xref: /openbmc/linux/drivers/s390/cio/blacklist.c (revision 8569c914) 
1 /*
2  *  drivers/s390/cio/blacklist.c
3  *   S/390 common I/O routines -- blacklisting of specific devices
4  *
5  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
6  *			      IBM Corporation
7  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
8  *		 Cornelia Huck (cornelia.huck@de.ibm.com)
9  *		 Arnd Bergmann (arndb@de.ibm.com)
10  */
11 
12 #include <linux/init.h>
13 #include <linux/vmalloc.h>
14 #include <linux/slab.h>
15 #include <linux/proc_fs.h>
16 #include <linux/seq_file.h>
17 #include <linux/ctype.h>
18 #include <linux/device.h>
19 
20 #include <asm/cio.h>
21 #include <asm/uaccess.h>
22 
23 #include "blacklist.h"
24 #include "cio.h"
25 #include "cio_debug.h"
26 #include "css.h"
27 #include "device.h"
28 
29 /*
30  * "Blacklisting" of certain devices:
31  * Device numbers given in the commandline as cio_ignore=... won't be known
32  * to Linux.
33  *
34  * These can be single devices or ranges of devices
35  */
36 
37 /* 65536 bits for each set to indicate if a devno is blacklisted or not */
38 #define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
39 			 (8*sizeof(long)))
40 static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
41 typedef enum {add, free} range_action;
42 
43 /*
44  * Function: blacklist_range
45  * (Un-)blacklist the devices from-to
46  */
47 static int blacklist_range(range_action action, unsigned int from_ssid,
48 			   unsigned int to_ssid, unsigned int from,
49 			   unsigned int to, int msgtrigger)
50 {
51 	if ((from_ssid > to_ssid) || ((from_ssid == to_ssid) && (from > to))) {
52 		if (msgtrigger)
53 			printk(KERN_WARNING "cio: Invalid cio_ignore range "
54 			       "0.%x.%04x-0.%x.%04x\n", from_ssid, from,
55 			       to_ssid, to);
56 		return 1;
57 	}
58 
59 	while ((from_ssid < to_ssid) || ((from_ssid == to_ssid) &&
60 	       (from <= to))) {
61 		if (action == add)
62 			set_bit(from, bl_dev[from_ssid]);
63 		else
64 			clear_bit(from, bl_dev[from_ssid]);
65 		from++;
66 		if (from > __MAX_SUBCHANNEL) {
67 			from_ssid++;
68 			from = 0;
69 		}
70 	}
71 
72 	return 0;
73 }
74 
75 static int pure_hex(char **cp, unsigned int *val, int min_digit,
76 		    int max_digit, int max_val)
77 {
78 	int diff;
79 	unsigned int value;
80 
81 	diff = 0;
82 	*val = 0;
83 
84 	while (isxdigit(**cp) && (diff <= max_digit)) {
85 
86 		if (isdigit(**cp))
87 			value = **cp - '0';
88 		else
89 			value = tolower(**cp) - 'a' + 10;
90 		*val = *val * 16 + value;
91 		(*cp)++;
92 		diff++;
93 	}
94 
95 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
96 		return 1;
97 
98 	return 0;
99 }
100 
101 static int parse_busid(char *str, unsigned int *cssid, unsigned int *ssid,
102 		       unsigned int *devno, int msgtrigger)
103 {
104 	char *str_work;
105 	int val, rc, ret;
106 
107 	rc = 1;
108 
109 	if (*str == '\0')
110 		goto out;
111 
112 	/* old style */
113 	str_work = str;
114 	val = simple_strtoul(str, &str_work, 16);
115 
116 	if (*str_work == '\0') {
117 		if (val <= __MAX_SUBCHANNEL) {
118 			*devno = val;
119 			*ssid = 0;
120 			*cssid = 0;
121 			rc = 0;
122 		}
123 		goto out;
124 	}
125 
126 	/* new style */
127 	str_work = str;
128 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
129 	if (ret || (str_work[0] != '.'))
130 		goto out;
131 	str_work++;
132 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
133 	if (ret || (str_work[0] != '.'))
134 		goto out;
135 	str_work++;
136 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
137 	if (ret || (str_work[0] != '\0'))
138 		goto out;
139 
140 	rc = 0;
141 out:
142 	if (rc && msgtrigger)
143 		printk(KERN_WARNING "cio: Invalid cio_ignore device '%s'\n",
144 		       str);
145 
146 	return rc;
147 }
148 
149 static int blacklist_parse_parameters(char *str, range_action action,
150 				      int msgtrigger)
151 {
152 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
153 	int rc, totalrc;
154 	char *parm;
155 	range_action ra;
156 
157 	totalrc = 0;
158 
159 	while ((parm = strsep(&str, ","))) {
160 		rc = 0;
161 		ra = action;
162 		if (*parm == '!') {
163 			if (ra == add)
164 				ra = free;
165 			else
166 				ra = add;
167 			parm++;
168 		}
169 		if (strcmp(parm, "all") == 0) {
170 			from_cssid = 0;
171 			from_ssid = 0;
172 			from = 0;
173 			to_cssid = __MAX_CSSID;
174 			to_ssid = __MAX_SSID;
175 			to = __MAX_SUBCHANNEL;
176 		} else {
177 			rc = parse_busid(strsep(&parm, "-"), &from_cssid,
178 					 &from_ssid, &from, msgtrigger);
179 			if (!rc) {
180 				if (parm != NULL)
181 					rc = parse_busid(parm, &to_cssid,
182 							 &to_ssid, &to,
183 							 msgtrigger);
184 				else {
185 					to_cssid = from_cssid;
186 					to_ssid = from_ssid;
187 					to = from;
188 				}
189 			}
190 		}
191 		if (!rc) {
192 			rc = blacklist_range(ra, from_ssid, to_ssid, from, to,
193 					     msgtrigger);
194 			if (rc)
195 				totalrc = -EINVAL;
196 		} else
197 			totalrc = -EINVAL;
198 	}
199 
200 	return totalrc;
201 }
202 
203 static int __init
204 blacklist_setup (char *str)
205 {
206 	CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
207 	if (blacklist_parse_parameters(str, add, 1))
208 		return 0;
209 	return 1;
210 }
211 
212 __setup ("cio_ignore=", blacklist_setup);
213 
214 /* Checking if devices are blacklisted */
215 
216 /*
217  * Function: is_blacklisted
218  * Returns 1 if the given devicenumber can be found in the blacklist,
219  * otherwise 0.
220  * Used by validate_subchannel()
221  */
222 int
223 is_blacklisted (int ssid, int devno)
224 {
225 	return test_bit (devno, bl_dev[ssid]);
226 }
227 
228 #ifdef CONFIG_PROC_FS
229 /*
230  * Function: blacklist_parse_proc_parameters
231  * parse the stuff which is piped to /proc/cio_ignore
232  */
233 static int blacklist_parse_proc_parameters(char *buf)
234 {
235 	int rc;
236 	char *parm;
237 
238 	parm = strsep(&buf, " ");
239 
240 	if (strcmp("free", parm) == 0)
241 		rc = blacklist_parse_parameters(buf, free, 0);
242 	else if (strcmp("add", parm) == 0)
243 		rc = blacklist_parse_parameters(buf, add, 0);
244 	else if (strcmp("purge", parm) == 0)
245 		return ccw_purge_blacklisted();
246 	else
247 		return -EINVAL;
248 
249 	css_schedule_reprobe();
250 
251 	return rc;
252 }
253 
254 /* Iterator struct for all devices. */
255 struct ccwdev_iter {
256 	int devno;
257 	int ssid;
258 	int in_range;
259 };
260 
261 static void *
262 cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
263 {
264 	struct ccwdev_iter *iter;
265 
266 	if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
267 		return NULL;
268 	iter = kzalloc(sizeof(struct ccwdev_iter), GFP_KERNEL);
269 	if (!iter)
270 		return ERR_PTR(-ENOMEM);
271 	iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);
272 	iter->devno = *offset % (__MAX_SUBCHANNEL + 1);
273 	return iter;
274 }
275 
276 static void
277 cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
278 {
279 	if (!IS_ERR(it))
280 		kfree(it);
281 }
282 
283 static void *
284 cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)
285 {
286 	struct ccwdev_iter *iter;
287 
288 	if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
289 		return NULL;
290 	iter = it;
291 	if (iter->devno == __MAX_SUBCHANNEL) {
292 		iter->devno = 0;
293 		iter->ssid++;
294 		if (iter->ssid > __MAX_SSID)
295 			return NULL;
296 	} else
297 		iter->devno++;
298 	(*offset)++;
299 	return iter;
300 }
301 
302 static int
303 cio_ignore_proc_seq_show(struct seq_file *s, void *it)
304 {
305 	struct ccwdev_iter *iter;
306 
307 	iter = it;
308 	if (!is_blacklisted(iter->ssid, iter->devno))
309 		/* Not blacklisted, nothing to output. */
310 		return 0;
311 	if (!iter->in_range) {
312 		/* First device in range. */
313 		if ((iter->devno == __MAX_SUBCHANNEL) ||
314 		    !is_blacklisted(iter->ssid, iter->devno + 1))
315 			/* Singular device. */
316 			return seq_printf(s, "0.%x.%04x\n",
317 					  iter->ssid, iter->devno);
318 		iter->in_range = 1;
319 		return seq_printf(s, "0.%x.%04x-", iter->ssid, iter->devno);
320 	}
321 	if ((iter->devno == __MAX_SUBCHANNEL) ||
322 	    !is_blacklisted(iter->ssid, iter->devno + 1)) {
323 		/* Last device in range. */
324 		iter->in_range = 0;
325 		return seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
326 	}
327 	return 0;
328 }
329 
330 static ssize_t
331 cio_ignore_write(struct file *file, const char __user *user_buf,
332 		 size_t user_len, loff_t *offset)
333 {
334 	char *buf;
335 	size_t i;
336 	ssize_t rc, ret;
337 
338 	if (*offset)
339 		return -EINVAL;
340 	if (user_len > 65536)
341 		user_len = 65536;
342 	buf = vmalloc (user_len + 1); /* maybe better use the stack? */
343 	if (buf == NULL)
344 		return -ENOMEM;
345 	memset(buf, 0, user_len + 1);
346 
347 	if (strncpy_from_user (buf, user_buf, user_len) < 0) {
348 		rc = -EFAULT;
349 		goto out_free;
350 	}
351 
352 	i = user_len - 1;
353 	while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {
354 		buf[i] = '\0';
355 		i--;
356 	}
357 	ret = blacklist_parse_proc_parameters(buf);
358 	if (ret)
359 		rc = ret;
360 	else
361 		rc = user_len;
362 
363 out_free:
364 	vfree (buf);
365 	return rc;
366 }
367 
368 static const struct seq_operations cio_ignore_proc_seq_ops = {
369 	.start = cio_ignore_proc_seq_start,
370 	.stop  = cio_ignore_proc_seq_stop,
371 	.next  = cio_ignore_proc_seq_next,
372 	.show  = cio_ignore_proc_seq_show,
373 };
374 
375 static int
376 cio_ignore_proc_open(struct inode *inode, struct file *file)
377 {
378 	return seq_open(file, &cio_ignore_proc_seq_ops);
379 }
380 
381 static const struct file_operations cio_ignore_proc_fops = {
382 	.open    = cio_ignore_proc_open,
383 	.read    = seq_read,
384 	.llseek  = seq_lseek,
385 	.release = seq_release,
386 	.write   = cio_ignore_write,
387 };
388 
389 static int
390 cio_ignore_proc_init (void)
391 {
392 	struct proc_dir_entry *entry;
393 
394 	entry = proc_create("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR, NULL,
395 			    &cio_ignore_proc_fops);
396 	if (!entry)
397 		return -ENOENT;
398 	return 0;
399 }
400 
401 __initcall (cio_ignore_proc_init);
402 
403 #endif /* CONFIG_PROC_FS */
404