xref: /openbmc/linux/drivers/s390/cio/blacklist.c (revision 7dd65feb) 
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 #define KMSG_COMPONENT "cio"
13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 
15 #include <linux/init.h>
16 #include <linux/vmalloc.h>
17 #include <linux/slab.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/ctype.h>
21 #include <linux/device.h>
22 
23 #include <asm/cio.h>
24 #include <asm/uaccess.h>
25 
26 #include "blacklist.h"
27 #include "cio.h"
28 #include "cio_debug.h"
29 #include "css.h"
30 #include "device.h"
31 
32 /*
33  * "Blacklisting" of certain devices:
34  * Device numbers given in the commandline as cio_ignore=... won't be known
35  * to Linux.
36  *
37  * These can be single devices or ranges of devices
38  */
39 
40 /* 65536 bits for each set to indicate if a devno is blacklisted or not */
41 #define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
42 			 (8*sizeof(long)))
43 static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
44 typedef enum {add, free} range_action;
45 
46 /*
47  * Function: blacklist_range
48  * (Un-)blacklist the devices from-to
49  */
50 static int blacklist_range(range_action action, unsigned int from_ssid,
51 			   unsigned int to_ssid, unsigned int from,
52 			   unsigned int to, int msgtrigger)
53 {
54 	if ((from_ssid > to_ssid) || ((from_ssid == to_ssid) && (from > to))) {
55 		if (msgtrigger)
56 			pr_warning("0.%x.%04x to 0.%x.%04x is not a valid "
57 				   "range for cio_ignore\n", from_ssid, from,
58 				   to_ssid, to);
59 
60 		return 1;
61 	}
62 
63 	while ((from_ssid < to_ssid) || ((from_ssid == to_ssid) &&
64 	       (from <= to))) {
65 		if (action == add)
66 			set_bit(from, bl_dev[from_ssid]);
67 		else
68 			clear_bit(from, bl_dev[from_ssid]);
69 		from++;
70 		if (from > __MAX_SUBCHANNEL) {
71 			from_ssid++;
72 			from = 0;
73 		}
74 	}
75 
76 	return 0;
77 }
78 
79 static int pure_hex(char **cp, unsigned int *val, int min_digit,
80 		    int max_digit, int max_val)
81 {
82 	int diff;
83 	unsigned int value;
84 
85 	diff = 0;
86 	*val = 0;
87 
88 	while (isxdigit(**cp) && (diff <= max_digit)) {
89 
90 		if (isdigit(**cp))
91 			value = **cp - '0';
92 		else
93 			value = tolower(**cp) - 'a' + 10;
94 		*val = *val * 16 + value;
95 		(*cp)++;
96 		diff++;
97 	}
98 
99 	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
100 		return 1;
101 
102 	return 0;
103 }
104 
105 static int parse_busid(char *str, unsigned int *cssid, unsigned int *ssid,
106 		       unsigned int *devno, int msgtrigger)
107 {
108 	char *str_work;
109 	int val, rc, ret;
110 
111 	rc = 1;
112 
113 	if (*str == '\0')
114 		goto out;
115 
116 	/* old style */
117 	str_work = str;
118 	val = simple_strtoul(str, &str_work, 16);
119 
120 	if (*str_work == '\0') {
121 		if (val <= __MAX_SUBCHANNEL) {
122 			*devno = val;
123 			*ssid = 0;
124 			*cssid = 0;
125 			rc = 0;
126 		}
127 		goto out;
128 	}
129 
130 	/* new style */
131 	str_work = str;
132 	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
133 	if (ret || (str_work[0] != '.'))
134 		goto out;
135 	str_work++;
136 	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
137 	if (ret || (str_work[0] != '.'))
138 		goto out;
139 	str_work++;
140 	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
141 	if (ret || (str_work[0] != '\0'))
142 		goto out;
143 
144 	rc = 0;
145 out:
146 	if (rc && msgtrigger)
147 		pr_warning("%s is not a valid device for the cio_ignore "
148 			   "kernel parameter\n", str);
149 
150 	return rc;
151 }
152 
153 static int blacklist_parse_parameters(char *str, range_action action,
154 				      int msgtrigger)
155 {
156 	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
157 	int rc, totalrc;
158 	char *parm;
159 	range_action ra;
160 
161 	totalrc = 0;
162 
163 	while ((parm = strsep(&str, ","))) {
164 		rc = 0;
165 		ra = action;
166 		if (*parm == '!') {
167 			if (ra == add)
168 				ra = free;
169 			else
170 				ra = add;
171 			parm++;
172 		}
173 		if (strcmp(parm, "all") == 0) {
174 			from_cssid = 0;
175 			from_ssid = 0;
176 			from = 0;
177 			to_cssid = __MAX_CSSID;
178 			to_ssid = __MAX_SSID;
179 			to = __MAX_SUBCHANNEL;
180 		} else {
181 			rc = parse_busid(strsep(&parm, "-"), &from_cssid,
182 					 &from_ssid, &from, msgtrigger);
183 			if (!rc) {
184 				if (parm != NULL)
185 					rc = parse_busid(parm, &to_cssid,
186 							 &to_ssid, &to,
187 							 msgtrigger);
188 				else {
189 					to_cssid = from_cssid;
190 					to_ssid = from_ssid;
191 					to = from;
192 				}
193 			}
194 		}
195 		if (!rc) {
196 			rc = blacklist_range(ra, from_ssid, to_ssid, from, to,
197 					     msgtrigger);
198 			if (rc)
199 				totalrc = -EINVAL;
200 		} else
201 			totalrc = -EINVAL;
202 	}
203 
204 	return totalrc;
205 }
206 
207 static int __init
208 blacklist_setup (char *str)
209 {
210 	CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
211 	if (blacklist_parse_parameters(str, add, 1))
212 		return 0;
213 	return 1;
214 }
215 
216 __setup ("cio_ignore=", blacklist_setup);
217 
218 /* Checking if devices are blacklisted */
219 
220 /*
221  * Function: is_blacklisted
222  * Returns 1 if the given devicenumber can be found in the blacklist,
223  * otherwise 0.
224  * Used by validate_subchannel()
225  */
226 int
227 is_blacklisted (int ssid, int devno)
228 {
229 	return test_bit (devno, bl_dev[ssid]);
230 }
231 
232 #ifdef CONFIG_PROC_FS
233 /*
234  * Function: blacklist_parse_proc_parameters
235  * parse the stuff which is piped to /proc/cio_ignore
236  */
237 static int blacklist_parse_proc_parameters(char *buf)
238 {
239 	int rc;
240 	char *parm;
241 
242 	parm = strsep(&buf, " ");
243 
244 	if (strcmp("free", parm) == 0)
245 		rc = blacklist_parse_parameters(buf, free, 0);
246 	else if (strcmp("add", parm) == 0)
247 		rc = blacklist_parse_parameters(buf, add, 0);
248 	else if (strcmp("purge", parm) == 0)
249 		return ccw_purge_blacklisted();
250 	else
251 		return -EINVAL;
252 
253 	css_schedule_reprobe();
254 
255 	return rc;
256 }
257 
258 /* Iterator struct for all devices. */
259 struct ccwdev_iter {
260 	int devno;
261 	int ssid;
262 	int in_range;
263 };
264 
265 static void *
266 cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
267 {
268 	struct ccwdev_iter *iter = s->private;
269 
270 	if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
271 		return NULL;
272 	memset(iter, 0, sizeof(*iter));
273 	iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);
274 	iter->devno = *offset % (__MAX_SUBCHANNEL + 1);
275 	return iter;
276 }
277 
278 static void
279 cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
280 {
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 	ssize_t rc, ret, i;
336 
337 	if (*offset)
338 		return -EINVAL;
339 	if (user_len > 65536)
340 		user_len = 65536;
341 	buf = vmalloc (user_len + 1); /* maybe better use the stack? */
342 	if (buf == NULL)
343 		return -ENOMEM;
344 	memset(buf, 0, user_len + 1);
345 
346 	if (strncpy_from_user (buf, user_buf, user_len) < 0) {
347 		rc = -EFAULT;
348 		goto out_free;
349 	}
350 
351 	i = user_len - 1;
352 	while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {
353 		buf[i] = '\0';
354 		i--;
355 	}
356 	ret = blacklist_parse_proc_parameters(buf);
357 	if (ret)
358 		rc = ret;
359 	else
360 		rc = user_len;
361 
362 out_free:
363 	vfree (buf);
364 	return rc;
365 }
366 
367 static const struct seq_operations cio_ignore_proc_seq_ops = {
368 	.start = cio_ignore_proc_seq_start,
369 	.stop  = cio_ignore_proc_seq_stop,
370 	.next  = cio_ignore_proc_seq_next,
371 	.show  = cio_ignore_proc_seq_show,
372 };
373 
374 static int
375 cio_ignore_proc_open(struct inode *inode, struct file *file)
376 {
377 	return seq_open_private(file, &cio_ignore_proc_seq_ops,
378 				sizeof(struct ccwdev_iter));
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_private,
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