x86: trim mtrr don't close gap for resource allocation.

[profile/ivi/kernel-x86-ivi.git] / arch / x86 / kernel / e820_64.c

diff --git a/arch/x86/kernel/e820_64.c b/arch/x86/kernel/e820_64.c
index 9f65b4c..9be6971 100644 (file)
--- a/arch/x86/kernel/e820_64.c
+++ b/arch/x86/kernel/e820_64.c
@@ -744,6 +744,33 @@ void __init finish_e820_parsing(void)
        }
 }
 
+void __init update_memory_range(u64 start, u64 size, unsigned old_type,
+                               unsigned new_type)
+{
+       int i;
+
+       BUG_ON(old_type == new_type);
+
+       for (i = 0; i < e820.nr_map; i++) {
+               struct e820entry *ei = &e820.map[i];
+               u64 final_start, final_end;
+               if (ei->type != old_type)
+                       continue;
+               /* totally covered? */
+               if (ei->addr >= start && ei->size <= size) {
+                       ei->type = new_type;
+                       continue;
+               }
+               /* partially covered */
+               final_start = max(start, ei->addr);
+               final_end = min(start + size, ei->addr + ei->size);
+               if (final_start >= final_end)
+                       continue;
+               add_memory_region(final_start, final_end - final_start,
+                                        new_type);
+       }
+}
+
 void __init update_e820(void)
 {
        u8 nr_map;