[linux-2.6-block.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 */
#define __INIT		.section	".init.text","ax"
#define __FINIT		.previous
#define __INITDATA	.section	".init.data","aw"

#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 saved_command_line[];
extern unsigned int reset_devices;

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

#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

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