ia64/pv_ops/xen: implement xen pv_time_ops.
[pv_ops_mirror.git] / kernel / params.c
blobafc46a23eb6d15ebfb328f242979d75998d6d4c4
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 inline char dash2underscore(char c)
35 if (c == '-')
36 return '_';
37 return c;
40 static inline int parameq(const char *input, const char *paramname)
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;
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))
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]);
66 if (handle_unknown) {
67 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
68 return handle_unknown(param, val);
71 DEBUGP("Unknown argument `%s'\n", param);
72 return -ENOENT;
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)
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;
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;
96 if (args[i] == '"')
97 in_quote = !in_quote;
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';
113 if (quoted && args[i-1] == '"')
114 args[i-1] = '\0';
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;
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))
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;
146 int irq_was_disabled;
148 args = next_arg(args, &param, &val);
149 irq_was_disabled = irqs_disabled();
150 ret = parse_one(param, val, params, num, unknown);
151 if (irq_was_disabled && !irqs_disabled()) {
152 printk(KERN_WARNING "parse_args(): option '%s' enabled "
153 "irq's!\n", param);
155 switch (ret) {
156 case -ENOENT:
157 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
158 name, param);
159 return ret;
160 case -ENOSPC:
161 printk(KERN_ERR
162 "%s: `%s' too large for parameter `%s'\n",
163 name, val ?: "", param);
164 return ret;
165 case 0:
166 break;
167 default:
168 printk(KERN_ERR
169 "%s: `%s' invalid for parameter `%s'\n",
170 name, val ?: "", param);
171 return ret;
175 /* All parsed OK. */
176 return 0;
179 /* Lazy bastard, eh? */
180 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
181 int param_set_##name(const char *val, struct kernel_param *kp) \
183 tmptype l; \
184 int ret; \
186 if (!val) return -EINVAL; \
187 ret = strtolfn(val, 0, &l); \
188 if (ret == -EINVAL || ((type)l != l)) \
189 return -EINVAL; \
190 *((type *)kp->arg) = l; \
191 return 0; \
193 int param_get_##name(char *buffer, struct kernel_param *kp) \
195 return sprintf(buffer, format, *((type *)kp->arg)); \
198 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
199 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
200 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
201 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
202 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
203 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
204 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
206 int param_set_charp(const char *val, struct kernel_param *kp)
208 if (!val) {
209 printk(KERN_ERR "%s: string parameter expected\n",
210 kp->name);
211 return -EINVAL;
214 if (strlen(val) > 1024) {
215 printk(KERN_ERR "%s: string parameter too long\n",
216 kp->name);
217 return -ENOSPC;
220 *(char **)kp->arg = (char *)val;
221 return 0;
224 int param_get_charp(char *buffer, struct kernel_param *kp)
226 return sprintf(buffer, "%s", *((char **)kp->arg));
229 int param_set_bool(const char *val, struct kernel_param *kp)
231 /* No equals means "set"... */
232 if (!val) val = "1";
234 /* One of =[yYnN01] */
235 switch (val[0]) {
236 case 'y': case 'Y': case '1':
237 *(int *)kp->arg = 1;
238 return 0;
239 case 'n': case 'N': case '0':
240 *(int *)kp->arg = 0;
241 return 0;
243 return -EINVAL;
246 int param_get_bool(char *buffer, struct kernel_param *kp)
248 /* Y and N chosen as being relatively non-coder friendly */
249 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
252 int param_set_invbool(const char *val, struct kernel_param *kp)
254 int boolval, ret;
255 struct kernel_param dummy;
257 dummy.arg = &boolval;
258 ret = param_set_bool(val, &dummy);
259 if (ret == 0)
260 *(int *)kp->arg = !boolval;
261 return ret;
264 int param_get_invbool(char *buffer, struct kernel_param *kp)
266 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'N' : 'Y');
269 /* We break the rule and mangle the string. */
270 static int param_array(const char *name,
271 const char *val,
272 unsigned int min, unsigned int max,
273 void *elem, int elemsize,
274 int (*set)(const char *, struct kernel_param *kp),
275 unsigned int *num)
277 int ret;
278 struct kernel_param kp;
279 char save;
281 /* Get the name right for errors. */
282 kp.name = name;
283 kp.arg = elem;
285 /* No equals sign? */
286 if (!val) {
287 printk(KERN_ERR "%s: expects arguments\n", name);
288 return -EINVAL;
291 *num = 0;
292 /* We expect a comma-separated list of values. */
293 do {
294 int len;
296 if (*num == max) {
297 printk(KERN_ERR "%s: can only take %i arguments\n",
298 name, max);
299 return -EINVAL;
301 len = strcspn(val, ",");
303 /* nul-terminate and parse */
304 save = val[len];
305 ((char *)val)[len] = '\0';
306 ret = set(val, &kp);
308 if (ret != 0)
309 return ret;
310 kp.arg += elemsize;
311 val += len+1;
312 (*num)++;
313 } while (save == ',');
315 if (*num < min) {
316 printk(KERN_ERR "%s: needs at least %i arguments\n",
317 name, min);
318 return -EINVAL;
320 return 0;
323 int param_array_set(const char *val, struct kernel_param *kp)
325 const struct kparam_array *arr = kp->arr;
326 unsigned int temp_num;
328 return param_array(kp->name, val, 1, arr->max, arr->elem,
329 arr->elemsize, arr->set, arr->num ?: &temp_num);
332 int param_array_get(char *buffer, struct kernel_param *kp)
334 int i, off, ret;
335 const struct kparam_array *arr = kp->arr;
336 struct kernel_param p;
338 p = *kp;
339 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
340 if (i)
341 buffer[off++] = ',';
342 p.arg = arr->elem + arr->elemsize * i;
343 ret = arr->get(buffer + off, &p);
344 if (ret < 0)
345 return ret;
346 off += ret;
348 buffer[off] = '\0';
349 return off;
352 int param_set_copystring(const char *val, struct kernel_param *kp)
354 const struct kparam_string *kps = kp->str;
356 if (!val) {
357 printk(KERN_ERR "%s: missing param set value\n", kp->name);
358 return -EINVAL;
360 if (strlen(val)+1 > kps->maxlen) {
361 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
362 kp->name, kps->maxlen-1);
363 return -ENOSPC;
365 strcpy(kps->string, val);
366 return 0;
369 int param_get_string(char *buffer, struct kernel_param *kp)
371 const struct kparam_string *kps = kp->str;
372 return strlcpy(buffer, kps->string, kps->maxlen);
375 /* sysfs output in /sys/modules/XYZ/parameters/ */
377 extern struct kernel_param __start___param[], __stop___param[];
379 struct param_attribute
381 struct module_attribute mattr;
382 struct kernel_param *param;
385 struct module_param_attrs
387 struct attribute_group grp;
388 struct param_attribute attrs[0];
391 #ifdef CONFIG_SYSFS
392 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
394 static ssize_t param_attr_show(struct module_attribute *mattr,
395 struct module *mod, char *buf)
397 int count;
398 struct param_attribute *attribute = to_param_attr(mattr);
400 if (!attribute->param->get)
401 return -EPERM;
403 count = attribute->param->get(buf, attribute->param);
404 if (count > 0) {
405 strcat(buf, "\n");
406 ++count;
408 return count;
411 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
412 static ssize_t param_attr_store(struct module_attribute *mattr,
413 struct module *owner,
414 const char *buf, size_t len)
416 int err;
417 struct param_attribute *attribute = to_param_attr(mattr);
419 if (!attribute->param->set)
420 return -EPERM;
422 err = attribute->param->set(buf, attribute->param);
423 if (!err)
424 return len;
425 return err;
427 #endif
429 #ifdef CONFIG_MODULES
430 #define __modinit
431 #else
432 #define __modinit __init
433 #endif
435 #ifdef CONFIG_SYSFS
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 = kzalloc(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.mode = kp->perm;
490 *(gattr++) = &(pattr++)->mattr.attr;
493 *gattr = NULL;
495 if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) {
496 kfree(mp);
497 return ERR_PTR(err);
499 return mp;
502 #ifdef CONFIG_MODULES
504 * module_param_sysfs_setup - setup sysfs support for one module
505 * @mod: module
506 * @kparam: module parameters (array)
507 * @num_params: number of module parameters
509 * Adds sysfs entries for module parameters, and creates a link from
510 * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/
512 int module_param_sysfs_setup(struct module *mod,
513 struct kernel_param *kparam,
514 unsigned int num_params)
516 struct module_param_attrs *mp;
518 mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
519 if (IS_ERR(mp))
520 return PTR_ERR(mp);
522 mod->param_attrs = mp;
523 return 0;
527 * module_param_sysfs_remove - remove sysfs support for one module
528 * @mod: module
530 * Remove sysfs entries for module parameters and the corresponding
531 * kobject.
533 void module_param_sysfs_remove(struct module *mod)
535 if (mod->param_attrs) {
536 sysfs_remove_group(&mod->mkobj.kobj,
537 &mod->param_attrs->grp);
538 /* We are positive that no one is using any param
539 * attrs at this point. Deallocate immediately. */
540 kfree(mod->param_attrs);
541 mod->param_attrs = NULL;
544 #endif
547 * kernel_param_sysfs_setup - wrapper for built-in params support
549 static void __init kernel_param_sysfs_setup(const char *name,
550 struct kernel_param *kparam,
551 unsigned int num_params,
552 unsigned int name_skip)
554 struct module_kobject *mk;
555 int ret;
557 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
558 BUG_ON(!mk);
560 mk->mod = THIS_MODULE;
561 mk->kobj.kset = module_kset;
562 ret = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, "%s", name);
563 if (ret) {
564 kobject_put(&mk->kobj);
565 printk(KERN_ERR "Module '%s' failed to be added to sysfs, "
566 "error number %d\n", name, ret);
567 printk(KERN_ERR "The system will be unstable now.\n");
568 return;
570 param_sysfs_setup(mk, kparam, num_params, name_skip);
571 kobject_uevent(&mk->kobj, KOBJ_ADD);
575 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
577 * Add module_parameters to sysfs for "modules" built into the kernel.
579 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
580 * "parameter" name is stored behind a dot in kernel_param->name. So,
581 * extract the "module" name for all built-in kernel_param-eters,
582 * and for all who have the same, call kernel_param_sysfs_setup.
584 static void __init param_sysfs_builtin(void)
586 struct kernel_param *kp, *kp_begin = NULL;
587 unsigned int i, name_len, count = 0;
588 char modname[MODULE_NAME_LEN + 1] = "";
590 for (i=0; i < __stop___param - __start___param; i++) {
591 char *dot;
592 size_t max_name_len;
594 kp = &__start___param[i];
595 max_name_len =
596 min_t(size_t, MODULE_NAME_LEN, strlen(kp->name));
598 dot = memchr(kp->name, '.', max_name_len);
599 if (!dot) {
600 DEBUGP("couldn't find period in first %d characters "
601 "of %s\n", MODULE_NAME_LEN, kp->name);
602 continue;
604 name_len = dot - kp->name;
606 /* new kbuild_modname? */
607 if (strlen(modname) != name_len
608 || strncmp(modname, kp->name, name_len) != 0) {
609 /* add a new kobject for previous kernel_params. */
610 if (count)
611 kernel_param_sysfs_setup(modname,
612 kp_begin,
613 count,
614 strlen(modname)+1);
616 strncpy(modname, kp->name, name_len);
617 modname[name_len] = '\0';
618 count = 0;
619 kp_begin = kp;
621 count++;
624 /* last kernel_params need to be registered as well */
625 if (count)
626 kernel_param_sysfs_setup(modname, kp_begin, count,
627 strlen(modname)+1);
631 /* module-related sysfs stuff */
633 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
634 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
636 static ssize_t module_attr_show(struct kobject *kobj,
637 struct attribute *attr,
638 char *buf)
640 struct module_attribute *attribute;
641 struct module_kobject *mk;
642 int ret;
644 attribute = to_module_attr(attr);
645 mk = to_module_kobject(kobj);
647 if (!attribute->show)
648 return -EIO;
650 ret = attribute->show(attribute, mk->mod, buf);
652 return ret;
655 static ssize_t module_attr_store(struct kobject *kobj,
656 struct attribute *attr,
657 const char *buf, size_t len)
659 struct module_attribute *attribute;
660 struct module_kobject *mk;
661 int ret;
663 attribute = to_module_attr(attr);
664 mk = to_module_kobject(kobj);
666 if (!attribute->store)
667 return -EIO;
669 ret = attribute->store(attribute, mk->mod, buf, len);
671 return ret;
674 static struct sysfs_ops module_sysfs_ops = {
675 .show = module_attr_show,
676 .store = module_attr_store,
679 static int uevent_filter(struct kset *kset, struct kobject *kobj)
681 struct kobj_type *ktype = get_ktype(kobj);
683 if (ktype == &module_ktype)
684 return 1;
685 return 0;
688 static struct kset_uevent_ops module_uevent_ops = {
689 .filter = uevent_filter,
692 struct kset *module_kset;
693 int module_sysfs_initialized;
695 struct kobj_type module_ktype = {
696 .sysfs_ops = &module_sysfs_ops,
700 * param_sysfs_init - wrapper for built-in params support
702 static int __init param_sysfs_init(void)
704 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
705 if (!module_kset) {
706 printk(KERN_WARNING "%s (%d): error creating kset\n",
707 __FILE__, __LINE__);
708 return -ENOMEM;
710 module_sysfs_initialized = 1;
712 param_sysfs_builtin();
714 return 0;
716 subsys_initcall(param_sysfs_init);
718 #endif /* CONFIG_SYSFS */
720 EXPORT_SYMBOL(param_set_byte);
721 EXPORT_SYMBOL(param_get_byte);
722 EXPORT_SYMBOL(param_set_short);
723 EXPORT_SYMBOL(param_get_short);
724 EXPORT_SYMBOL(param_set_ushort);
725 EXPORT_SYMBOL(param_get_ushort);
726 EXPORT_SYMBOL(param_set_int);
727 EXPORT_SYMBOL(param_get_int);
728 EXPORT_SYMBOL(param_set_uint);
729 EXPORT_SYMBOL(param_get_uint);
730 EXPORT_SYMBOL(param_set_long);
731 EXPORT_SYMBOL(param_get_long);
732 EXPORT_SYMBOL(param_set_ulong);
733 EXPORT_SYMBOL(param_get_ulong);
734 EXPORT_SYMBOL(param_set_charp);
735 EXPORT_SYMBOL(param_get_charp);
736 EXPORT_SYMBOL(param_set_bool);
737 EXPORT_SYMBOL(param_get_bool);
738 EXPORT_SYMBOL(param_set_invbool);
739 EXPORT_SYMBOL(param_get_invbool);
740 EXPORT_SYMBOL(param_array_set);
741 EXPORT_SYMBOL(param_array_get);
742 EXPORT_SYMBOL(param_set_copystring);
743 EXPORT_SYMBOL(param_get_string);