[deliverable/linux.git] / include / linux / init.h

#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;
 * static char linux_logo[] __initdata = { 0x32, 0x36, ... };
 *
 * 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) */
#define __init		__attribute__ ((__section__ (".init.text")))
#define __initdata	__attribute__ ((__section__ (".init.data")))
#define __exitdata	__attribute__ ((__section__(".exit.data")))
#define __exit_call	__attribute_used__ __attribute__ ((__section__ (".exitcall.exit")))

#ifdef MODULE
#define __exit		__attribute__ ((__section__(".exit.text")))
#else
#define __exit		__attribute_used__ __attribute__ ((__section__(".exit.text")))
#endif

/* For assembly routines */
#ifdef CONFIG_HOTPLUG_CPU
#define __INIT		.section	".text","ax"
#define __INITDATA	.section	".data","aw"
#else
#define __INIT		.section	".init.text","ax"
#define __INITDATA	.section	".init.data","aw"
#endif
#define __FINIT		.previous

#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[];

/* Defined in init/main.c */
extern char __initdata boot_command_line[];
extern char *saved_command_line;
extern unsigned int reset_devices;

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

#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.
 *
 * The `id' arg to __define_initcall() is needed so that multiple initcalls
 * can point at the same handler without causing duplicate-symbol build errors.
 */

#define __define_initcall(level,fn,id) \
	static initcall_t __initcall_##fn##id __attribute_used__ \
	__attribute__((__section__(".initcall" level ".init"))) = fn

/*
 * 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.
 */
#define pure_initcall(fn)		__define_initcall("0",fn,1)

#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)
#define rootfs_initcall(fn)		__define_initcall("rootfs",fn,rootfs)
#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)

#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 \
	__attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn

#define security_initcall(fn) \
	static initcall_t __initcall_##fn \
	__attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn

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)			\
	static char __setup_str_##unique_id[] __initdata = str;	\
	static struct obs_kernel_param __setup_##unique_id	\
		__attribute_used__				\
		__attribute__((__section__(".init.setup")))	\
		__attribute__((aligned((sizeof(long)))))	\
		= { __setup_str_##unique_id, fn, early }

#define __setup_null_param(str, unique_id)			\
	__setup_param(str, unique_id, NULL, 0)

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

#define __obsolete_setup(str)					\
	__setup_null_param(str, __LINE__)

/* 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)

/* Relies on boot_command_line being set */
void __init parse_early_param(void);
#endif /* __ASSEMBLY__ */

/**
 * module_init() - driver initialization entry point
 * @x: function to be run at kernel boot time or module insertion
 * 
 * module_init() will either be called during do_initcalls() (if
 * 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... */
#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)

/* These macros create a dummy inline: gcc 2.9x does not count alias
 as usage, hence the `unused function' warning when __init functions
 are declared static. We use the dummy __*_module_inline functions
 both to kill the warning and check the type of the init/cleanup
 function. */

/* Each module must use one module_init(), or one no_module_init */
#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_null_param(str, unique_id) 	/* nothing */
#define __setup(str, func) 			/* nothing */
#define __obsolete_setup(str) 			/* nothing */
#endif

/* Data marked not to be saved by software suspend */
#define __nosavedata __attribute__ ((__section__ (".data.nosave")))

/* 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
#else
#define __init_or_module __init
#define __initdata_or_module __initdata
#endif /*CONFIG_MODULES*/

#ifdef CONFIG_HOTPLUG
#define __devinit
#define __devinitdata
#define __devexit
#define __devexitdata
#else
#define __devinit __init
#define __devinitdata __initdata
#define __devexit __exit
#define __devexitdata __exitdata
#endif

#ifdef CONFIG_HOTPLUG_CPU
#define __cpuinit
#define __cpuinitdata
#define __cpuexit
#define __cpuexitdata
#else
#define __cpuinit	__init
#define __cpuinitdata __initdata
#define __cpuexit __exit
#define __cpuexitdata	__exitdata
#endif

#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_ACPI_HOTPLUG_MEMORY) \
	|| defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)
#define __meminit
#define __meminitdata
#define __memexit
#define __memexitdata
#else
#define __meminit	__init
#define __meminitdata __initdata
#define __memexit __exit
#define __memexitdata	__exitdata
#endif

/* 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 */
Commit	Line	Data
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) */
	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 */
86c0baf1 PB	55	#ifdef CONFIG_HOTPLUG_CPU
	56	#define __INIT .section ".text","ax"
	57	#define __INITDATA .section ".data","aw"
	58	#else
1da177e4	59	#define __INIT .section ".init.text","ax"
1da177e4	60	#define __INITDATA .section ".init.data","aw"
86c0baf1 PB	61	#endif
86c0baf1 PB	62	#define __FINIT .previous
1da177e4 LT	63
	64	#ifndef __ASSEMBLY__
	65	/*
	66	* Used for initialization calls..
	67	*/
	68	typedef int (*initcall_t)(void);
	69	typedef void (*exitcall_t)(void);
	70
	71	extern initcall_t __con_initcall_start[], __con_initcall_end[];
	72	extern initcall_t __security_initcall_start[], __security_initcall_end[];
	73
	74	/* Defined in init/main.c */
30d7e0d4 ABL	75	extern char __initdata boot_command_line[];
30d7e0d4 ABL	76	extern char *saved_command_line;
7e96287d	77	extern unsigned int reset_devices;
77d47582 AB	78
77d47582 AB	79	/* used by init/main.c */
46595390 AB	80	void setup_arch(char **);
46595390 AB	81	void prepare_namespace(void);
77d47582	82
1da177e4 LT	83	#endif
	84
	85	#ifndef MODULE
	86
	87	#ifndef __ASSEMBLY__
	88
	89	/* initcalls are now grouped by functionality into separate
	90	* subsections. Ordering inside the subsections is determined
	91	* by link order.
	92	* For backwards compatibility, initcall() puts the call in
	93	* the device init subsection.
735a7ffb AM	94	*
	95	* The `id' arg to __define_initcall() is needed so that multiple initcalls
	96	* can point at the same handler without causing duplicate-symbol build errors.
1da177e4 LT	97	*/
1da177e4 LT	98
735a7ffb AM	99	#define __define_initcall(level,fn,id) \
735a7ffb AM	100	static initcall_t __initcall_##fn##id __attribute_used__ \
1da177e4 LT	101	__attribute__((__section__(".initcall" level ".init"))) = fn
1da177e4 LT	102
b3438f82 LT	103	/*
	104	* A "pure" initcall has no dependencies on anything else, and purely
	105	* initializes variables that couldn't be statically initialized.
	106	*
	107	* This only exists for built-in code, not for modules.
	108	*/
	109	#define pure_initcall(fn) __define_initcall("0",fn,1)
	110
735a7ffb AM	111	#define core_initcall(fn) __define_initcall("1",fn,1)
	112	#define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
	113	#define postcore_initcall(fn) __define_initcall("2",fn,2)
	114	#define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
	115	#define arch_initcall(fn) __define_initcall("3",fn,3)
	116	#define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
	117	#define subsys_initcall(fn) __define_initcall("4",fn,4)
	118	#define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
	119	#define fs_initcall(fn) __define_initcall("5",fn,5)
	120	#define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
8d610dd5	121	#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
735a7ffb AM	122	#define device_initcall(fn) __define_initcall("6",fn,6)
	123	#define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
	124	#define late_initcall(fn) __define_initcall("7",fn,7)
	125	#define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
1da177e4 LT	126
	127	#define __initcall(fn) device_initcall(fn)
	128
	129	#define __exitcall(fn) \
	130	static exitcall_t __exitcall_##fn __exit_call = fn
	131
	132	#define console_initcall(fn) \
	133	static initcall_t __initcall_##fn \
	134	__attribute_used__ __attribute__((__section__(".con_initcall.init")))=fn
	135
	136	#define security_initcall(fn) \
	137	static initcall_t __initcall_##fn \
	138	__attribute_used__ __attribute__((__section__(".security_initcall.init"))) = fn
	139
	140	struct obs_kernel_param {
	141	const char *str;
	142	int (setup_func)(char );
	143	int early;
	144	};
	145
	146	/*
	147	* Only for really core code. See moduleparam.h for the normal way.
	148	*
	149	* Force the alignment so the compiler doesn't space elements of the
	150	* obs_kernel_param "array" too far apart in .init.setup.
	151	*/
	152	#define __setup_param(str, unique_id, fn, early) \
	153	static char __setup_str_##unique_id[] __initdata = str; \
	154	static struct obs_kernel_param __setup_##unique_id \
	155	__attribute_used__ \
	156	__attribute__((__section__(".init.setup"))) \
	157	__attribute__((aligned((sizeof(long))))) \
	158	= { __setup_str_##unique_id, fn, early }
	159
	160	#define __setup_null_param(str, unique_id) \
	161	__setup_param(str, unique_id, NULL, 0)
	162
	163	#define __setup(str, fn) \
	164	__setup_param(str, fn, fn, 0)
	165
	166	#define __obsolete_setup(str) \
	167	__setup_null_param(str, __LINE__)
	168
	169	/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
	170	* returns non-zero. */
	171	#define early_param(str, fn) \
	172	__setup_param(str, fn, fn, 1)
	173
30d7e0d4	174	/* Relies on boot_command_line being set */
1da177e4 LT	175	void __init parse_early_param(void);
	176	#endif /* __ASSEMBLY__ */
	177
	178	/**
	179	* module_init() - driver initialization entry point
	180	* @x: function to be run at kernel boot time or module insertion
	181	*
72fd4a35	182	* module_init() will either be called during do_initcalls() (if
1da177e4 LT	183	* builtin) or at module insertion time (if a module). There can only
	184	* be one per module.
	185	*/
	186	#define module_init(x) __initcall(x);
	187
	188	/**
	189	* module_exit() - driver exit entry point
	190	* @x: function to be run when driver is removed
	191	*
	192	* module_exit() will wrap the driver clean-up code
	193	* with cleanup_module() when used with rmmod when
	194	* the driver is a module. If the driver is statically
	195	* compiled into the kernel, module_exit() has no effect.
	196	* There can only be one per module.
	197	*/
	198	#define module_exit(x) __exitcall(x);
	199
	200	#else /* MODULE */
	201
	202	/* Don't use these in modules, but some people do... */
	203	#define core_initcall(fn) module_init(fn)
	204	#define postcore_initcall(fn) module_init(fn)
	205	#define arch_initcall(fn) module_init(fn)
	206	#define subsys_initcall(fn) module_init(fn)
	207	#define fs_initcall(fn) module_init(fn)
	208	#define device_initcall(fn) module_init(fn)
	209	#define late_initcall(fn) module_init(fn)
	210
	211	#define security_initcall(fn) module_init(fn)
	212
	213	/* These macros create a dummy inline: gcc 2.9x does not count alias
	214	as usage, hence the `unused function' warning when __init functions
	215	are declared static. We use the dummy __*_module_inline functions
	216	both to kill the warning and check the type of the init/cleanup
	217	function. */
	218
	219	/* Each module must use one module_init(), or one no_module_init */
	220	#define module_init(initfn) \
	221	static inline initcall_t __inittest(void) \
	222	{ return initfn; } \
	223	int init_module(void) __attribute__((alias(#initfn)));
	224
	225	/* This is only required if you want to be unloadable. */
	226	#define module_exit(exitfn) \
	227	static inline exitcall_t __exittest(void) \
	228	{ return exitfn; } \
	229	void cleanup_module(void) __attribute__((alias(#exitfn)));
	230
	231	#define __setup_param(str, unique_id, fn) /* nothing */
	232	#define __setup_null_param(str, unique_id) /* nothing */
	233	#define __setup(str, func) /* nothing */
	234	#define __obsolete_setup(str) /* nothing */
	235	#endif
	236
ab3bfca7	237	/* Data marked not to be saved by software suspend */
1da177e4 LT	238	#define __nosavedata __attribute__ ((__section__ (".data.nosave")))
	239
	240	/* This means "can be init if no module support, otherwise module load
	241	may call it." */
	242	#ifdef CONFIG_MODULES
	243	#define __init_or_module
	244	#define __initdata_or_module
	245	#else
	246	#define __init_or_module __init
	247	#define __initdata_or_module __initdata
	248	#endif /CONFIG_MODULES/
	249
	250	#ifdef CONFIG_HOTPLUG
	251	#define __devinit
	252	#define __devinitdata
	253	#define __devexit
	254	#define __devexitdata
	255	#else
	256	#define __devinit __init
	257	#define __devinitdata __initdata
	258	#define __devexit __exit
	259	#define __devexitdata __exitdata
	260	#endif
	261
e6982c67 AR	262	#ifdef CONFIG_HOTPLUG_CPU
	263	#define __cpuinit
	264	#define __cpuinitdata
	265	#define __cpuexit
	266	#define __cpuexitdata
	267	#else
	268	#define __cpuinit __init
	269	#define __cpuinitdata __initdata
	270	#define __cpuexit __exit
	271	#define __cpuexitdata __exitdata
	272	#endif
	273
9d99aaa3 AK	274	#if defined(CONFIG_MEMORY_HOTPLUG) \|\| defined(CONFIG_ACPI_HOTPLUG_MEMORY) \
9d99aaa3 AK	275	\|\| defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)
c09b4240 MT	276	#define __meminit
	277	#define __meminitdata
	278	#define __memexit
	279	#define __memexitdata
	280	#else
	281	#define __meminit __init
	282	#define __meminitdata __initdata
	283	#define __memexit __exit
	284	#define __memexitdata __exitdata
	285	#endif
	286
1da177e4 LT	287	/* Functions marked as __devexit may be discarded at kernel link time, depending
	288	on config options. Newer versions of binutils detect references from
	289	retained sections to discarded sections and flag an error. Pointers to
	290	__devexit functions must use __devexit_p(function_name), the wrapper will
	291	insert either the function_name or NULL, depending on the config options.
	292	*/
	293	#if defined(MODULE) \|\| defined(CONFIG_HOTPLUG)
	294	#define __devexit_p(x) x
	295	#else
	296	#define __devexit_p(x) NULL
	297	#endif
	298
	299	#ifdef MODULE
	300	#define __exit_p(x) x
	301	#else
	302	#define __exit_p(x) NULL
	303	#endif
	304
	305	#endif /* _LINUX_INIT_H */