xen/mmu: some early pagetable cleanups

1. make sure early-allocated ptes are pinned, so they can be later
   unpinned
2. don't pin pmd+pud, just make them RO
3. scatter some __inits around

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 67d2ab4..df87c80 100644 (file)
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1013,7 +1013,7 @@ static __init int xen_mark_pinned(struct mm_struct *mm, struct page *page,
        return 0;
 }
 
-void __init xen_mark_init_mm_pinned(void)
+static void __init xen_mark_init_mm_pinned(void)
 {
        xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
 }
@@ -1461,10 +1461,29 @@ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
 }
 #endif
 
+static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
+{
+       struct mmuext_op op;
+       op.cmd = cmd;
+       op.arg1.mfn = pfn_to_mfn(pfn);
+       if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
+               BUG();
+}
+
 /* Early in boot, while setting up the initial pagetable, assume
    everything is pinned. */
 static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
 {
+#ifdef CONFIG_FLATMEM
+       BUG_ON(mem_map);        /* should only be used early */
+#endif
+       make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
+       pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
+}
+
+/* Used for pmd and pud */
+static __init void xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn)
+{
 #ifdef CONFIG_FLATMEM
        BUG_ON(mem_map);        /* should only be used early */
 #endif
@@ -1473,18 +1492,15 @@ static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
 
 /* Early release_pte assumes that all pts are pinned, since there's
    only init_mm and anything attached to that is pinned. */
-static void xen_release_pte_init(unsigned long pfn)
+static __init void xen_release_pte_init(unsigned long pfn)
 {
+       pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
        make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
 }
 
-static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
+static __init void xen_release_pmd_init(unsigned long pfn)
 {
-       struct mmuext_op op;
-       op.cmd = cmd;
-       op.arg1.mfn = pfn_to_mfn(pfn);
-       if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
-               BUG();
+       make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
 }
 
 /* This needs to make sure the new pte page is pinned iff its being
@@ -1873,9 +1889,9 @@ const struct pv_mmu_ops xen_mmu_ops __initdata = {
 
        .alloc_pte = xen_alloc_pte_init,
        .release_pte = xen_release_pte_init,
-       .alloc_pmd = xen_alloc_pte_init,
+       .alloc_pmd = xen_alloc_pmd_init,
        .alloc_pmd_clone = paravirt_nop,
-       .release_pmd = xen_release_pte_init,
+       .release_pmd = xen_release_pmd_init,
 
 #ifdef CONFIG_HIGHPTE
        .kmap_atomic_pte = xen_kmap_atomic_pte,
@@ -1914,8 +1930,8 @@ const struct pv_mmu_ops xen_mmu_ops __initdata = {
        .make_pud = PV_CALLEE_SAVE(xen_make_pud),
        .set_pgd = xen_set_pgd_hyper,
 
-       .alloc_pud = xen_alloc_pte_init,
-       .release_pud = xen_release_pte_init,
+       .alloc_pud = xen_alloc_pmd_init,
+       .release_pud = xen_release_pmd_init,
 #endif /* PAGETABLE_LEVELS == 4 */
 
        .activate_mm = xen_activate_mm,

diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index f897cdf..5c50a10 100644 (file)
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -56,8 +56,6 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id);
 
 bool xen_vcpu_stolen(int vcpu);
 
-void xen_mark_init_mm_pinned(void);
-
 void xen_setup_vcpu_info_placement(void);
 
 #ifdef CONFIG_SMP