[PATCH 18/39] lmb: Add lmb_reserve_area_overlap_ok()

[Yinghai Lu <yinghai@kernel.org>]

Some areas from firmware could be reserved several times from different callers.

If these area are overlapped, We may have overlapped entries in lmb.reserved.

Try to free the area at first, before rerserve them again.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 include/linux/lmb.h |    1 +
 mm/lmb.c            |   27 +++++++++++++++++++++++++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/include/linux/lmb.h b/include/linux/lmb.h
index 8332934..3c8095f 100644
--- a/include/linux/lmb.h
+++ b/include/linux/lmb.h
@@ -86,6 +86,7 @@ lmb_end_pfn(struct lmb_region *type, unsigned long region_nr)
 }
 
 void lmb_reserve_area(u64 start, u64 end, char *name);
+void lmb_reserve_area_overlap_ok(u64 start, u64 end, char *name);
 void lmb_free_area(u64 start, u64 end);
 void lmb_add_memory(u64 start, u64 end);
 u64 __lmb_find_area(u64 ei_start, u64 ei_last, u64 start, u64 end,
diff --git a/mm/lmb.c b/mm/lmb.c
index feb3dfa..34fc030 100644
--- a/mm/lmb.c
+++ b/mm/lmb.c
@@ -605,6 +605,12 @@ void __init lmb_add_memory(u64 start, u64 end)
 	__check_and_double_region_array(&lmb.memory, &lmb_memory_region[0]);
 }
 
+static void __init __lmb_reserve_area(u64 start, u64 end, char *name)
+{
+	lmb_add_region(&lmb.reserved, start, end - start);
+	__check_and_double_region_array(&lmb.reserved, &lmb_reserved_region[0]);
+}
+
 void __init lmb_reserve_area(u64 start, u64 end, char *name)
 {
 	if (start == end)
@@ -613,8 +619,25 @@ void __init lmb_reserve_area(u64 start, u64 end, char *name)
 	if (WARN_ONCE(start > end, "lmb_reserve_area: wrong range [%#llx, %#llx]\n", start, end))
 		return;
 
-	lmb_add_region(&lmb.reserved, start, end - start);
-	__check_and_double_region_array(&lmb.reserved, &lmb_reserved_region[0]);
+	__lmb_reserve_area(start, end, name);
+}
+
+/*
+ * Could be used to avoid having overlap entries in lmb.reserved.region.
+ *  Don't need to use it with area that is from lmb_find_area()
+ *  Only use it for the area that fw hidden area.
+ */
+void __init lmb_reserve_area_overlap_ok(u64 start, u64 end, char *name)
+{
+	if (start == end)
+		return;
+
+	if (WARN_ONCE(start > end, "lmb_reserve_area_overlap_ok: wrong range [%#llx, %#llx]\n", start, end))
+		return;
+
+	/* Free that region at first */
+	lmb_free(start, end - start);
+	__lmb_reserve_area(start, end, name);
 }
 
 void __init lmb_free_area(u64 start, u64 end)
-- 
1.6.4.2