4 #include <linux/compiler.h>
5 #include <linux/section-names.h>
6 #include <linux/stringify.h>
8 /* These macros are used to mark some functions or
9 * initialized data (doesn't apply to uninitialized data)
10 * as `initialization' functions. The kernel can take this
11 * as hint that the function is used only during the initialization
12 * phase and free up used memory resources after
17 * You should add __init immediately before the function name, like:
19 * static void __init initme(int x, int y)
21 * extern int z; z = x * y;
24 * If the function has a prototype somewhere, you can also add
25 * __init between closing brace of the prototype and semicolon:
27 * extern int initialize_foobar_device(int, int, int) __init;
29 * For initialized data:
30 * You should insert __initdata between the variable name and equal
31 * sign followed by value, e.g.:
33 * static int init_variable __initdata = 0;
34 * static char linux_logo[] __initdata = { 0x32, 0x36, ... };
36 * Don't forget to initialize data not at file scope, i.e. within a function,
37 * as gcc otherwise puts the data into the bss section and not into the init
40 * Also note, that this data cannot be "const".
43 /* These are for everybody (although not all archs will actually
44 discard it in modules) */
45 #define __init __section(.init.text) __cold notrace
46 #define __initdata __section(.init.data)
47 #define __initconst __section(.init.rodata)
48 #define __exitdata __section(.exit.data)
49 #define __exit_call __used __section(.exitcall.exit)
51 /* modpost check for section mismatches during the kernel build.
52 * A section mismatch happens when there are references from a
53 * code or data section to an init section (both code or data).
54 * The init sections are (for most archs) discarded by the kernel
55 * when early init has completed so all such references are potential bugs.
56 * For exit sections the same issue exists.
57 * The following markers are used for the cases where the reference to
58 * the *init / *exit section (code or data) is valid and will teach
59 * modpost not to issue a warning.
60 * The markers follow same syntax rules as __init / __initdata. */
61 #define __ref __section(.ref.text) noinline
62 #define __refdata __section(.ref.data)
63 #define __refconst __section(.ref.rodata)
65 /* backward compatibility note
66 * A few places hardcode the old section names:
70 * They should be converted to use the defines from this file
73 /* compatibility defines */
74 #define __init_refok __ref
75 #define __initdata_refok __refdata
76 #define __exit_refok __ref
82 #define __exitused __used
85 #define __exit __section(.exit.text) __exitused __cold
87 /* Used for HOTPLUG */
88 #define __devinit __section(.devinit.text) __cold
89 #define __devinitdata __section(.devinit.data)
90 #define __devinitconst __section(.devinit.rodata)
91 #define __devexit __section(.devexit.text) __exitused __cold
92 #define __devexitdata __section(.devexit.data)
93 #define __devexitconst __section(.devexit.rodata)
95 /* Used for HOTPLUG_CPU */
96 #define __cpuinit __section(.cpuinit.text) __cold
97 #define __cpuinitdata __section(.cpuinit.data)
98 #define __cpuinitconst __section(.cpuinit.rodata)
99 #define __cpuexit __section(.cpuexit.text) __exitused __cold
100 #define __cpuexitdata __section(.cpuexit.data)
101 #define __cpuexitconst __section(.cpuexit.rodata)
103 /* Used for MEMORY_HOTPLUG */
104 #define __meminit __section(.meminit.text) __cold
105 #define __meminitdata __section(.meminit.data)
106 #define __meminitconst __section(.meminit.rodata)
107 #define __memexit __section(.memexit.text) __exitused __cold
108 #define __memexitdata __section(.memexit.data)
109 #define __memexitconst __section(.memexit.rodata)
111 /* For assembly routines */
112 #define __HEAD .section __stringify(HEAD_TEXT_SECTION),"ax"
113 #define __INIT .section ".init.text","ax"
114 #define __FINIT .previous
116 #define __INITDATA .section ".init.data","aw"
117 #define __INITRODATA .section ".init.rodata","a"
118 #define __FINITDATA .previous
120 #define __DEVINIT .section ".devinit.text", "ax"
121 #define __DEVINITDATA .section ".devinit.data", "aw"
122 #define __DEVINITRODATA .section ".devinit.rodata", "a"
124 #define __CPUINIT .section ".cpuinit.text", "ax"
125 #define __CPUINITDATA .section ".cpuinit.data", "aw"
126 #define __CPUINITRODATA .section ".cpuinit.rodata", "a"
128 #define __MEMINIT .section ".meminit.text", "ax"
129 #define __MEMINITDATA .section ".meminit.data", "aw"
130 #define __MEMINITRODATA .section ".meminit.rodata", "a"
132 /* silence warnings when references are OK */
133 #define __REF .section ".ref.text", "ax"
134 #define __REFDATA .section ".ref.data", "aw"
135 #define __REFCONST .section ".ref.rodata", "a"
139 * Used for initialization calls..
141 typedef int (*initcall_t)(void);
142 typedef void (*exitcall_t)(void);
144 extern initcall_t __con_initcall_start[], __con_initcall_end[];
145 extern initcall_t __security_initcall_start[], __security_initcall_end[];
147 /* Defined in init/main.c */
148 extern int do_one_initcall(initcall_t fn);
149 extern char __initdata boot_command_line[];
150 extern char *saved_command_line;
151 extern unsigned int reset_devices;
153 /* used by init/main.c */
154 void setup_arch(char **);
155 void prepare_namespace(void);
157 extern void (*late_time_init)(void);
165 /* initcalls are now grouped by functionality into separate
166 * subsections. Ordering inside the subsections is determined
168 * For backwards compatibility, initcall() puts the call in
169 * the device init subsection.
171 * The `id' arg to __define_initcall() is needed so that multiple initcalls
172 * can point at the same handler without causing duplicate-symbol build errors.
175 #define __define_initcall(level,fn,id) \
176 static initcall_t __initcall_##fn##id __used \
177 __attribute__((__section__(".initcall" level ".init"))) = fn
180 * Early initcalls run before initializing SMP.
182 * Only for built-in code, not modules.
184 #define early_initcall(fn) __define_initcall("early",fn,early)
187 * A "pure" initcall has no dependencies on anything else, and purely
188 * initializes variables that couldn't be statically initialized.
190 * This only exists for built-in code, not for modules.
192 #define pure_initcall(fn) __define_initcall("0",fn,0)
194 #define core_initcall(fn) __define_initcall("1",fn,1)
195 #define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
196 #define postcore_initcall(fn) __define_initcall("2",fn,2)
197 #define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
198 #define arch_initcall(fn) __define_initcall("3",fn,3)
199 #define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
200 #define subsys_initcall(fn) __define_initcall("4",fn,4)
201 #define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
202 #define fs_initcall(fn) __define_initcall("5",fn,5)
203 #define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
204 #define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
205 #define device_initcall(fn) __define_initcall("6",fn,6)
206 #define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
207 #define late_initcall(fn) __define_initcall("7",fn,7)
208 #define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
210 #define __initcall(fn) device_initcall(fn)
212 #define __exitcall(fn) \
213 static exitcall_t __exitcall_##fn __exit_call = fn
215 #define console_initcall(fn) \
216 static initcall_t __initcall_##fn \
217 __used __section(.con_initcall.init) = fn
219 #define security_initcall(fn) \
220 static initcall_t __initcall_##fn \
221 __used __section(.security_initcall.init) = fn
223 struct obs_kernel_param {
225 int (*setup_func)(char *);
230 * Only for really core code. See moduleparam.h for the normal way.
232 * Force the alignment so the compiler doesn't space elements of the
233 * obs_kernel_param "array" too far apart in .init.setup.
235 #define __setup_param(str, unique_id, fn, early) \
236 static char __setup_str_##unique_id[] __initdata __aligned(1) = str; \
237 static struct obs_kernel_param __setup_##unique_id \
238 __used __section(.init.setup) \
239 __attribute__((aligned((sizeof(long))))) \
240 = { __setup_str_##unique_id, fn, early }
242 #define __setup(str, fn) \
243 __setup_param(str, fn, fn, 0)
245 /* NOTE: fn is as per module_param, not __setup! Emits warning if fn
246 * returns non-zero. */
247 #define early_param(str, fn) \
248 __setup_param(str, fn, fn, 1)
250 /* Relies on boot_command_line being set */
251 void __init parse_early_param(void);
252 void __init parse_early_options(char *cmdline);
253 #endif /* __ASSEMBLY__ */
256 * module_init() - driver initialization entry point
257 * @x: function to be run at kernel boot time or module insertion
259 * module_init() will either be called during do_initcalls() (if
260 * builtin) or at module insertion time (if a module). There can only
263 #define module_init(x) __initcall(x);
266 * module_exit() - driver exit entry point
267 * @x: function to be run when driver is removed
269 * module_exit() will wrap the driver clean-up code
270 * with cleanup_module() when used with rmmod when
271 * the driver is a module. If the driver is statically
272 * compiled into the kernel, module_exit() has no effect.
273 * There can only be one per module.
275 #define module_exit(x) __exitcall(x);
279 /* Don't use these in modules, but some people do... */
280 #define core_initcall(fn) module_init(fn)
281 #define postcore_initcall(fn) module_init(fn)
282 #define arch_initcall(fn) module_init(fn)
283 #define subsys_initcall(fn) module_init(fn)
284 #define fs_initcall(fn) module_init(fn)
285 #define device_initcall(fn) module_init(fn)
286 #define late_initcall(fn) module_init(fn)
288 #define security_initcall(fn) module_init(fn)
290 /* Each module must use one module_init(). */
291 #define module_init(initfn) \
292 static inline initcall_t __inittest(void) \
294 int init_module(void) __attribute__((alias(#initfn)));
296 /* This is only required if you want to be unloadable. */
297 #define module_exit(exitfn) \
298 static inline exitcall_t __exittest(void) \
300 void cleanup_module(void) __attribute__((alias(#exitfn)));
302 #define __setup_param(str, unique_id, fn) /* nothing */
303 #define __setup(str, func) /* nothing */
306 /* Data marked not to be saved by software suspend */
307 #define __nosavedata __section(.data.nosave)
309 /* This means "can be init if no module support, otherwise module load
311 #ifdef CONFIG_MODULES
312 #define __init_or_module
313 #define __initdata_or_module
315 #define __init_or_module __init
316 #define __initdata_or_module __initdata
317 #endif /*CONFIG_MODULES*/
319 /* Functions marked as __devexit may be discarded at kernel link time, depending
320 on config options. Newer versions of binutils detect references from
321 retained sections to discarded sections and flag an error. Pointers to
322 __devexit functions must use __devexit_p(function_name), the wrapper will
323 insert either the function_name or NULL, depending on the config options.
325 #if defined(MODULE) || defined(CONFIG_HOTPLUG)
326 #define __devexit_p(x) x
328 #define __devexit_p(x) NULL
332 #define __exit_p(x) x
334 #define __exit_p(x) NULL
337 #endif /* _LINUX_INIT_H */