From fd862dde18c3e360f510780e1d1bf615866b11c2 Mon Sep 17 00:00:00 2001
From: "Gustavo F. Padovan" <gustavo@las.ic.unicamp.br>
Date: Sun, 15 Feb 2009 21:48:54 -0300
Subject: 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>
---
arch/x86/mm/pgtable.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
(limited to 'arch/x86/mm/pgtable.c')
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)
--
cgit v1.2.3