aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/init.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/init.h')
-rw-r--r--include/linux/init.h250
1 files changed, 250 insertions, 0 deletions
diff --git a/include/linux/init.h b/include/linux/init.h
new file mode 100644
index 0000000..05c83e0
--- /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 */