasing-test.c
@@ -0,0 +1,247 @@
+/*
+ * Exercise /dev/mem mmap cases that have been troublesome in the past
+ *
+ * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ * Bjorn Helgaas <bjorn.helgaas@hp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <fnmatch.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+int sum;
+
+int map_mem(char *path, off_t offset, size_t length, int touch)
+{
+ int fd, rc;
+ void *addr;
+ int *c;
+
+ fd = open(path, O_RDWR);
+ if (fd == -1) {
+ perror(path);
+ return -1;
+ }
+
+ addr = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_SHARED, fd, offset);
+ if (addr == MAP_FAILED)
+ return 1;
+
+ if (touch) {
+ c = (int *) addr;
+ while (c < (int *) (offset + length))
+ sum += *c++;
+ }
+
+ rc = munmap(addr, length);
+ if (rc == -1) {
+ perror("munmap");
+ return -1;
+ }
+
+ close(fd);
+ return 0;
+}
+
+int scan_sysfs(char *path, char *file, off_t offset, size_t length, int touch)
+{
+ struct dirent **namelist;
+ char *name, *path2;
+ int i, n, r, rc, result = 0;
+ struct stat buf;
+
+ n = scandir(path, &namelist, 0, alphasort);
+ if (n < 0) {
+ perror("scandir");
+ return -1;
+ }
+
+ for (i = 0; i < n; i++) {
+ name = namelist[i]->d_name;
+
+ if (fnmatch(".", name, 0) == 0)
+ goto skip;
+ if (fnmatch("..", name, 0) == 0)
+ goto skip;
+
+ path2 = malloc(strlen(path) + strlen(name) + 3);
+ strcpy(path2, path);
+ strcat(path2, "/");
+ strcat(path2, name);
+
+ if (fnmatch(file, name, 0) == 0) {
+ rc = map_mem(path2, offset, length, touch);
+ if (rc == 0)
+ fprintf(stderr, "PASS: %s 0x%lx-0x%lx is %s\n", path2, offset, offset + length, touch ? "readable" : "mappable");
+ else if (rc > 0)
+ fprintf(stderr, "PASS: %s 0x%lx-0x%lx not mappable\n", path2, offset, offset + length);
+ else {
+ fprintf(stderr, "FAIL: %s 0x%lx-0x%lx not accessible\n", path2, offset, offset + length);
+ return rc;
+ }
+ } else {
+ r = lstat(path2, &buf);
+ if (r == 0 && S_ISDIR(buf.st_mode)) {
+ rc = scan_sysfs(path2, file, offset, length, touch);
+ if (rc < 0)
+ return rc;
+ }
+ }
+
+ result |= rc;
+ free(path2);
+
+skip:
+ free(namelist[i]);
+ }
+ free(namelist);
+ return rc;
+}
+
+char buf[1024];
+
+int read_rom(char *path)
+{
+ int fd, rc;
+ size_t size = 0;
+
+ fd = open(path, O_RDWR);
+ if (fd == -1) {
+ perror(path);
+ return -1;
+ }
+
+ rc = write(fd, "1", 2);
+ if (rc <= 0) {
+ perror("write");
+ return -1;
+ }
+
+ do {
+ rc = read(fd, buf, sizeof(buf));
+ if (rc > 0)
+ size += rc;
+ } while (rc > 0);
+
+ close(fd);
+ return size;
+}
+
+int scan_rom(char *path, char *file)
+{
+ struct dirent **namelist;
+ char *name, *path2;
+ int i, n, r, rc, result = 0;
+ struct stat buf;
+
+ n = scandir(path, &namelist, 0, alphasort);
+ if (n < 0) {
+ perror("scandir");
+ return -1;
+ }
+
+ for (i = 0; i < n; i++) {
+ name = namelist[i]->d_name;
+
+ if (fnmatch(".", name, 0) == 0)
+ goto skip;
+ if (fnmatch("..", name, 0) == 0)
+ goto skip;
+
+ path2 = malloc(strlen(path) + strlen(name) + 3);
+ strcpy(path2, path);
+ strcat(path2, "/");
+ strcat(path2, name);
+
+ if (fnmatch(file, name, 0) == 0) {
+ rc = read_rom(path2);
+
+ /*
+ * It's OK if the ROM is unreadable. Maybe there
+ * is no ROM, or some other error ocurred. The
+ * important thing is that no MCA happened.
+ */
+ if (rc > 0)
+ fprintf(stderr, "PASS: %s read %ld bytes\n", path2, rc);
+ else {
+ fprintf(stderr, "PASS: %s not readable\n", path2);
+ return rc;
+ }
+ } else {
+ r = lstat(path2, &buf);
+ if (r == 0 && S_ISDIR(buf.st_mode)) {
+ rc = scan_rom(path2, file);
+ if (rc < 0)
+ return rc;
+ }
+ }
+
+ result |= rc;
+ free(path2);
+
+skip:
+ free(namelist[i]);
+ }
+ free(namelist);
+ return rc;
+}
+
+main()
+{
+ int rc;
+
+ if (map_mem("/dev/mem", 0, 0xA0000, 1) == 0)
+ fprintf(stderr, "PASS: /dev/mem 0x0-0xa0000 is readable\n");
+ else
+ fprintf(stderr, "FAIL: /dev/mem 0x0-0xa0000 not accessible\n");
+
+ /*
+ * It's not safe to blindly read the VGA frame buffer. If you know
+ * how to poke the card the right way, it should respond, but it's
+ * not safe in general. Many machines, e.g., Intel chipsets, cover
+ * up a non-responding card by just returning -1, but others will
+ * report the failure as a machine check.
+ */
+ if (map_mem("/dev/mem", 0xA0000, 0x20000, 0) == 0)
+ fprintf(stderr, "PASS: /dev/mem 0xa0000-0xc0000 is mappable\n");
+ else
+ fprintf(stderr, "FAIL: /dev/mem 0xa0000-0xc0000 not accessible\n");
+
+ if (map_mem("/dev/mem", 0xC0000, 0x40000, 1) == 0)
+ fprintf(stderr, "PASS: /dev/mem 0xc0000-0x100000 is readable\n");
+ else
+ fprintf(stderr, "FAIL: /dev/mem 0xc0000-0x100000 not accessible\n");
+
+ /*
+ * Often you can map all the individual pieces above (0-0xA0000,
+ * 0xA0000-0xC0000, and 0xC0000-0x100000), but can't map the whole
+ * thing at once. This is because the individual pieces use different
+ * attributes, and there's no single attribute supported over the
+ * whole region.
+ */
+ rc = map_mem("/dev/mem", 0, 1024*1024, 0);
+ if (rc == 0)
+ fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 is mappable\n");
+ else if (rc > 0)
+ fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 not mappable\n");
+ else
+ fprintf(stderr, "FAIL: /dev/mem 0x0-0x100000 not accessible\n");
+
+ scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0, 0xA0000, 1);
+ scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0xA0000, 0x20000, 0);
+ scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0xC0000, 0x40000, 1);
+ scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0, 1024*1024, 0);
+
+ scan_rom("/sys/devices", "rom");
+}