x86: reserve end-of-conventional-memory to 1MB, 64-bit

This patch is an add-on to the 64-bit ebda patch. It makes
the functions reserve_ebda_region (renamed from reserve_ebda)
and copy_e820_map equal to the 32-bit versions of the previous
patch.

Changes:

Use u64 and u32 for local variables in copy_e820_map.

The amount of conventional memory and the start of the EBDA are
detected by reading the BIOS data area directly. Paravirtual
environments do not provide this area, so we bail out early
in that case. They will just have to set up a correct memory
map to start with.

Add a safety net for zeroed out BIOS data area.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/x86/kernel/e820_64.c b/arch/x86/kernel/e820_64.c
index 8b914a833ac6..4a0953857cb2 100644
--- a/arch/x86/kernel/e820_64.c
+++ b/arch/x86/kernel/e820_64.c
@@ -621,10 +621,10 @@ static int __init copy_e820_map(struct e820entry *biosmap, int nr_map)
                 return -1;
 
         do {
-                unsigned long start = biosmap->addr;
-                unsigned long size = biosmap->size;
-                unsigned long end = start + size;
-                unsigned long type = biosmap->type;
+                u64 start = biosmap->addr;
+                u64 size = biosmap->size;
+                u64 end = start + size;
+                u32 type = biosmap->type;
 
                 /* Overflow in 64 bits? Ignore the memory map. */
                 if (start > end)