x86: trim mtrr don't close gap for resource allocation.
fix the bug reported here:
http://bugzilla.kernel.org/show_bug.cgi?id=10232
use update_memory_range() instead of add_memory_range() directly
to avoid closing the gap.
( the new code only affects and runs on systems where the MTRR
workaround triggers. )
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/e820_32.c b/arch/x86/kernel/e820_32.c
index 4e16ef4..80444c5 100644
--- a/arch/x86/kernel/e820_32.c
+++ b/arch/x86/kernel/e820_32.c
@@ -749,6 +749,32 @@
return 0;
}
early_param("memmap", parse_memmap);
+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;