[PATCH] x86_64: Implement early DMI scanning

There are more and more cases where we need to know DMI information
early to work around bugs.  i386 already had early DMI scanning, but
x86-64 didn't.  Implement this now.

This required some cleanup in the i386 code.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 675a45691338..54c7f5975b44 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -225,6 +225,33 @@ static __meminit void unmap_low_page(int i)
         ti->allocated = 0; 
 } 
 
+/* Must run before zap_low_mappings */
+__init void *early_ioremap(unsigned long addr, unsigned long size)
+{
+        unsigned long map = round_down(addr, LARGE_PAGE_SIZE); 
+
+        /* actually usually some more */
+        if (size >= LARGE_PAGE_SIZE) { 
+                printk("SMBIOS area too long %lu\n", size);
+                return NULL;
+        }
+        set_pmd(temp_mappings[0].pmd,  __pmd(map | _KERNPG_TABLE | _PAGE_PSE));
+        map += LARGE_PAGE_SIZE;
+        set_pmd(temp_mappings[1].pmd,  __pmd(map | _KERNPG_TABLE | _PAGE_PSE));
+        __flush_tlb();
+        return temp_mappings[0].address + (addr & (LARGE_PAGE_SIZE-1));
+}
+
+/* To avoid virtual aliases later */
+__init void early_iounmap(void *addr, unsigned long size)
+{
+        if ((void *)round_down((unsigned long)addr, LARGE_PAGE_SIZE) != temp_mappings[0].address)
+                printk("early_iounmap: bad address %p\n", addr);
+        set_pmd(temp_mappings[0].pmd, __pmd(0));
+        set_pmd(temp_mappings[1].pmd, __pmd(0));
+        __flush_tlb();
+}
+
 static void __meminit
 phys_pmd_init(pmd_t *pmd, unsigned long address, unsigned long end)
 {