[PATCH V3 06/10] xen/arm: introduce PGC_reserved

[Penny Zheng <penny.zheng@arm.com>]

This patch introduces a new page flag PGC_reserved in order to differentiate
pages of static memory from those allocated from heap.

Mark pages of static memory PGC_reserved when initializing them.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
---
v3 change:
- introduce PGC_reserved when it is firstly used.
---
 xen/common/page_alloc.c  | 3 +++
 xen/include/asm-arm/mm.h | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index f394d6627a..15edaca227 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -1536,6 +1536,9 @@ void __init free_staticmem_pages(struct page_info *pg, unsigned long nr_mfns,
             /* TODO: asynchronous scrubbing for pages of static memory. */
             scrub_one_page(pg);
         }
+
+        /* In case initializing page of static memory, mark it PGC_reserved. */
+        pg[i].count_info |= PGC_reserved;
     }
 }
 #endif
diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index ded74d29da..7b5e7b7f69 100644
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -108,6 +108,9 @@ struct page_info
   /* Page is Xen heap? */
 #define _PGC_xen_heap     PG_shift(2)
 #define PGC_xen_heap      PG_mask(1, 2)
+  /* Page is reserved */
+#define _PGC_reserved     PG_shift(3)
+#define PGC_reserved      PG_mask(1, 3)
 /* ... */
 /* Page is broken? */
 #define _PGC_broken       PG_shift(7)
-- 
2.25.1