]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blame - include/linux/init.h
kexec jump: save/restore device state
[mirror_ubuntu-bionic-kernel.git] / include / linux / init.h
CommitLineData
1da177e4
LT
1#ifndef _LINUX_INIT_H
2#define _LINUX_INIT_H
3
1da177e4
LT
4#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) */
f3fe866d
SR
43#define __init __section(.init.text) __cold
44#define __initdata __section(.init.data)
37c514e3 45#define __initconst __section(.init.rodata)
f3fe866d 46#define __exitdata __section(.exit.data)
3ff6eecc 47#define __exit_call __used __section(.exitcall.exit)
1da177e4 48
0e0d314e
SR
49/* modpost check for section mismatches during the kernel build.
50 * A section mismatch happens when there are references from a
51 * code or data section to an init section (both code or data).
52 * The init sections are (for most archs) discarded by the kernel
53 * when early init has completed so all such references are potential bugs.
54 * For exit sections the same issue exists.
55 * The following markers are used for the cases where the reference to
312b1485
SR
56 * the *init / *exit section (code or data) is valid and will teach
57 * modpost not to issue a warning.
0e0d314e 58 * The markers follow same syntax rules as __init / __initdata. */
312b1485
SR
59#define __ref __section(.ref.text) noinline
60#define __refdata __section(.ref.data)
61#define __refconst __section(.ref.rodata)
62
63/* backward compatibility note
64 * A few places hardcode the old section names:
65 * .text.init.refok
66 * .data.init.refok
67 * .exit.text.refok
68 * They should be converted to use the defines from this file
69 */
70
71/* compatibility defines */
72#define __init_refok __ref
73#define __initdata_refok __refdata
74#define __exit_refok __ref
75
0e0d314e 76
1da177e4 77#ifdef MODULE
eb8f6890 78#define __exitused
1da177e4 79#else
eb8f6890 80#define __exitused __used
1da177e4
LT
81#endif
82
eb8f6890
SR
83#define __exit __section(.exit.text) __exitused __cold
84
85/* Used for HOTPLUG */
86#define __devinit __section(.devinit.text) __cold
87#define __devinitdata __section(.devinit.data)
88#define __devinitconst __section(.devinit.rodata)
89#define __devexit __section(.devexit.text) __exitused __cold
90#define __devexitdata __section(.devexit.data)
91#define __devexitconst __section(.devexit.rodata)
92
93/* Used for HOTPLUG_CPU */
94#define __cpuinit __section(.cpuinit.text) __cold
95#define __cpuinitdata __section(.cpuinit.data)
96#define __cpuinitconst __section(.cpuinit.rodata)
97#define __cpuexit __section(.cpuexit.text) __exitused __cold
98#define __cpuexitdata __section(.cpuexit.data)
99#define __cpuexitconst __section(.cpuexit.rodata)
100
101/* Used for MEMORY_HOTPLUG */
102#define __meminit __section(.meminit.text) __cold
103#define __meminitdata __section(.meminit.data)
104#define __meminitconst __section(.meminit.rodata)
105#define __memexit __section(.memexit.text) __exitused __cold
106#define __memexitdata __section(.memexit.data)
107#define __memexitconst __section(.memexit.rodata)
108
1da177e4 109/* For assembly routines */
37c514e3 110#define __HEAD .section ".head.text","ax"
1da177e4 111#define __INIT .section ".init.text","ax"
86c0baf1 112#define __FINIT .previous
eb8f6890 113
838c4118 114#define __INITDATA .section ".init.data","aw"
9f9975a5 115#define __FINITDATA .previous
1da177e4 116
eb8f6890
SR
117#define __DEVINIT .section ".devinit.text", "ax"
118#define __DEVINITDATA .section ".devinit.data", "aw"
119
120#define __CPUINIT .section ".cpuinit.text", "ax"
121#define __CPUINITDATA .section ".cpuinit.data", "aw"
122
123#define __MEMINIT .section ".meminit.text", "ax"
124#define __MEMINITDATA .section ".meminit.data", "aw"
125
312b1485
SR
126/* silence warnings when references are OK */
127#define __REF .section ".ref.text", "ax"
128#define __REFDATA .section ".ref.data", "aw"
129#define __REFCONST .section ".ref.rodata", "aw"
312b1485 130
1da177e4
LT
131#ifndef __ASSEMBLY__
132/*
133 * Used for initialization calls..
134 */
135typedef int (*initcall_t)(void);
136typedef void (*exitcall_t)(void);
137
138extern initcall_t __con_initcall_start[], __con_initcall_end[];
139extern initcall_t __security_initcall_start[], __security_initcall_end[];
140
141/* Defined in init/main.c */
30d7e0d4
ABL
142extern char __initdata boot_command_line[];
143extern char *saved_command_line;
7e96287d 144extern unsigned int reset_devices;
77d47582
AB
145
146/* used by init/main.c */
46595390
AB
147void setup_arch(char **);
148void prepare_namespace(void);
77d47582 149
7d195a54
AB
150extern void (*late_time_init)(void);
151
1da177e4
LT
152#endif
153
154#ifndef MODULE
155
156#ifndef __ASSEMBLY__
157
158/* initcalls are now grouped by functionality into separate
159 * subsections. Ordering inside the subsections is determined
160 * by link order.
161 * For backwards compatibility, initcall() puts the call in
162 * the device init subsection.
735a7ffb
AM
163 *
164 * The `id' arg to __define_initcall() is needed so that multiple initcalls
165 * can point at the same handler without causing duplicate-symbol build errors.
1da177e4
LT
166 */
167
735a7ffb 168#define __define_initcall(level,fn,id) \
3ff6eecc 169 static initcall_t __initcall_##fn##id __used \
1da177e4
LT
170 __attribute__((__section__(".initcall" level ".init"))) = fn
171
b3438f82
LT
172/*
173 * A "pure" initcall has no dependencies on anything else, and purely
174 * initializes variables that couldn't be statically initialized.
175 *
176 * This only exists for built-in code, not for modules.
177 */
73dd1166 178#define pure_initcall(fn) __define_initcall("0",fn,0)
b3438f82 179
735a7ffb
AM
180#define core_initcall(fn) __define_initcall("1",fn,1)
181#define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
182#define postcore_initcall(fn) __define_initcall("2",fn,2)
183#define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
184#define arch_initcall(fn) __define_initcall("3",fn,3)
185#define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
186#define subsys_initcall(fn) __define_initcall("4",fn,4)
187#define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
188#define fs_initcall(fn) __define_initcall("5",fn,5)
189#define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
8d610dd5 190#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
735a7ffb
AM
191#define device_initcall(fn) __define_initcall("6",fn,6)
192#define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
193#define late_initcall(fn) __define_initcall("7",fn,7)
194#define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
1da177e4
LT
195
196#define __initcall(fn) device_initcall(fn)
197
198#define __exitcall(fn) \
199 static exitcall_t __exitcall_##fn __exit_call = fn
200
201#define console_initcall(fn) \
202 static initcall_t __initcall_##fn \
3ff6eecc 203 __used __section(.con_initcall.init) = fn
1da177e4
LT
204
205#define security_initcall(fn) \
206 static initcall_t __initcall_##fn \
3ff6eecc 207 __used __section(.security_initcall.init) = fn
1da177e4
LT
208
209struct obs_kernel_param {
210 const char *str;
211 int (*setup_func)(char *);
212 int early;
213};
214
215/*
216 * Only for really core code. See moduleparam.h for the normal way.
217 *
218 * Force the alignment so the compiler doesn't space elements of the
219 * obs_kernel_param "array" too far apart in .init.setup.
220 */
221#define __setup_param(str, unique_id, fn, early) \
d5aa0daf 222 static char __setup_str_##unique_id[] __initdata __aligned(1) = str; \
1da177e4 223 static struct obs_kernel_param __setup_##unique_id \
3ff6eecc 224 __used __section(.init.setup) \
1da177e4
LT
225 __attribute__((aligned((sizeof(long))))) \
226 = { __setup_str_##unique_id, fn, early }
227
228#define __setup_null_param(str, unique_id) \
229 __setup_param(str, unique_id, NULL, 0)
230
231#define __setup(str, fn) \
232 __setup_param(str, fn, fn, 0)
233
1da177e4
LT
234/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
235 * returns non-zero. */
236#define early_param(str, fn) \
237 __setup_param(str, fn, fn, 1)
238
30d7e0d4 239/* Relies on boot_command_line being set */
1da177e4
LT
240void __init parse_early_param(void);
241#endif /* __ASSEMBLY__ */
242
243/**
244 * module_init() - driver initialization entry point
245 * @x: function to be run at kernel boot time or module insertion
246 *
72fd4a35 247 * module_init() will either be called during do_initcalls() (if
1da177e4
LT
248 * builtin) or at module insertion time (if a module). There can only
249 * be one per module.
250 */
251#define module_init(x) __initcall(x);
252
253/**
254 * module_exit() - driver exit entry point
255 * @x: function to be run when driver is removed
256 *
257 * module_exit() will wrap the driver clean-up code
258 * with cleanup_module() when used with rmmod when
259 * the driver is a module. If the driver is statically
260 * compiled into the kernel, module_exit() has no effect.
261 * There can only be one per module.
262 */
263#define module_exit(x) __exitcall(x);
264
265#else /* MODULE */
266
267/* Don't use these in modules, but some people do... */
268#define core_initcall(fn) module_init(fn)
269#define postcore_initcall(fn) module_init(fn)
270#define arch_initcall(fn) module_init(fn)
271#define subsys_initcall(fn) module_init(fn)
272#define fs_initcall(fn) module_init(fn)
273#define device_initcall(fn) module_init(fn)
274#define late_initcall(fn) module_init(fn)
275
276#define security_initcall(fn) module_init(fn)
277
4500d067 278/* Each module must use one module_init(). */
1da177e4
LT
279#define module_init(initfn) \
280 static inline initcall_t __inittest(void) \
281 { return initfn; } \
282 int init_module(void) __attribute__((alias(#initfn)));
283
284/* This is only required if you want to be unloadable. */
285#define module_exit(exitfn) \
286 static inline exitcall_t __exittest(void) \
287 { return exitfn; } \
288 void cleanup_module(void) __attribute__((alias(#exitfn)));
289
290#define __setup_param(str, unique_id, fn) /* nothing */
291#define __setup_null_param(str, unique_id) /* nothing */
292#define __setup(str, func) /* nothing */
1da177e4
LT
293#endif
294
ab3bfca7 295/* Data marked not to be saved by software suspend */
f3fe866d 296#define __nosavedata __section(.data.nosave)
1da177e4
LT
297
298/* This means "can be init if no module support, otherwise module load
299 may call it." */
300#ifdef CONFIG_MODULES
301#define __init_or_module
302#define __initdata_or_module
303#else
304#define __init_or_module __init
305#define __initdata_or_module __initdata
306#endif /*CONFIG_MODULES*/
307
1da177e4
LT
308/* Functions marked as __devexit may be discarded at kernel link time, depending
309 on config options. Newer versions of binutils detect references from
310 retained sections to discarded sections and flag an error. Pointers to
311 __devexit functions must use __devexit_p(function_name), the wrapper will
312 insert either the function_name or NULL, depending on the config options.
313 */
314#if defined(MODULE) || defined(CONFIG_HOTPLUG)
315#define __devexit_p(x) x
316#else
317#define __devexit_p(x) NULL
318#endif
319
320#ifdef MODULE
321#define __exit_p(x) x
322#else
323#define __exit_p(x) NULL
324#endif
325
326#endif /* _LINUX_INIT_H */