sysdev: Add utility functions for simple int/ulong variable sysdev attributes

This adds a new sysdev_ext_attribute that stores a pointer to the variable
it manages and some utility functions/macro to easily use them.

Previously all users wrote custom macros to generate show/store
functions for each variable, with this it is possible to avoid
that in many cases.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Andi Kleen 2008-07-01 18:48:42 +02:00 committed by Greg Kroah-Hartman
parent 4a0b2b4dbe
commit 9800794ac1
2 changed files with 83 additions and 0 deletions

View File

@ -479,3 +479,52 @@ int __init system_bus_init(void)
EXPORT_SYMBOL_GPL(sysdev_register);
EXPORT_SYMBOL_GPL(sysdev_unregister);
#define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr)
ssize_t sysdev_store_ulong(struct sys_device *sysdev,
struct sysdev_attribute *attr,
const char *buf, size_t size)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
char *end;
unsigned long new = simple_strtoul(buf, &end, 0);
if (end == buf)
return -EINVAL;
*(unsigned long *)(ea->var) = new;
return end - buf;
}
EXPORT_SYMBOL_GPL(sysdev_store_ulong);
ssize_t sysdev_show_ulong(struct sys_device *sysdev,
struct sysdev_attribute *attr,
char *buf)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
}
EXPORT_SYMBOL_GPL(sysdev_show_ulong);
ssize_t sysdev_store_int(struct sys_device *sysdev,
struct sysdev_attribute *attr,
const char *buf, size_t size)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
char *end;
long new = simple_strtol(buf, &end, 0);
if (end == buf || new > INT_MAX || new < INT_MIN)
return -EINVAL;
*(int *)(ea->var) = new;
return end - buf;
}
EXPORT_SYMBOL_GPL(sysdev_store_int);
ssize_t sysdev_show_int(struct sys_device *sysdev,
struct sysdev_attribute *attr,
char *buf)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
}
EXPORT_SYMBOL_GPL(sysdev_show_int);

View File

@ -119,4 +119,38 @@ struct sysdev_attribute {
extern int sysdev_create_file(struct sys_device *, struct sysdev_attribute *);
extern void sysdev_remove_file(struct sys_device *, struct sysdev_attribute *);
struct sysdev_ext_attribute {
struct sysdev_attribute attr;
void *var;
};
/*
* Support for simple variable sysdev attributes.
* The pointer to the variable is stored in a sysdev_ext_attribute
*/
/* Add more types as needed */
extern ssize_t sysdev_show_ulong(struct sys_device *, struct sysdev_attribute *,
char *);
extern ssize_t sysdev_store_ulong(struct sys_device *,
struct sysdev_attribute *, const char *, size_t);
extern ssize_t sysdev_show_int(struct sys_device *, struct sysdev_attribute *,
char *);
extern ssize_t sysdev_store_int(struct sys_device *,
struct sysdev_attribute *, const char *, size_t);
#define _SYSDEV_ULONG_ATTR(_name, _mode, _var) \
{ _SYSDEV_ATTR(_name, _mode, sysdev_show_ulong, sysdev_store_ulong), \
&(_var) }
#define SYSDEV_ULONG_ATTR(_name, _mode, _var) \
struct sysdev_ext_attribute attr_##_name = \
_SYSDEV_ULONG_ATTR(_name, _mode, _var);
#define _SYSDEV_INT_ATTR(_name, _mode, _var) \
{ _SYSDEV_ATTR(_name, _mode, sysdev_show_int, sysdev_store_int), \
&(_var) }
#define SYSDEV_INT_ATTR(_name, _mode, _var) \
struct sysdev_ext_attribute attr_##_name = \
_SYSDEV_INT_ATTR(_name, _mode, _var);
#endif /* _SYSDEV_H_ */