All new accounts created on Gitlab now require administrator approval. If you invite any collaborators, please let Flux staff know so they can approve the accounts.

init.h 11.7 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
#ifndef _LINUX_INIT_H
#define _LINUX_INIT_H

#include <linux/compiler.h>

/* These macros are used to mark some functions or 
 * initialized data (doesn't apply to uninitialized data)
 * as `initialization' functions. The kernel can take this
 * as hint that the function is used only during the initialization
 * phase and free up used memory resources after
 *
 * Usage:
 * For functions:
 * 
 * You should add __init immediately before the function name, like:
 *
 * static void __init initme(int x, int y)
 * {
 *    extern int z; z = x * y;
 * }
 *
 * If the function has a prototype somewhere, you can also add
 * __init between closing brace of the prototype and semicolon:
 *
 * extern int initialize_foobar_device(int, int, int) __init;
 *
 * For initialized data:
 * You should insert __initdata between the variable name and equal
 * sign followed by value, e.g.:
 *
 * static int init_variable __initdata = 0;
32
 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
Linus Torvalds's avatar
Linus Torvalds committed
33 34 35 36 37 38 39 40 41 42
 *
 * Don't forget to initialize data not at file scope, i.e. within a function,
 * as gcc otherwise puts the data into the bss section and not into the init
 * section.
 * 
 * Also note, that this data cannot be "const".
 */

/* These are for everybody (although not all archs will actually
   discard it in modules) */
43
#define __init		__section(.init.text) __cold notrace
44
#define __initdata	__section(.init.data)
45
#define __initconst	__section(.init.rodata)
46
#define __exitdata	__section(.exit.data)
Adrian Bunk's avatar
Adrian Bunk committed
47
#define __exit_call	__used __section(.exitcall.exit)
Linus Torvalds's avatar
Linus Torvalds committed
48

49 50
/*
 * modpost check for section mismatches during the kernel build.
51 52 53 54 55
 * A section mismatch happens when there are references from a
 * code or data section to an init section (both code or data).
 * The init sections are (for most archs) discarded by the kernel
 * when early init has completed so all such references are potential bugs.
 * For exit sections the same issue exists.
56
 *
57
 * The following markers are used for the cases where the reference to
58
 * the *init / *exit section (code or data) is valid and will teach
59 60 61 62 63 64 65
 * modpost not to issue a warning.  Intended semantics is that a code or
 * data tagged __ref* can reference code or data from init section without
 * producing a warning (of course, no warning does not mean code is
 * correct, so optimally document why the __ref is needed and why it's OK).
 *
 * The markers follow same syntax rules as __init / __initdata.
 */
66 67 68 69 70 71 72 73 74
#define __ref            __section(.ref.text) noinline
#define __refdata        __section(.ref.data)
#define __refconst       __section(.ref.rodata)

/* compatibility defines */
#define __init_refok     __ref
#define __initdata_refok __refdata
#define __exit_refok     __ref

75

Linus Torvalds's avatar
Linus Torvalds committed
76
#ifdef MODULE
77
#define __exitused
Linus Torvalds's avatar
Linus Torvalds committed
78
#else
79
#define __exitused  __used
Linus Torvalds's avatar
Linus Torvalds committed
80 81
#endif

82
#define __exit          __section(.exit.text) __exitused __cold notrace
83 84

/* Used for HOTPLUG */
85
#define __devinit        __section(.devinit.text) __cold notrace
86 87
#define __devinitdata    __section(.devinit.data)
#define __devinitconst   __section(.devinit.rodata)
88
#define __devexit        __section(.devexit.text) __exitused __cold notrace
89 90 91 92
#define __devexitdata    __section(.devexit.data)
#define __devexitconst   __section(.devexit.rodata)

/* Used for HOTPLUG_CPU */
93
#define __cpuinit        __section(.cpuinit.text) __cold notrace
94 95
#define __cpuinitdata    __section(.cpuinit.data)
#define __cpuinitconst   __section(.cpuinit.rodata)
96
#define __cpuexit        __section(.cpuexit.text) __exitused __cold notrace
97 98 99 100
#define __cpuexitdata    __section(.cpuexit.data)
#define __cpuexitconst   __section(.cpuexit.rodata)

/* Used for MEMORY_HOTPLUG */
101
#define __meminit        __section(.meminit.text) __cold notrace
102 103
#define __meminitdata    __section(.meminit.data)
#define __meminitconst   __section(.meminit.rodata)
104
#define __memexit        __section(.memexit.text) __exitused __cold notrace
105 106 107
#define __memexitdata    __section(.memexit.data)
#define __memexitconst   __section(.memexit.rodata)

Linus Torvalds's avatar
Linus Torvalds committed
108
/* For assembly routines */
Sam Ravnborg's avatar
Sam Ravnborg committed
109
#define __HEAD		.section	".head.text","ax"
Linus Torvalds's avatar
Linus Torvalds committed
110
#define __INIT		.section	".init.text","ax"
111
#define __FINIT		.previous
112

113 114
#define __INITDATA	.section	".init.data","aw",%progbits
#define __INITRODATA	.section	".init.rodata","a",%progbits
Ingo Molnar's avatar
Ingo Molnar committed
115
#define __FINITDATA	.previous
Linus Torvalds's avatar
Linus Torvalds committed
116

117 118
#define __DEVINIT        .section	".devinit.text", "ax"
#define __DEVINITDATA    .section	".devinit.data", "aw"
Jan Beulich's avatar
Jan Beulich committed
119
#define __DEVINITRODATA  .section	".devinit.rodata", "a"
120 121 122

#define __CPUINIT        .section	".cpuinit.text", "ax"
#define __CPUINITDATA    .section	".cpuinit.data", "aw"
Jan Beulich's avatar
Jan Beulich committed
123
#define __CPUINITRODATA  .section	".cpuinit.rodata", "a"
124 125 126

#define __MEMINIT        .section	".meminit.text", "ax"
#define __MEMINITDATA    .section	".meminit.data", "aw"
Jan Beulich's avatar
Jan Beulich committed
127
#define __MEMINITRODATA  .section	".meminit.rodata", "a"
128

129 130 131
/* silence warnings when references are OK */
#define __REF            .section       ".ref.text", "ax"
#define __REFDATA        .section       ".ref.data", "aw"
Jan Beulich's avatar
Jan Beulich committed
132
#define __REFCONST       .section       ".ref.rodata", "a"
133

Linus Torvalds's avatar
Linus Torvalds committed
134 135 136 137 138 139 140 141 142 143
#ifndef __ASSEMBLY__
/*
 * Used for initialization calls..
 */
typedef int (*initcall_t)(void);
typedef void (*exitcall_t)(void);

extern initcall_t __con_initcall_start[], __con_initcall_end[];
extern initcall_t __security_initcall_start[], __security_initcall_end[];

144 145 146
/* Used for contructor calls. */
typedef void (*ctor_fn_t)(void);

Linus Torvalds's avatar
Linus Torvalds committed
147
/* Defined in init/main.c */
148
extern int do_one_initcall(initcall_t fn);
149 150
extern char __initdata boot_command_line[];
extern char *saved_command_line;
151
extern unsigned int reset_devices;
152 153

/* used by init/main.c */
154 155
void setup_arch(char **);
void prepare_namespace(void);
156

Adrian Bunk's avatar
Adrian Bunk committed
157 158
extern void (*late_time_init)(void);

159 160
extern int initcall_debug;

Linus Torvalds's avatar
Linus Torvalds committed
161 162 163 164 165 166 167 168 169 170 171
#endif
  
#ifndef MODULE

#ifndef __ASSEMBLY__

/* initcalls are now grouped by functionality into separate 
 * subsections. Ordering inside the subsections is determined
 * by link order. 
 * For backwards compatibility, initcall() puts the call in 
 * the device init subsection.
172 173 174
 *
 * The `id' arg to __define_initcall() is needed so that multiple initcalls
 * can point at the same handler without causing duplicate-symbol build errors.
Linus Torvalds's avatar
Linus Torvalds committed
175 176
 */

177
#define __define_initcall(level,fn,id) \
Adrian Bunk's avatar
Adrian Bunk committed
178
	static initcall_t __initcall_##fn##id __used \
Linus Torvalds's avatar
Linus Torvalds committed
179 180
	__attribute__((__section__(".initcall" level ".init"))) = fn

181 182 183 184 185 186 187
/*
 * Early initcalls run before initializing SMP.
 *
 * Only for built-in code, not modules.
 */
#define early_initcall(fn)		__define_initcall("early",fn,early)

188 189 190 191 192 193
/*
 * A "pure" initcall has no dependencies on anything else, and purely
 * initializes variables that couldn't be statically initialized.
 *
 * This only exists for built-in code, not for modules.
 */
194
#define pure_initcall(fn)		__define_initcall("0",fn,0)
195

196 197 198 199 200 201 202 203 204 205
#define core_initcall(fn)		__define_initcall("1",fn,1)
#define core_initcall_sync(fn)		__define_initcall("1s",fn,1s)
#define postcore_initcall(fn)		__define_initcall("2",fn,2)
#define postcore_initcall_sync(fn)	__define_initcall("2s",fn,2s)
#define arch_initcall(fn)		__define_initcall("3",fn,3)
#define arch_initcall_sync(fn)		__define_initcall("3s",fn,3s)
#define subsys_initcall(fn)		__define_initcall("4",fn,4)
#define subsys_initcall_sync(fn)	__define_initcall("4s",fn,4s)
#define fs_initcall(fn)			__define_initcall("5",fn,5)
#define fs_initcall_sync(fn)		__define_initcall("5s",fn,5s)
206
#define rootfs_initcall(fn)		__define_initcall("rootfs",fn,rootfs)
207 208 209 210
#define device_initcall(fn)		__define_initcall("6",fn,6)
#define device_initcall_sync(fn)	__define_initcall("6s",fn,6s)
#define late_initcall(fn)		__define_initcall("7",fn,7)
#define late_initcall_sync(fn)		__define_initcall("7s",fn,7s)
Linus Torvalds's avatar
Linus Torvalds committed
211 212 213 214 215 216 217 218

#define __initcall(fn) device_initcall(fn)

#define __exitcall(fn) \
	static exitcall_t __exitcall_##fn __exit_call = fn

#define console_initcall(fn) \
	static initcall_t __initcall_##fn \
Adrian Bunk's avatar
Adrian Bunk committed
219
	__used __section(.con_initcall.init) = fn
Linus Torvalds's avatar
Linus Torvalds committed
220 221 222

#define security_initcall(fn) \
	static initcall_t __initcall_##fn \
Adrian Bunk's avatar
Adrian Bunk committed
223
	__used __section(.security_initcall.init) = fn
Linus Torvalds's avatar
Linus Torvalds committed
224 225 226 227 228 229 230 231 232 233 234 235 236 237

struct obs_kernel_param {
	const char *str;
	int (*setup_func)(char *);
	int early;
};

/*
 * Only for really core code.  See moduleparam.h for the normal way.
 *
 * Force the alignment so the compiler doesn't space elements of the
 * obs_kernel_param "array" too far apart in .init.setup.
 */
#define __setup_param(str, unique_id, fn, early)			\
Jan Beulich's avatar
Jan Beulich committed
238 239
	static const char __setup_str_##unique_id[] __initconst	\
		__aligned(1) = str; \
Linus Torvalds's avatar
Linus Torvalds committed
240
	static struct obs_kernel_param __setup_##unique_id	\
Adrian Bunk's avatar
Adrian Bunk committed
241
		__used __section(.init.setup)			\
Linus Torvalds's avatar
Linus Torvalds committed
242 243 244 245 246 247 248 249 250 251 252
		__attribute__((aligned((sizeof(long)))))	\
		= { __setup_str_##unique_id, fn, early }

#define __setup(str, fn)					\
	__setup_param(str, fn, fn, 0)

/* NOTE: fn is as per module_param, not __setup!  Emits warning if fn
 * returns non-zero. */
#define early_param(str, fn)					\
	__setup_param(str, fn, fn, 1)

253
/* Relies on boot_command_line being set */
Linus Torvalds's avatar
Linus Torvalds committed
254
void __init parse_early_param(void);
255
void __init parse_early_options(char *cmdline);
Linus Torvalds's avatar
Linus Torvalds committed
256 257 258 259 260 261
#endif /* __ASSEMBLY__ */

/**
 * module_init() - driver initialization entry point
 * @x: function to be run at kernel boot time or module insertion
 * 
262
 * module_init() will either be called during do_initcalls() (if
Linus Torvalds's avatar
Linus Torvalds committed
263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282
 * builtin) or at module insertion time (if a module).  There can only
 * be one per module.
 */
#define module_init(x)	__initcall(x);

/**
 * module_exit() - driver exit entry point
 * @x: function to be run when driver is removed
 * 
 * module_exit() will wrap the driver clean-up code
 * with cleanup_module() when used with rmmod when
 * the driver is a module.  If the driver is statically
 * compiled into the kernel, module_exit() has no effect.
 * There can only be one per module.
 */
#define module_exit(x)	__exitcall(x);

#else /* MODULE */

/* Don't use these in modules, but some people do... */
283
#define early_initcall(fn)		module_init(fn)
Linus Torvalds's avatar
Linus Torvalds committed
284 285 286 287 288 289 290 291 292 293
#define core_initcall(fn)		module_init(fn)
#define postcore_initcall(fn)		module_init(fn)
#define arch_initcall(fn)		module_init(fn)
#define subsys_initcall(fn)		module_init(fn)
#define fs_initcall(fn)			module_init(fn)
#define device_initcall(fn)		module_init(fn)
#define late_initcall(fn)		module_init(fn)

#define security_initcall(fn)		module_init(fn)

294
/* Each module must use one module_init(). */
Linus Torvalds's avatar
Linus Torvalds committed
295 296 297 298 299 300 301 302 303 304 305 306 307 308 309
#define module_init(initfn)					\
	static inline initcall_t __inittest(void)		\
	{ return initfn; }					\
	int init_module(void) __attribute__((alias(#initfn)));

/* This is only required if you want to be unloadable. */
#define module_exit(exitfn)					\
	static inline exitcall_t __exittest(void)		\
	{ return exitfn; }					\
	void cleanup_module(void) __attribute__((alias(#exitfn)));

#define __setup_param(str, unique_id, fn)	/* nothing */
#define __setup(str, func) 			/* nothing */
#endif

Johannes Berg's avatar
Johannes Berg committed
310
/* Data marked not to be saved by software suspend */
311
#define __nosavedata __section(.data..nosave)
Linus Torvalds's avatar
Linus Torvalds committed
312 313 314 315 316 317

/* This means "can be init if no module support, otherwise module load
   may call it." */
#ifdef CONFIG_MODULES
#define __init_or_module
#define __initdata_or_module
318 319 320 321
#define __initconst_or_module
#define __INIT_OR_MODULE	.text
#define __INITDATA_OR_MODULE	.data
#define __INITRODATA_OR_MODULE	.section ".rodata","a",%progbits
Linus Torvalds's avatar
Linus Torvalds committed
322 323 324
#else
#define __init_or_module __init
#define __initdata_or_module __initdata
325 326 327 328
#define __initconst_or_module __initconst
#define __INIT_OR_MODULE __INIT
#define __INITDATA_OR_MODULE __INITDATA
#define __INITRODATA_OR_MODULE __INITRODATA
Linus Torvalds's avatar
Linus Torvalds committed
329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349
#endif /*CONFIG_MODULES*/

/* Functions marked as __devexit may be discarded at kernel link time, depending
   on config options.  Newer versions of binutils detect references from
   retained sections to discarded sections and flag an error.  Pointers to
   __devexit functions must use __devexit_p(function_name), the wrapper will
   insert either the function_name or NULL, depending on the config options.
 */
#if defined(MODULE) || defined(CONFIG_HOTPLUG)
#define __devexit_p(x) x
#else
#define __devexit_p(x) NULL
#endif

#ifdef MODULE
#define __exit_p(x) x
#else
#define __exit_p(x) NULL
#endif

#endif /* _LINUX_INIT_H */