[RFC v2 30/43] memblock: PKRAM: mark memblocks that contain preserved pages

[Anthony Yznaga]

To support deferred initialization of page structs for preserved pages,
separate memblocks containing preserved pages by setting a new flag
when adding them to the memblock reserved list.

Signed-off-by: Anthony Yznaga <anthony.yzn...@oracle.com>
---
 include/linux/memblock.h | 6 ++++++
 mm/pkram.c               | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index d13e3cd938b4..39c53d08d9f7 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -37,6 +37,7 @@ enum memblock_flags {
        MEMBLOCK_HOTPLUG        = 0x1,  /* hotpluggable region */
        MEMBLOCK_MIRROR         = 0x2,  /* mirrored region */
        MEMBLOCK_NOMAP          = 0x4,  /* don't add to kernel direct mapping */
+       MEMBLOCK_PRESERVED      = 0x8,  /* preserved pages region */
 };
 
 /**
@@ -248,6 +249,11 @@ static inline bool memblock_is_nomap(struct 
memblock_region *m)
        return m->flags & MEMBLOCK_NOMAP;
 }
 
+static inline bool memblock_is_preserved(struct memblock_region *m)
+{
+       return m->flags & MEMBLOCK_PRESERVED;
+}
+
 int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
                            unsigned long  *end_pfn);
 void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
diff --git a/mm/pkram.c b/mm/pkram.c
index b8d6b549fa6c..08144c18d425 100644
--- a/mm/pkram.c
+++ b/mm/pkram.c
@@ -1607,6 +1607,7 @@ int __init pkram_create_merged_reserved(struct 
memblock_type *new)
                } else if (pkr->base + pkr->size <= r->base) {
                        rgn->base = pkr->base;
                        rgn->size = pkr->size;
+                       rgn->flags = MEMBLOCK_PRESERVED;
                        memblock_set_region_node(rgn, MAX_NUMNODES);
 
                        nr_preserved +=  (rgn->size >> PAGE_SHIFT);
@@ -1636,6 +1637,7 @@ int __init pkram_create_merged_reserved(struct 
memblock_type *new)
                rgn = &new->regions[k];
                rgn->base = pkr->base;
                rgn->size = pkr->size;
+               rgn->flags = MEMBLOCK_PRESERVED;
                memblock_set_region_node(rgn, MAX_NUMNODES);
 
                nr_preserved += (rgn->size >> PAGE_SHIFT);
-- 
1.8.3.1