xref: /freebsd/sys/compat/linuxkpi/common/include/linux/shrinker.h (revision 05dfaadde4ae0f5d823836d5d849e3ba5ebdbf17)
1 /*-
2  * Copyright (c) 2020 Emmanuel Vadot <manu@FreeBSD.org>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #ifndef _LINUXKPI_LINUX_SHRINKER_H_
27 #define	_LINUXKPI_LINUX_SHRINKER_H_
28 
29 #include <sys/queue.h>
30 
31 #include <linux/bitops.h>
32 #include <linux/gfp.h>
33 
34 struct shrink_control {
35 	gfp_t		gfp_mask;
36 	unsigned long	nr_to_scan;
37 	unsigned long	nr_scanned;
38 };
39 
40 struct shrinker {
41 	unsigned long		(*count_objects)(struct shrinker *, struct shrink_control *);
42 	unsigned long		(*scan_objects)(struct shrinker *, struct shrink_control *);
43 	int			seeks;
44 	unsigned int		flags;
45 	void *			private_data;
46 	long			batch;
47 	TAILQ_ENTRY(shrinker)	next;
48 };
49 
50 #define	SHRINK_STOP	(~0UL)
51 
52 #define	DEFAULT_SEEKS	2
53 
54 #define SHRINKER_REGISTERED	BIT(0)
55 #define SHRINKER_ALLOCATED	BIT(1)
56 
57 struct shrinker *linuxkpi_shrinker_alloc(
58     unsigned int flags, const char *fmt, ...);
59 int	linuxkpi_register_shrinker(struct shrinker *s);
60 void	linuxkpi_unregister_shrinker(struct shrinker *s);
61 void	linuxkpi_shrinker_free(struct shrinker *shrinker);
62 void	linuxkpi_synchronize_shrinkers(void);
63 
64 #define	shrinker_alloc(flags, fmt, ...) \
65     linuxkpi_shrinker_alloc(flags, fmt __VA_OPT__(,) __VA_ARGS__)
66 #define	shrinker_register(shrinker) \
67     linuxkpi_register_shrinker(shrinker)
68 #define	shrinker_free(shrinker) \
69     linuxkpi_shrinker_free(shrinker)
70 
71 #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 60000
72 #define	register_shrinker(s, ...)	linuxkpi_register_shrinker(s)
73 #else
74 #define	register_shrinker(s)	linuxkpi_register_shrinker(s)
75 #endif
76 #define	unregister_shrinker(s)	linuxkpi_unregister_shrinker(s)
77 #define	synchronize_shrinkers()	linuxkpi_synchronize_shrinkers()
78 
79 #endif	/* _LINUXKPI_LINUX_SHRINKER_H_ */
80