blob: e92b1455d7afd8c908bfc0722be018a09c46c226 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_INIT_H
2#define _LINUX_INIT_H
3
Linus Torvalds1da177e2005-04-16 15:20:36 -07004#include <linux/compiler.h>
5
6/* These macros are used to mark some functions or
7 * initialized data (doesn't apply to uninitialized data)
8 * as `initialization' functions. The kernel can take this
9 * as hint that the function is used only during the initialization
10 * phase and free up used memory resources after
11 *
12 * Usage:
13 * For functions:
14 *
15 * You should add __init immediately before the function name, like:
16 *
17 * static void __init initme(int x, int y)
18 * {
19 * extern int z; z = x * y;
20 * }
21 *
22 * If the function has a prototype somewhere, you can also add
23 * __init between closing brace of the prototype and semicolon:
24 *
25 * extern int initialize_foobar_device(int, int, int) __init;
26 *
27 * For initialized data:
28 * You should insert __initdata between the variable name and equal
29 * sign followed by value, e.g.:
30 *
31 * static int init_variable __initdata = 0;
32 * static char linux_logo[] __initdata = { 0x32, 0x36, ... };
33 *
34 * Don't forget to initialize data not at file scope, i.e. within a function,
35 * as gcc otherwise puts the data into the bss section and not into the init
36 * section.
37 *
38 * Also note, that this data cannot be "const".
39 */
40
41/* These are for everybody (although not all archs will actually
42 discard it in modules) */
43#define __init __attribute__ ((__section__ (".init.text")))
44#define __initdata __attribute__ ((__section__ (".init.data")))
45#define __exitdata __attribute__ ((__section__(".exit.data")))
46#define __exit_call __attribute_used__ __attribute__ ((__section__ (".exitcall.exit")))
47
48#ifdef MODULE
49#define __exit __attribute__ ((__section__(".exit.text")))
50#else
51#define __exit __attribute_used__ __attribute__ ((__section__(".exit.text")))
52#endif
53
54/* For assembly routines */
55#define __INIT .section ".init.text","ax"
56#define __FINIT .previous
57#define __INITDATA .section ".init.data","aw"
58
59#ifndef __ASSEMBLY__
60/*
61 * Used for initialization calls..
62 */
63typedef int (*initcall_t)(void);
64typedef void (*exitcall_t)(void);
65
66extern initcall_t __con_initcall_start[], __con_initcall_end[];
67extern initcall_t __security_initcall_start[], __security_initcall_end[];
68
69/* Defined in init/main.c */
70extern char saved_command_line[];
Vivek Goyal7e962872006-09-27 01:50:44 -070071extern unsigned int reset_devices;
Adrian Bunk77d47582006-03-25 03:07:39 -080072
73/* used by init/main.c */
74extern void setup_arch(char **);
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076#endif
77
78#ifndef MODULE
79
80#ifndef __ASSEMBLY__
81
82/* initcalls are now grouped by functionality into separate
83 * subsections. Ordering inside the subsections is determined
84 * by link order.
85 * For backwards compatibility, initcall() puts the call in
86 * the device init subsection.
87 */
88
89#define __define_initcall(level,fn) \
90 static initcall_t __initcall_##fn __attribute_used__ \
91 __attribute__((__section__(".initcall" level ".init"))) = fn
92
93#define core_initcall(fn) __define_initcall("1",fn)
94#define postcore_initcall(fn) __define_initcall("2",fn)
95#define arch_initcall(fn) __define_initcall("3",fn)
96#define subsys_initcall(fn) __define_initcall("4",fn)
97#define fs_initcall(fn) __define_initcall("5",fn)
98#define device_initcall(fn) __define_initcall("6",fn)
99#define late_initcall(fn) __define_initcall("7",fn)
100
101#define __initcall(fn) device_initcall(fn)
102
103#define __exitcall(fn) \
104 static exitcall_t __exitcall_##fn __exit_call = fn
105
106#define console_initcall(fn) \
107 static initcall_t __initcall_##fn \
108 __attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn
109
110#define security_initcall(fn) \
111 static initcall_t __initcall_##fn \
112 __attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn
113
114struct obs_kernel_param {
115 const char *str;
116 int (*setup_func)(char *);
117 int early;
118};
119
120/*
121 * Only for really core code. See moduleparam.h for the normal way.
122 *
123 * Force the alignment so the compiler doesn't space elements of the
124 * obs_kernel_param "array" too far apart in .init.setup.
125 */
126#define __setup_param(str, unique_id, fn, early) \
127 static char __setup_str_##unique_id[] __initdata = str; \
128 static struct obs_kernel_param __setup_##unique_id \
129 __attribute_used__ \
130 __attribute__((__section__(".init.setup"))) \
131 __attribute__((aligned((sizeof(long))))) \
132 = { __setup_str_##unique_id, fn, early }
133
134#define __setup_null_param(str, unique_id) \
135 __setup_param(str, unique_id, NULL, 0)
136
137#define __setup(str, fn) \
138 __setup_param(str, fn, fn, 0)
139
140#define __obsolete_setup(str) \
141 __setup_null_param(str, __LINE__)
142
143/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
144 * returns non-zero. */
145#define early_param(str, fn) \
146 __setup_param(str, fn, fn, 1)
147
148/* Relies on saved_command_line being set */
149void __init parse_early_param(void);
150#endif /* __ASSEMBLY__ */
151
152/**
153 * module_init() - driver initialization entry point
154 * @x: function to be run at kernel boot time or module insertion
155 *
156 * module_init() will either be called during do_initcalls (if
157 * builtin) or at module insertion time (if a module). There can only
158 * be one per module.
159 */
160#define module_init(x) __initcall(x);
161
162/**
163 * module_exit() - driver exit entry point
164 * @x: function to be run when driver is removed
165 *
166 * module_exit() will wrap the driver clean-up code
167 * with cleanup_module() when used with rmmod when
168 * the driver is a module. If the driver is statically
169 * compiled into the kernel, module_exit() has no effect.
170 * There can only be one per module.
171 */
172#define module_exit(x) __exitcall(x);
173
174#else /* MODULE */
175
176/* Don't use these in modules, but some people do... */
177#define core_initcall(fn) module_init(fn)
178#define postcore_initcall(fn) module_init(fn)
179#define arch_initcall(fn) module_init(fn)
180#define subsys_initcall(fn) module_init(fn)
181#define fs_initcall(fn) module_init(fn)
182#define device_initcall(fn) module_init(fn)
183#define late_initcall(fn) module_init(fn)
184
185#define security_initcall(fn) module_init(fn)
186
187/* These macros create a dummy inline: gcc 2.9x does not count alias
188 as usage, hence the `unused function' warning when __init functions
189 are declared static. We use the dummy __*_module_inline functions
190 both to kill the warning and check the type of the init/cleanup
191 function. */
192
193/* Each module must use one module_init(), or one no_module_init */
194#define module_init(initfn) \
195 static inline initcall_t __inittest(void) \
196 { return initfn; } \
197 int init_module(void) __attribute__((alias(#initfn)));
198
199/* This is only required if you want to be unloadable. */
200#define module_exit(exitfn) \
201 static inline exitcall_t __exittest(void) \
202 { return exitfn; } \
203 void cleanup_module(void) __attribute__((alias(#exitfn)));
204
205#define __setup_param(str, unique_id, fn) /* nothing */
206#define __setup_null_param(str, unique_id) /* nothing */
207#define __setup(str, func) /* nothing */
208#define __obsolete_setup(str) /* nothing */
209#endif
210
211/* Data marked not to be saved by software_suspend() */
212#define __nosavedata __attribute__ ((__section__ (".data.nosave")))
213
214/* This means "can be init if no module support, otherwise module load
215 may call it." */
216#ifdef CONFIG_MODULES
217#define __init_or_module
218#define __initdata_or_module
219#else
220#define __init_or_module __init
221#define __initdata_or_module __initdata
222#endif /*CONFIG_MODULES*/
223
224#ifdef CONFIG_HOTPLUG
225#define __devinit
226#define __devinitdata
227#define __devexit
228#define __devexitdata
229#else
230#define __devinit __init
231#define __devinitdata __initdata
232#define __devexit __exit
233#define __devexitdata __exitdata
234#endif
235
Ashok Raje6982c62005-06-25 14:54:58 -0700236#ifdef CONFIG_HOTPLUG_CPU
237#define __cpuinit
238#define __cpuinitdata
239#define __cpuexit
240#define __cpuexitdata
241#else
242#define __cpuinit __init
243#define __cpuinitdata __initdata
244#define __cpuexit __exit
245#define __cpuexitdata __exitdata
246#endif
247
Andi Kleen9d99aaa2006-04-07 19:49:15 +0200248#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_ACPI_HOTPLUG_MEMORY) \
249 || defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)
Matt Tolentinoc09b4242006-01-17 07:03:44 +0100250#define __meminit
251#define __meminitdata
252#define __memexit
253#define __memexitdata
254#else
255#define __meminit __init
256#define __meminitdata __initdata
257#define __memexit __exit
258#define __memexitdata __exitdata
259#endif
260
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261/* Functions marked as __devexit may be discarded at kernel link time, depending
262 on config options. Newer versions of binutils detect references from
263 retained sections to discarded sections and flag an error. Pointers to
264 __devexit functions must use __devexit_p(function_name), the wrapper will
265 insert either the function_name or NULL, depending on the config options.
266 */
267#if defined(MODULE) || defined(CONFIG_HOTPLUG)
268#define __devexit_p(x) x
269#else
270#define __devexit_p(x) NULL
271#endif
272
273#ifdef MODULE
274#define __exit_p(x) x
275#else
276#define __exit_p(x) NULL
277#endif
278
279#endif /* _LINUX_INIT_H */