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>

3 files changed, 26 insertions, 17 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index d17d482a04f4..230687ba5ba5 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -517,11 +517,19 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
                              int checktype)
 {
         int i;
+        u64 end;
         u64 real_removed_size = 0;
 
         if (size > (ULLONG_MAX - start))
                 size = ULLONG_MAX - start;
 
+        end = start + size;
+        printk(KERN_DEBUG "e820 remove range: %016Lx - %016Lx ",
+                       (unsigned long long) start,
+                       (unsigned long long) end);
+        e820_print_type(old_type);
+        printk(KERN_CONT "\n");
+
         for (i = 0; i < e820.nr_map; i++) {
                 struct e820entry *ei = &e820.map[i];
                 u64 final_start, final_end;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index cdb6a8a506dd..f9b1f4e5ab74 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -650,6 +650,23 @@ static struct dmi_system_id __initdata bad_bios_dmi_table[] = {
         {}
 };
 
+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 @@ void __init setup_arch(char **cmdline_p)
         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,
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 334e63ca7b2b..30e068d6462e 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -29,22 +29,6 @@ int page_is_ram(unsigned long pagenr)
         resource_size_t addr, end;
         int i;
 
-        /*
-         * 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.
-         */
-        if (pagenr == 0)
-                return 0;
-
-        /*
-         * Second special case: Some BIOSen report the PC BIOS
-         * area (640->1Mb) as ram even though it is not.
-         */
-        if (pagenr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
-                    pagenr < (BIOS_END >> PAGE_SHIFT))
-                return 0;
-
         for (i = 0; i < e820.nr_map; i++) {
                 /*
                  * Not usable memory: