Commit 9800794a authored by Andi Kleen's avatar Andi Kleen Committed by Greg Kroah-Hartman
Browse files

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: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4a0b2b4d

drivers/base/sys.c

+49 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/sysdev.h

+34 −0
Original line number Diff line number Diff line
@@ -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_ */

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