1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/compiler.h>
6 #include <linux/types.h>
8 /* Built-in __init functions needn't be compiled with retpoline */
9 #if defined(__noretpoline) && !defined(MODULE)
10 #define __noinitretpoline __noretpoline
12 #define __noinitretpoline
15 /* These macros are used to mark some functions or
16 * initialized data (doesn't apply to uninitialized data)
17 * as `initialization' functions. The kernel can take this
18 * as hint that the function is used only during the initialization
19 * phase and free up used memory resources after
24 * You should add __init immediately before the function name, like:
26 * static void __init initme(int x, int y)
28 * extern int z; z = x * y;
31 * If the function has a prototype somewhere, you can also add
32 * __init between closing brace of the prototype and semicolon:
34 * extern int initialize_foobar_device(int, int, int) __init;
36 * For initialized data:
37 * You should insert __initdata or __initconst between the variable name
38 * and equal sign followed by value, e.g.:
40 * static int init_variable __initdata = 0;
41 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
43 * Don't forget to initialize data not at file scope, i.e. within a function,
44 * as gcc otherwise puts the data into the bss section and not into the init
48 /* These are for everybody (although not all archs will actually
49 discard it in modules) */
50 #define __init __section(.init.text) __cold __inittrace __latent_entropy __noinitretpoline
51 #define __initdata __section(.init.data)
52 #define __initconst __section(.init.rodata)
53 #define __exitdata __section(.exit.data)
54 #define __exit_call __used __section(.exitcall.exit)
57 * modpost check for section mismatches during the kernel build.
58 * A section mismatch happens when there are references from a
59 * code or data section to an init section (both code or data).
60 * The init sections are (for most archs) discarded by the kernel
61 * when early init has completed so all such references are potential bugs.
62 * For exit sections the same issue exists.
64 * The following markers are used for the cases where the reference to
65 * the *init / *exit section (code or data) is valid and will teach
66 * modpost not to issue a warning. Intended semantics is that a code or
67 * data tagged __ref* can reference code or data from init section without
68 * producing a warning (of course, no warning does not mean code is
69 * correct, so optimally document why the __ref is needed and why it's OK).
71 * The markers follow same syntax rules as __init / __initdata.
73 #define __ref __section(.ref.text) noinline
74 #define __refdata __section(.ref.data)
75 #define __refconst __section(.ref.rodata)
79 #define __inittrace notrace
81 #define __exitused __used
85 #define __exit __section(.exit.text) __exitused __cold notrace
87 /* Used for MEMORY_HOTPLUG */
88 #define __meminit __section(.meminit.text) __cold notrace \
90 #define __meminitdata __section(.meminit.data)
91 #define __meminitconst __section(.meminit.rodata)
92 #define __memexit __section(.memexit.text) __exitused __cold notrace
93 #define __memexitdata __section(.memexit.data)
94 #define __memexitconst __section(.memexit.rodata)
96 /* For assembly routines */
97 #define __HEAD .section ".head.text","ax"
98 #define __INIT .section ".init.text","ax"
99 #define __FINIT .previous
101 #define __INITDATA .section ".init.data","aw",%progbits
102 #define __INITRODATA .section ".init.rodata","a",%progbits
103 #define __FINITDATA .previous
105 #define __MEMINIT .section ".meminit.text", "ax"
106 #define __MEMINITDATA .section ".meminit.data", "aw"
107 #define __MEMINITRODATA .section ".meminit.rodata", "a"
109 /* silence warnings when references are OK */
110 #define __REF .section ".ref.text", "ax"
111 #define __REFDATA .section ".ref.data", "aw"
112 #define __REFCONST .section ".ref.rodata", "a"
116 * Used for initialization calls..
118 typedef int (*initcall_t)(void);
119 typedef void (*exitcall_t)(void);
121 extern initcall_t __con_initcall_start[], __con_initcall_end[];
122 extern initcall_t __security_initcall_start[], __security_initcall_end[];
124 /* Used for contructor calls. */
125 typedef void (*ctor_fn_t)(void);
127 /* Defined in init/main.c */
128 extern int do_one_initcall(initcall_t fn);
129 extern char __initdata boot_command_line[];
130 extern char *saved_command_line;
131 extern unsigned int reset_devices;
133 /* used by init/main.c */
134 void setup_arch(char **);
135 void prepare_namespace(void);
136 void __init load_default_modules(void);
137 int __init init_rootfs(void);
139 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
140 extern bool rodata_enabled;
142 #ifdef CONFIG_STRICT_KERNEL_RWX
143 void mark_rodata_ro(void);
146 extern void (*late_time_init)(void);
148 extern bool initcall_debug;
157 * initcalls are now grouped by functionality into separate
158 * subsections. Ordering inside the subsections is determined
160 * For backwards compatibility, initcall() puts the call in
161 * the device init subsection.
163 * The `id' arg to __define_initcall() is needed so that multiple initcalls
164 * can point at the same handler without causing duplicate-symbol build errors.
166 * Initcalls are run by placing pointers in initcall sections that the
167 * kernel iterates at runtime. The linker can do dead code / data elimination
168 * and remove that completely, so the initcall sections have to be marked
169 * as KEEP() in the linker script.
172 #define __define_initcall(fn, id) \
173 static initcall_t __initcall_##fn##id __used \
174 __attribute__((__section__(".initcall" #id ".init"))) = fn;
177 * Early initcalls run before initializing SMP.
179 * Only for built-in code, not modules.
181 #define early_initcall(fn) __define_initcall(fn, early)
184 * A "pure" initcall has no dependencies on anything else, and purely
185 * initializes variables that couldn't be statically initialized.
187 * This only exists for built-in code, not for modules.
188 * Keep main.c:initcall_level_names[] in sync.
190 #define pure_initcall(fn) __define_initcall(fn, 0)
192 #define core_initcall(fn) __define_initcall(fn, 1)
193 #define core_initcall_sync(fn) __define_initcall(fn, 1s)
194 #define postcore_initcall(fn) __define_initcall(fn, 2)
195 #define postcore_initcall_sync(fn) __define_initcall(fn, 2s)
196 #define arch_initcall(fn) __define_initcall(fn, 3)
197 #define arch_initcall_sync(fn) __define_initcall(fn, 3s)
198 #define subsys_initcall(fn) __define_initcall(fn, 4)
199 #define subsys_initcall_sync(fn) __define_initcall(fn, 4s)
200 #define fs_initcall(fn) __define_initcall(fn, 5)
201 #define fs_initcall_sync(fn) __define_initcall(fn, 5s)
202 #define rootfs_initcall(fn) __define_initcall(fn, rootfs)
203 #define device_initcall(fn) __define_initcall(fn, 6)
204 #define device_initcall_sync(fn) __define_initcall(fn, 6s)
205 #define late_initcall(fn) __define_initcall(fn, 7)
206 #define late_initcall_sync(fn) __define_initcall(fn, 7s)
208 #define __initcall(fn) device_initcall(fn)
210 #define __exitcall(fn) \
211 static exitcall_t __exitcall_##fn __exit_call = fn
213 #define console_initcall(fn) \
214 static initcall_t __initcall_##fn \
215 __used __section(.con_initcall.init) = fn
217 #define security_initcall(fn) \
218 static initcall_t __initcall_##fn \
219 __used __section(.security_initcall.init) = fn
221 struct obs_kernel_param {
223 int (*setup_func)(char *);
228 * Only for really core code. See moduleparam.h for the normal way.
230 * Force the alignment so the compiler doesn't space elements of the
231 * obs_kernel_param "array" too far apart in .init.setup.
233 #define __setup_param(str, unique_id, fn, early) \
234 static const char __setup_str_##unique_id[] __initconst \
235 __aligned(1) = str; \
236 static struct obs_kernel_param __setup_##unique_id \
237 __used __section(.init.setup) \
238 __attribute__((aligned((sizeof(long))))) \
239 = { __setup_str_##unique_id, fn, early }
241 #define __setup(str, fn) \
242 __setup_param(str, fn, fn, 0)
245 * NOTE: fn is as per module_param, not __setup!
246 * Emits warning if fn returns non-zero.
248 #define early_param(str, fn) \
249 __setup_param(str, fn, fn, 1)
251 #define early_param_on_off(str_on, str_off, var, config) \
253 int var = IS_ENABLED(config); \
255 static int __init parse_##var##_on(char *arg) \
260 __setup_param(str_on, parse_##var##_on, parse_##var##_on, 1); \
262 static int __init parse_##var##_off(char *arg) \
267 __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1)
269 /* Relies on boot_command_line being set */
270 void __init parse_early_param(void);
271 void __init parse_early_options(char *cmdline);
272 #endif /* __ASSEMBLY__ */
276 #define __setup_param(str, unique_id, fn) /* nothing */
277 #define __setup(str, func) /* nothing */
280 /* Data marked not to be saved by software suspend */
281 #define __nosavedata __section(.data..nosave)
284 #define __exit_p(x) x
286 #define __exit_p(x) NULL
289 #endif /* _LINUX_INIT_H */