1/*
2 *   S/390 common I/O routines -- blacklisting of specific devices
3 *
4 *    Copyright IBM Corp. 1999, 2013
5 *    Author(s): Ingo Adlung (adlung@de.ibm.com)
6 *		 Cornelia Huck (cornelia.huck@de.ibm.com)
7 *		 Arnd Bergmann (arndb@de.ibm.com)
8 */
9
10#define KMSG_COMPONENT "cio"
11#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12
13#include <linux/init.h>
14#include <linux/vmalloc.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/uaccess.h>
21#include <asm/cio.h>
22#include <asm/ipl.h>
23
24#include "blacklist.h"
25#include "cio.h"
26#include "cio_debug.h"
27#include "css.h"
28#include "device.h"
29
30/*
31 * "Blacklisting" of certain devices:
32 * Device numbers given in the commandline as cio_ignore=... won't be known
33 * to Linux.
34 *
35 * These can be single devices or ranges of devices
36 */
37
38/* 65536 bits for each set to indicate if a devno is blacklisted or not */
39#define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
40			 (8*sizeof(long)))
41static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
42typedef enum {add, free} range_action;
43
44/*
45 * Function: blacklist_range
46 * (Un-)blacklist the devices from-to
47 */
48static int blacklist_range(range_action action, unsigned int from_ssid,
49			   unsigned int to_ssid, unsigned int from,
50			   unsigned int to, int msgtrigger)
51{
52	if ((from_ssid > to_ssid) || ((from_ssid == to_ssid) && (from > to))) {
53		if (msgtrigger)
54			pr_warning("0.%x.%04x to 0.%x.%04x is not a valid "
55				   "range for cio_ignore\n", from_ssid, from,
56				   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
77static 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
101static 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;
141out:
142	if (rc && msgtrigger)
143		pr_warning("%s is not a valid device for the cio_ignore "
144			   "kernel parameter\n", str);
145
146	return rc;
147}
148
149static 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
226static int __init
227blacklist_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 */
245int
246is_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 */
256static 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		css_schedule_eval_all_unreg(0);
266	} else if (strcmp("add", parm) == 0)
267		rc = blacklist_parse_parameters(buf, add, 0);
268	else if (strcmp("purge", parm) == 0)
269		return ccw_purge_blacklisted();
270	else
271		return -EINVAL;
272
273
274	return rc;
275}
276
277/* Iterator struct for all devices. */
278struct ccwdev_iter {
279	int devno;
280	int ssid;
281	int in_range;
282};
283
284static void *
285cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
286{
287	struct ccwdev_iter *iter = s->private;
288
289	if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
290		return NULL;
291	memset(iter, 0, sizeof(*iter));
292	iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);
293	iter->devno = *offset % (__MAX_SUBCHANNEL + 1);
294	return iter;
295}
296
297static void
298cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
299{
300}
301
302static void *
303cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)
304{
305	struct ccwdev_iter *iter;
306
307	if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
308		return NULL;
309	iter = it;
310	if (iter->devno == __MAX_SUBCHANNEL) {
311		iter->devno = 0;
312		iter->ssid++;
313		if (iter->ssid > __MAX_SSID)
314			return NULL;
315	} else
316		iter->devno++;
317	(*offset)++;
318	return iter;
319}
320
321static int
322cio_ignore_proc_seq_show(struct seq_file *s, void *it)
323{
324	struct ccwdev_iter *iter;
325
326	iter = it;
327	if (!is_blacklisted(iter->ssid, iter->devno))
328		/* Not blacklisted, nothing to output. */
329		return 0;
330	if (!iter->in_range) {
331		/* First device in range. */
332		if ((iter->devno == __MAX_SUBCHANNEL) ||
333		    !is_blacklisted(iter->ssid, iter->devno + 1)) {
334			/* Singular device. */
335			seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
336			return 0;
337		}
338		iter->in_range = 1;
339		seq_printf(s, "0.%x.%04x-", iter->ssid, iter->devno);
340		return 0;
341	}
342	if ((iter->devno == __MAX_SUBCHANNEL) ||
343	    !is_blacklisted(iter->ssid, iter->devno + 1)) {
344		/* Last device in range. */
345		iter->in_range = 0;
346		seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
347	}
348	return 0;
349}
350
351static ssize_t
352cio_ignore_write(struct file *file, const char __user *user_buf,
353		 size_t user_len, loff_t *offset)
354{
355	char *buf;
356	ssize_t rc, ret, i;
357
358	if (*offset)
359		return -EINVAL;
360	if (user_len > 65536)
361		user_len = 65536;
362	buf = vzalloc(user_len + 1); /* maybe better use the stack? */
363	if (buf == NULL)
364		return -ENOMEM;
365
366	if (strncpy_from_user (buf, user_buf, user_len) < 0) {
367		rc = -EFAULT;
368		goto out_free;
369	}
370
371	i = user_len - 1;
372	while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {
373		buf[i] = '\0';
374		i--;
375	}
376	ret = blacklist_parse_proc_parameters(buf);
377	if (ret)
378		rc = ret;
379	else
380		rc = user_len;
381
382out_free:
383	vfree (buf);
384	return rc;
385}
386
387static const struct seq_operations cio_ignore_proc_seq_ops = {
388	.start = cio_ignore_proc_seq_start,
389	.stop  = cio_ignore_proc_seq_stop,
390	.next  = cio_ignore_proc_seq_next,
391	.show  = cio_ignore_proc_seq_show,
392};
393
394static int
395cio_ignore_proc_open(struct inode *inode, struct file *file)
396{
397	return seq_open_private(file, &cio_ignore_proc_seq_ops,
398				sizeof(struct ccwdev_iter));
399}
400
401static const struct file_operations cio_ignore_proc_fops = {
402	.open    = cio_ignore_proc_open,
403	.read    = seq_read,
404	.llseek  = seq_lseek,
405	.release = seq_release_private,
406	.write   = cio_ignore_write,
407};
408
409static int
410cio_ignore_proc_init (void)
411{
412	struct proc_dir_entry *entry;
413
414	entry = proc_create("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR, NULL,
415			    &cio_ignore_proc_fops);
416	if (!entry)
417		return -ENOENT;
418	return 0;
419}
420
421__initcall (cio_ignore_proc_init);
422
423#endif /* CONFIG_PROC_FS */
424