[RFC PATCH 21/23 V2] memblock: limit memory address from memblock

[Lai Jiangshan <laijs-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>]

From: Yasuaki Ishimatsu <isimatu.yasuaki-+CUm20s59erQFUHtdCDX3A@public.gmane.org>

Setting kernelcore_max_pfn means all memory which is bigger than
the boot parameter is allocated as ZONE_MOVABLE. So memory which
is allocated by memblock also should be limited by the parameter.

The patch limits memory from memblock.

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
Signed-off-by: Lai Jiangshan <laijs-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
---
 include/linux/memblock.h |    1 +
 mm/memblock.c            |    5 ++++-
 mm/page_alloc.c          |    6 +++++-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 19dc455..f2977ae 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -42,6 +42,7 @@ struct memblock {
 
 extern struct memblock memblock;
 extern int memblock_debug;
+extern phys_addr_t memblock_limit;
 
 #define memblock_dbg(fmt, ...) \
 	if (memblock_debug) printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
diff --git a/mm/memblock.c b/mm/memblock.c
index 5cc6731..663b805 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -931,7 +931,10 @@ int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t si
 
 void __init_memblock memblock_set_current_limit(phys_addr_t limit)
 {
-	memblock.current_limit = limit;
+	if (!memblock_limit || (memblock_limit > limit))
+		memblock.current_limit = limit;
+	else
+		memblock.current_limit = memblock_limit;
 }
 
 static void __init_memblock memblock_dump(struct memblock_type *type, char *name)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 65ac5c9..c4d3aa0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -209,6 +209,8 @@ static unsigned long __initdata required_kernelcore;
 static unsigned long __initdata required_movablecore;
 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
 
+phys_addr_t memblock_limit;
+
 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
 int movable_zone;
 EXPORT_SYMBOL(movable_zone);
@@ -4876,7 +4878,9 @@ static int __init cmdline_parse_core(char *p, unsigned long *core)
  */
 static int __init cmdline_parse_kernelcore_max_addr(char *p)
 {
-	return cmdline_parse_core(p, &required_kernelcore_max_pfn);
+	cmdline_parse_core(p, &required_kernelcore_max_pfn);
+	memblock_limit = required_kernelcore_max_pfn << PAGE_SHIFT;
+	return 0;
 }
 early_param("kernelcore_max_addr", cmdline_parse_kernelcore_max_addr);
 #endif
-- 
1.7.1