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 /* Used for MEMORY_HOTPLUG */
102 #define __meminit __section(.meminit.text) __cold notrace
103 #define __meminitdata __section(.meminit.data)
104 #define __meminitconst __constsection(.meminit.rodata)
105 #define __memexit __section(.memexit.text) __exitused __cold notrace
106 #define __memexitdata __section(.memexit.data)
107 #define __memexitconst __constsection(.memexit.rodata)
109 /* For assembly routines */
110 #define __HEAD .section ".head.text","ax"
111 #define __INIT .section ".init.text","ax"
112 #define __FINIT .previous
114 #define __INITDATA .section ".init.data","aw",%progbits
115 #define __INITRODATA .section ".init.rodata","a",%progbits
116 #define __FINITDATA .previous
118 #define __MEMINIT .section ".meminit.text", "ax"
119 #define __MEMINITDATA .section ".meminit.data", "aw"
120 #define __MEMINITRODATA .section ".meminit.rodata", "a"
122 /* silence warnings when references are OK */
123 #define __REF .section ".ref.text", "ax"
124 #define __REFDATA .section ".ref.data", "aw"
125 #define __REFCONST .section ".ref.rodata", "a"
129 * Used for initialization calls..
131 typedef int (*initcall_t)(void);
132 typedef void (*exitcall_t)(void);
134 extern initcall_t __con_initcall_start[], __con_initcall_end[];
135 extern initcall_t __security_initcall_start[], __security_initcall_end[];
137 /* Used for contructor calls. */
138 typedef void (*ctor_fn_t)(void);
140 /* Defined in init/main.c */
141 extern int do_one_initcall(initcall_t fn);
142 extern char __initdata boot_command_line[];
143 extern char *saved_command_line;
144 extern unsigned int reset_devices;
146 /* used by init/main.c */
147 void setup_arch(char **);
148 void prepare_namespace(void);
149 void __init load_default_modules(void);
150 int __init init_rootfs(void);
152 #ifdef CONFIG_DEBUG_RODATA
153 void mark_rodata_ro(void);
156 extern void (*late_time_init)(void);
158 extern bool initcall_debug;
167 * initcalls are now grouped by functionality into separate
168 * subsections. Ordering inside the subsections is determined
170 * For backwards compatibility, initcall() puts the call in
171 * the device init subsection.
173 * The `id' arg to __define_initcall() is needed so that multiple initcalls
174 * can point at the same handler without causing duplicate-symbol build errors.
176 * Initcalls are run by placing pointers in initcall sections that the
177 * kernel iterates at runtime. The linker can do dead code / data elimination
178 * and remove that completely, so the initcall sections have to be marked
179 * as KEEP() in the linker script.
182 #define __define_initcall(fn, id) \
183 static initcall_t __initcall_##fn##id __used \
184 __attribute__((__section__(".initcall" #id ".init"))) = fn;
187 * Early initcalls run before initializing SMP.
189 * Only for built-in code, not modules.
191 #define early_initcall(fn) __define_initcall(fn, early)
194 * A "pure" initcall has no dependencies on anything else, and purely
195 * initializes variables that couldn't be statically initialized.
197 * This only exists for built-in code, not for modules.
198 * Keep main.c:initcall_level_names[] in sync.
200 #define pure_initcall(fn) __define_initcall(fn, 0)
202 #define core_initcall(fn) __define_initcall(fn, 1)
203 #define core_initcall_sync(fn) __define_initcall(fn, 1s)
204 #define postcore_initcall(fn) __define_initcall(fn, 2)
205 #define postcore_initcall_sync(fn) __define_initcall(fn, 2s)
206 #define arch_initcall(fn) __define_initcall(fn, 3)
207 #define arch_initcall_sync(fn) __define_initcall(fn, 3s)
208 #define subsys_initcall(fn) __define_initcall(fn, 4)
209 #define subsys_initcall_sync(fn) __define_initcall(fn, 4s)
210 #define fs_initcall(fn) __define_initcall(fn, 5)
211 #define fs_initcall_sync(fn) __define_initcall(fn, 5s)
212 #define rootfs_initcall(fn) __define_initcall(fn, rootfs)
213 #define device_initcall(fn) __define_initcall(fn, 6)
214 #define device_initcall_sync(fn) __define_initcall(fn, 6s)
215 #define late_initcall(fn) __define_initcall(fn, 7)
216 #define late_initcall_sync(fn) __define_initcall(fn, 7s)
218 #define __initcall(fn) device_initcall(fn)
220 #define __exitcall(fn) \
221 static exitcall_t __exitcall_##fn __exit_call = fn
223 #define console_initcall(fn) \
224 static initcall_t __initcall_##fn \
225 __used __section(.con_initcall.init) = fn
227 #define security_initcall(fn) \
228 static initcall_t __initcall_##fn \
229 __used __section(.security_initcall.init) = fn
231 struct obs_kernel_param {
233 int (*setup_func)(char *);
238 * Only for really core code. See moduleparam.h for the normal way.
240 * Force the alignment so the compiler doesn't space elements of the
241 * obs_kernel_param "array" too far apart in .init.setup.
243 #define __setup_param(str, unique_id, fn, early) \
244 static const char __setup_str_##unique_id[] __initconst \
245 __aligned(1) = str; \
246 static struct obs_kernel_param __setup_##unique_id \
247 __used __section(.init.setup) \
248 __attribute__((aligned((sizeof(long))))) \
249 = { __setup_str_##unique_id, fn, early }
251 #define __setup(str, fn) \
252 __setup_param(str, fn, fn, 0)
255 * NOTE: fn is as per module_param, not __setup!
256 * Emits warning if fn returns non-zero.
258 #define early_param(str, fn) \
259 __setup_param(str, fn, fn, 1)
261 #define early_param_on_off(str_on, str_off, var, config) \
263 int var = IS_ENABLED(config); \
265 static int __init parse_##var##_on(char *arg) \
270 __setup_param(str_on, parse_##var##_on, parse_##var##_on, 1); \
272 static int __init parse_##var##_off(char *arg) \
277 __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1)
279 /* Relies on boot_command_line being set */
280 void __init parse_early_param(void);
281 void __init parse_early_options(char *cmdline);
282 #endif /* __ASSEMBLY__ */
286 #define __setup_param(str, unique_id, fn) /* nothing */
287 #define __setup(str, func) /* nothing */
290 /* Data marked not to be saved by software suspend */
291 #define __nosavedata __section(.data..nosave)
294 #define __exit_p(x) x
296 #define __exit_p(x) NULL
299 #endif /* _LINUX_INIT_H */