xref: /freebsd/sys/sys/module.h (revision aa0a1e58)
1 /*-
2  * Copyright (c) 1997 Doug Rabson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _SYS_MODULE_H_
30 #define _SYS_MODULE_H_
31 
32 /*
33  * Module metadata types
34  */
35 #define	MDT_DEPEND	1		/* argument is a module name */
36 #define	MDT_MODULE	2		/* module declaration */
37 #define	MDT_VERSION	3		/* module version(s) */
38 
39 #define	MDT_STRUCT_VERSION	1	/* version of metadata structure */
40 #define	MDT_SETNAME	"modmetadata_set"
41 
42 typedef enum modeventtype {
43 	MOD_LOAD,
44 	MOD_UNLOAD,
45 	MOD_SHUTDOWN,
46 	MOD_QUIESCE
47 } modeventtype_t;
48 
49 typedef struct module *module_t;
50 typedef int (*modeventhand_t)(module_t, int /* modeventtype_t */, void *);
51 
52 /*
53  * Struct for registering modules statically via SYSINIT.
54  */
55 typedef struct moduledata {
56 	const char	*name;		/* module name */
57 	modeventhand_t  evhand;		/* event handler */
58 	void		*priv;		/* extra data */
59 } moduledata_t;
60 
61 /*
62  * A module can use this to report module specific data to the user via
63  * kldstat(2).
64  */
65 typedef union modspecific {
66 	int	intval;
67 	u_int	uintval;
68 	long	longval;
69 	u_long	ulongval;
70 } modspecific_t;
71 
72 /*
73  * Module dependency declarartion
74  */
75 struct mod_depend {
76 	int	md_ver_minimum;
77 	int	md_ver_preferred;
78 	int	md_ver_maximum;
79 };
80 
81 /*
82  * Module version declaration
83  */
84 struct mod_version {
85 	int	mv_version;
86 };
87 
88 struct mod_metadata {
89 	int		md_version;	/* structure version MDTV_* */
90 	int		md_type;	/* type of entry MDT_* */
91 	void		*md_data;	/* specific data */
92 	const char	*md_cval;	/* common string label */
93 };
94 
95 #ifdef	_KERNEL
96 
97 #include <sys/linker_set.h>
98 
99 #define	MODULE_METADATA(uniquifier, type, data, cval)			\
100 	static struct mod_metadata _mod_metadata##uniquifier = {	\
101 		MDT_STRUCT_VERSION,					\
102 		type,							\
103 		data,							\
104 		cval							\
105 	};								\
106 	DATA_SET(modmetadata_set, _mod_metadata##uniquifier)
107 
108 #define	MODULE_DEPEND(module, mdepend, vmin, vpref, vmax)		\
109 	static struct mod_depend _##module##_depend_on_##mdepend = {	\
110 		vmin,							\
111 		vpref,							\
112 		vmax							\
113 	};								\
114 	MODULE_METADATA(_md_##module##_on_##mdepend, MDT_DEPEND,	\
115 	    &_##module##_depend_on_##mdepend, #mdepend)
116 
117 /*
118  * Every kernel has a 'kernel' module with the version set to
119  * __FreeBSD_version.  We embed a MODULE_DEPEND() inside every module
120  * that depends on the 'kernel' module.  It uses the current value of
121  * __FreeBSD_version as the minimum and preferred versions.  For the
122  * maximum version it rounds the version up to the end of its branch
123  * (i.e. M99999 for M.x).  This allows a module built on M.x to work
124  * on M.y systems where y >= x, but fail on M.z systems where z < x.
125  */
126 #define	MODULE_KERNEL_MAXVER	(roundup(__FreeBSD_version, 100000) - 1)
127 
128 #define	DECLARE_MODULE_WITH_MAXVER(name, data, sub, order, maxver)	\
129 	MODULE_DEPEND(name, kernel, __FreeBSD_version,			\
130 	    __FreeBSD_version, maxver);			\
131 	MODULE_METADATA(_md_##name, MDT_MODULE, &data, #name);		\
132 	SYSINIT(name##module, sub, order, module_register_init, &data);	\
133 	struct __hack
134 
135 #define	DECLARE_MODULE(name, data, sub, order)				\
136 	DECLARE_MODULE_WITH_MAXVER(name, data, sub, order, MODULE_KERNEL_MAXVER)
137 
138 /*
139  * The module declared with DECLARE_MODULE_TIED can only be loaded
140  * into the kernel with exactly the same __FreeBSD_version.
141  *
142  * Use it for modules that use kernel interfaces that are not stable
143  * even on STABLE/X branches.
144  */
145 #define	DECLARE_MODULE_TIED(name, data, sub, order)				\
146 	DECLARE_MODULE_WITH_MAXVER(name, data, sub, order, __FreeBSD_version)
147 
148 #define	MODULE_VERSION(module, version)					\
149 	static struct mod_version _##module##_version = {		\
150 		version							\
151 	};								\
152 	MODULE_METADATA(_##module##_version, MDT_VERSION,		\
153 	    &_##module##_version, #module)
154 
155 extern struct sx modules_sx;
156 
157 #define	MOD_XLOCK	sx_xlock(&modules_sx)
158 #define	MOD_SLOCK	sx_slock(&modules_sx)
159 #define	MOD_XUNLOCK	sx_xunlock(&modules_sx)
160 #define	MOD_SUNLOCK	sx_sunlock(&modules_sx)
161 #define	MOD_LOCK_ASSERT	sx_assert(&modules_sx, SX_LOCKED)
162 #define	MOD_XLOCK_ASSERT	sx_assert(&modules_sx, SX_XLOCKED)
163 
164 struct linker_file;
165 
166 void	module_register_init(const void *);
167 int	module_register(const struct moduledata *, struct linker_file *);
168 module_t	module_lookupbyname(const char *);
169 module_t	module_lookupbyid(int);
170 int	module_quiesce(module_t);
171 void	module_reference(module_t);
172 void	module_release(module_t);
173 int	module_unload(module_t);
174 int	module_getid(module_t);
175 module_t	module_getfnext(module_t);
176 const char *	module_getname(module_t);
177 void	module_setspecific(module_t, modspecific_t *);
178 struct linker_file *module_file(module_t);
179 
180 #ifdef	MOD_DEBUG
181 extern int mod_debug;
182 #define	MOD_DEBUG_REFS	1
183 
184 #define	MOD_DPF(cat, args) do {						\
185 	if (mod_debug & MOD_DEBUG_##cat)				\
186 		printf(args);						\
187 } while (0)
188 
189 #else	/* !MOD_DEBUG */
190 
191 #define	MOD_DPF(cat, args)
192 #endif
193 #endif	/* _KERNEL */
194 
195 #define	MAXMODNAME	32
196 
197 struct module_stat {
198 	int		version;	/* set to sizeof(struct module_stat) */
199 	char		name[MAXMODNAME];
200 	int		refs;
201 	int		id;
202 	modspecific_t	data;
203 };
204 
205 #ifndef _KERNEL
206 
207 #include <sys/cdefs.h>
208 
209 __BEGIN_DECLS
210 int	modnext(int _modid);
211 int	modfnext(int _modid);
212 int	modstat(int _modid, struct module_stat *_stat);
213 int	modfind(const char *_name);
214 __END_DECLS
215 
216 #endif
217 
218 #endif	/* !_SYS_MODULE_H_ */
219