1/*
2 * Exercise /dev/mem mmap cases that have been troublesome in the past
3 *
4 * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
5 *	Bjorn Helgaas <bjorn.helgaas@hp.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <stdlib.h>
13#include <stdio.h>
14#include <sys/types.h>
15#include <dirent.h>
16#include <fcntl.h>
17#include <fnmatch.h>
18#include <string.h>
19#include <sys/ioctl.h>
20#include <sys/mman.h>
21#include <sys/stat.h>
22#include <unistd.h>
23#include <linux/pci.h>
24
25int sum;
26
27static int map_mem(char *path, off_t offset, size_t length, int touch)
28{
29	int fd, rc;
30	void *addr;
31	int *c;
32
33	fd = open(path, O_RDWR);
34	if (fd == -1) {
35		perror(path);
36		return -1;
37	}
38
39	if (fnmatch("/proc/bus/pci/*", path, 0) == 0) {
40		rc = ioctl(fd, PCIIOC_MMAP_IS_MEM);
41		if (rc == -1)
42			perror("PCIIOC_MMAP_IS_MEM ioctl");
43	}
44
45	addr = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_SHARED, fd, offset);
46	if (addr == MAP_FAILED)
47		return 1;
48
49	if (touch) {
50		c = (int *) addr;
51		while (c < (int *) (addr + length))
52			sum += *c++;
53	}
54
55	rc = munmap(addr, length);
56	if (rc == -1) {
57		perror("munmap");
58		return -1;
59	}
60
61	close(fd);
62	return 0;
63}
64
65static int scan_tree(char *path, char *file, off_t offset, size_t length, int touch)
66{
67	struct dirent **namelist;
68	char *name, *path2;
69	int i, n, r, rc = 0, result = 0;
70	struct stat buf;
71
72	n = scandir(path, &namelist, 0, alphasort);
73	if (n < 0) {
74		perror("scandir");
75		return -1;
76	}
77
78	for (i = 0; i < n; i++) {
79		name = namelist[i]->d_name;
80
81		if (fnmatch(".", name, 0) == 0)
82			goto skip;
83		if (fnmatch("..", name, 0) == 0)
84			goto skip;
85
86		path2 = malloc(strlen(path) + strlen(name) + 3);
87		strcpy(path2, path);
88		strcat(path2, "/");
89		strcat(path2, name);
90
91		if (fnmatch(file, name, 0) == 0) {
92			rc = map_mem(path2, offset, length, touch);
93			if (rc == 0)
94				fprintf(stderr, "PASS: %s 0x%lx-0x%lx is %s\n", path2, offset, offset + length, touch ? "readable" : "mappable");
95			else if (rc > 0)
96				fprintf(stderr, "PASS: %s 0x%lx-0x%lx not mappable\n", path2, offset, offset + length);
97			else {
98				fprintf(stderr, "FAIL: %s 0x%lx-0x%lx not accessible\n", path2, offset, offset + length);
99				return rc;
100			}
101		} else {
102			r = lstat(path2, &buf);
103			if (r == 0 && S_ISDIR(buf.st_mode)) {
104				rc = scan_tree(path2, file, offset, length, touch);
105				if (rc < 0)
106					return rc;
107			}
108		}
109
110		result |= rc;
111		free(path2);
112
113skip:
114		free(namelist[i]);
115	}
116	free(namelist);
117	return result;
118}
119
120char buf[1024];
121
122static int read_rom(char *path)
123{
124	int fd, rc;
125	size_t size = 0;
126
127	fd = open(path, O_RDWR);
128	if (fd == -1) {
129		perror(path);
130		return -1;
131	}
132
133	rc = write(fd, "1", 2);
134	if (rc <= 0) {
135		close(fd);
136		perror("write");
137		return -1;
138	}
139
140	do {
141		rc = read(fd, buf, sizeof(buf));
142		if (rc > 0)
143			size += rc;
144	} while (rc > 0);
145
146	close(fd);
147	return size;
148}
149
150static int scan_rom(char *path, char *file)
151{
152	struct dirent **namelist;
153	char *name, *path2;
154	int i, n, r, rc = 0, result = 0;
155	struct stat buf;
156
157	n = scandir(path, &namelist, 0, alphasort);
158	if (n < 0) {
159		perror("scandir");
160		return -1;
161	}
162
163	for (i = 0; i < n; i++) {
164		name = namelist[i]->d_name;
165
166		if (fnmatch(".", name, 0) == 0)
167			goto skip;
168		if (fnmatch("..", name, 0) == 0)
169			goto skip;
170
171		path2 = malloc(strlen(path) + strlen(name) + 3);
172		strcpy(path2, path);
173		strcat(path2, "/");
174		strcat(path2, name);
175
176		if (fnmatch(file, name, 0) == 0) {
177			rc = read_rom(path2);
178
179			/*
180			 * It's OK if the ROM is unreadable.  Maybe there
181			 * is no ROM, or some other error occurred.  The
182			 * important thing is that no MCA happened.
183			 */
184			if (rc > 0)
185				fprintf(stderr, "PASS: %s read %d bytes\n", path2, rc);
186			else {
187				fprintf(stderr, "PASS: %s not readable\n", path2);
188				return rc;
189			}
190		} else {
191			r = lstat(path2, &buf);
192			if (r == 0 && S_ISDIR(buf.st_mode)) {
193				rc = scan_rom(path2, file);
194				if (rc < 0)
195					return rc;
196			}
197		}
198
199		result |= rc;
200		free(path2);
201
202skip:
203		free(namelist[i]);
204	}
205	free(namelist);
206	return result;
207}
208
209int main(void)
210{
211	int rc;
212
213	if (map_mem("/dev/mem", 0, 0xA0000, 1) == 0)
214		fprintf(stderr, "PASS: /dev/mem 0x0-0xa0000 is readable\n");
215	else
216		fprintf(stderr, "FAIL: /dev/mem 0x0-0xa0000 not accessible\n");
217
218	/*
219	 * It's not safe to blindly read the VGA frame buffer.  If you know
220	 * how to poke the card the right way, it should respond, but it's
221	 * not safe in general.  Many machines, e.g., Intel chipsets, cover
222	 * up a non-responding card by just returning -1, but others will
223	 * report the failure as a machine check.
224	 */
225	if (map_mem("/dev/mem", 0xA0000, 0x20000, 0) == 0)
226		fprintf(stderr, "PASS: /dev/mem 0xa0000-0xc0000 is mappable\n");
227	else
228		fprintf(stderr, "FAIL: /dev/mem 0xa0000-0xc0000 not accessible\n");
229
230	if (map_mem("/dev/mem", 0xC0000, 0x40000, 1) == 0)
231		fprintf(stderr, "PASS: /dev/mem 0xc0000-0x100000 is readable\n");
232	else
233		fprintf(stderr, "FAIL: /dev/mem 0xc0000-0x100000 not accessible\n");
234
235	/*
236	 * Often you can map all the individual pieces above (0-0xA0000,
237	 * 0xA0000-0xC0000, and 0xC0000-0x100000), but can't map the whole
238	 * thing at once.  This is because the individual pieces use different
239	 * attributes, and there's no single attribute supported over the
240	 * whole region.
241	 */
242	rc = map_mem("/dev/mem", 0, 1024*1024, 0);
243	if (rc == 0)
244		fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 is mappable\n");
245	else if (rc > 0)
246		fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 not mappable\n");
247	else
248		fprintf(stderr, "FAIL: /dev/mem 0x0-0x100000 not accessible\n");
249
250	scan_tree("/sys/class/pci_bus", "legacy_mem", 0, 0xA0000, 1);
251	scan_tree("/sys/class/pci_bus", "legacy_mem", 0xA0000, 0x20000, 0);
252	scan_tree("/sys/class/pci_bus", "legacy_mem", 0xC0000, 0x40000, 1);
253	scan_tree("/sys/class/pci_bus", "legacy_mem", 0, 1024*1024, 0);
254
255	scan_rom("/sys/devices", "rom");
256
257	scan_tree("/proc/bus/pci", "??.?", 0, 0xA0000, 1);
258	scan_tree("/proc/bus/pci", "??.?", 0xA0000, 0x20000, 0);
259	scan_tree("/proc/bus/pci", "??.?", 0xC0000, 0x40000, 1);
260	scan_tree("/proc/bus/pci", "??.?", 0, 1024*1024, 0);
261
262	return rc;
263}
264