summaryrefslogtreecommitdiffstats
path: root/drivers/s390/cio/blacklist.c
blob: daf21e03b21d43b5e632713f03e0bb9794624558 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
/*
 *  drivers/s390/cio/blacklist.c
 *   S/390 common I/O routines -- blacklisting of specific devices
 *   $Revision: 1.39 $
 *
 *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
 *			      IBM Corporation
 *    Author(s): Ingo Adlung (adlung@de.ibm.com)
 *		 Cornelia Huck (cohuck@de.ibm.com)
 *		 Arnd Bergmann (arndb@de.ibm.com)
 */

#include <linux/config.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/ctype.h>
#include <linux/device.h>

#include <asm/cio.h>
#include <asm/uaccess.h>

#include "blacklist.h"
#include "cio.h"
#include "cio_debug.h"
#include "css.h"

/*
 * "Blacklisting" of certain devices:
 * Device numbers given in the commandline as cio_ignore=... won't be known
 * to Linux.
 *
 * These can be single devices or ranges of devices
 */

/* 65536 bits for each set to indicate if a devno is blacklisted or not */
#define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
			 (8*sizeof(long)))
static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
typedef enum {add, free} range_action;

/*
 * Function: blacklist_range
 * (Un-)blacklist the devices from-to
 */
static inline void
blacklist_range (range_action action, unsigned int from, unsigned int to,
		 unsigned int ssid)
{
	if (!to)
		to = from;

	if (from > to || to > __MAX_SUBCHANNEL || ssid > __MAX_SSID) {
		printk (KERN_WARNING "Invalid blacklist range "
			"0.%x.%04x to 0.%x.%04x, skipping\n",
			ssid, from, ssid, to);
		return;
	}
	for (; from <= to; from++) {
		if (action == add)
			set_bit (from, bl_dev[ssid]);
		else
			clear_bit (from, bl_dev[ssid]);
	}
}

/*
 * Function: blacklist_busid
 * Get devno/busid from given string.
 * Shamelessly grabbed from dasd_devmap.c.
 */
static inline int
blacklist_busid(char **str, int *id0, int *ssid, int *devno)
{
	int val, old_style;
	char *sav;

	sav = *str;

	/* check for leading '0x' */
	old_style = 0;
	if ((*str)[0] == '0' && (*str)[1] == 'x') {
		*str += 2;
		old_style = 1;
	}
	if (!isxdigit((*str)[0]))	/* We require at least one hex digit */
		goto confused;
	val = simple_strtoul(*str, str, 16);
	if (old_style || (*str)[0] != '.') {
		*id0 = *ssid = 0;
		if (val < 0 || val > 0xffff)
			goto confused;
		*devno = val;
		if ((*str)[0] != ',' && (*str)[0] != '-' &&
		    (*str)[0] != '\n' && (*str)[0] != '\0')
			goto confused;
		return 0;
	}
	/* New style x.y.z busid */
	if (val < 0 || val > 0xff)
		goto confused;
	*id0 = val;
	(*str)++;
	if (!isxdigit((*str)[0]))	/* We require at least one hex digit */
		goto confused;
	val = simple_strtoul(*str, str, 16);
	if (val < 0 || val > 0xff || (*str)++[0] != '.')
		goto confused;
	*ssid = val;
	if (!isxdigit((*str)[0]))	/* We require at least one hex digit */
		goto confused;
	val = simple_strtoul(*str, str, 16);
	if (val < 0 || val > 0xffff)
		goto confused;
	*devno = val;
	if ((*str)[0] != ',' && (*str)[0] != '-' &&
	    (*str)[0] != '\n' && (*str)[0] != '\0')
		goto confused;
	return 0;
confused:
	strsep(str, ",\n");
	printk(KERN_WARNING "Invalid cio_ignore parameter '%s'\n", sav);
	return 1;
}

static inline int
blacklist_parse_parameters (char *str, range_action action)
{
	unsigned int from, to, from_id0, to_id0, from_ssid, to_ssid;

	while (*str != 0 && *str != '\n') {
		range_action ra = action;
		while(*str == ',')
			str++;
		if (*str == '!') {
			ra = !action;
			++str;
		}

		/*
		 * Since we have to parse the proc commands and the
		 * kernel arguments we have to check four cases
		 */
		if (strncmp(str,"all,",4) == 0 || strcmp(str,"all") == 0 ||
		    strncmp(str,"all\n",4) == 0 || strncmp(str,"all ",4) == 0) {
			int j;

			str += 3;
			for (j=0; j <= __MAX_SSID; j++)
				blacklist_range(ra, 0, __MAX_SUBCHANNEL, j);
		} else {
			int rc;

			rc = blacklist_busid(&str, &from_id0,
					     &from_ssid, &from);
			if (rc)
				continue;
			to = from;
			to_id0 = from_id0;
			to_ssid = from_ssid;
			if (*str == '-') {
				str++;
				rc = blacklist_busid(&str, &to_id0,
						     &to_ssid, &to);
				if (rc)
					continue;
			}
			if (*str == '-') {
				printk(KERN_WARNING "invalid cio_ignore "
					"parameter '%s'\n",
					strsep(&str, ",\n"));
				continue;
			}
			if ((from_id0 != to_id0) ||
			    (from_ssid != to_ssid)) {
				printk(KERN_WARNING "invalid cio_ignore range "
					"%x.%x.%04x-%x.%x.%04x\n",
					from_id0, from_ssid, from,
					to_id0, to_ssid, to);
				continue;
			}
			pr_debug("blacklist_setup: adding range "
				 "from %x.%x.%04x to %x.%x.%04x\n",
				 from_id0, from_ssid, from, to_id0, to_ssid, to);
			blacklist_range (ra, from, to, to_ssid);
		}
	}
	return 1;
}

/* Parsing the commandline for blacklist parameters, e.g. to blacklist
 * bus ids 0.0.1234, 0.0.1235 and 0.0.1236, you could use any of:
 * - cio_ignore=1234-1236
 * - cio_ignore=0x1234-0x1235,1236
 * - cio_ignore=0x1234,1235-1236
 * - cio_ignore=1236 cio_ignore=1234-0x1236
 * - cio_ignore=1234 cio_ignore=1236 cio_ignore=0x1235
 * - cio_ignore=0.0.1234-0.0.1236
 * - cio_ignore=0.0.1234,0x1235,1236
 * - ...
 */
static int __init
blacklist_setup (char *str)
{
	CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
	return blacklist_parse_parameters (str, add);
}

__setup ("cio_ignore=", blacklist_setup);

/* Checking if devices are blacklisted */

/*
 * Function: is_blacklisted
 * Returns 1 if the given devicenumber can be found in the blacklist,
 * otherwise 0.
 * Used by validate_subchannel()
 */
int
is_blacklisted (int ssid, int devno)
{
	return test_bit (devno, bl_dev[ssid]);
}

#ifdef CONFIG_PROC_FS
static int
__s390_redo_validation(struct subchannel_id schid, void *data)
{
	int ret;
	struct subchannel *sch;

	sch = get_subchannel_by_schid(schid);
	if (sch) {
		/* Already known. */
		put_device(&sch->dev);
		return 0;
	}
	ret = css_probe_device(schid);
	if (ret == -ENXIO)
		return ret; /* We're through. */
	if (ret == -ENOMEM)
		/* Stop validation for now. Bad, but no need for a panic. */
		return ret;
	return 0;
}

/*
 * Function: s390_redo_validation
 * Look for no longer blacklisted devices
 * FIXME: there must be a better way to do this */
static inline void
s390_redo_validation (void)
{
	CIO_TRACE_EVENT (0, "redoval");

	for_each_subchannel(__s390_redo_validation, NULL);
}

/*
 * Function: blacklist_parse_proc_parameters
 * parse the stuff which is piped to /proc/cio_ignore
 */
static inline void
blacklist_parse_proc_parameters (char *buf)
{
	if (strncmp (buf, "free ", 5) == 0) {
		blacklist_parse_parameters (buf + 5, free);
	} else if (strncmp (buf, "add ", 4) == 0) {
		/* 
		 * We don't need to check for known devices since
		 * css_probe_device will handle this correctly. 
		 */
		blacklist_parse_parameters (buf + 4, add);
	} else {
		printk (KERN_WARNING "cio_ignore: Parse error; \n"
			KERN_WARNING "try using 'free all|<devno-range>,"
				     "<devno-range>,...'\n"
			KERN_WARNING "or 'add <devno-range>,"
				     "<devno-range>,...'\n");
		return;
	}

	s390_redo_validation ();
}

/* Iterator struct for all devices. */
struct ccwdev_iter {
	int devno;
	int ssid;
	int in_range;
};

static void *
cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
{
	struct ccwdev_iter *iter;

	if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
		return NULL;
	iter = kzalloc(sizeof(struct ccwdev_iter), GFP_KERNEL);
	if (!iter)
		return ERR_PTR(-ENOMEM);
	iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);
	iter->devno = *offset % (__MAX_SUBCHANNEL + 1);
	return iter;
}

static void
cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
{
	if (!IS_ERR(it))
		kfree(it);
}

static void *
cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)
{
	struct ccwdev_iter *iter;

	if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
		return NULL;
	iter = it;
	if (iter->devno == __MAX_SUBCHANNEL) {
		iter->devno = 0;
		iter->ssid++;
		if (iter->ssid > __MAX_SSID)
			return NULL;
	} else
		iter->devno++;
	(*offset)++;
	return iter;
}

static int
cio_ignore_proc_seq_show(struct seq_file *s, void *it)
{
	struct ccwdev_iter *iter;

	iter = it;
	if (!is_blacklisted(iter->ssid, iter->devno))
		/* Not blacklisted, nothing to output. */
		return 0;
	if (!iter->in_range) {
		/* First device in range. */
		if ((iter->devno == __MAX_SUBCHANNEL) ||
		    !is_blacklisted(iter->ssid, iter->devno + 1))
			/* Singular device. */
			return seq_printf(s, "0.%x.%04x\n",
					  iter->ssid, iter->devno);
		iter->in_range = 1;
		return seq_printf(s, "0.%x.%04x-", iter->ssid, iter->devno);
	}
	if ((iter->devno == __MAX_SUBCHANNEL) ||
	    !is_blacklisted(iter->ssid, iter->devno + 1)) {
		/* Last device in range. */
		iter->in_range = 0;
		return seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
	}
	return 0;
}

static ssize_t
cio_ignore_write(struct file *file, const char __user *user_buf,
		 size_t user_len, loff_t *offset)
{
	char *buf;

	if (*offset)
		return -EINVAL;
	if (user_len > 65536)
		user_len = 65536;
	buf = vmalloc (user_len + 1); /* maybe better use the stack? */
	if (buf == NULL)
		return -ENOMEM;
	if (strncpy_from_user (buf, user_buf, user_len) < 0) {
		vfree (buf);
		return -EFAULT;
	}
	buf[user_len] = '\0';

	blacklist_parse_proc_parameters (buf);

	vfree (buf);
	return user_len;
}

static struct seq_operations cio_ignore_proc_seq_ops = {
	.start = cio_ignore_proc_seq_start,
	.stop  = cio_ignore_proc_seq_stop,
	.next  = cio_ignore_proc_seq_next,
	.show  = cio_ignore_proc_seq_show,
};

static int
cio_ignore_proc_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &cio_ignore_proc_seq_ops);
}

static struct file_operations cio_ignore_proc_fops = {
	.open    = cio_ignore_proc_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release,
	.write   = cio_ignore_write,
};

static int
cio_ignore_proc_init (void)
{
	struct proc_dir_entry *entry;

	entry = create_proc_entry ("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR,
				   &proc_root);
	if (!entry)
		return 0;

	entry->proc_fops = &cio_ignore_proc_fops;

	return 1;
}

__initcall (cio_ignore_proc_init);

#endif /* CONFIG_PROC_FS */
OpenPOWER on IntegriCloud