ia64/linux-2.6.18-xen.hg

view kernel/params.c @ 562:66faefe721eb

pvSCSI backend driver

Signed-off-by: Tomonari Horikoshi <t.horikoshi@jp.fujitsu.com>
Signed-off-by: Jun Kamada <kama@jp.fujitsu.com>
author Keir Fraser <keir.fraser@citrix.com>
date Mon Jun 02 09:58:27 2008 +0100 (2008-06-02)
parents 831230e53067
children
line source
1 /* Helpers for initial module or kernel cmdline parsing
2 Copyright (C) 2001 Rusty Russell.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18 #include <linux/moduleparam.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/module.h>
23 #include <linux/device.h>
24 #include <linux/err.h>
25 #include <linux/slab.h>
27 #if 0
28 #define DEBUGP printk
29 #else
30 #define DEBUGP(fmt, a...)
31 #endif
33 static inline char dash2underscore(char c)
34 {
35 if (c == '-')
36 return '_';
37 return c;
38 }
40 static inline int parameq(const char *input, const char *paramname)
41 {
42 unsigned int i;
43 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
44 if (input[i] == '\0')
45 return 1;
46 return 0;
47 }
49 static int parse_one(char *param,
50 char *val,
51 struct kernel_param *params,
52 unsigned num_params,
53 int (*handle_unknown)(char *param, char *val))
54 {
55 unsigned int i;
57 /* Find parameter */
58 for (i = 0; i < num_params; i++) {
59 if (parameq(param, params[i].name)) {
60 DEBUGP("They are equal! Calling %p\n",
61 params[i].set);
62 return params[i].set(val, &params[i]);
63 }
64 }
66 if (handle_unknown) {
67 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
68 return handle_unknown(param, val);
69 }
71 DEBUGP("Unknown argument `%s'\n", param);
72 return -ENOENT;
73 }
75 /* You can use " around spaces, but can't escape ". */
76 /* Hyphens and underscores equivalent in parameter names. */
77 static char *next_arg(char *args, char **param, char **val)
78 {
79 unsigned int i, equals = 0;
80 int in_quote = 0, quoted = 0;
81 char *next;
83 if (*args == '"') {
84 args++;
85 in_quote = 1;
86 quoted = 1;
87 }
89 for (i = 0; args[i]; i++) {
90 if (args[i] == ' ' && !in_quote)
91 break;
92 if (equals == 0) {
93 if (args[i] == '=')
94 equals = i;
95 }
96 if (args[i] == '"')
97 in_quote = !in_quote;
98 }
100 *param = args;
101 if (!equals)
102 *val = NULL;
103 else {
104 args[equals] = '\0';
105 *val = args + equals + 1;
107 /* Don't include quotes in value. */
108 if (**val == '"') {
109 (*val)++;
110 if (args[i-1] == '"')
111 args[i-1] = '\0';
112 }
113 if (quoted && args[i-1] == '"')
114 args[i-1] = '\0';
115 }
117 if (args[i]) {
118 args[i] = '\0';
119 next = args + i + 1;
120 } else
121 next = args + i;
123 /* Chew up trailing spaces. */
124 while (*next == ' ')
125 next++;
126 return next;
127 }
129 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
130 int parse_args(const char *name,
131 char *args,
132 struct kernel_param *params,
133 unsigned num,
134 int (*unknown)(char *param, char *val))
135 {
136 char *param, *val;
138 DEBUGP("Parsing ARGS: %s\n", args);
140 /* Chew leading spaces */
141 while (*args == ' ')
142 args++;
144 while (*args) {
145 int ret;
147 args = next_arg(args, &param, &val);
148 ret = parse_one(param, val, params, num, unknown);
149 switch (ret) {
150 case -ENOENT:
151 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
152 name, param);
153 return ret;
154 case -ENOSPC:
155 printk(KERN_ERR
156 "%s: `%s' too large for parameter `%s'\n",
157 name, val ?: "", param);
158 return ret;
159 case 0:
160 break;
161 default:
162 printk(KERN_ERR
163 "%s: `%s' invalid for parameter `%s'\n",
164 name, val ?: "", param);
165 return ret;
166 }
167 }
169 /* All parsed OK. */
170 return 0;
171 }
173 /* Lazy bastard, eh? */
174 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
175 int param_set_##name(const char *val, struct kernel_param *kp) \
176 { \
177 char *endp; \
178 tmptype l; \
179 \
180 if (!val) return -EINVAL; \
181 l = strtolfn(val, &endp, 0); \
182 if (endp == val || ((type)l != l)) \
183 return -EINVAL; \
184 *((type *)kp->arg) = l; \
185 return 0; \
186 } \
187 int param_get_##name(char *buffer, struct kernel_param *kp) \
188 { \
189 return sprintf(buffer, format, *((type *)kp->arg)); \
190 }
192 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, simple_strtoul);
193 STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol);
194 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, simple_strtoul);
195 STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol);
196 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, simple_strtoul);
197 STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol);
198 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_strtoul);
200 int param_set_charp(const char *val, struct kernel_param *kp)
201 {
202 if (!val) {
203 printk(KERN_ERR "%s: string parameter expected\n",
204 kp->name);
205 return -EINVAL;
206 }
208 if (strlen(val) > 1024) {
209 printk(KERN_ERR "%s: string parameter too long\n",
210 kp->name);
211 return -ENOSPC;
212 }
214 *(char **)kp->arg = (char *)val;
215 return 0;
216 }
218 int param_get_charp(char *buffer, struct kernel_param *kp)
219 {
220 return sprintf(buffer, "%s", *((char **)kp->arg));
221 }
223 int param_set_bool(const char *val, struct kernel_param *kp)
224 {
225 /* No equals means "set"... */
226 if (!val) val = "1";
228 /* One of =[yYnN01] */
229 switch (val[0]) {
230 case 'y': case 'Y': case '1':
231 *(int *)kp->arg = 1;
232 return 0;
233 case 'n': case 'N': case '0':
234 *(int *)kp->arg = 0;
235 return 0;
236 }
237 return -EINVAL;
238 }
240 int param_get_bool(char *buffer, struct kernel_param *kp)
241 {
242 /* Y and N chosen as being relatively non-coder friendly */
243 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
244 }
246 int param_set_invbool(const char *val, struct kernel_param *kp)
247 {
248 int boolval, ret;
249 struct kernel_param dummy = { .arg = &boolval };
251 ret = param_set_bool(val, &dummy);
252 if (ret == 0)
253 *(int *)kp->arg = !boolval;
254 return ret;
255 }
257 int param_get_invbool(char *buffer, struct kernel_param *kp)
258 {
259 int val;
260 struct kernel_param dummy = { .arg = &val };
262 val = !*(int *)kp->arg;
263 return param_get_bool(buffer, &dummy);
264 }
266 /* We cheat here and temporarily mangle the string. */
267 static int param_array(const char *name,
268 const char *val,
269 unsigned int min, unsigned int max,
270 void *elem, int elemsize,
271 int (*set)(const char *, struct kernel_param *kp),
272 int *num)
273 {
274 int ret;
275 struct kernel_param kp;
276 char save;
278 /* Get the name right for errors. */
279 kp.name = name;
280 kp.arg = elem;
282 /* No equals sign? */
283 if (!val) {
284 printk(KERN_ERR "%s: expects arguments\n", name);
285 return -EINVAL;
286 }
288 *num = 0;
289 /* We expect a comma-separated list of values. */
290 do {
291 int len;
293 if (*num == max) {
294 printk(KERN_ERR "%s: can only take %i arguments\n",
295 name, max);
296 return -EINVAL;
297 }
298 len = strcspn(val, ",");
300 /* nul-terminate and parse */
301 save = val[len];
302 ((char *)val)[len] = '\0';
303 ret = set(val, &kp);
305 if (ret != 0)
306 return ret;
307 kp.arg += elemsize;
308 val += len+1;
309 (*num)++;
310 } while (save == ',');
312 if (*num < min) {
313 printk(KERN_ERR "%s: needs at least %i arguments\n",
314 name, min);
315 return -EINVAL;
316 }
317 return 0;
318 }
320 int param_array_set(const char *val, struct kernel_param *kp)
321 {
322 struct kparam_array *arr = kp->arg;
323 unsigned int temp_num;
325 return param_array(kp->name, val, 1, arr->max, arr->elem,
326 arr->elemsize, arr->set, arr->num ?: &temp_num);
327 }
329 int param_array_get(char *buffer, struct kernel_param *kp)
330 {
331 int i, off, ret;
332 struct kparam_array *arr = kp->arg;
333 struct kernel_param p;
335 p = *kp;
336 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
337 if (i)
338 buffer[off++] = ',';
339 p.arg = arr->elem + arr->elemsize * i;
340 ret = arr->get(buffer + off, &p);
341 if (ret < 0)
342 return ret;
343 off += ret;
344 }
345 buffer[off] = '\0';
346 return off;
347 }
349 int param_set_copystring(const char *val, struct kernel_param *kp)
350 {
351 struct kparam_string *kps = kp->arg;
353 if (strlen(val)+1 > kps->maxlen) {
354 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
355 kp->name, kps->maxlen-1);
356 return -ENOSPC;
357 }
358 strcpy(kps->string, val);
359 return 0;
360 }
362 int param_get_string(char *buffer, struct kernel_param *kp)
363 {
364 struct kparam_string *kps = kp->arg;
365 return strlcpy(buffer, kps->string, kps->maxlen);
366 }
368 /* sysfs output in /sys/modules/XYZ/parameters/ */
370 extern struct kernel_param __start___param[], __stop___param[];
372 #define MAX_KBUILD_MODNAME KOBJ_NAME_LEN
374 struct param_attribute
375 {
376 struct module_attribute mattr;
377 struct kernel_param *param;
378 };
380 struct module_param_attrs
381 {
382 struct attribute_group grp;
383 struct param_attribute attrs[0];
384 };
386 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
388 static ssize_t param_attr_show(struct module_attribute *mattr,
389 struct module *mod, char *buf)
390 {
391 int count;
392 struct param_attribute *attribute = to_param_attr(mattr);
394 if (!attribute->param->get)
395 return -EPERM;
397 count = attribute->param->get(buf, attribute->param);
398 if (count > 0) {
399 strcat(buf, "\n");
400 ++count;
401 }
402 return count;
403 }
405 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
406 static ssize_t param_attr_store(struct module_attribute *mattr,
407 struct module *owner,
408 const char *buf, size_t len)
409 {
410 int err;
411 struct param_attribute *attribute = to_param_attr(mattr);
413 if (!attribute->param->set)
414 return -EPERM;
416 err = attribute->param->set(buf, attribute->param);
417 if (!err)
418 return len;
419 return err;
420 }
422 #ifdef CONFIG_MODULES
423 #define __modinit
424 #else
425 #define __modinit __init
426 #endif
428 /*
429 * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME
430 * @mk: struct module_kobject (contains parent kobject)
431 * @kparam: array of struct kernel_param, the actual parameter definitions
432 * @num_params: number of entries in array
433 * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules"
434 *
435 * Create a kobject for a (per-module) group of parameters, and create files
436 * in sysfs. A pointer to the param_kobject is returned on success,
437 * NULL if there's no parameter to export, or other ERR_PTR(err).
438 */
439 static __modinit struct module_param_attrs *
440 param_sysfs_setup(struct module_kobject *mk,
441 struct kernel_param *kparam,
442 unsigned int num_params,
443 unsigned int name_skip)
444 {
445 struct module_param_attrs *mp;
446 unsigned int valid_attrs = 0;
447 unsigned int i, size[2];
448 struct param_attribute *pattr;
449 struct attribute **gattr;
450 int err;
452 for (i=0; i<num_params; i++) {
453 if (kparam[i].perm)
454 valid_attrs++;
455 }
457 if (!valid_attrs)
458 return NULL;
460 size[0] = ALIGN(sizeof(*mp) +
461 valid_attrs * sizeof(mp->attrs[0]),
462 sizeof(mp->grp.attrs[0]));
463 size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]);
465 mp = kmalloc(size[0] + size[1], GFP_KERNEL);
466 if (!mp)
467 return ERR_PTR(-ENOMEM);
469 mp->grp.name = "parameters";
470 mp->grp.attrs = (void *)mp + size[0];
472 pattr = &mp->attrs[0];
473 gattr = &mp->grp.attrs[0];
474 for (i = 0; i < num_params; i++) {
475 struct kernel_param *kp = &kparam[i];
476 if (kp->perm) {
477 pattr->param = kp;
478 pattr->mattr.show = param_attr_show;
479 pattr->mattr.store = param_attr_store;
480 pattr->mattr.attr.name = (char *)&kp->name[name_skip];
481 pattr->mattr.attr.owner = mk->mod;
482 pattr->mattr.attr.mode = kp->perm;
483 *(gattr++) = &(pattr++)->mattr.attr;
484 }
485 }
486 *gattr = NULL;
488 if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) {
489 kfree(mp);
490 return ERR_PTR(err);
491 }
492 return mp;
493 }
496 #ifdef CONFIG_MODULES
498 /*
499 * module_param_sysfs_setup - setup sysfs support for one module
500 * @mod: module
501 * @kparam: module parameters (array)
502 * @num_params: number of module parameters
503 *
504 * Adds sysfs entries for module parameters, and creates a link from
505 * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/
506 */
507 int module_param_sysfs_setup(struct module *mod,
508 struct kernel_param *kparam,
509 unsigned int num_params)
510 {
511 struct module_param_attrs *mp;
513 mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
514 if (IS_ERR(mp))
515 return PTR_ERR(mp);
517 mod->param_attrs = mp;
518 return 0;
519 }
521 /*
522 * module_param_sysfs_remove - remove sysfs support for one module
523 * @mod: module
524 *
525 * Remove sysfs entries for module parameters and the corresponding
526 * kobject.
527 */
528 void module_param_sysfs_remove(struct module *mod)
529 {
530 if (mod->param_attrs) {
531 sysfs_remove_group(&mod->mkobj.kobj,
532 &mod->param_attrs->grp);
533 /* We are positive that no one is using any param
534 * attrs at this point. Deallocate immediately. */
535 kfree(mod->param_attrs);
536 mod->param_attrs = NULL;
537 }
538 }
539 #endif
541 /*
542 * kernel_param_sysfs_setup - wrapper for built-in params support
543 */
544 static void __init kernel_param_sysfs_setup(const char *name,
545 struct kernel_param *kparam,
546 unsigned int num_params,
547 unsigned int name_skip)
548 {
549 struct module_kobject *mk;
551 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
552 BUG_ON(!mk);
554 mk->mod = THIS_MODULE;
555 kobj_set_kset_s(mk, module_subsys);
556 kobject_set_name(&mk->kobj, name);
557 kobject_register(&mk->kobj);
559 /* no need to keep the kobject if no parameter is exported */
560 if (!param_sysfs_setup(mk, kparam, num_params, name_skip)) {
561 kobject_unregister(&mk->kobj);
562 kfree(mk);
563 }
564 }
566 /*
567 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
568 *
569 * Add module_parameters to sysfs for "modules" built into the kernel.
570 *
571 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
572 * "parameter" name is stored behind a dot in kernel_param->name. So,
573 * extract the "module" name for all built-in kernel_param-eters,
574 * and for all who have the same, call kernel_param_sysfs_setup.
575 */
576 static void __init param_sysfs_builtin(void)
577 {
578 struct kernel_param *kp, *kp_begin = NULL;
579 unsigned int i, name_len, count = 0;
580 char modname[MAX_KBUILD_MODNAME + 1] = "";
582 for (i=0; i < __stop___param - __start___param; i++) {
583 char *dot;
585 kp = &__start___param[i];
587 /* We do not handle args without periods. */
588 dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME);
589 if (!dot) {
590 DEBUGP("couldn't find period in %s\n", kp->name);
591 continue;
592 }
593 name_len = dot - kp->name;
595 /* new kbuild_modname? */
596 if (strlen(modname) != name_len
597 || strncmp(modname, kp->name, name_len) != 0) {
598 /* add a new kobject for previous kernel_params. */
599 if (count)
600 kernel_param_sysfs_setup(modname,
601 kp_begin,
602 count,
603 strlen(modname)+1);
605 strncpy(modname, kp->name, name_len);
606 modname[name_len] = '\0';
607 count = 0;
608 kp_begin = kp;
609 }
610 count++;
611 }
613 /* last kernel_params need to be registered as well */
614 if (count)
615 kernel_param_sysfs_setup(modname, kp_begin, count,
616 strlen(modname)+1);
617 }
620 /* module-related sysfs stuff */
621 #ifdef CONFIG_SYSFS
623 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
624 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
626 static ssize_t module_attr_show(struct kobject *kobj,
627 struct attribute *attr,
628 char *buf)
629 {
630 struct module_attribute *attribute;
631 struct module_kobject *mk;
632 int ret;
634 attribute = to_module_attr(attr);
635 mk = to_module_kobject(kobj);
637 if (!attribute->show)
638 return -EIO;
640 ret = attribute->show(attribute, mk->mod, buf);
642 return ret;
643 }
645 static ssize_t module_attr_store(struct kobject *kobj,
646 struct attribute *attr,
647 const char *buf, size_t len)
648 {
649 struct module_attribute *attribute;
650 struct module_kobject *mk;
651 int ret;
653 attribute = to_module_attr(attr);
654 mk = to_module_kobject(kobj);
656 if (!attribute->store)
657 return -EIO;
659 ret = attribute->store(attribute, mk->mod, buf, len);
661 return ret;
662 }
664 static struct sysfs_ops module_sysfs_ops = {
665 .show = module_attr_show,
666 .store = module_attr_store,
667 };
669 #else
670 static struct sysfs_ops module_sysfs_ops = {
671 .show = NULL,
672 .store = NULL,
673 };
674 #endif
676 static struct kobj_type module_ktype = {
677 .sysfs_ops = &module_sysfs_ops,
678 };
680 decl_subsys(module, &module_ktype, NULL);
682 /*
683 * param_sysfs_init - wrapper for built-in params support
684 */
685 static int __init param_sysfs_init(void)
686 {
687 subsystem_register(&module_subsys);
689 param_sysfs_builtin();
691 return 0;
692 }
693 __initcall(param_sysfs_init);
695 EXPORT_SYMBOL(param_set_byte);
696 EXPORT_SYMBOL(param_get_byte);
697 EXPORT_SYMBOL(param_set_short);
698 EXPORT_SYMBOL(param_get_short);
699 EXPORT_SYMBOL(param_set_ushort);
700 EXPORT_SYMBOL(param_get_ushort);
701 EXPORT_SYMBOL(param_set_int);
702 EXPORT_SYMBOL(param_get_int);
703 EXPORT_SYMBOL(param_set_uint);
704 EXPORT_SYMBOL(param_get_uint);
705 EXPORT_SYMBOL(param_set_long);
706 EXPORT_SYMBOL(param_get_long);
707 EXPORT_SYMBOL(param_set_ulong);
708 EXPORT_SYMBOL(param_get_ulong);
709 EXPORT_SYMBOL(param_set_charp);
710 EXPORT_SYMBOL(param_get_charp);
711 EXPORT_SYMBOL(param_set_bool);
712 EXPORT_SYMBOL(param_get_bool);
713 EXPORT_SYMBOL(param_set_invbool);
714 EXPORT_SYMBOL(param_get_invbool);
715 EXPORT_SYMBOL(param_array_set);
716 EXPORT_SYMBOL(param_array_get);
717 EXPORT_SYMBOL(param_set_copystring);
718 EXPORT_SYMBOL(param_get_string);