init,mm: move mm_init() to mm/mm_init.c and rename it to mm_core_init()

Make mm_init() a part of mm/ codebase.  mm_core_init() better describes
what the function does and does not clash with mm_init() in kernel/fork.c

Link: https://lkml.kernel.org/r/20230321170513.2401534-8-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/mm.h

@@ -38,6 +38,7 @@ struct pt_regs;
 
 extern int sysctl_page_lock_unfairness;
 
+void mm_core_init(void);
 void init_mm_internals(void);
 
 #ifndef CONFIG_NUMA		/* Don't use mapnrs, do it properly */

init/main.c

@@ -807,73 +807,6 @@ static inline void initcall_debug_enable(void)
 }
 #endif
 
-/* Report memory auto-initialization states for this boot. */
-static void __init report_meminit(void)
-{
-	const char *stack;
-
-	if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
-		stack = "all(pattern)";
-	else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
-		stack = "all(zero)";
-	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
-		stack = "byref_all(zero)";
-	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
-		stack = "byref(zero)";
-	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
-		stack = "__user(zero)";
-	else
-		stack = "off";
-
-	pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
-		stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
-		want_init_on_free() ? "on" : "off");
-	if (want_init_on_free())
-		pr_info("mem auto-init: clearing system memory may take some time...\n");
-}
-
-/*
- * Set up kernel memory allocators
- */
-static void __init mm_init(void)
-{
-	/* Initializations relying on SMP setup */
-	build_all_zonelists(NULL);
-	page_alloc_init_cpuhp();
-
-	/*
-	 * page_ext requires contiguous pages,
-	 * bigger than MAX_ORDER unless SPARSEMEM.
-	 */
-	page_ext_init_flatmem();
-	init_mem_debugging_and_hardening();
-	kfence_alloc_pool();
-	report_meminit();
-	kmsan_init_shadow();
-	stack_depot_early_init();
-	mem_init();
-	mem_init_print_info();
-	kmem_cache_init();
-	/*
-	 * page_owner must be initialized after buddy is ready, and also after
-	 * slab is ready so that stack_depot_init() works properly
-	 */
-	page_ext_init_flatmem_late();
-	kmemleak_init();
-	pgtable_init();
-	debug_objects_mem_init();
-	vmalloc_init();
-	/* If no deferred init page_ext now, as vmap is fully initialized */
-	if (!deferred_struct_pages)
-		page_ext_init();
-	/* Should be run before the first non-init thread is created */
-	init_espfix_bsp();
-	/* Should be run after espfix64 is set up. */
-	pti_init();
-	kmsan_init_runtime();
-	mm_cache_init();
-}
-
 #ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
 			   randomize_kstack_offset);
@@ -997,13 +930,13 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
 
 	/*
 	 * These use large bootmem allocations and must precede
-	 * kmem_cache_init()
+	 * initalization of page allocator
 	 */
 	setup_log_buf(0);
 	vfs_caches_init_early();
 	sort_main_extable();
 	trap_init();
-	mm_init();
+	mm_core_init();
 	poking_init();
 	ftrace_init();
 

mm/mm_init.c

@@ -20,9 +20,15 @@
 #include <linux/nmi.h>
 #include <linux/buffer_head.h>
 #include <linux/kmemleak.h>
+#include <linux/kfence.h>
+#include <linux/page_ext.h>
+#include <linux/pti.h>
+#include <linux/pgtable.h>
 #include "internal.h"
 #include "shuffle.h"
 
+#include <asm/setup.h>
+
 #ifdef CONFIG_DEBUG_MEMORY_INIT
 int __meminitdata mminit_loglevel;
 
@@ -2524,3 +2530,70 @@ void __init memblock_free_pages(struct page *page, unsigned long pfn,
 	}
 	__free_pages_core(page, order);
 }
+
+/* Report memory auto-initialization states for this boot. */
+static void __init report_meminit(void)
+{
+	const char *stack;
+
+	if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
+		stack = "all(pattern)";
+	else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
+		stack = "all(zero)";
+	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
+		stack = "byref_all(zero)";
+	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
+		stack = "byref(zero)";
+	else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
+		stack = "__user(zero)";
+	else
+		stack = "off";
+
+	pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
+		stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
+		want_init_on_free() ? "on" : "off");
+	if (want_init_on_free())
+		pr_info("mem auto-init: clearing system memory may take some time...\n");
+}
+
+/*
+ * Set up kernel memory allocators
+ */
+void __init mm_core_init(void)
+{
+	/* Initializations relying on SMP setup */
+	build_all_zonelists(NULL);
+	page_alloc_init_cpuhp();
+
+	/*
+	 * page_ext requires contiguous pages,
+	 * bigger than MAX_ORDER unless SPARSEMEM.
+	 */
+	page_ext_init_flatmem();
+	init_mem_debugging_and_hardening();
+	kfence_alloc_pool();
+	report_meminit();
+	kmsan_init_shadow();
+	stack_depot_early_init();
+	mem_init();
+	mem_init_print_info();
+	kmem_cache_init();
+	/*
+	 * page_owner must be initialized after buddy is ready, and also after
+	 * slab is ready so that stack_depot_init() works properly
+	 */
+	page_ext_init_flatmem_late();
+	kmemleak_init();
+	pgtable_init();
+	debug_objects_mem_init();
+	vmalloc_init();
+	/* If no deferred init page_ext now, as vmap is fully initialized */
+	if (!deferred_struct_pages)
+		page_ext_init();
+	/* Should be run before the first non-init thread is created */
+	init_espfix_bsp();
+	/* Should be run after espfix64 is set up. */
+	pti_init();
+	kmsan_init_runtime();
+	mm_cache_init();
+}