module: relocate module_init from init.h to module.h

Modular users will always be users of init functionality, but
users of init functionality are not necessarily always modules.

Hence any functionality like module_init and module_exit would
be more at home in the module.h file.  And module.h should
explicitly include init.h to make the dependency clear.

We've already done all the legwork needed to ensure that this
move does not cause any build regressions due to implicit
header file include assumptions about where module_init lives.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/include/linux/module.h b/include/linux/module.h
index d67b193..3a19c79 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -11,6 +11,7 @@
 #include <linux/compiler.h>
 #include <linux/cache.h>
 #include <linux/kmod.h>
+#include <linux/init.h>
 #include <linux/elf.h>
 #include <linux/stringify.h>
 #include <linux/kobject.h>
@@ -71,6 +72,89 @@ extern struct module_attribute module_uevent;
 extern int init_module(void);
 extern void cleanup_module(void);
 
+#ifndef MODULE
+/**
+ * module_init() - driver initialization entry point
+ * @x: function to be run at kernel boot time or module insertion
+ *
+ * module_init() will either be called during do_initcalls() (if
+ * builtin) or at module insertion time (if a module).  There can only
+ * be one per module.
+ */
+#define module_init(x)	__initcall(x);
+
+/**
+ * module_exit() - driver exit entry point
+ * @x: function to be run when driver is removed
+ *
+ * module_exit() will wrap the driver clean-up code
+ * with cleanup_module() when used with rmmod when
+ * the driver is a module.  If the driver is statically
+ * compiled into the kernel, module_exit() has no effect.
+ * There can only be one per module.
+ */
+#define module_exit(x)	__exitcall(x);
+
+#else /* MODULE */
+
+/*
+ * In most cases loadable modules do not need custom
+ * initcall levels. There are still some valid cases where
+ * a driver may be needed early if built in, and does not
+ * matter when built as a loadable module. Like bus
+ * snooping debug drivers.
+ */
+#define early_initcall(fn)		module_init(fn)
+#define core_initcall(fn)		module_init(fn)
+#define core_initcall_sync(fn)		module_init(fn)
+#define postcore_initcall(fn)		module_init(fn)
+#define postcore_initcall_sync(fn)	module_init(fn)
+#define arch_initcall(fn)		module_init(fn)
+#define subsys_initcall(fn)		module_init(fn)
+#define subsys_initcall_sync(fn)	module_init(fn)
+#define fs_initcall(fn)			module_init(fn)
+#define fs_initcall_sync(fn)		module_init(fn)
+#define rootfs_initcall(fn)		module_init(fn)
+#define device_initcall(fn)		module_init(fn)
+#define device_initcall_sync(fn)	module_init(fn)
+#define late_initcall(fn)		module_init(fn)
+#define late_initcall_sync(fn)		module_init(fn)
+
+#define console_initcall(fn)		module_init(fn)
+#define security_initcall(fn)		module_init(fn)
+
+/* Each module must use one module_init(). */
+#define module_init(initfn)					\
+	static inline initcall_t __inittest(void)		\
+	{ return initfn; }					\
+	int init_module(void) __attribute__((alias(#initfn)));
+
+/* This is only required if you want to be unloadable. */
+#define module_exit(exitfn)					\
+	static inline exitcall_t __exittest(void)		\
+	{ return exitfn; }					\
+	void cleanup_module(void) __attribute__((alias(#exitfn)));
+
+#endif
+
+/* This means "can be init if no module support, otherwise module load
+   may call it." */
+#ifdef CONFIG_MODULES
+#define __init_or_module
+#define __initdata_or_module
+#define __initconst_or_module
+#define __INIT_OR_MODULE	.text
+#define __INITDATA_OR_MODULE	.data
+#define __INITRODATA_OR_MODULE	.section ".rodata","a",%progbits
+#else
+#define __init_or_module __init
+#define __initdata_or_module __initdata
+#define __initconst_or_module __initconst
+#define __INIT_OR_MODULE __INIT
+#define __INITDATA_OR_MODULE __INITDATA
+#define __INITRODATA_OR_MODULE __INITRODATA
+#endif /*CONFIG_MODULES*/
+
 /* Archs provide a method of finding the correct exception table. */
 struct exception_table_entry;