[deliverable/lttng-modules.git] / wrapper / writeback.h

#ifndef _LTTNG_WRAPPER_WRITEBACK_H
#define _LTTNG_WRAPPER_WRITEBACK_H

/*
 * wrapper/writeback.h
 *
 * wrapper around global_dirty_limit read. Using KALLSYMS with KALLSYMS_ALL
 * to get its address when available, else we need to have a kernel that
 * exports this variable to GPL modules.
 *
 * Copyright (C) 2013 Mentor Graphics Corp.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifdef CONFIG_KALLSYMS_ALL

#include <linux/kallsyms.h>
#include <wrapper/kallsyms.h>

static unsigned long *global_dirty_limit_sym;

static inline
unsigned long wrapper_global_dirty_limit(void)
{
	if (!global_dirty_limit_sym)
		global_dirty_limit_sym =
			(void *) kallsyms_lookup_dataptr("global_dirty_limit");
	if (global_dirty_limit_sym) {
		return *global_dirty_limit_sym;
	} else {
		printk_once(KERN_WARNING "LTTng: global_dirty_limit symbol lookup failed.\n");
		return 0;
	}
}

#else

#include <linux/writeback.h>

static inline
unsigned long wrapper_global_dirty_limit(void)
{
	return global_dirty_limit;
}

#endif

#endif /* _LTTNG_WRAPPER_WRITEBACK_H */
Commit	Line	Data
	1	#ifndef _LTTNG_WRAPPER_WRITEBACK_H
	2	#define _LTTNG_WRAPPER_WRITEBACK_H
	3
	4	/*
	5	* wrapper/writeback.h
	6	*
	7	* wrapper around global_dirty_limit read. Using KALLSYMS with KALLSYMS_ALL
	8	* to get its address when available, else we need to have a kernel that
	9	* exports this variable to GPL modules.
	10	*
	11	* Copyright (C) 2013 Mentor Graphics Corp.
	12	*
	13	* This library is free software; you can redistribute it and/or
	14	* modify it under the terms of the GNU Lesser General Public
	15	* License as published by the Free Software Foundation; only
	16	* version 2.1 of the License.
	17	*
	18	* This library is distributed in the hope that it will be useful,
	19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	21	* Lesser General Public License for more details.
	22	*
	23	* You should have received a copy of the GNU Lesser General Public
	24	* License along with this library; if not, write to the Free Software
	25	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	26	*/
	27
	28	#ifdef CONFIG_KALLSYMS_ALL
	29
	30	#include <linux/kallsyms.h>
	31	#include <wrapper/kallsyms.h>
	32
	33	static unsigned long *global_dirty_limit_sym;
	34
	35	static inline
	36	unsigned long wrapper_global_dirty_limit(void)
	37	{
	38	if (!global_dirty_limit_sym)
	39	global_dirty_limit_sym =
	40	(void *) kallsyms_lookup_dataptr("global_dirty_limit");
	41	if (global_dirty_limit_sym) {
	42	return *global_dirty_limit_sym;
	43	} else {
	44	printk_once(KERN_WARNING "LTTng: global_dirty_limit symbol lookup failed.\n");
	45	return 0;
	46	}
	47	}
	48
	49	#else
	50
	51	#include <linux/writeback.h>
	52
	53	static inline
	54	unsigned long wrapper_global_dirty_limit(void)
	55	{
	56	return global_dirty_limit;
	57	}
	58
	59	#endif
	60
	61	#endif /* _LTTNG_WRAPPER_WRITEBACK_H */