4 #include <linux/compiler.h>
5 #include <linux/types.h>
7 /* Built-in __init functions needn't be compiled with retpoline */
8 #if defined(RETPOLINE) && !defined(MODULE)
9 #define __noretpoline __attribute__((indirect_branch("keep")))
14 /* These macros are used to mark some functions or
15 * initialized data (doesn't apply to uninitialized data)
16 * as `initialization' functions. The kernel can take this
17 * as hint that the function is used only during the initialization
18 * phase and free up used memory resources after
23 * You should add __init immediately before the function name, like:
25 * static void __init initme(int x, int y)
27 * extern int z; z = x * y;
30 * If the function has a prototype somewhere, you can also add
31 * __init between closing brace of the prototype and semicolon:
33 * extern int initialize_foobar_device(int, int, int) __init;
35 * For initialized data:
36 * You should insert __initdata or __initconst between the variable name
37 * and equal sign followed by value, e.g.:
39 * static int init_variable __initdata = 0;
40 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
42 * Don't forget to initialize data not at file scope, i.e. within a function,
43 * as gcc otherwise puts the data into the bss section and not into the init
47 /* These are for everybody (although not all archs will actually
48 discard it in modules) */
49 #define __init __section(.init.text) __cold notrace __noretpoline
50 #define __initdata __section(.init.data)
51 #define __initconst __constsection(.init.rodata)
52 #define __exitdata __section(.exit.data)
53 #define __exit_call __used __section(.exitcall.exit)
56 * Some architecture have tool chains which do not handle rodata attributes
57 * correctly. For those disable special sections for const, so that other
58 * architectures can annotate correctly.
60 #ifdef CONFIG_BROKEN_RODATA
61 #define __constsection(x)
63 #define __constsection(x) __section(x)
67 * modpost check for section mismatches during the kernel build.
68 * A section mismatch happens when there are references from a
69 * code or data section to an init section (both code or data).
70 * The init sections are (for most archs) discarded by the kernel
71 * when early init has completed so all such references are potential bugs.
72 * For exit sections the same issue exists.
74 * The following markers are used for the cases where the reference to
75 * the *init / *exit section (code or data) is valid and will teach
76 * modpost not to issue a warning. Intended semantics is that a code or
77 * data tagged __ref* can reference code or data from init section without
78 * producing a warning (of course, no warning does not mean code is
79 * correct, so optimally document why the __ref is needed and why it's OK).
81 * The markers follow same syntax rules as __init / __initdata.
83 #define __ref __section(.ref.text) noinline
84 #define __refdata __section(.ref.data)
85 #define __refconst __constsection(.ref.rodata)
87 /* compatibility defines */
88 #define __init_refok __ref
89 #define __initdata_refok __refdata
90 #define __exit_refok __ref
96 #define __exitused __used
99 #define __exit __section(.exit.text) __exitused __cold notrace
101 /* temporary, until all users are removed */
103 #define __cpuinitdata
104 #define __cpuinitconst
106 #define __cpuexitdata
107 #define __cpuexitconst
109 /* Used for MEMORY_HOTPLUG */
110 #define __meminit __section(.meminit.text) __cold notrace
111 #define __meminitdata __section(.meminit.data)
112 #define __meminitconst __constsection(.meminit.rodata)
113 #define __memexit __section(.memexit.text) __exitused __cold notrace
114 #define __memexitdata __section(.memexit.data)
115 #define __memexitconst __constsection(.memexit.rodata)
117 /* For assembly routines */
118 #define __HEAD .section ".head.text","ax"
119 #define __INIT .section ".init.text","ax"
120 #define __FINIT .previous
122 #define __INITDATA .section ".init.data","aw",%progbits
123 #define __INITRODATA .section ".init.rodata","a",%progbits
124 #define __FINITDATA .previous
126 /* temporary, until all users are removed */
129 #define __MEMINIT .section ".meminit.text", "ax"
130 #define __MEMINITDATA .section ".meminit.data", "aw"
131 #define __MEMINITRODATA .section ".meminit.rodata", "a"
133 /* silence warnings when references are OK */
134 #define __REF .section ".ref.text", "ax"
135 #define __REFDATA .section ".ref.data", "aw"
136 #define __REFCONST .section ".ref.rodata", "a"
140 * Used for initialization calls..
142 typedef int (*initcall_t)(void);
143 typedef void (*exitcall_t)(void);
145 extern initcall_t __con_initcall_start[], __con_initcall_end[];
146 extern initcall_t __security_initcall_start[], __security_initcall_end[];
148 /* Used for contructor calls. */
149 typedef void (*ctor_fn_t)(void);
151 /* Defined in init/main.c */
152 extern int do_one_initcall(initcall_t fn);
153 extern char __initdata boot_command_line[];
154 extern char *saved_command_line;
155 extern unsigned int reset_devices;
157 /* used by init/main.c */
158 void setup_arch(char **);
159 void prepare_namespace(void);
160 void __init load_default_modules(void);
161 int __init init_rootfs(void);
163 extern void (*late_time_init)(void);
165 extern bool initcall_debug;
174 /* Work around a LTO gcc problem: when there is no reference to a variable
175 * in a module it will be moved to the end of the program. This causes
176 * reordering of initcalls which the kernel does not like.
177 * Add a dummy reference function to avoid this. The function is
178 * deleted by the linker.
180 #define LTO_REFERENCE_INITCALL(x) \
181 ; /* yes this is needed */ \
182 static __used __exit void *reference_##x(void) \
187 #define LTO_REFERENCE_INITCALL(x)
190 /* initcalls are now grouped by functionality into separate
191 * subsections. Ordering inside the subsections is determined
193 * For backwards compatibility, initcall() puts the call in
194 * the device init subsection.
196 * The `id' arg to __define_initcall() is needed so that multiple initcalls
197 * can point at the same handler without causing duplicate-symbol build errors.
200 #define __define_initcall(fn, id) \
201 static initcall_t __initcall_##fn##id __used \
202 __attribute__((__section__(".initcall" #id ".init"))) = fn; \
203 LTO_REFERENCE_INITCALL(__initcall_##fn##id)
206 * Early initcalls run before initializing SMP.
208 * Only for built-in code, not modules.
210 #define early_initcall(fn) __define_initcall(fn, early)
213 * A "pure" initcall has no dependencies on anything else, and purely
214 * initializes variables that couldn't be statically initialized.
216 * This only exists for built-in code, not for modules.
217 * Keep main.c:initcall_level_names[] in sync.
219 #define pure_initcall(fn) __define_initcall(fn, 0)
221 #define core_initcall(fn) __define_initcall(fn, 1)
222 #define core_initcall_sync(fn) __define_initcall(fn, 1s)
223 #define postcore_initcall(fn) __define_initcall(fn, 2)
224 #define postcore_initcall_sync(fn) __define_initcall(fn, 2s)
225 #define arch_initcall(fn) __define_initcall(fn, 3)
226 #define arch_initcall_sync(fn) __define_initcall(fn, 3s)
227 #define subsys_initcall(fn) __define_initcall(fn, 4)
228 #define subsys_initcall_sync(fn) __define_initcall(fn, 4s)
229 #define fs_initcall(fn) __define_initcall(fn, 5)
230 #define fs_initcall_sync(fn) __define_initcall(fn, 5s)
231 #define rootfs_initcall(fn) __define_initcall(fn, rootfs)
232 #define device_initcall(fn) __define_initcall(fn, 6)
233 #define device_initcall_sync(fn) __define_initcall(fn, 6s)
234 #define late_initcall(fn) __define_initcall(fn, 7)
235 #define late_initcall_sync(fn) __define_initcall(fn, 7s)
237 #define __initcall(fn) device_initcall(fn)
239 #define __exitcall(fn) \
240 static exitcall_t __exitcall_##fn __exit_call = fn
242 #define console_initcall(fn) \
243 static initcall_t __initcall_##fn \
244 __used __section(.con_initcall.init) = fn
246 #define security_initcall(fn) \
247 static initcall_t __initcall_##fn \
248 __used __section(.security_initcall.init) = fn
250 struct obs_kernel_param {
252 int (*setup_func)(char *);
257 * Only for really core code. See moduleparam.h for the normal way.
259 * Force the alignment so the compiler doesn't space elements of the
260 * obs_kernel_param "array" too far apart in .init.setup.
262 #define __setup_param(str, unique_id, fn, early) \
263 static const char __setup_str_##unique_id[] __initconst \
264 __aligned(1) = str; \
265 static struct obs_kernel_param __setup_##unique_id \
266 __used __section(.init.setup) \
267 __attribute__((aligned((sizeof(long))))) \
268 = { __setup_str_##unique_id, fn, early }
270 #define __setup(str, fn) \
271 __setup_param(str, fn, fn, 0)
273 /* NOTE: fn is as per module_param, not __setup! Emits warning if fn
274 * returns non-zero. */
275 #define early_param(str, fn) \
276 __setup_param(str, fn, fn, 1)
278 /* Relies on boot_command_line being set */
279 void __init parse_early_param(void);
280 void __init parse_early_options(char *cmdline);
281 #endif /* __ASSEMBLY__ */
284 * module_init() - driver initialization entry point
285 * @x: function to be run at kernel boot time or module insertion
287 * module_init() will either be called during do_initcalls() (if
288 * builtin) or at module insertion time (if a module). There can only
291 #define module_init(x) __initcall(x);
294 * module_exit() - driver exit entry point
295 * @x: function to be run when driver is removed
297 * module_exit() will wrap the driver clean-up code
298 * with cleanup_module() when used with rmmod when
299 * the driver is a module. If the driver is statically
300 * compiled into the kernel, module_exit() has no effect.
301 * There can only be one per module.
303 #define module_exit(x) __exitcall(x);
308 * In most cases loadable modules do not need custom
309 * initcall levels. There are still some valid cases where
310 * a driver may be needed early if built in, and does not
311 * matter when built as a loadable module. Like bus
312 * snooping debug drivers.
314 #define early_initcall(fn) module_init(fn)
315 #define core_initcall(fn) module_init(fn)
316 #define core_initcall_sync(fn) module_init(fn)
317 #define postcore_initcall(fn) module_init(fn)
318 #define postcore_initcall_sync(fn) module_init(fn)
319 #define arch_initcall(fn) module_init(fn)
320 #define subsys_initcall(fn) module_init(fn)
321 #define subsys_initcall_sync(fn) module_init(fn)
322 #define fs_initcall(fn) module_init(fn)
323 #define fs_initcall_sync(fn) module_init(fn)
324 #define rootfs_initcall(fn) module_init(fn)
325 #define device_initcall(fn) module_init(fn)
326 #define device_initcall_sync(fn) module_init(fn)
327 #define late_initcall(fn) module_init(fn)
328 #define late_initcall_sync(fn) module_init(fn)
330 #define console_initcall(fn) module_init(fn)
331 #define security_initcall(fn) module_init(fn)
333 /* Each module must use one module_init(). */
334 #define module_init(initfn) \
335 static inline initcall_t __inittest(void) \
337 int init_module(void) __attribute__((alias(#initfn)));
339 /* This is only required if you want to be unloadable. */
340 #define module_exit(exitfn) \
341 static inline exitcall_t __exittest(void) \
343 void cleanup_module(void) __attribute__((alias(#exitfn)));
345 #define __setup_param(str, unique_id, fn) /* nothing */
346 #define __setup(str, func) /* nothing */
349 /* Data marked not to be saved by software suspend */
350 #define __nosavedata __section(.data..nosave)
352 /* This means "can be init if no module support, otherwise module load
354 #ifdef CONFIG_MODULES
355 #define __init_or_module
356 #define __initdata_or_module
357 #define __initconst_or_module
358 #define __INIT_OR_MODULE .text
359 #define __INITDATA_OR_MODULE .data
360 #define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits
362 #define __init_or_module __init
363 #define __initdata_or_module __initdata
364 #define __initconst_or_module __initconst
365 #define __INIT_OR_MODULE __INIT
366 #define __INITDATA_OR_MODULE __INITDATA
367 #define __INITRODATA_OR_MODULE __INITRODATA
368 #endif /*CONFIG_MODULES*/
371 #define __exit_p(x) x
373 #define __exit_p(x) NULL
376 #endif /* _LINUX_INIT_H */