x86, fixmap: define reserve_top_address for x86_64

Impact: new interface (not yet use)

Define reserve_top_address for x86_64; only for later x86 integration.

Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Acked-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

3 files changed, 20 insertions, 16 deletions

diff --git a/arch/x86/include/asm/fixmap_64.h b/arch/x86/include/asm/fixmap_64.h
index d905de086753..b6c06dd55f1c 100644
--- a/arch/x86/include/asm/fixmap_64.h
+++ b/arch/x86/include/asm/fixmap_64.h
@@ -68,6 +68,8 @@ enum fixed_addresses {
         __end_of_fixed_addresses
 };
 
+extern void reserve_top_address(unsigned long reserve);
+
 #define FIXADDR_TOP     (VSYSCALL_END-PAGE_SIZE)
 
 #define FIXADDR_SIZE    (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 86f2ffc43c3d..5b7c7c8464fe 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -313,6 +313,24 @@ int ptep_clear_flush_young(struct vm_area_struct *vma,
         return young;
 }
 
+/**
+ * reserve_top_address - reserves a hole in the top of kernel address space
+ * @reserve - size of hole to reserve
+ *
+ * Can be used to relocate the fixmap area and poke a hole in the top
+ * of kernel address space to make room for a hypervisor.
+ */
+void __init reserve_top_address(unsigned long reserve)
+{
+#ifdef CONFIG_X86_32
+        BUG_ON(fixmaps_set > 0);
+        printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
+               (int)-reserve);
+        __FIXADDR_TOP = -reserve - PAGE_SIZE;
+        __VMALLOC_RESERVE += reserve;
+#endif
+}
+
 int fixmaps_set;
 
 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte)
diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c
index 0951db9ee519..c3cf6e115768 100644
--- a/arch/x86/mm/pgtable_32.c
+++ b/arch/x86/mm/pgtable_32.c
@@ -97,22 +97,6 @@ void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
 unsigned long __FIXADDR_TOP = 0xfffff000;
 EXPORT_SYMBOL(__FIXADDR_TOP);
 
-/**
- * reserve_top_address - reserves a hole in the top of kernel address space
- * @reserve - size of hole to reserve
- *
- * Can be used to relocate the fixmap area and poke a hole in the top
- * of kernel address space to make room for a hypervisor.
- */
-void __init reserve_top_address(unsigned long reserve)
-{
-        BUG_ON(fixmaps_set > 0);
-        printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
-               (int)-reserve);
-        __FIXADDR_TOP = -reserve - PAGE_SIZE;
-        __VMALLOC_RESERVE += reserve;
-}
-
 /*
  * vmalloc=size forces the vmalloc area to be exactly 'size'
  * bytes. This can be used to increase (or decrease) the