| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_INIT_H |
| #define _LINUX_INIT_H |
| |
| #include <linux/compiler.h> |
| #include <linux/types.h> |
| |
| /* Built-in __init functions needn't be compiled with retpoline */ |
| #if defined(__noretpoline) && !defined(MODULE) |
| #define __noinitretpoline __noretpoline |
| #else |
| #define __noinitretpoline |
| #endif |
| |
| /* These macros are used to mark some functions or |
| * initialized data (doesn't apply to uninitialized data) |
| * as `initialization' functions. The kernel can take this |
| * as hint that the function is used only during the initialization |
| * phase and free up used memory resources after |
| * |
| * Usage: |
| * For functions: |
| * |
| * You should add __init immediately before the function name, like: |
| * |
| * static void __init initme(int x, int y) |
| * { |
| * extern int z; z = x * y; |
| * } |
| * |
| * If the function has a prototype somewhere, you can also add |
| * __init between closing brace of the prototype and semicolon: |
| * |
| * extern int initialize_foobar_device(int, int, int) __init; |
| * |
| * For initialized data: |
| * You should insert __initdata or __initconst between the variable name |
| * and equal sign followed by value, e.g.: |
| * |
| * static int init_variable __initdata = 0; |
| * static const char linux_logo[] __initconst = { 0x32, 0x36, ... }; |
| * |
| * Don't forget to initialize data not at file scope, i.e. within a function, |
| * as gcc otherwise puts the data into the bss section and not into the init |
| * section. |
| */ |
| |
| /* These are for everybody (although not all archs will actually |
| discard it in modules) */ |
| #define __init __section(".init.text") __cold __latent_entropy __noinitretpoline |
| #define __initdata __section(".init.data") |
| #define __initconst __section(".init.rodata") |
| #define __exitdata __section(".exit.data") |
| #define __exit_call __used __section(".exitcall.exit") |
| |
| /* |
| * modpost check for section mismatches during the kernel build. |
| * A section mismatch happens when there are references from a |
| * code or data section to an init section (both code or data). |
| * The init sections are (for most archs) discarded by the kernel |
| * when early init has completed so all such references are potential bugs. |
| * For exit sections the same issue exists. |
| * |
| * The following markers are used for the cases where the reference to |
| * the *init / *exit section (code or data) is valid and will teach |
| * modpost not to issue a warning. Intended semantics is that a code or |
| * data tagged __ref* can reference code or data from init section without |
| * producing a warning (of course, no warning does not mean code is |
| * correct, so optimally document why the __ref is needed and why it's OK). |
| * |
| * The markers follow same syntax rules as __init / __initdata. |
| */ |
| #define __ref __section(".ref.text") noinline |
| #define __refdata __section(".ref.data") |
| #define __refconst __section(".ref.rodata") |
| |
| #ifdef MODULE |
| #define __exitused |
| #else |
| #define __exitused __used |
| #endif |
| |
| #define __exit __section(".exit.text") __exitused __cold notrace |
| |
| /* Used for MEMORY_HOTPLUG */ |
| #define __meminit __section(".meminit.text") __cold notrace \ |
| __latent_entropy |
| #define __meminitdata __section(".meminit.data") |
| #define __meminitconst __section(".meminit.rodata") |
| #define __memexit __section(".memexit.text") __exitused __cold notrace |
| #define __memexitdata __section(".memexit.data") |
| #define __memexitconst __section(".memexit.rodata") |
| |
| /* For assembly routines */ |
| #define __HEAD .section ".head.text","ax" |
| #define __INIT .section ".init.text","ax" |
| #define __FINIT .previous |
| |
| #define __INITDATA .section ".init.data","aw",%progbits |
| #define __INITRODATA .section ".init.rodata","a",%progbits |
| #define __FINITDATA .previous |
| |
| #define __MEMINIT .section ".meminit.text", "ax" |
| #define __MEMINITDATA .section ".meminit.data", "aw" |
| #define __MEMINITRODATA .section ".meminit.rodata", "a" |
| |
| /* silence warnings when references are OK */ |
| #define __REF .section ".ref.text", "ax" |
| #define __REFDATA .section ".ref.data", "aw" |
| #define __REFCONST .section ".ref.rodata", "a" |
| |
| #ifndef __ASSEMBLY__ |
| /* |
| * Used for initialization calls.. |
| */ |
| typedef int (*initcall_t)(void); |
| typedef void (*exitcall_t)(void); |
| |
| #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
| typedef int initcall_entry_t; |
| |
| static inline initcall_t initcall_from_entry(initcall_entry_t *entry) |
| { |
| return offset_to_ptr(entry); |
| } |
| #else |
| typedef initcall_t initcall_entry_t; |
| |
| static inline initcall_t initcall_from_entry(initcall_entry_t *entry) |
| { |
| return *entry; |
| } |
| #endif |
| |
| extern initcall_entry_t __con_initcall_start[], __con_initcall_end[]; |
| |
| /* Used for contructor calls. */ |
| typedef void (*ctor_fn_t)(void); |
| |
| struct file_system_type; |
| |
| /* Defined in init/main.c */ |
| extern int do_one_initcall(initcall_t fn); |
| extern char __initdata boot_command_line[]; |
| extern char *saved_command_line; |
| extern unsigned int reset_devices; |
| |
| /* used by init/main.c */ |
| void setup_arch(char **); |
| void prepare_namespace(void); |
| void __init init_rootfs(void); |
| extern struct file_system_type rootfs_fs_type; |
| |
| #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) |
| extern bool rodata_enabled; |
| #endif |
| #ifdef CONFIG_STRICT_KERNEL_RWX |
| void mark_rodata_ro(void); |
| #endif |
| |
| extern void (*late_time_init)(void); |
| |
| extern bool initcall_debug; |
| |
| #endif |
| |
| #ifndef MODULE |
| |
| #ifndef __ASSEMBLY__ |
| |
| /* |
| * initcalls are now grouped by functionality into separate |
| * subsections. Ordering inside the subsections is determined |
| * by link order. |
| * For backwards compatibility, initcall() puts the call in |
| * the device init subsection. |
| * |
| * The `id' arg to __define_initcall() is needed so that multiple initcalls |
| * can point at the same handler without causing duplicate-symbol build errors. |
| * |
| * Initcalls are run by placing pointers in initcall sections that the |
| * kernel iterates at runtime. The linker can do dead code / data elimination |
| * and remove that completely, so the initcall sections have to be marked |
| * as KEEP() in the linker script. |
| */ |
| |
| /* Format: <modname>__<counter>_<line>_<fn> */ |
| #define __initcall_id(fn) \ |
| __PASTE(__KBUILD_MODNAME, \ |
| __PASTE(__, \ |
| __PASTE(__COUNTER__, \ |
| __PASTE(_, \ |
| __PASTE(__LINE__, \ |
| __PASTE(_, fn)))))) |
| |
| /* Format: __<prefix>__<iid><id> */ |
| #define __initcall_name(prefix, __iid, id) \ |
| __PASTE(__, \ |
| __PASTE(prefix, \ |
| __PASTE(__, \ |
| __PASTE(__iid, id)))) |
| |
| #ifdef CONFIG_LTO_CLANG |
| /* |
| * With LTO, the compiler doesn't necessarily obey link order for |
| * initcalls. In order to preserve the correct order, we add each |
| * variable into its own section and generate a linker script (in |
| * scripts/link-vmlinux.sh) to specify the order of the sections. |
| */ |
| #define __initcall_section(__sec, __iid) \ |
| #__sec ".init.." #__iid |
| |
| /* |
| * With LTO, the compiler can rename static functions to avoid |
| * global naming collisions. We use a global stub function for |
| * initcalls to create a stable symbol name whose address can be |
| * taken in inline assembly when PREL32 relocations are used. |
| */ |
| #define __initcall_stub(fn, __iid, id) \ |
| __initcall_name(initstub, __iid, id) |
| |
| #define __define_initcall_stub(__stub, fn) \ |
| int __init __stub(void); \ |
| int __init __stub(void) \ |
| { \ |
| return fn(); \ |
| } \ |
| __ADDRESSABLE(__stub) |
| #else |
| #define __initcall_section(__sec, __iid) \ |
| #__sec ".init" |
| |
| #define __initcall_stub(fn, __iid, id) fn |
| |
| #define __define_initcall_stub(__stub, fn) \ |
| __ADDRESSABLE(fn) |
| #endif |
| |
| #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
| #define ____define_initcall(fn, __stub, __name, __sec) \ |
| __define_initcall_stub(__stub, fn) \ |
| asm(".section \"" __sec "\", \"a\" \n" \ |
| __stringify(__name) ": \n" \ |
| ".long " __stringify(__stub) " - . \n" \ |
| ".previous \n"); |
| #else |
| #define ____define_initcall(fn, __unused, __name, __sec) \ |
| static initcall_t __name __used \ |
| __attribute__((__section__(__sec))) = fn; |
| #endif |
| |
| #define __unique_initcall(fn, id, __sec, __iid) \ |
| ____define_initcall(fn, \ |
| __initcall_stub(fn, __iid, id), \ |
| __initcall_name(initcall, __iid, id), \ |
| __initcall_section(__sec, __iid)) |
| |
| #define ___define_initcall(fn, id, __sec) \ |
| __unique_initcall(fn, id, __sec, __initcall_id(fn)) |
| |
| #define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id) |
| |
| /* |
| * Early initcalls run before initializing SMP. |
| * |
| * Only for built-in code, not modules. |
| */ |
| #define early_initcall(fn) __define_initcall(fn, early) |
| |
| /* |
| * A "pure" initcall has no dependencies on anything else, and purely |
| * initializes variables that couldn't be statically initialized. |
| * |
| * This only exists for built-in code, not for modules. |
| * Keep main.c:initcall_level_names[] in sync. |
| */ |
| #define pure_initcall(fn) __define_initcall(fn, 0) |
| |
| #define core_initcall(fn) __define_initcall(fn, 1) |
| #define core_initcall_sync(fn) __define_initcall(fn, 1s) |
| #define postcore_initcall(fn) __define_initcall(fn, 2) |
| #define postcore_initcall_sync(fn) __define_initcall(fn, 2s) |
| #define arch_initcall(fn) __define_initcall(fn, 3) |
| #define arch_initcall_sync(fn) __define_initcall(fn, 3s) |
| #define subsys_initcall(fn) __define_initcall(fn, 4) |
| #define subsys_initcall_sync(fn) __define_initcall(fn, 4s) |
| #define fs_initcall(fn) __define_initcall(fn, 5) |
| #define fs_initcall_sync(fn) __define_initcall(fn, 5s) |
| #define rootfs_initcall(fn) __define_initcall(fn, rootfs) |
| #define device_initcall(fn) __define_initcall(fn, 6) |
| #define device_initcall_sync(fn) __define_initcall(fn, 6s) |
| #define late_initcall(fn) __define_initcall(fn, 7) |
| #define late_initcall_sync(fn) __define_initcall(fn, 7s) |
| |
| #define __initcall(fn) device_initcall(fn) |
| |
| #define __exitcall(fn) \ |
| static exitcall_t __exitcall_##fn __exit_call = fn |
| |
| #define console_initcall(fn) ___define_initcall(fn, con, .con_initcall) |
| |
| struct obs_kernel_param { |
| const char *str; |
| int (*setup_func)(char *); |
| int early; |
| }; |
| |
| /* |
| * Only for really core code. See moduleparam.h for the normal way. |
| * |
| * Force the alignment so the compiler doesn't space elements of the |
| * obs_kernel_param "array" too far apart in .init.setup. |
| */ |
| #define __setup_param(str, unique_id, fn, early) \ |
| static const char __setup_str_##unique_id[] __initconst \ |
| __aligned(1) = str; \ |
| static struct obs_kernel_param __setup_##unique_id \ |
| __used __section(".init.setup") \ |
| __aligned(__alignof__(struct obs_kernel_param)) \ |
| = { __setup_str_##unique_id, fn, early } |
| |
| #define __setup(str, fn) \ |
| __setup_param(str, fn, fn, 0) |
| |
| /* |
| * NOTE: fn is as per module_param, not __setup! |
| * Emits warning if fn returns non-zero. |
| */ |
| #define early_param(str, fn) \ |
| __setup_param(str, fn, fn, 1) |
| |
| #define early_param_on_off(str_on, str_off, var, config) \ |
| \ |
| int var = IS_ENABLED(config); \ |
| \ |
| static int __init parse_##var##_on(char *arg) \ |
| { \ |
| var = 1; \ |
| return 0; \ |
| } \ |
| early_param(str_on, parse_##var##_on); \ |
| \ |
| static int __init parse_##var##_off(char *arg) \ |
| { \ |
| var = 0; \ |
| return 0; \ |
| } \ |
| early_param(str_off, parse_##var##_off) |
| |
| /* Relies on boot_command_line being set */ |
| void __init parse_early_param(void); |
| void __init parse_early_options(char *cmdline); |
| #endif /* __ASSEMBLY__ */ |
| |
| #else /* MODULE */ |
| |
| #define __setup_param(str, unique_id, fn) /* nothing */ |
| #define __setup(str, func) /* nothing */ |
| #endif |
| |
| /* Data marked not to be saved by software suspend */ |
| #define __nosavedata __section(".data..nosave") |
| |
| #ifdef MODULE |
| #define __exit_p(x) x |
| #else |
| #define __exit_p(x) NULL |
| #endif |
| |
| #endif /* _LINUX_INIT_H */ |