init/modpost: conditionally check section mismatch to __meminit*

This reverts commit eb8f689046 ("Use separate sections for __dev/
_cpu/__mem code/data").

Check section mismatch to __meminit* only when CONFIG_MEMORY_HOTPLUG=n.

With this change, the linker script and modpost become simpler, and we
can get rid of the __ref annotations from the memory hotplug code.

[sfr@canb.auug.org.au: remove MEM_KEEP from arch/powerpc/kernel/vmlinux.lds.S]
  Link: https://lkml.kernel.org/r/20240710093213.2aefb25f@canb.auug.org.au
Link: https://lkml.kernel.org/r/20240706160511.2331061-2-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/asm-generic/vmlinux.lds.h

@@ -141,14 +141,6 @@
  * often happens at runtime)
  */
 
-#if defined(CONFIG_MEMORY_HOTPLUG)
-#define MEM_KEEP(sec)    *(.mem##sec)
-#define MEM_DISCARD(sec)
-#else
-#define MEM_KEEP(sec)
-#define MEM_DISCARD(sec) *(.mem##sec)
-#endif
-
 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
 #define KEEP_PATCHABLE		KEEP(*(__patchable_function_entries))
 #define PATCHABLE_DISCARDS
@@ -357,7 +349,6 @@
 	*(.data..decrypted)						\
 	*(.ref.data)							\
 	*(.data..shared_aligned) /* percpu related */			\
-	MEM_KEEP(init.data*)						\
 	*(.data.unlikely)						\
 	__start_once = .;						\
 	*(.data.once)							\
@@ -542,7 +533,6 @@
 	/* __*init sections */						\
 	__init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) {		\
 		*(.ref.rodata)						\
-		MEM_KEEP(init.rodata)					\
 	}								\
 									\
 	/* Built-in module parameters. */				\
@@ -593,8 +583,7 @@
 		*(.text.unknown .text.unknown.*)			\
 		NOINSTR_TEXT						\
 		*(.ref.text)						\
-		*(.text.asan.* .text.tsan.*)				\
-	MEM_KEEP(init.text*)						\
+		*(.text.asan.* .text.tsan.*)
 
 
 /* sched.text is aling to function alignment to secure we have same
@@ -701,7 +690,6 @@
 #define INIT_DATA							\
 	KEEP(*(SORT(___kentry+*)))					\
 	*(.init.data .init.data.*)					\
-	MEM_DISCARD(init.data*)						\
 	KERNEL_CTORS()							\
 	MCOUNT_REC()							\
 	*(.init.rodata .init.rodata.*)					\
@@ -709,7 +697,6 @@
 	TRACE_SYSCALLS()						\
 	KPROBE_BLACKLIST()						\
 	ERROR_INJECT_WHITELIST()					\
-	MEM_DISCARD(init.rodata)					\
 	CLK_OF_TABLES()							\
 	RESERVEDMEM_OF_TABLES()						\
 	TIMER_OF_TABLES()						\
@@ -727,8 +714,7 @@
 
 #define INIT_TEXT							\
 	*(.init.text .init.text.*)					\
-	*(.text.startup)						\
-	MEM_DISCARD(init.text*)
+	*(.text.startup)
 
 #define EXIT_DATA							\
 	*(.exit.data .exit.data.*)					\