!1790 [sync] PR-1650: mm: disable kernelcore=mirror when no mirror memory

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/1650 
 
PR sync from: Wupeng Ma <mawupeng1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/Q626MLFO7JFVGNUVF6P3WFB2J7I2UMFY/ 
 
https://gitee.com/openeuler/kernel/issues/I7QV2C 
 
Link:https://gitee.com/openeuler/kernel/pulls/1790 

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> 
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> 

include/linux/mm.h

@@ -2493,6 +2493,7 @@ extern void get_pfn_range_for_nid(unsigned int nid,
 extern unsigned long find_min_pfn_with_active_regions(void);
 
 extern bool mirrored_kernelcore;
+extern bool memblock_has_mirror(void);
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 static inline int early_pfn_to_nid(unsigned long pfn)

mm/memblock.c

@@ -161,6 +161,11 @@ static int memblock_can_resize __initdata_memblock;
 static int memblock_memory_in_slab __initdata_memblock = 0;
 static int memblock_reserved_in_slab __initdata_memblock = 0;
 
+bool __init_memblock memblock_has_mirror(void)
+{
+	return system_has_some_mirror;
+}
+
 static enum memblock_flags __init_memblock choose_memblock_flags(void)
 {
 	return system_has_some_mirror ? MEMBLOCK_MIRROR : MEMBLOCK_NONE;

mm/page_alloc.c

@@ -7741,6 +7741,11 @@ static void __init find_zone_movable_pfns_for_nodes(void)
 		bool has_unmirrored_mem = false;
 		unsigned long mirrored_sz = 0;
 
+		if (!memblock_has_mirror()) {
+			pr_warn("The system has no mirror memory, ignore kernelcore=mirror.\n");
+			goto out;
+		}
+
 		for_each_mem_region(r) {
 			if (memblock_is_mirror(r)) {
 				mirrored_sz += r->size;