1 files changed, 63 insertions, 10 deletions

diff --git a/mm/memblock.c b/mm/memblock.c
index ac1248933..483197ef6 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -20,7 +20,7 @@
 #include <linux/seq_file.h>
 #include <linux/memblock.h>
 
-#include <asm-generic/sections.h>
+#include <asm/sections.h>
 #include <linux/io.h>
 
 #include "internal.h"
@@ -482,7 +482,7 @@ static void __init_memblock memblock_merge_regions(struct memblock_type *type)
  * @flags:	flags of the new region
  *
  * Insert new memblock region [@base,@base+@size) into @type at @idx.
- * @type must already have extra room to accomodate the new region.
+ * @type must already have extra room to accommodate the new region.
  */
 static void __init_memblock memblock_insert_region(struct memblock_type *type,
 						   int idx, phys_addr_t base,
@@ -544,7 +544,7 @@ repeat:
 	/*
 	 * The following is executed twice.  Once with %false @insert and
 	 * then with %true.  The first counts the number of regions needed
-	 * to accomodate the new area.  The second actually inserts them.
+	 * to accommodate the new area.  The second actually inserts them.
 	 */
 	base = obase;
 	nr_new = 0;
@@ -584,6 +584,9 @@ repeat:
 					       nid, flags);
 	}
 
+	if (!nr_new)
+		return 0;
+
 	/*
 	 * If this was the first round, resize array and repeat for actual
 	 * insertions; otherwise, merge and return.
@@ -991,7 +994,10 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid, ulong flags,
 
 	if (*idx == (u64)ULLONG_MAX) {
 		idx_a = type_a->cnt - 1;
-		idx_b = type_b->cnt;
+		if (type_b != NULL)
+			idx_b = type_b->cnt;
+		else
+			idx_b = 0;
 	}
 
 	for (; idx_a >= 0; idx_a--) {
@@ -1024,7 +1030,7 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid, ulong flags,
 				*out_end = m_end;
 			if (out_nid)
 				*out_nid = m_nid;
-			idx_a++;
+			idx_a--;
 			*idx = (u32)idx_a | (u64)idx_b << 32;
 			return;
 		}
@@ -1462,15 +1468,16 @@ phys_addr_t __init_memblock memblock_end_of_DRAM(void)
 	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
 }
 
-void __init memblock_enforce_memory_limit(phys_addr_t limit)
+static phys_addr_t __init_memblock __find_max_addr(phys_addr_t limit)
 {
 	phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;
 	struct memblock_region *r;
 
-	if (!limit)
-		return;
-
-	/* find out max address */
+	/*
+	 * translate the memory @limit size into the max address within one of
+	 * the memory memblock regions, if the @limit exceeds the total size
+	 * of those regions, max_addr will keep original value ULLONG_MAX
+	 */
 	for_each_memblock(memory, r) {
 		if (limit <= r->size) {
 			max_addr = r->base + limit;
@@ -1479,6 +1486,22 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit)
 		limit -= r->size;
 	}
 
+	return max_addr;
+}
+
+void __init memblock_enforce_memory_limit(phys_addr_t limit)
+{
+	phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;
+
+	if (!limit)
+		return;
+
+	max_addr = __find_max_addr(limit);
+
+	/* @limit exceeds the total size of the memory, do nothing */
+	if (max_addr == (phys_addr_t)ULLONG_MAX)
+		return;
+
 	/* truncate both memory and reserved regions */
 	memblock_remove_range(&memblock.memory, max_addr,
 			      (phys_addr_t)ULLONG_MAX);
@@ -1486,6 +1509,36 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit)
 			      (phys_addr_t)ULLONG_MAX);
 }
 
+void __init memblock_mem_limit_remove_map(phys_addr_t limit)
+{
+	struct memblock_type *type = &memblock.memory;
+	phys_addr_t max_addr;
+	int i, ret, start_rgn, end_rgn;
+
+	if (!limit)
+		return;
+
+	max_addr = __find_max_addr(limit);
+
+	/* @limit exceeds the total size of the memory, do nothing */
+	if (max_addr == (phys_addr_t)ULLONG_MAX)
+		return;
+
+	ret = memblock_isolate_range(type, max_addr, (phys_addr_t)ULLONG_MAX,
+				&start_rgn, &end_rgn);
+	if (ret)
+		return;
+
+	/* remove all the MAP regions above the limit */
+	for (i = end_rgn - 1; i >= start_rgn; i--) {
+		if (!memblock_is_nomap(&type->regions[i]))
+			memblock_remove_region(type, i);
+	}
+	/* truncate the reserved regions */
+	memblock_remove_range(&memblock.reserved, max_addr,
+			      (phys_addr_t)ULLONG_MAX);
+}
+
 static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
 {
 	unsigned int left = 0, right = type->cnt;