4 #include <linux/compiler.h>
6 /* These macros are used to mark some functions or
7 * initialized data (doesn't apply to uninitialized data)
8 * as `initialization' functions. The kernel can take this
9 * as hint that the function is used only during the initialization
10 * phase and free up used memory resources after
15 * You should add __init immediately before the function name, like:
17 * static void __init initme(int x, int y)
19 * extern int z; z = x * y;
22 * If the function has a prototype somewhere, you can also add
23 * __init between closing brace of the prototype and semicolon:
25 * extern int initialize_foobar_device(int, int, int) __init;
27 * For initialized data:
28 * You should insert __initdata between the variable name and equal
29 * sign followed by value, e.g.:
31 * static int init_variable __initdata = 0;
32 * static char linux_logo[] __initdata = { 0x32, 0x36, ... };
34 * Don't forget to initialize data not at file scope, i.e. within a function,
35 * as gcc otherwise puts the data into the bss section and not into the init
38 * Also note, that this data cannot be "const".
41 /* These are for everybody (although not all archs will actually
42 discard it in modules) */
43 #define __init __section(.init.text) __cold
44 #define __initdata __section(.init.data)
45 #define __exitdata __section(.exit.data)
46 #define __exit_call __used __section(.exitcall.exit)
48 /* modpost check for section mismatches during the kernel build.
49 * A section mismatch happens when there are references from a
50 * code or data section to an init section (both code or data).
51 * The init sections are (for most archs) discarded by the kernel
52 * when early init has completed so all such references are potential bugs.
53 * For exit sections the same issue exists.
54 * The following markers are used for the cases where the reference to
55 * the *init / *exit section (code or data) is valid and will teach
56 * modpost not to issue a warning.
57 * The markers follow same syntax rules as __init / __initdata. */
58 #define __ref __section(.ref.text) noinline
59 #define __refdata __section(.ref.data)
60 #define __refconst __section(.ref.rodata)
62 /* backward compatibility note
63 * A few places hardcode the old section names:
67 * They should be converted to use the defines from this file
70 /* compatibility defines */
71 #define __init_refok __ref
72 #define __initdata_refok __refdata
73 #define __exit_refok __ref
79 #define __exitused __used
82 #define __exit __section(.exit.text) __exitused __cold
84 /* Used for HOTPLUG */
85 #define __devinit __section(.devinit.text) __cold
86 #define __devinitdata __section(.devinit.data)
87 #define __devinitconst __section(.devinit.rodata)
88 #define __devexit __section(.devexit.text) __exitused __cold
89 #define __devexitdata __section(.devexit.data)
90 #define __devexitconst __section(.devexit.rodata)
92 /* Used for HOTPLUG_CPU */
93 #define __cpuinit __section(.cpuinit.text) __cold
94 #define __cpuinitdata __section(.cpuinit.data)
95 #define __cpuinitconst __section(.cpuinit.rodata)
96 #define __cpuexit __section(.cpuexit.text) __exitused __cold
97 #define __cpuexitdata __section(.cpuexit.data)
98 #define __cpuexitconst __section(.cpuexit.rodata)
100 /* Used for MEMORY_HOTPLUG */
101 #define __meminit __section(.meminit.text) __cold
102 #define __meminitdata __section(.meminit.data)
103 #define __meminitconst __section(.meminit.rodata)
104 #define __memexit __section(.memexit.text) __exitused __cold
105 #define __memexitdata __section(.memexit.data)
106 #define __memexitconst __section(.memexit.rodata)
108 /* For assembly routines */
109 #define __INIT .section ".init.text","ax"
110 #define __FINIT .previous
112 #define __INITDATA .section ".init.data","aw"
114 #define __DEVINIT .section ".devinit.text", "ax"
115 #define __DEVINITDATA .section ".devinit.data", "aw"
117 #define __CPUINIT .section ".cpuinit.text", "ax"
118 #define __CPUINITDATA .section ".cpuinit.data", "aw"
120 #define __MEMINIT .section ".meminit.text", "ax"
121 #define __MEMINITDATA .section ".meminit.data", "aw"
123 /* silence warnings when references are OK */
124 #define __REF .section ".ref.text", "ax"
125 #define __REFDATA .section ".ref.data", "aw"
126 #define __REFCONST .section ".ref.rodata", "aw"
130 * Used for initialization calls..
132 typedef int (*initcall_t)(void);
133 typedef void (*exitcall_t)(void);
135 extern initcall_t __con_initcall_start[], __con_initcall_end[];
136 extern initcall_t __security_initcall_start[], __security_initcall_end[];
138 /* Defined in init/main.c */
139 extern char __initdata boot_command_line[];
140 extern char *saved_command_line;
141 extern unsigned int reset_devices;
143 /* used by init/main.c */
144 void setup_arch(char **);
145 void prepare_namespace(void);
153 /* initcalls are now grouped by functionality into separate
154 * subsections. Ordering inside the subsections is determined
156 * For backwards compatibility, initcall() puts the call in
157 * the device init subsection.
159 * The `id' arg to __define_initcall() is needed so that multiple initcalls
160 * can point at the same handler without causing duplicate-symbol build errors.
163 #define __define_initcall(level,fn,id) \
164 static initcall_t __initcall_##fn##id __used \
165 __attribute__((__section__(".initcall" level ".init"))) = fn
168 * A "pure" initcall has no dependencies on anything else, and purely
169 * initializes variables that couldn't be statically initialized.
171 * This only exists for built-in code, not for modules.
173 #define pure_initcall(fn) __define_initcall("0",fn,0)
175 #define core_initcall(fn) __define_initcall("1",fn,1)
176 #define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
177 #define postcore_initcall(fn) __define_initcall("2",fn,2)
178 #define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
179 #define arch_initcall(fn) __define_initcall("3",fn,3)
180 #define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
181 #define subsys_initcall(fn) __define_initcall("4",fn,4)
182 #define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
183 #define fs_initcall(fn) __define_initcall("5",fn,5)
184 #define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
185 #define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
186 #define device_initcall(fn) __define_initcall("6",fn,6)
187 #define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
188 #define late_initcall(fn) __define_initcall("7",fn,7)
189 #define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
191 #define __initcall(fn) device_initcall(fn)
193 #define __exitcall(fn) \
194 static exitcall_t __exitcall_##fn __exit_call = fn
196 #define console_initcall(fn) \
197 static initcall_t __initcall_##fn \
198 __used __section(.con_initcall.init) = fn
200 #define security_initcall(fn) \
201 static initcall_t __initcall_##fn \
202 __used __section(.security_initcall.init) = fn
204 struct obs_kernel_param {
206 int (*setup_func)(char *);
211 * Only for really core code. See moduleparam.h for the normal way.
213 * Force the alignment so the compiler doesn't space elements of the
214 * obs_kernel_param "array" too far apart in .init.setup.
216 #define __setup_param(str, unique_id, fn, early) \
217 static char __setup_str_##unique_id[] __initdata __aligned(1) = str; \
218 static struct obs_kernel_param __setup_##unique_id \
219 __used __section(.init.setup) \
220 __attribute__((aligned((sizeof(long))))) \
221 = { __setup_str_##unique_id, fn, early }
223 #define __setup_null_param(str, unique_id) \
224 __setup_param(str, unique_id, NULL, 0)
226 #define __setup(str, fn) \
227 __setup_param(str, fn, fn, 0)
229 /* NOTE: fn is as per module_param, not __setup! Emits warning if fn
230 * returns non-zero. */
231 #define early_param(str, fn) \
232 __setup_param(str, fn, fn, 1)
234 /* Relies on boot_command_line being set */
235 void __init parse_early_param(void);
236 #endif /* __ASSEMBLY__ */
239 * module_init() - driver initialization entry point
240 * @x: function to be run at kernel boot time or module insertion
242 * module_init() will either be called during do_initcalls() (if
243 * builtin) or at module insertion time (if a module). There can only
246 #define module_init(x) __initcall(x);
249 * module_exit() - driver exit entry point
250 * @x: function to be run when driver is removed
252 * module_exit() will wrap the driver clean-up code
253 * with cleanup_module() when used with rmmod when
254 * the driver is a module. If the driver is statically
255 * compiled into the kernel, module_exit() has no effect.
256 * There can only be one per module.
258 #define module_exit(x) __exitcall(x);
262 /* Don't use these in modules, but some people do... */
263 #define core_initcall(fn) module_init(fn)
264 #define postcore_initcall(fn) module_init(fn)
265 #define arch_initcall(fn) module_init(fn)
266 #define subsys_initcall(fn) module_init(fn)
267 #define fs_initcall(fn) module_init(fn)
268 #define device_initcall(fn) module_init(fn)
269 #define late_initcall(fn) module_init(fn)
271 #define security_initcall(fn) module_init(fn)
273 /* These macros create a dummy inline: gcc 2.9x does not count alias
274 as usage, hence the `unused function' warning when __init functions
275 are declared static. We use the dummy __*_module_inline functions
276 both to kill the warning and check the type of the init/cleanup
279 /* Each module must use one module_init(), or one no_module_init */
280 #define module_init(initfn) \
281 static inline initcall_t __inittest(void) \
283 int init_module(void) __attribute__((alias(#initfn)));
285 /* This is only required if you want to be unloadable. */
286 #define module_exit(exitfn) \
287 static inline exitcall_t __exittest(void) \
289 void cleanup_module(void) __attribute__((alias(#exitfn)));
291 #define __setup_param(str, unique_id, fn) /* nothing */
292 #define __setup_null_param(str, unique_id) /* nothing */
293 #define __setup(str, func) /* nothing */
296 /* Data marked not to be saved by software suspend */
297 #define __nosavedata __section(.data.nosave)
299 /* This means "can be init if no module support, otherwise module load
301 #ifdef CONFIG_MODULES
302 #define __init_or_module
303 #define __initdata_or_module
305 #define __init_or_module __init
306 #define __initdata_or_module __initdata
307 #endif /*CONFIG_MODULES*/
309 /* Functions marked as __devexit may be discarded at kernel link time, depending
310 on config options. Newer versions of binutils detect references from
311 retained sections to discarded sections and flag an error. Pointers to
312 __devexit functions must use __devexit_p(function_name), the wrapper will
313 insert either the function_name or NULL, depending on the config options.
315 #if defined(MODULE) || defined(CONFIG_HOTPLUG)
316 #define __devexit_p(x) x
318 #define __devexit_p(x) NULL
322 #define __exit_p(x) x
324 #define __exit_p(x) NULL
327 #endif /* _LINUX_INIT_H */