1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *   S/390 common I/O routines -- blacklisting of specific devices
4  *
5  *    Copyright IBM Corp. 1999, 2013
6  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
7  *		 Cornelia Huck (cornelia.huck@de.ibm.com)
8  *		 Arnd Bergmann (arndb@de.ibm.com)
9  */
10 
11 #define KMSG_COMPONENT "cio"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 
14 #include <linux/init.h>
15 #include <linux/vmalloc.h>
16 #include <linux/proc_fs.h>
17 #include <linux/seq_file.h>
18 #include <linux/ctype.h>
19 #include <linux/device.h>
20 
21 #include <linux/uaccess.h>
22 #include <asm/cio.h>
23 #include <asm/ipl.h>
24 
25 #include "blacklist.h"
26 #include "cio.h"
27 #include "cio_debug.h"
28 #include "css.h"
29 #include "device.h"
30 
31 /*
32  * "Blacklisting" of certain devices:
33  * Device numbers given in the commandline as cio_ignore=... won't be known
34  * to Linux.
35  *
36  * These can be single devices or ranges of devices
37  */
38 
39 /* 65536 bits for each set to indicate if a devno is blacklisted or not */
40 #define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
41 			 (8*sizeof(long)))
42 static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
43 typedef enum {add, free} range_action;
44 
45 /*
46  * Function: blacklist_range
47  * (Un-)blacklist the devices from-to
48  */
blacklist_range(range_action action,unsigned int from_ssid,unsigned int to_ssid,unsigned int from,unsigned int to,int msgtrigger)49 static int blacklist_range(range_action action, unsigned int from_ssid,
50 			   unsigned int to_ssid, unsigned int from,
51 			   unsigned int to, int msgtrigger)
52 {
53 	if ((from_ssid > to_ssid) || ((from_ssid == to_ssid) && (from > to))) {
54 		if (msgtrigger)
55 			pr_warn("0.%x.%04x to 0.%x.%04x is not a valid range for cio_ignore\n",
56 				from_ssid, from, to_ssid, to);
57 
58 		return 1;
59 	}
60 
61 	while ((from_ssid < to_ssid) || ((from_ssid == to_ssid) &&
62 	       (from <= to))) {
63 		if (action == add)
64 			set_bit(from, bl_dev[from_ssid]);
65 		else
66 			clear_bit(from, bl_dev[from_ssid]);
67 		from++;
68 		if (from > __MAX_SUBCHANNEL) {
69 			from_ssid++;
70 			from = 0;
71 		}
72 	}
73 
74 	return 0;
75 }
76 
pure_hex(char ** cp,unsigned int * val,int min_digit,int max_digit,int max_val)77 static int pure_hex(char **cp, unsigned int *val, int min_digit,
78 		    int max_digit, int max_val)
79 {
80 	int diff;
81 
82 	diff = 0;
83 	*val = 0;
84 
85 	while (diff <= max_digit) {
86 		int value = hex_to_bin(**cp);
87 
88 		if (value < 0)
89 			break;
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 
parse_busid(char * str,unsigned int * cssid,unsigned int * ssid,unsigned int * devno,int msgtrigger)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 		pr_warn("%s is not a valid device for the cio_ignore kernel parameter\n",
144 			str);
145 
146 	return rc;
147 }
148 
blacklist_parse_parameters(char * str,range_action action,int msgtrigger)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 if (strcmp(parm, "ipldev") == 0) {
177 			if (ipl_info.type == IPL_TYPE_CCW) {
178 				from_cssid = 0;
179 				from_ssid = ipl_info.data.ccw.dev_id.ssid;
180 				from = ipl_info.data.ccw.dev_id.devno;
181 			} else if (ipl_info.type == IPL_TYPE_FCP ||
182 				   ipl_info.type == IPL_TYPE_FCP_DUMP) {
183 				from_cssid = 0;
184 				from_ssid = ipl_info.data.fcp.dev_id.ssid;
185 				from = ipl_info.data.fcp.dev_id.devno;
186 			} else {
187 				continue;
188 			}
189 			to_cssid = from_cssid;
190 			to_ssid = from_ssid;
191 			to = from;
192 		} else if (strcmp(parm, "condev") == 0) {
193 			if (console_devno == -1)
194 				continue;
195 
196 			from_cssid = to_cssid = 0;
197 			from_ssid = to_ssid = 0;
198 			from = to = console_devno;
199 		} else {
200 			rc = parse_busid(strsep(&parm, "-"), &from_cssid,
201 					 &from_ssid, &from, msgtrigger);
202 			if (!rc) {
203 				if (parm != NULL)
204 					rc = parse_busid(parm, &to_cssid,
205 							 &to_ssid, &to,
206 							 msgtrigger);
207 				else {
208 					to_cssid = from_cssid;
209 					to_ssid = from_ssid;
210 					to = from;
211 				}
212 			}
213 		}
214 		if (!rc) {
215 			rc = blacklist_range(ra, from_ssid, to_ssid, from, to,
216 					     msgtrigger);
217 			if (rc)
218 				totalrc = -EINVAL;
219 		} else
220 			totalrc = -EINVAL;
221 	}
222 
223 	return totalrc;
224 }
225 
226 static int __init
blacklist_setup(char * str)227 blacklist_setup (char *str)
228 {
229 	CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
230 	if (blacklist_parse_parameters(str, add, 1))
231 		return 0;
232 	return 1;
233 }
234 
235 __setup ("cio_ignore=", blacklist_setup);
236 
237 /* Checking if devices are blacklisted */
238 
239 /*
240  * Function: is_blacklisted
241  * Returns 1 if the given devicenumber can be found in the blacklist,
242  * otherwise 0.
243  * Used by validate_subchannel()
244  */
245 int
is_blacklisted(int ssid,int devno)246 is_blacklisted (int ssid, int devno)
247 {
248 	return test_bit (devno, bl_dev[ssid]);
249 }
250 
251 #ifdef CONFIG_PROC_FS
252 /*
253  * Function: blacklist_parse_proc_parameters
254  * parse the stuff which is piped to /proc/cio_ignore
255  */
blacklist_parse_proc_parameters(char * buf)256 static int blacklist_parse_proc_parameters(char *buf)
257 {
258 	int rc;
259 	char *parm;
260 
261 	parm = strsep(&buf, " ");
262 
263 	if (strcmp("free", parm) == 0) {
264 		rc = blacklist_parse_parameters(buf, free, 0);
265 		/*
266 		 * Evaluate the subchannels without an online device. This way,
267 		 * no path-verification will be triggered on those subchannels
268 		 * and it avoids unnecessary delays.
269 		 */
270 		css_schedule_eval_cond(CSS_EVAL_NOT_ONLINE, 0);
271 	} else if (strcmp("add", parm) == 0)
272 		rc = blacklist_parse_parameters(buf, add, 0);
273 	else if (strcmp("purge", parm) == 0)
274 		return ccw_purge_blacklisted();
275 	else
276 		return -EINVAL;
277 
278 
279 	return rc;
280 }
281 
282 /* Iterator struct for all devices. */
283 struct ccwdev_iter {
284 	int devno;
285 	int ssid;
286 	int in_range;
287 };
288 
289 static void *
cio_ignore_proc_seq_start(struct seq_file * s,loff_t * offset)290 cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
291 {
292 	struct ccwdev_iter *iter = s->private;
293 
294 	if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
295 		return NULL;
296 	memset(iter, 0, sizeof(*iter));
297 	iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);
298 	iter->devno = *offset % (__MAX_SUBCHANNEL + 1);
299 	return iter;
300 }
301 
302 static void
cio_ignore_proc_seq_stop(struct seq_file * s,void * it)303 cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
304 {
305 }
306 
307 static void *
cio_ignore_proc_seq_next(struct seq_file * s,void * it,loff_t * offset)308 cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)
309 {
310 	struct ccwdev_iter *iter;
311 	loff_t p = *offset;
312 
313 	(*offset)++;
314 	if (p >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
315 		return NULL;
316 	iter = it;
317 	if (iter->devno == __MAX_SUBCHANNEL) {
318 		iter->devno = 0;
319 		iter->ssid++;
320 		if (iter->ssid > __MAX_SSID)
321 			return NULL;
322 	} else
323 		iter->devno++;
324 	return iter;
325 }
326 
327 static int
cio_ignore_proc_seq_show(struct seq_file * s,void * it)328 cio_ignore_proc_seq_show(struct seq_file *s, void *it)
329 {
330 	struct ccwdev_iter *iter;
331 
332 	iter = it;
333 	if (!is_blacklisted(iter->ssid, iter->devno))
334 		/* Not blacklisted, nothing to output. */
335 		return 0;
336 	if (!iter->in_range) {
337 		/* First device in range. */
338 		if ((iter->devno == __MAX_SUBCHANNEL) ||
339 		    !is_blacklisted(iter->ssid, iter->devno + 1)) {
340 			/* Singular device. */
341 			seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
342 			return 0;
343 		}
344 		iter->in_range = 1;
345 		seq_printf(s, "0.%x.%04x-", iter->ssid, iter->devno);
346 		return 0;
347 	}
348 	if ((iter->devno == __MAX_SUBCHANNEL) ||
349 	    !is_blacklisted(iter->ssid, iter->devno + 1)) {
350 		/* Last device in range. */
351 		iter->in_range = 0;
352 		seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
353 	}
354 	return 0;
355 }
356 
357 static ssize_t
cio_ignore_write(struct file * file,const char __user * user_buf,size_t user_len,loff_t * offset)358 cio_ignore_write(struct file *file, const char __user *user_buf,
359 		 size_t user_len, loff_t *offset)
360 {
361 	char *buf;
362 	ssize_t rc, ret, i;
363 
364 	if (*offset)
365 		return -EINVAL;
366 	if (user_len > 65536)
367 		user_len = 65536;
368 	buf = vzalloc(user_len + 1); /* maybe better use the stack? */
369 	if (buf == NULL)
370 		return -ENOMEM;
371 
372 	if (strncpy_from_user (buf, user_buf, user_len) < 0) {
373 		rc = -EFAULT;
374 		goto out_free;
375 	}
376 
377 	i = user_len - 1;
378 	while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {
379 		buf[i] = '\0';
380 		i--;
381 	}
382 	ret = blacklist_parse_proc_parameters(buf);
383 	if (ret)
384 		rc = ret;
385 	else
386 		rc = user_len;
387 
388 out_free:
389 	vfree (buf);
390 	return rc;
391 }
392 
393 static const struct seq_operations cio_ignore_proc_seq_ops = {
394 	.start = cio_ignore_proc_seq_start,
395 	.stop  = cio_ignore_proc_seq_stop,
396 	.next  = cio_ignore_proc_seq_next,
397 	.show  = cio_ignore_proc_seq_show,
398 };
399 
400 static int
cio_ignore_proc_open(struct inode * inode,struct file * file)401 cio_ignore_proc_open(struct inode *inode, struct file *file)
402 {
403 	return seq_open_private(file, &cio_ignore_proc_seq_ops,
404 				sizeof(struct ccwdev_iter));
405 }
406 
407 static const struct proc_ops cio_ignore_proc_ops = {
408 	.proc_open	= cio_ignore_proc_open,
409 	.proc_read	= seq_read,
410 	.proc_lseek	= seq_lseek,
411 	.proc_release	= seq_release_private,
412 	.proc_write	= cio_ignore_write,
413 };
414 
415 static int
cio_ignore_proc_init(void)416 cio_ignore_proc_init (void)
417 {
418 	struct proc_dir_entry *entry;
419 
420 	entry = proc_create("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR, NULL,
421 			    &cio_ignore_proc_ops);
422 	if (!entry)
423 		return -ENOENT;
424 	return 0;
425 }
426 
427 __initcall (cio_ignore_proc_init);
428 
429 #endif /* CONFIG_PROC_FS */
430