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-rw-r--r--arch/x86/kernel/e820.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 00628130292..a2335d9de05 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1371,6 +1371,23 @@ void __init e820_reserve_resources(void)
}
}
+/* How much should we pad RAM ending depending on where it is? */
+static unsigned long ram_alignment(resource_size_t pos)
+{
+ unsigned long mb = pos >> 20;
+
+ /* To 64kB in the first megabyte */
+ if (!mb)
+ return 64*1024;
+
+ /* To 1MB in the first 16MB */
+ if (mb < 16)
+ return 1024*1024;
+
+ /* To 32MB for anything above that */
+ return 32*1024*1024;
+}
+
void __init e820_reserve_resources_late(void)
{
int i;
@@ -1382,6 +1399,24 @@ void __init e820_reserve_resources_late(void)
insert_resource_expand_to_fit(&iomem_resource, res);
res++;
}
+
+ /*
+ * Try to bump up RAM regions to reasonable boundaries to
+ * avoid stolen RAM:
+ */
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *entry = &e820_saved.map[i];
+ resource_size_t start, end;
+
+ if (entry->type != E820_RAM)
+ continue;
+ start = entry->addr + entry->size;
+ end = round_up(start, ram_alignment(start));
+ if (start == end)
+ continue;
+ reserve_region_with_split(&iomem_resource, start,
+ end - 1, "RAM buffer");
+ }
}
char *__init default_machine_specific_memory_setup(void)