[PATCH 35 of 55] xen64: defer setting pagetable alloc/release ops

[Jeremy Fitzhardinge <jeremy@goop.org>]

We need to wait until the page structure is available to use the
proper pagetable page alloc/release operations, since they use struct
page to determine if a pagetable is pinned.

This happened to work in 32bit because nobody allocated new pagetable
pages in the interim between xen_pagetable_setup_done and
xen_post_allocator_init, but the 64-bit kenrel needs to allocate more
pagetable levels.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---
 arch/x86/xen/enlighten.c |   25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -878,6 +878,18 @@
 
 static __init void xen_pagetable_setup_done(pgd_t *base)
 {
+	xen_setup_shared_info();
+}
+
+static __init void xen_post_allocator_init(void)
+{
+	pv_mmu_ops.set_pte = xen_set_pte;
+	pv_mmu_ops.set_pmd = xen_set_pmd;
+	pv_mmu_ops.set_pud = xen_set_pud;
+#if PAGETABLE_LEVELS == 4
+	pv_mmu_ops.set_pgd = xen_set_pgd;
+#endif
+
 	/* This will work as long as patching hasn't happened yet
 	   (which it hasn't) */
 	pv_mmu_ops.alloc_pte = xen_alloc_pte;
@@ -887,19 +899,6 @@
 #if PAGETABLE_LEVELS == 4
 	pv_mmu_ops.alloc_pud = xen_alloc_pud;
 	pv_mmu_ops.release_pud = xen_release_pud;
-#endif
-
-	pv_mmu_ops.set_pte = xen_set_pte;
-
-	xen_setup_shared_info();
-}
-
-static __init void xen_post_allocator_init(void)
-{
-	pv_mmu_ops.set_pmd = xen_set_pmd;
-	pv_mmu_ops.set_pud = xen_set_pud;
-#if PAGETABLE_LEVELS == 4
-	pv_mmu_ops.set_pgd = xen_set_pgd;
 #endif
 
 	xen_mark_init_mm_pinned();