[ALSA] snd_hwdep_release() racefix
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / params.c
blob553cf7d6a4be113f0dcb89f1be51aa9989d51453
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
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 struct kobj_type module_ktype;
35 static inline char dash2underscore(char c)
37 if (c == '-')
38 return '_';
39 return c;
42 static inline int parameq(const char *input, const char *paramname)
44 unsigned int i;
45 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
46 if (input[i] == '\0')
47 return 1;
48 return 0;
51 static int parse_one(char *param,
52 char *val,
53 struct kernel_param *params,
54 unsigned num_params,
55 int (*handle_unknown)(char *param, char *val))
57 unsigned int i;
59 /* Find parameter */
60 for (i = 0; i < num_params; i++) {
61 if (parameq(param, params[i].name)) {
62 DEBUGP("They are equal! Calling %p\n",
63 params[i].set);
64 return params[i].set(val, &params[i]);
68 if (handle_unknown) {
69 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
70 return handle_unknown(param, val);
73 DEBUGP("Unknown argument `%s'\n", param);
74 return -ENOENT;
77 /* You can use " around spaces, but can't escape ". */
78 /* Hyphens and underscores equivalent in parameter names. */
79 static char *next_arg(char *args, char **param, char **val)
81 unsigned int i, equals = 0;
82 int in_quote = 0, quoted = 0;
83 char *next;
85 if (*args == '"') {
86 args++;
87 in_quote = 1;
88 quoted = 1;
91 for (i = 0; args[i]; i++) {
92 if (args[i] == ' ' && !in_quote)
93 break;
94 if (equals == 0) {
95 if (args[i] == '=')
96 equals = i;
98 if (args[i] == '"')
99 in_quote = !in_quote;
102 *param = args;
103 if (!equals)
104 *val = NULL;
105 else {
106 args[equals] = '\0';
107 *val = args + equals + 1;
109 /* Don't include quotes in value. */
110 if (**val == '"') {
111 (*val)++;
112 if (args[i-1] == '"')
113 args[i-1] = '\0';
115 if (quoted && args[i-1] == '"')
116 args[i-1] = '\0';
119 if (args[i]) {
120 args[i] = '\0';
121 next = args + i + 1;
122 } else
123 next = args + i;
125 /* Chew up trailing spaces. */
126 while (*next == ' ')
127 next++;
128 return next;
131 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
132 int parse_args(const char *name,
133 char *args,
134 struct kernel_param *params,
135 unsigned num,
136 int (*unknown)(char *param, char *val))
138 char *param, *val;
140 DEBUGP("Parsing ARGS: %s\n", args);
142 /* Chew leading spaces */
143 while (*args == ' ')
144 args++;
146 while (*args) {
147 int ret;
148 int irq_was_disabled;
150 args = next_arg(args, &param, &val);
151 irq_was_disabled = irqs_disabled();
152 ret = parse_one(param, val, params, num, unknown);
153 if (irq_was_disabled && !irqs_disabled()) {
154 printk(KERN_WARNING "parse_args(): option '%s' enabled "
155 "irq's!\n", param);
157 switch (ret) {
158 case -ENOENT:
159 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
160 name, param);
161 return ret;
162 case -ENOSPC:
163 printk(KERN_ERR
164 "%s: `%s' too large for parameter `%s'\n",
165 name, val ?: "", param);
166 return ret;
167 case 0:
168 break;
169 default:
170 printk(KERN_ERR
171 "%s: `%s' invalid for parameter `%s'\n",
172 name, val ?: "", param);
173 return ret;
177 /* All parsed OK. */
178 return 0;
181 /* Lazy bastard, eh? */
182 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
183 int param_set_##name(const char *val, struct kernel_param *kp) \
185 char *endp; \
186 tmptype l; \
188 if (!val) return -EINVAL; \
189 l = strtolfn(val, &endp, 0); \
190 if (endp == val || ((type)l != l)) \
191 return -EINVAL; \
192 *((type *)kp->arg) = l; \
193 return 0; \
195 int param_get_##name(char *buffer, struct kernel_param *kp) \
197 return sprintf(buffer, format, *((type *)kp->arg)); \
200 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, simple_strtoul);
201 STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol);
202 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, simple_strtoul);
203 STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol);
204 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, simple_strtoul);
205 STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol);
206 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_strtoul);
208 int param_set_charp(const char *val, struct kernel_param *kp)
210 if (!val) {
211 printk(KERN_ERR "%s: string parameter expected\n",
212 kp->name);
213 return -EINVAL;
216 if (strlen(val) > 1024) {
217 printk(KERN_ERR "%s: string parameter too long\n",
218 kp->name);
219 return -ENOSPC;
222 *(char **)kp->arg = (char *)val;
223 return 0;
226 int param_get_charp(char *buffer, struct kernel_param *kp)
228 return sprintf(buffer, "%s", *((char **)kp->arg));
231 int param_set_bool(const char *val, struct kernel_param *kp)
233 /* No equals means "set"... */
234 if (!val) val = "1";
236 /* One of =[yYnN01] */
237 switch (val[0]) {
238 case 'y': case 'Y': case '1':
239 *(int *)kp->arg = 1;
240 return 0;
241 case 'n': case 'N': case '0':
242 *(int *)kp->arg = 0;
243 return 0;
245 return -EINVAL;
248 int param_get_bool(char *buffer, struct kernel_param *kp)
250 /* Y and N chosen as being relatively non-coder friendly */
251 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
254 int param_set_invbool(const char *val, struct kernel_param *kp)
256 int boolval, ret;
257 struct kernel_param dummy = { .arg = &boolval };
259 ret = param_set_bool(val, &dummy);
260 if (ret == 0)
261 *(int *)kp->arg = !boolval;
262 return ret;
265 int param_get_invbool(char *buffer, struct kernel_param *kp)
267 int val;
268 struct kernel_param dummy = { .arg = &val };
270 val = !*(int *)kp->arg;
271 return param_get_bool(buffer, &dummy);
274 /* We cheat here and temporarily mangle the string. */
275 static int param_array(const char *name,
276 const char *val,
277 unsigned int min, unsigned int max,
278 void *elem, int elemsize,
279 int (*set)(const char *, struct kernel_param *kp),
280 int *num)
282 int ret;
283 struct kernel_param kp;
284 char save;
286 /* Get the name right for errors. */
287 kp.name = name;
288 kp.arg = elem;
290 /* No equals sign? */
291 if (!val) {
292 printk(KERN_ERR "%s: expects arguments\n", name);
293 return -EINVAL;
296 *num = 0;
297 /* We expect a comma-separated list of values. */
298 do {
299 int len;
301 if (*num == max) {
302 printk(KERN_ERR "%s: can only take %i arguments\n",
303 name, max);
304 return -EINVAL;
306 len = strcspn(val, ",");
308 /* nul-terminate and parse */
309 save = val[len];
310 ((char *)val)[len] = '\0';
311 ret = set(val, &kp);
313 if (ret != 0)
314 return ret;
315 kp.arg += elemsize;
316 val += len+1;
317 (*num)++;
318 } while (save == ',');
320 if (*num < min) {
321 printk(KERN_ERR "%s: needs at least %i arguments\n",
322 name, min);
323 return -EINVAL;
325 return 0;
328 int param_array_set(const char *val, struct kernel_param *kp)
330 struct kparam_array *arr = kp->arg;
331 unsigned int temp_num;
333 return param_array(kp->name, val, 1, arr->max, arr->elem,
334 arr->elemsize, arr->set, arr->num ?: &temp_num);
337 int param_array_get(char *buffer, struct kernel_param *kp)
339 int i, off, ret;
340 struct kparam_array *arr = kp->arg;
341 struct kernel_param p;
343 p = *kp;
344 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
345 if (i)
346 buffer[off++] = ',';
347 p.arg = arr->elem + arr->elemsize * i;
348 ret = arr->get(buffer + off, &p);
349 if (ret < 0)
350 return ret;
351 off += ret;
353 buffer[off] = '\0';
354 return off;
357 int param_set_copystring(const char *val, struct kernel_param *kp)
359 struct kparam_string *kps = kp->arg;
361 if (strlen(val)+1 > kps->maxlen) {
362 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
363 kp->name, kps->maxlen-1);
364 return -ENOSPC;
366 strcpy(kps->string, val);
367 return 0;
370 int param_get_string(char *buffer, struct kernel_param *kp)
372 struct kparam_string *kps = kp->arg;
373 return strlcpy(buffer, kps->string, kps->maxlen);
376 /* sysfs output in /sys/modules/XYZ/parameters/ */
378 extern struct kernel_param __start___param[], __stop___param[];
380 #define MAX_KBUILD_MODNAME KOBJ_NAME_LEN
382 struct param_attribute
384 struct module_attribute mattr;
385 struct kernel_param *param;
388 struct module_param_attrs
390 struct attribute_group grp;
391 struct param_attribute attrs[0];
394 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
396 static ssize_t param_attr_show(struct module_attribute *mattr,
397 struct module *mod, char *buf)
399 int count;
400 struct param_attribute *attribute = to_param_attr(mattr);
402 if (!attribute->param->get)
403 return -EPERM;
405 count = attribute->param->get(buf, attribute->param);
406 if (count > 0) {
407 strcat(buf, "\n");
408 ++count;
410 return count;
413 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
414 static ssize_t param_attr_store(struct module_attribute *mattr,
415 struct module *owner,
416 const char *buf, size_t len)
418 int err;
419 struct param_attribute *attribute = to_param_attr(mattr);
421 if (!attribute->param->set)
422 return -EPERM;
424 err = attribute->param->set(buf, attribute->param);
425 if (!err)
426 return len;
427 return err;
430 #ifdef CONFIG_MODULES
431 #define __modinit
432 #else
433 #define __modinit __init
434 #endif
437 * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME
438 * @mk: struct module_kobject (contains parent kobject)
439 * @kparam: array of struct kernel_param, the actual parameter definitions
440 * @num_params: number of entries in array
441 * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules"
443 * Create a kobject for a (per-module) group of parameters, and create files
444 * in sysfs. A pointer to the param_kobject is returned on success,
445 * NULL if there's no parameter to export, or other ERR_PTR(err).
447 static __modinit struct module_param_attrs *
448 param_sysfs_setup(struct module_kobject *mk,
449 struct kernel_param *kparam,
450 unsigned int num_params,
451 unsigned int name_skip)
453 struct module_param_attrs *mp;
454 unsigned int valid_attrs = 0;
455 unsigned int i, size[2];
456 struct param_attribute *pattr;
457 struct attribute **gattr;
458 int err;
460 for (i=0; i<num_params; i++) {
461 if (kparam[i].perm)
462 valid_attrs++;
465 if (!valid_attrs)
466 return NULL;
468 size[0] = ALIGN(sizeof(*mp) +
469 valid_attrs * sizeof(mp->attrs[0]),
470 sizeof(mp->grp.attrs[0]));
471 size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]);
473 mp = kmalloc(size[0] + size[1], GFP_KERNEL);
474 if (!mp)
475 return ERR_PTR(-ENOMEM);
477 mp->grp.name = "parameters";
478 mp->grp.attrs = (void *)mp + size[0];
480 pattr = &mp->attrs[0];
481 gattr = &mp->grp.attrs[0];
482 for (i = 0; i < num_params; i++) {
483 struct kernel_param *kp = &kparam[i];
484 if (kp->perm) {
485 pattr->param = kp;
486 pattr->mattr.show = param_attr_show;
487 pattr->mattr.store = param_attr_store;
488 pattr->mattr.attr.name = (char *)&kp->name[name_skip];
489 pattr->mattr.attr.owner = mk->mod;
490 pattr->mattr.attr.mode = kp->perm;
491 *(gattr++) = &(pattr++)->mattr.attr;
494 *gattr = NULL;
496 if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) {
497 kfree(mp);
498 return ERR_PTR(err);
500 return mp;
504 #ifdef CONFIG_MODULES
507 * module_param_sysfs_setup - setup sysfs support for one module
508 * @mod: module
509 * @kparam: module parameters (array)
510 * @num_params: number of module parameters
512 * Adds sysfs entries for module parameters, and creates a link from
513 * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/
515 int module_param_sysfs_setup(struct module *mod,
516 struct kernel_param *kparam,
517 unsigned int num_params)
519 struct module_param_attrs *mp;
521 mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
522 if (IS_ERR(mp))
523 return PTR_ERR(mp);
525 mod->param_attrs = mp;
526 return 0;
530 * module_param_sysfs_remove - remove sysfs support for one module
531 * @mod: module
533 * Remove sysfs entries for module parameters and the corresponding
534 * kobject.
536 void module_param_sysfs_remove(struct module *mod)
538 if (mod->param_attrs) {
539 sysfs_remove_group(&mod->mkobj.kobj,
540 &mod->param_attrs->grp);
541 /* We are positive that no one is using any param
542 * attrs at this point. Deallocate immediately. */
543 kfree(mod->param_attrs);
544 mod->param_attrs = NULL;
547 #endif
550 * kernel_param_sysfs_setup - wrapper for built-in params support
552 static void __init kernel_param_sysfs_setup(const char *name,
553 struct kernel_param *kparam,
554 unsigned int num_params,
555 unsigned int name_skip)
557 struct module_kobject *mk;
558 int ret;
560 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
561 BUG_ON(!mk);
563 mk->mod = THIS_MODULE;
564 kobj_set_kset_s(mk, module_subsys);
565 kobject_set_name(&mk->kobj, name);
566 kobject_init(&mk->kobj);
567 ret = kobject_add(&mk->kobj);
568 BUG_ON(ret < 0);
569 param_sysfs_setup(mk, kparam, num_params, name_skip);
570 kobject_uevent(&mk->kobj, KOBJ_ADD);
574 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
576 * Add module_parameters to sysfs for "modules" built into the kernel.
578 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
579 * "parameter" name is stored behind a dot in kernel_param->name. So,
580 * extract the "module" name for all built-in kernel_param-eters,
581 * and for all who have the same, call kernel_param_sysfs_setup.
583 static void __init param_sysfs_builtin(void)
585 struct kernel_param *kp, *kp_begin = NULL;
586 unsigned int i, name_len, count = 0;
587 char modname[MAX_KBUILD_MODNAME + 1] = "";
589 for (i=0; i < __stop___param - __start___param; i++) {
590 char *dot;
592 kp = &__start___param[i];
594 /* We do not handle args without periods. */
595 dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME);
596 if (!dot) {
597 DEBUGP("couldn't find period in %s\n", kp->name);
598 continue;
600 name_len = dot - kp->name;
602 /* new kbuild_modname? */
603 if (strlen(modname) != name_len
604 || strncmp(modname, kp->name, name_len) != 0) {
605 /* add a new kobject for previous kernel_params. */
606 if (count)
607 kernel_param_sysfs_setup(modname,
608 kp_begin,
609 count,
610 strlen(modname)+1);
612 strncpy(modname, kp->name, name_len);
613 modname[name_len] = '\0';
614 count = 0;
615 kp_begin = kp;
617 count++;
620 /* last kernel_params need to be registered as well */
621 if (count)
622 kernel_param_sysfs_setup(modname, kp_begin, count,
623 strlen(modname)+1);
627 /* module-related sysfs stuff */
628 #ifdef CONFIG_SYSFS
630 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
631 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
633 static ssize_t module_attr_show(struct kobject *kobj,
634 struct attribute *attr,
635 char *buf)
637 struct module_attribute *attribute;
638 struct module_kobject *mk;
639 int ret;
641 attribute = to_module_attr(attr);
642 mk = to_module_kobject(kobj);
644 if (!attribute->show)
645 return -EIO;
647 ret = attribute->show(attribute, mk->mod, buf);
649 return ret;
652 static ssize_t module_attr_store(struct kobject *kobj,
653 struct attribute *attr,
654 const char *buf, size_t len)
656 struct module_attribute *attribute;
657 struct module_kobject *mk;
658 int ret;
660 attribute = to_module_attr(attr);
661 mk = to_module_kobject(kobj);
663 if (!attribute->store)
664 return -EIO;
666 ret = attribute->store(attribute, mk->mod, buf, len);
668 return ret;
671 static struct sysfs_ops module_sysfs_ops = {
672 .show = module_attr_show,
673 .store = module_attr_store,
676 static int uevent_filter(struct kset *kset, struct kobject *kobj)
678 struct kobj_type *ktype = get_ktype(kobj);
680 if (ktype == &module_ktype)
681 return 1;
682 return 0;
685 static struct kset_uevent_ops module_uevent_ops = {
686 .filter = uevent_filter,
689 #else
690 static struct sysfs_ops module_sysfs_ops = {
691 .show = NULL,
692 .store = NULL,
694 #endif
696 static struct kobj_type module_ktype = {
697 .sysfs_ops = &module_sysfs_ops,
700 decl_subsys(module, &module_ktype, &module_uevent_ops);
703 * param_sysfs_init - wrapper for built-in params support
705 static int __init param_sysfs_init(void)
707 int ret;
709 ret = subsystem_register(&module_subsys);
710 if (ret < 0) {
711 printk(KERN_WARNING "%s (%d): subsystem_register error: %d\n",
712 __FILE__, __LINE__, ret);
713 return ret;
716 param_sysfs_builtin();
718 return 0;
720 subsys_initcall(param_sysfs_init);
722 EXPORT_SYMBOL(param_set_byte);
723 EXPORT_SYMBOL(param_get_byte);
724 EXPORT_SYMBOL(param_set_short);
725 EXPORT_SYMBOL(param_get_short);
726 EXPORT_SYMBOL(param_set_ushort);
727 EXPORT_SYMBOL(param_get_ushort);
728 EXPORT_SYMBOL(param_set_int);
729 EXPORT_SYMBOL(param_get_int);
730 EXPORT_SYMBOL(param_set_uint);
731 EXPORT_SYMBOL(param_get_uint);
732 EXPORT_SYMBOL(param_set_long);
733 EXPORT_SYMBOL(param_get_long);
734 EXPORT_SYMBOL(param_set_ulong);
735 EXPORT_SYMBOL(param_get_ulong);
736 EXPORT_SYMBOL(param_set_charp);
737 EXPORT_SYMBOL(param_get_charp);
738 EXPORT_SYMBOL(param_set_bool);
739 EXPORT_SYMBOL(param_get_bool);
740 EXPORT_SYMBOL(param_set_invbool);
741 EXPORT_SYMBOL(param_get_invbool);
742 EXPORT_SYMBOL(param_array_set);
743 EXPORT_SYMBOL(param_array_get);
744 EXPORT_SYMBOL(param_set_copystring);
745 EXPORT_SYMBOL(param_get_string);