From 8d228fbbce34bcb79d2ece6b828b628bd9b80d7c Mon Sep 17 00:00:00 2001
From: Zhenhua Huang <zhenhuah@codeaurora.org>
Date: Mon, 31 Aug 2020 00:20:35 +0800
Subject: [PATCH] mm: fix the page_owner initializing issue for arm32

arm32 original logic:
1. allocated memory for page_ext(using memblock).
2. invoke the init callback of page_ext_ops like
page_owner(using buddy).
3. initialize buddy.

after this change:
1. allocated memory for page_ext(using memblock).
2. initialize buddy.
3. invoke the init callback of page_ext_ops like
page_owner(using buddy).

with the change, failure/dummy_handle can get its correct value.

Change-Id: I6598481299da115ff4be50bf0e5a61a012d5ac83
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>
---
 include/linux/page_ext.h | 8 ++++++++
 init/main.c              | 2 ++
 mm/page_ext.c            | 8 +++++++-
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
index e01df4271585..00e8988e5a84 100644
--- a/include/linux/page_ext.h
+++ b/include/linux/page_ext.h
@@ -44,8 +44,12 @@ static inline void page_ext_init_flatmem(void)
 {
 }
 extern void page_ext_init(void);
+static inline void page_ext_init_flatmem_late(void)
+{
+}
 #else
 extern void page_ext_init_flatmem(void);
+extern void page_ext_init_flatmem_late(void);
 static inline void page_ext_init(void)
 {
 }
@@ -69,6 +73,10 @@ static inline void page_ext_init(void)
 {
 }
 
+static inline void page_ext_init_flatmem_late(void)
+{
+}
+
 static inline void page_ext_init_flatmem(void)
 {
 }
diff --git a/init/main.c b/init/main.c
index 7942ad3cdb42..ed884e3dfb3b 100644
--- a/init/main.c
+++ b/init/main.c
@@ -541,6 +541,8 @@ static void __init mm_init(void)
 	page_ext_init_flatmem();
 	report_meminit();
 	mem_init();
+	/* page_owner must be initialized after buddy is ready */
+	page_ext_init_flatmem_late();
 	kmem_cache_init();
 	pgtable_init();
 	vmalloc_init();
diff --git a/mm/page_ext.c b/mm/page_ext.c
index aad120123688..9e7f56e45b5a 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -102,6 +102,13 @@ static void __init invoke_init_callbacks(void)
 	}
 }
 
+#if !defined(CONFIG_SPARSEMEM)
+void __init page_ext_init_flatmem_late(void)
+{
+	invoke_init_callbacks();
+}
+#endif
+
 static unsigned long get_entry_size(void)
 {
 	return sizeof(struct page_ext) + extra_mem;
@@ -185,7 +192,6 @@ void __init page_ext_init_flatmem(void)
 			goto fail;
 	}
 	pr_info("allocated %ld bytes of page_ext\n", total_usage);
-	invoke_init_callbacks();
 	return;
 
 fail: