4 #include <linux/compiler.h>
5 #include <linux/types.h>
7 /* These macros are used to mark some functions or
8 * initialized data (doesn't apply to uninitialized data)
9 * as `initialization' functions. The kernel can take this
10 * as hint that the function is used only during the initialization
11 * phase and free up used memory resources after
16 * You should add __init immediately before the function name, like:
18 * static void __init initme(int x, int y)
20 * extern int z; z = x * y;
23 * If the function has a prototype somewhere, you can also add
24 * __init between closing brace of the prototype and semicolon:
26 * extern int initialize_foobar_device(int, int, int) __init;
28 * For initialized data:
29 * You should insert __initdata or __initconst between the variable name
30 * and equal sign followed by value, e.g.:
32 * static int init_variable __initdata = 0;
33 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
35 * Don't forget to initialize data not at file scope, i.e. within a function,
36 * as gcc otherwise puts the data into the bss section and not into the init
40 /* These are for everybody (although not all archs will actually
41 discard it in modules) */
42 #define __init __section(.init.text) __cold notrace
43 #define __initdata __section(.init.data)
44 #define __initconst __section(.init.rodata)
45 #define __exitdata __section(.exit.data)
46 #define __exit_call __used __section(.exitcall.exit)
49 * modpost check for section mismatches during the kernel build.
50 * A section mismatch happens when there are references from a
51 * code or data section to an init section (both code or data).
52 * The init sections are (for most archs) discarded by the kernel
53 * when early init has completed so all such references are potential bugs.
54 * For exit sections the same issue exists.
56 * The following markers are used for the cases where the reference to
57 * the *init / *exit section (code or data) is valid and will teach
58 * modpost not to issue a warning. Intended semantics is that a code or
59 * data tagged __ref* can reference code or data from init section without
60 * producing a warning (of course, no warning does not mean code is
61 * correct, so optimally document why the __ref is needed and why it's OK).
63 * The markers follow same syntax rules as __init / __initdata.
65 #define __ref __section(.ref.text) noinline
66 #define __refdata __section(.ref.data)
67 #define __refconst __section(.ref.rodata)
72 #define __exitused __used
75 #define __exit __section(.exit.text) __exitused __cold notrace
77 /* Used for MEMORY_HOTPLUG */
78 #define __meminit __section(.meminit.text) __cold notrace
79 #define __meminitdata __section(.meminit.data)
80 #define __meminitconst __section(.meminit.rodata)
81 #define __memexit __section(.memexit.text) __exitused __cold notrace
82 #define __memexitdata __section(.memexit.data)
83 #define __memexitconst __section(.memexit.rodata)
85 /* For assembly routines */
86 #define __HEAD .section ".head.text","ax"
87 #define __INIT .section ".init.text","ax"
88 #define __FINIT .previous
90 #define __INITDATA .section ".init.data","aw",%progbits
91 #define __INITRODATA .section ".init.rodata","a",%progbits
92 #define __FINITDATA .previous
94 #define __MEMINIT .section ".meminit.text", "ax"
95 #define __MEMINITDATA .section ".meminit.data", "aw"
96 #define __MEMINITRODATA .section ".meminit.rodata", "a"
98 /* silence warnings when references are OK */
99 #define __REF .section ".ref.text", "ax"
100 #define __REFDATA .section ".ref.data", "aw"
101 #define __REFCONST .section ".ref.rodata", "a"
105 * Used for initialization calls..
107 typedef int (*initcall_t
)(void);
108 typedef void (*exitcall_t
)(void);
110 extern initcall_t __con_initcall_start
[], __con_initcall_end
[];
111 extern initcall_t __security_initcall_start
[], __security_initcall_end
[];
113 /* Used for contructor calls. */
114 typedef void (*ctor_fn_t
)(void);
116 /* Defined in init/main.c */
117 extern int do_one_initcall(initcall_t fn
);
118 extern char __initdata boot_command_line
[];
119 extern char *saved_command_line
;
120 extern unsigned int reset_devices
;
122 /* used by init/main.c */
123 void setup_arch(char **);
124 void prepare_namespace(void);
125 void __init
load_default_modules(void);
126 int __init
init_rootfs(void);
128 #ifdef CONFIG_DEBUG_RODATA
129 void mark_rodata_ro(void);
132 extern void (*late_time_init
)(void);
134 extern bool initcall_debug
;
143 * initcalls are now grouped by functionality into separate
144 * subsections. Ordering inside the subsections is determined
146 * For backwards compatibility, initcall() puts the call in
147 * the device init subsection.
149 * The `id' arg to __define_initcall() is needed so that multiple initcalls
150 * can point at the same handler without causing duplicate-symbol build errors.
152 * Initcalls are run by placing pointers in initcall sections that the
153 * kernel iterates at runtime. The linker can do dead code / data elimination
154 * and remove that completely, so the initcall sections have to be marked
155 * as KEEP() in the linker script.
158 #define __define_initcall(fn, id) \
159 static initcall_t __initcall_##fn##id __used \
160 __attribute__((__section__(".initcall" #id ".init"))) = fn;
163 * Early initcalls run before initializing SMP.
165 * Only for built-in code, not modules.
167 #define early_initcall(fn) __define_initcall(fn, early)
170 * A "pure" initcall has no dependencies on anything else, and purely
171 * initializes variables that couldn't be statically initialized.
173 * This only exists for built-in code, not for modules.
174 * Keep main.c:initcall_level_names[] in sync.
176 #define pure_initcall(fn) __define_initcall(fn, 0)
178 #define core_initcall(fn) __define_initcall(fn, 1)
179 #define core_initcall_sync(fn) __define_initcall(fn, 1s)
180 #define postcore_initcall(fn) __define_initcall(fn, 2)
181 #define postcore_initcall_sync(fn) __define_initcall(fn, 2s)
182 #define arch_initcall(fn) __define_initcall(fn, 3)
183 #define arch_initcall_sync(fn) __define_initcall(fn, 3s)
184 #define subsys_initcall(fn) __define_initcall(fn, 4)
185 #define subsys_initcall_sync(fn) __define_initcall(fn, 4s)
186 #define fs_initcall(fn) __define_initcall(fn, 5)
187 #define fs_initcall_sync(fn) __define_initcall(fn, 5s)
188 #define rootfs_initcall(fn) __define_initcall(fn, rootfs)
189 #define device_initcall(fn) __define_initcall(fn, 6)
190 #define device_initcall_sync(fn) __define_initcall(fn, 6s)
191 #define late_initcall(fn) __define_initcall(fn, 7)
192 #define late_initcall_sync(fn) __define_initcall(fn, 7s)
194 #define __initcall(fn) device_initcall(fn)
196 #define __exitcall(fn) \
197 static exitcall_t __exitcall_##fn __exit_call = fn
199 #define console_initcall(fn) \
200 static initcall_t __initcall_##fn \
201 __used __section(.con_initcall.init) = fn
203 #define security_initcall(fn) \
204 static initcall_t __initcall_##fn \
205 __used __section(.security_initcall.init) = fn
207 struct obs_kernel_param
{
209 int (*setup_func
)(char *);
214 * Only for really core code. See moduleparam.h for the normal way.
216 * Force the alignment so the compiler doesn't space elements of the
217 * obs_kernel_param "array" too far apart in .init.setup.
219 #define __setup_param(str, unique_id, fn, early) \
220 static const char __setup_str_##unique_id[] __initconst \
221 __aligned(1) = str; \
222 static struct obs_kernel_param __setup_##unique_id \
223 __used __section(.init.setup) \
224 __attribute__((aligned((sizeof(long))))) \
225 = { __setup_str_##unique_id, fn, early }
227 #define __setup(str, fn) \
228 __setup_param(str, fn, fn, 0)
231 * NOTE: fn is as per module_param, not __setup!
232 * Emits warning if fn returns non-zero.
234 #define early_param(str, fn) \
235 __setup_param(str, fn, fn, 1)
237 #define early_param_on_off(str_on, str_off, var, config) \
239 int var = IS_ENABLED(config); \
241 static int __init parse_##var##_on(char *arg) \
246 __setup_param(str_on, parse_##var##_on, parse_##var##_on, 1); \
248 static int __init parse_##var##_off(char *arg) \
253 __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1)
255 /* Relies on boot_command_line being set */
256 void __init
parse_early_param(void);
257 void __init
parse_early_options(char *cmdline
);
258 #endif /* __ASSEMBLY__ */
262 #define __setup_param(str, unique_id, fn) /* nothing */
263 #define __setup(str, func) /* nothing */
266 /* Data marked not to be saved by software suspend */
267 #define __nosavedata __section(.data..nosave)
270 #define __exit_p(x) x
272 #define __exit_p(x) NULL
275 #endif /* _LINUX_INIT_H */