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Diffstat (limited to 'include/linux/init.h')
| -rw-r--r-- | include/linux/init.h | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/include/linux/init.h b/include/linux/init.h new file mode 100644 index 000000000000..05c83e0521ca --- /dev/null +++ b/include/linux/init.h @@ -0,0 +1,250 @@ +#ifndef _LINUX_INIT_H +#define _LINUX_INIT_H + +#include <linux/config.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[]; +#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. + */ + +#define __define_initcall(level,fn) \ + static initcall_t __initcall_##fn __attribute_used__ \ + __attribute__((__section__(".initcall" level ".init"))) = fn + +#define core_initcall(fn) __define_initcall("1",fn) +#define postcore_initcall(fn) __define_initcall("2",fn) +#define arch_initcall(fn) __define_initcall("3",fn) +#define subsys_initcall(fn) __define_initcall("4",fn) +#define fs_initcall(fn) __define_initcall("5",fn) +#define device_initcall(fn) __define_initcall("6",fn) +#define late_initcall(fn) __define_initcall("7",fn) + +#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 + +/* 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 */ |