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