1 files changed, 35 insertions, 1 deletions

diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c
index 293cd71a266a..62776c07cff1 100644
--- a/arch/x86_64/kernel/e820.c
+++ b/arch/x86_64/kernel/e820.c
@@ -80,7 +80,12 @@ static inline int bad_addr(unsigned long *addrp, unsigned long size)
         return 0;
 } 
 
-int __init e820_mapped(unsigned long start, unsigned long end, unsigned type) 
+/*
+ * This function checks if any part of the range <start,end> is mapped
+ * with type.
+ */
+int __meminit
+e820_any_mapped(unsigned long start, unsigned long end, unsigned type)
 { 
         int i;
         for (i = 0; i < e820.nr_map; i++) { 
@@ -94,6 +99,35 @@ int __init e820_mapped(unsigned long start, unsigned long end, unsigned type)
         return 0;
 }
 
+/*
+ * This function checks if the entire range <start,end> is mapped with type.
+ *
+ * Note: this function only works correct if the e820 table is sorted and
+ * not-overlapping, which is the case
+ */
+int __init e820_all_mapped(unsigned long start, unsigned long end, unsigned type)
+{
+        int i;
+        for (i = 0; i < e820.nr_map; i++) {
+                struct e820entry *ei = &e820.map[i];
+                if (type && ei->type != type)
+                        continue;
+                /* is the region (part) in overlap with the current region ?*/
+                if (ei->addr >= end || ei->addr + ei->size <= start)
+                        continue;
+
+                /* if the region is at the beginning of <start,end> we move
+                 * start to the end of the region since it's ok until there
+                 */
+                if (ei->addr <= start)
+                        start = ei->addr + ei->size;
+                /* if start is now at or beyond end, we're done, full coverage */
+                if (start >= end)
+                        return 1; /* we're done */
+        }
+        return 0;
+}
+
 /* 
  * Find a free area in a specific range. 
  */