x86: Remove BIOS data range from e820
In preparation for moving to the generic page_is_ram(), make explicit
what we expect to be reserved and not reserved.
Tested-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20100122033004.335813103@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index cdb6a8a5..f9b1f4e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -650,6 +650,23 @@
{}
};
+static void __init trim_bios_range(void)
+{
+ /*
+ * A special case is the first 4Kb of memory;
+ * This is a BIOS owned area, not kernel ram, but generally
+ * not listed as such in the E820 table.
+ */
+ e820_update_range(0, PAGE_SIZE, E820_RAM, E820_RESERVED);
+ /*
+ * special case: Some BIOSen report the PC BIOS
+ * area (640->1Mb) as ram even though it is not.
+ * take them out.
+ */
+ e820_remove_range(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_RAM, 1);
+ sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+}
+
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
@@ -813,7 +830,7 @@
insert_resource(&iomem_resource, &data_resource);
insert_resource(&iomem_resource, &bss_resource);
-
+ trim_bios_range();
#ifdef CONFIG_X86_32
if (ppro_with_ram_bug()) {
e820_update_range(0x70000000ULL, 0x40000ULL, E820_RAM,
