[PATCH v3] mm: add setup_initial_init_mm() helper

[Kefeng Wang]

Add setup_initial_init_mm() helper to setup kernel text,
data and brk.

Cc: linux-snps-arc@xxxxxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-csky@xxxxxxxxxxxxxxx
Cc: uclinux-h8-devel@xxxxxxxxxxxxxxxxxxxx
Cc: linux-m68k@xxxxxxxxxxxxxxxxxxxx
Cc: openrisc@xxxxxxxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
Cc: linux-sh@xxxxxxxxxxxxxxx
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
v3: declaration in mm.h, implemention in init-mm.c
 include/linux/mm.h | 3 +++
 mm/init-mm.c       | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c274f75efcf9..02aa057540b7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -244,6 +244,9 @@ int __add_to_page_cache_locked(struct page *page, struct address_space *mapping,
 
 #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
 
+void setup_initial_init_mm(void *start_code, void *end_code,
+			   void *end_data, void *brk);
+
 /*
  * Linux kernel virtual memory manager primitives.
  * The idea being to have a "virtual" mm in the same way
diff --git a/mm/init-mm.c b/mm/init-mm.c
index 153162669f80..b4a6f38fb51d 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -40,3 +40,12 @@ struct mm_struct init_mm = {
 	.cpu_bitmap	= CPU_BITS_NONE,
 	INIT_MM_CONTEXT(init_mm)
 };
+
+void setup_initial_init_mm(void *start_code, void *end_code,
+			   void *end_data, void *brk)
+{
+	init_mm.start_code = (unsigned long)start_code;
+	init_mm.end_code = (unsigned long)end_code;
+	init_mm.end_data = (unsigned long)end_data;
+	init_mm.brk = (unsigned long)brk;
+}
-- 
2.26.2