10 files changed, 133 insertions, 330 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index e3c6a06cf72..dd7b88f2ec7 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -235,7 +235,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 	*dx &= maskedx;
 }
 
-static __init void xen_init_cpuid_mask(void)
+static void __init xen_init_cpuid_mask(void)
 {
 	unsigned int ax, bx, cx, dx;
 	unsigned int xsave_mask;
@@ -400,7 +400,7 @@ static void xen_load_gdt(const struct desc_ptr *dtr)
 /*
  * load_gdt for early boot, when the gdt is only mapped once
  */
-static __init void xen_load_gdt_boot(const struct desc_ptr *dtr)
+static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
 {
 	unsigned long va = dtr->address;
 	unsigned int size = dtr->size + 1;
@@ -662,7 +662,7 @@ static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
  * Version of write_gdt_entry for use at early boot-time needed to
  * update an entry as simply as possible.
  */
-static __init void xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
+static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
 					    const void *desc, int type)
 {
 	switch (type) {
@@ -933,18 +933,18 @@ static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
 	return ret;
 }
 
-static const struct pv_info xen_info __initdata = {
+static const struct pv_info xen_info __initconst = {
 	.paravirt_enabled = 1,
 	.shared_kernel_pmd = 0,
 
 	.name = "Xen",
 };
 
-static const struct pv_init_ops xen_init_ops __initdata = {
+static const struct pv_init_ops xen_init_ops __initconst = {
 	.patch = xen_patch,
 };
 
-static const struct pv_cpu_ops xen_cpu_ops __initdata = {
+static const struct pv_cpu_ops xen_cpu_ops __initconst = {
 	.cpuid = xen_cpuid,
 
 	.set_debugreg = xen_set_debugreg,
@@ -1004,7 +1004,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = {
 	.end_context_switch = xen_end_context_switch,
 };
 
-static const struct pv_apic_ops xen_apic_ops __initdata = {
+static const struct pv_apic_ops xen_apic_ops __initconst = {
 #ifdef CONFIG_X86_LOCAL_APIC
 	.startup_ipi_hook = paravirt_nop,
 #endif
@@ -1055,7 +1055,7 @@ int xen_panic_handler_init(void)
 	return 0;
 }
 
-static const struct machine_ops __initdata xen_machine_ops = {
+static const struct machine_ops xen_machine_ops __initconst = {
 	.restart = xen_restart,
 	.halt = xen_machine_halt,
 	.power_off = xen_machine_halt,
@@ -1332,7 +1332,7 @@ static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
 	return NOTIFY_OK;
 }
 
-static struct notifier_block __cpuinitdata xen_hvm_cpu_notifier = {
+static struct notifier_block xen_hvm_cpu_notifier __cpuinitdata = {
 	.notifier_call	= xen_hvm_cpu_notify,
 };
 
@@ -1381,7 +1381,7 @@ bool xen_hvm_need_lapic(void)
 }
 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
 
-const __refconst struct hypervisor_x86 x86_hyper_xen_hvm = {
+const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = {
 	.name			= "Xen HVM",
 	.detect			= xen_hvm_platform,
 	.init_platform		= xen_hvm_guest_init,
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 6a6fe893964..8bbb465b6f0 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -113,7 +113,7 @@ static void xen_halt(void)
 		xen_safe_halt();
 }
 
-static const struct pv_irq_ops xen_irq_ops __initdata = {
+static const struct pv_irq_ops xen_irq_ops __initconst = {
 	.save_fl = PV_CALLEE_SAVE(xen_save_fl),
 	.restore_fl = PV_CALLEE_SAVE(xen_restore_fl),
 	.irq_disable = PV_CALLEE_SAVE(xen_irq_disable),
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 0684f3c74d5..dc708dcc62f 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -75,67 +75,12 @@
 #include "mmu.h"
 #include "debugfs.h"
 
-#define MMU_UPDATE_HISTO	30
-
 /*
  * Protects atomic reservation decrease/increase against concurrent increases.
  * Also protects non-atomic updates of current_pages and balloon lists.
  */
 DEFINE_SPINLOCK(xen_reservation_lock);
 
-#ifdef CONFIG_XEN_DEBUG_FS
-
-static struct {
-	u32 pgd_update;
-	u32 pgd_update_pinned;
-	u32 pgd_update_batched;
-
-	u32 pud_update;
-	u32 pud_update_pinned;
-	u32 pud_update_batched;
-
-	u32 pmd_update;
-	u32 pmd_update_pinned;
-	u32 pmd_update_batched;
-
-	u32 pte_update;
-	u32 pte_update_pinned;
-	u32 pte_update_batched;
-
-	u32 mmu_update;
-	u32 mmu_update_extended;
-	u32 mmu_update_histo[MMU_UPDATE_HISTO];
-
-	u32 prot_commit;
-	u32 prot_commit_batched;
-
-	u32 set_pte_at;
-	u32 set_pte_at_batched;
-	u32 set_pte_at_pinned;
-	u32 set_pte_at_current;
-	u32 set_pte_at_kernel;
-} mmu_stats;
-
-static u8 zero_stats;
-
-static inline void check_zero(void)
-{
-	if (unlikely(zero_stats)) {
-		memset(&mmu_stats, 0, sizeof(mmu_stats));
-		zero_stats = 0;
-	}
-}
-
-#define ADD_STATS(elem, val)			\
-	do { check_zero(); mmu_stats.elem += (val); } while(0)
-
-#else  /* !CONFIG_XEN_DEBUG_FS */
-
-#define ADD_STATS(elem, val)	do { (void)(val); } while(0)
-
-#endif /* CONFIG_XEN_DEBUG_FS */
-
-
 /*
  * Identity map, in addition to plain kernel map.  This needs to be
  * large enough to allocate page table pages to allocate the rest.
@@ -243,11 +188,6 @@ static bool xen_page_pinned(void *ptr)
 	return PagePinned(page);
 }
 
-static bool xen_iomap_pte(pte_t pte)
-{
-	return pte_flags(pte) & _PAGE_IOMAP;
-}
-
 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid)
 {
 	struct multicall_space mcs;
@@ -257,7 +197,7 @@ void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid)
 	u = mcs.args;
 
 	/* ptep might be kmapped when using 32-bit HIGHPTE */
-	u->ptr = arbitrary_virt_to_machine(ptep).maddr;
+	u->ptr = virt_to_machine(ptep).maddr;
 	u->val = pte_val_ma(pteval);
 
 	MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, domid);
@@ -266,11 +206,6 @@ void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid)
 }
 EXPORT_SYMBOL_GPL(xen_set_domain_pte);
 
-static void xen_set_iomap_pte(pte_t *ptep, pte_t pteval)
-{
-	xen_set_domain_pte(ptep, pteval, DOMID_IO);
-}
-
 static void xen_extend_mmu_update(const struct mmu_update *update)
 {
 	struct multicall_space mcs;
@@ -279,27 +214,17 @@ static void xen_extend_mmu_update(const struct mmu_update *update)
 	mcs = xen_mc_extend_args(__HYPERVISOR_mmu_update, sizeof(*u));
 
 	if (mcs.mc != NULL) {
-		ADD_STATS(mmu_update_extended, 1);
-		ADD_STATS(mmu_update_histo[mcs.mc->args[1]], -1);
-
 		mcs.mc->args[1]++;
-
-		if (mcs.mc->args[1] < MMU_UPDATE_HISTO)
-			ADD_STATS(mmu_update_histo[mcs.mc->args[1]], 1);
-		else
-			ADD_STATS(mmu_update_histo[0], 1);
 	} else {
-		ADD_STATS(mmu_update, 1);
 		mcs = __xen_mc_entry(sizeof(*u));
 		MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
-		ADD_STATS(mmu_update_histo[1], 1);
 	}
 
 	u = mcs.args;
 	*u = *update;
 }
 
-void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
+static void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
 {
 	struct mmu_update u;
 
@@ -312,17 +237,13 @@ void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
 	u.val = pmd_val_ma(val);
 	xen_extend_mmu_update(&u);
 
-	ADD_STATS(pmd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
-
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 
 	preempt_enable();
 }
 
-void xen_set_pmd(pmd_t *ptr, pmd_t val)
+static void xen_set_pmd(pmd_t *ptr, pmd_t val)
 {
-	ADD_STATS(pmd_update, 1);
-
 	/* If page is not pinned, we can just update the entry
 	   directly */
 	if (!xen_page_pinned(ptr)) {
@@ -330,8 +251,6 @@ void xen_set_pmd(pmd_t *ptr, pmd_t val)
 		return;
 	}
 
-	ADD_STATS(pmd_update_pinned, 1);
-
 	xen_set_pmd_hyper(ptr, val);
 }
 
@@ -344,35 +263,34 @@ void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
 	set_pte_vaddr(vaddr, mfn_pte(mfn, flags));
 }
 
-void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
-		    pte_t *ptep, pte_t pteval)
+static bool xen_batched_set_pte(pte_t *ptep, pte_t pteval)
 {
-	if (xen_iomap_pte(pteval)) {
-		xen_set_iomap_pte(ptep, pteval);
-		goto out;
-	}
+	struct mmu_update u;
 
-	ADD_STATS(set_pte_at, 1);
-//	ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
-	ADD_STATS(set_pte_at_current, mm == current->mm);
-	ADD_STATS(set_pte_at_kernel, mm == &init_mm);
+	if (paravirt_get_lazy_mode() != PARAVIRT_LAZY_MMU)
+		return false;
 
-	if (mm == current->mm || mm == &init_mm) {
-		if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
-			struct multicall_space mcs;
-			mcs = xen_mc_entry(0);
+	xen_mc_batch();
 
-			MULTI_update_va_mapping(mcs.mc, addr, pteval, 0);
-			ADD_STATS(set_pte_at_batched, 1);
-			xen_mc_issue(PARAVIRT_LAZY_MMU);
-			goto out;
-		} else
-			if (HYPERVISOR_update_va_mapping(addr, pteval, 0) == 0)
-				goto out;
-	}
-	xen_set_pte(ptep, pteval);
+	u.ptr = virt_to_machine(ptep).maddr | MMU_NORMAL_PT_UPDATE;
+	u.val = pte_val_ma(pteval);
+	xen_extend_mmu_update(&u);
+
+	xen_mc_issue(PARAVIRT_LAZY_MMU);
 
-out:	return;
+	return true;
+}
+
+static void xen_set_pte(pte_t *ptep, pte_t pteval)
+{
+	if (!xen_batched_set_pte(ptep, pteval))
+		native_set_pte(ptep, pteval);
+}
+
+static void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
+		    pte_t *ptep, pte_t pteval)
+{
+	xen_set_pte(ptep, pteval);
 }
 
 pte_t xen_ptep_modify_prot_start(struct mm_struct *mm,
@@ -389,13 +307,10 @@ void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
 
 	xen_mc_batch();
 
-	u.ptr = arbitrary_virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
+	u.ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
 	u.val = pte_val_ma(pte);
 	xen_extend_mmu_update(&u);
 
-	ADD_STATS(prot_commit, 1);
-	ADD_STATS(prot_commit_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
-
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
 
@@ -463,7 +378,7 @@ static pteval_t iomap_pte(pteval_t val)
 	return val;
 }
 
-pteval_t xen_pte_val(pte_t pte)
+static pteval_t xen_pte_val(pte_t pte)
 {
 	pteval_t pteval = pte.pte;
 
@@ -480,7 +395,7 @@ pteval_t xen_pte_val(pte_t pte)
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val);
 
-pgdval_t xen_pgd_val(pgd_t pgd)
+static pgdval_t xen_pgd_val(pgd_t pgd)
 {
 	return pte_mfn_to_pfn(pgd.pgd);
 }
@@ -511,7 +426,7 @@ void xen_set_pat(u64 pat)
 	WARN_ON(pat != 0x0007010600070106ull);
 }
 
-pte_t xen_make_pte(pteval_t pte)
+static pte_t xen_make_pte(pteval_t pte)
 {
 	phys_addr_t addr = (pte & PTE_PFN_MASK);
 
@@ -581,20 +496,20 @@ pte_t xen_make_pte_debug(pteval_t pte)
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_debug);
 #endif
 
-pgd_t xen_make_pgd(pgdval_t pgd)
+static pgd_t xen_make_pgd(pgdval_t pgd)
 {
 	pgd = pte_pfn_to_mfn(pgd);
 	return native_make_pgd(pgd);
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pgd);
 
-pmdval_t xen_pmd_val(pmd_t pmd)
+static pmdval_t xen_pmd_val(pmd_t pmd)
 {
 	return pte_mfn_to_pfn(pmd.pmd);
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val);
 
-void xen_set_pud_hyper(pud_t *ptr, pud_t val)
+static void xen_set_pud_hyper(pud_t *ptr, pud_t val)
 {
 	struct mmu_update u;
 
@@ -607,17 +522,13 @@ void xen_set_pud_hyper(pud_t *ptr, pud_t val)
 	u.val = pud_val_ma(val);
 	xen_extend_mmu_update(&u);
 
-	ADD_STATS(pud_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
-
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 
 	preempt_enable();
 }
 
-void xen_set_pud(pud_t *ptr, pud_t val)
+static void xen_set_pud(pud_t *ptr, pud_t val)
 {
-	ADD_STATS(pud_update, 1);
-
 	/* If page is not pinned, we can just update the entry
 	   directly */
 	if (!xen_page_pinned(ptr)) {
@@ -625,56 +536,28 @@ void xen_set_pud(pud_t *ptr, pud_t val)
 		return;
 	}
 
-	ADD_STATS(pud_update_pinned, 1);
-
 	xen_set_pud_hyper(ptr, val);
 }
 
-void xen_set_pte(pte_t *ptep, pte_t pte)
-{
-	if (xen_iomap_pte(pte)) {
-		xen_set_iomap_pte(ptep, pte);
-		return;
-	}
-
-	ADD_STATS(pte_update, 1);
-//	ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
-	ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
-
 #ifdef CONFIG_X86_PAE
-	ptep->pte_high = pte.pte_high;
-	smp_wmb();
-	ptep->pte_low = pte.pte_low;
-#else
-	*ptep = pte;
-#endif
-}
-
-#ifdef CONFIG_X86_PAE
-void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
+static void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
 {
-	if (xen_iomap_pte(pte)) {
-		xen_set_iomap_pte(ptep, pte);
-		return;
-	}
-
 	set_64bit((u64 *)ptep, native_pte_val(pte));
 }
 
-void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+static void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
-	ptep->pte_low = 0;
-	smp_wmb();		/* make sure low gets written first */
-	ptep->pte_high = 0;
+	if (!xen_batched_set_pte(ptep, native_make_pte(0)))
+		native_pte_clear(mm, addr, ptep);
 }
 
-void xen_pmd_clear(pmd_t *pmdp)
+static void xen_pmd_clear(pmd_t *pmdp)
 {
 	set_pmd(pmdp, __pmd(0));
 }
 #endif	/* CONFIG_X86_PAE */
 
-pmd_t xen_make_pmd(pmdval_t pmd)
+static pmd_t xen_make_pmd(pmdval_t pmd)
 {
 	pmd = pte_pfn_to_mfn(pmd);
 	return native_make_pmd(pmd);
@@ -682,13 +565,13 @@ pmd_t xen_make_pmd(pmdval_t pmd)
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd);
 
 #if PAGETABLE_LEVELS == 4
-pudval_t xen_pud_val(pud_t pud)
+static pudval_t xen_pud_val(pud_t pud)
 {
 	return pte_mfn_to_pfn(pud.pud);
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val);
 
-pud_t xen_make_pud(pudval_t pud)
+static pud_t xen_make_pud(pudval_t pud)
 {
 	pud = pte_pfn_to_mfn(pud);
 
@@ -696,7 +579,7 @@ pud_t xen_make_pud(pudval_t pud)
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pud);
 
-pgd_t *xen_get_user_pgd(pgd_t *pgd)
+static pgd_t *xen_get_user_pgd(pgd_t *pgd)
 {
 	pgd_t *pgd_page = (pgd_t *)(((unsigned long)pgd) & PAGE_MASK);
 	unsigned offset = pgd - pgd_page;
@@ -728,7 +611,7 @@ static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
  *  2. It is always pinned
  *  3. It has no user pagetable attached to it
  */
-void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
+static void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
 {
 	preempt_disable();
 
@@ -741,12 +624,10 @@ void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
 	preempt_enable();
 }
 
-void xen_set_pgd(pgd_t *ptr, pgd_t val)
+static void xen_set_pgd(pgd_t *ptr, pgd_t val)
 {
 	pgd_t *user_ptr = xen_get_user_pgd(ptr);
 
-	ADD_STATS(pgd_update, 1);
-
 	/* If page is not pinned, we can just update the entry
 	   directly */
 	if (!xen_page_pinned(ptr)) {
@@ -758,9 +639,6 @@ void xen_set_pgd(pgd_t *ptr, pgd_t val)
 		return;
 	}
 
-	ADD_STATS(pgd_update_pinned, 1);
-	ADD_STATS(pgd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
-
 	/* If it's pinned, then we can at least batch the kernel and
 	   user updates together. */
 	xen_mc_batch();
@@ -1054,7 +932,7 @@ void xen_mm_pin_all(void)
  * that's before we have page structures to store the bits.  So do all
  * the book-keeping now.
  */
-static __init int xen_mark_pinned(struct mm_struct *mm, struct page *page,
+static int __init xen_mark_pinned(struct mm_struct *mm, struct page *page,
 				  enum pt_level level)
 {
 	SetPagePinned(page);
@@ -1162,14 +1040,14 @@ void xen_mm_unpin_all(void)
 	spin_unlock(&pgd_lock);
 }
 
-void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
+static void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
 {
 	spin_lock(&next->page_table_lock);
 	xen_pgd_pin(next);
 	spin_unlock(&next->page_table_lock);
 }
 
-void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
+static void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
 {
 	spin_lock(&mm->page_table_lock);
 	xen_pgd_pin(mm);
@@ -1187,7 +1065,7 @@ static void drop_other_mm_ref(void *info)
 
 	active_mm = percpu_read(cpu_tlbstate.active_mm);
 
-	if (active_mm == mm)
+	if (active_mm == mm && percpu_read(cpu_tlbstate.state) != TLBSTATE_OK)
 		leave_mm(smp_processor_id());
 
 	/* If this cpu still has a stale cr3 reference, then make sure
@@ -1256,7 +1134,7 @@ static void xen_drop_mm_ref(struct mm_struct *mm)
  * pagetable because of lazy tlb flushing.  This means we need need to
  * switch all CPUs off this pagetable before we can unpin it.
  */
-void xen_exit_mmap(struct mm_struct *mm)
+static void xen_exit_mmap(struct mm_struct *mm)
 {
 	get_cpu();		/* make sure we don't move around */
 	xen_drop_mm_ref(mm);
@@ -1271,7 +1149,7 @@ void xen_exit_mmap(struct mm_struct *mm)
 	spin_unlock(&mm->page_table_lock);
 }
 
-static __init void xen_pagetable_setup_start(pgd_t *base)
+static void __init xen_pagetable_setup_start(pgd_t *base)
 {
 }
 
@@ -1291,7 +1169,7 @@ static __init void xen_mapping_pagetable_reserve(u64 start, u64 end)
 
 static void xen_post_allocator_init(void);
 
-static __init void xen_pagetable_setup_done(pgd_t *base)
+static void __init xen_pagetable_setup_done(pgd_t *base)
 {
 	xen_setup_shared_info();
 	xen_post_allocator_init();
@@ -1488,7 +1366,7 @@ static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
 }
 
 #ifdef CONFIG_X86_32
-static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
+static pte_t __init mask_rw_pte(pte_t *ptep, pte_t pte)
 {
 	/* If there's an existing pte, then don't allow _PAGE_RW to be set */
 	if (pte_val_ma(*ptep) & _PAGE_PRESENT)
@@ -1498,7 +1376,7 @@ static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
 	return pte;
 }
 #else /* CONFIG_X86_64 */
-static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
+static pte_t __init mask_rw_pte(pte_t *ptep, pte_t pte)
 {
 	unsigned long pfn = pte_pfn(pte);
 
@@ -1519,7 +1397,7 @@ static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
 
 /* Init-time set_pte while constructing initial pagetables, which
    doesn't allow RO pagetable pages to be remapped RW */
-static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
+static void __init xen_set_pte_init(pte_t *ptep, pte_t pte)
 {
 	pte = mask_rw_pte(ptep, pte);
 
@@ -1537,7 +1415,7 @@ static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
 
 /* 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)
+static void __init xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
 {
 #ifdef CONFIG_FLATMEM
 	BUG_ON(mem_map);	/* should only be used early */
@@ -1547,7 +1425,7 @@ static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
 }
 
 /* Used for pmd and pud */
-static __init void xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn)
+static void __init xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn)
 {
 #ifdef CONFIG_FLATMEM
 	BUG_ON(mem_map);	/* should only be used early */
@@ -1557,13 +1435,13 @@ static __init void xen_alloc_pmd_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 __init void xen_release_pte_init(unsigned long pfn)
+static void __init xen_release_pte_init(unsigned long pfn)
 {
 	pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
 	make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
 }
 
-static __init void xen_release_pmd_init(unsigned long pfn)
+static void __init xen_release_pmd_init(unsigned long pfn)
 {
 	make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
 }
@@ -1689,7 +1567,7 @@ static void set_page_prot(void *addr, pgprot_t prot)
 		BUG();
 }
 
-static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
+static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
 {
 	unsigned pmdidx, pteidx;
 	unsigned ident_pte;
@@ -1772,7 +1650,7 @@ static void convert_pfn_mfn(void *v)
  * of the physical mapping once some sort of allocator has been set
  * up.
  */
-__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
+pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
 					 unsigned long max_pfn)
 {
 	pud_t *l3;
@@ -1843,7 +1721,7 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
 static RESERVE_BRK_ARRAY(pmd_t, initial_kernel_pmd, PTRS_PER_PMD);
 static RESERVE_BRK_ARRAY(pmd_t, swapper_kernel_pmd, PTRS_PER_PMD);
 
-static __init void xen_write_cr3_init(unsigned long cr3)
+static void __init xen_write_cr3_init(unsigned long cr3)
 {
 	unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));
 
@@ -1880,7 +1758,7 @@ static __init void xen_write_cr3_init(unsigned long cr3)
 	pv_mmu_ops.write_cr3 = &xen_write_cr3;
 }
 
-__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
+pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
 					 unsigned long max_pfn)
 {
 	pmd_t *kernel_pmd;
@@ -1986,7 +1864,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
 #endif
 }
 
-__init void xen_ident_map_ISA(void)
+void __init xen_ident_map_ISA(void)
 {
 	unsigned long pa;
 
@@ -2009,7 +1887,7 @@ __init void xen_ident_map_ISA(void)
 	xen_flush_tlb();
 }
 
-static __init void xen_post_allocator_init(void)
+static void __init xen_post_allocator_init(void)
 {
 #ifdef CONFIG_XEN_DEBUG
 	pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte_debug);
@@ -2046,7 +1924,7 @@ static void xen_leave_lazy_mmu(void)
 	preempt_enable();
 }
 
-static const struct pv_mmu_ops xen_mmu_ops __initdata = {
+static const struct pv_mmu_ops xen_mmu_ops __initconst = {
 	.read_cr2 = xen_read_cr2,
 	.write_cr2 = xen_write_cr2,
 
@@ -2371,7 +2249,7 @@ static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,
 	struct remap_data *rmd = data;
 	pte_t pte = pte_mkspecial(pfn_pte(rmd->mfn++, rmd->prot));
 
-	rmd->mmu_update->ptr = arbitrary_virt_to_machine(ptep).maddr;
+	rmd->mmu_update->ptr = virt_to_machine(ptep).maddr;
 	rmd->mmu_update->val = pte_val_ma(pte);
 	rmd->mmu_update++;
 
@@ -2425,7 +2303,6 @@ out:
 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
 
 #ifdef CONFIG_XEN_DEBUG_FS
-
 static int p2m_dump_open(struct inode *inode, struct file *filp)
 {
 	return single_open(filp, p2m_dump_show, NULL);
@@ -2437,65 +2314,4 @@ static const struct file_operations p2m_dump_fops = {
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
-
-static struct dentry *d_mmu_debug;
-
-static int __init xen_mmu_debugfs(void)
-{
-	struct dentry *d_xen = xen_init_debugfs();
-
-	if (d_xen == NULL)
-		return -ENOMEM;
-
-	d_mmu_debug = debugfs_create_dir("mmu", d_xen);
-
-	debugfs_create_u8("zero_stats", 0644, d_mmu_debug, &zero_stats);
-
-	debugfs_create_u32("pgd_update", 0444, d_mmu_debug, &mmu_stats.pgd_update);
-	debugfs_create_u32("pgd_update_pinned", 0444, d_mmu_debug,
-			   &mmu_stats.pgd_update_pinned);
-	debugfs_create_u32("pgd_update_batched", 0444, d_mmu_debug,
-			   &mmu_stats.pgd_update_pinned);
-
-	debugfs_create_u32("pud_update", 0444, d_mmu_debug, &mmu_stats.pud_update);
-	debugfs_create_u32("pud_update_pinned", 0444, d_mmu_debug,
-			   &mmu_stats.pud_update_pinned);
-	debugfs_create_u32("pud_update_batched", 0444, d_mmu_debug,
-			   &mmu_stats.pud_update_pinned);
-
-	debugfs_create_u32("pmd_update", 0444, d_mmu_debug, &mmu_stats.pmd_update);
-	debugfs_create_u32("pmd_update_pinned", 0444, d_mmu_debug,
-			   &mmu_stats.pmd_update_pinned);
-	debugfs_create_u32("pmd_update_batched", 0444, d_mmu_debug,
-			   &mmu_stats.pmd_update_pinned);
-
-	debugfs_create_u32("pte_update", 0444, d_mmu_debug, &mmu_stats.pte_update);
-//	debugfs_create_u32("pte_update_pinned", 0444, d_mmu_debug,
-//			   &mmu_stats.pte_update_pinned);
-	debugfs_create_u32("pte_update_batched", 0444, d_mmu_debug,
-			   &mmu_stats.pte_update_pinned);
-
-	debugfs_create_u32("mmu_update", 0444, d_mmu_debug, &mmu_stats.mmu_update);
-	debugfs_create_u32("mmu_update_extended", 0444, d_mmu_debug,
-			   &mmu_stats.mmu_update_extended);
-	xen_debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug,
-				     mmu_stats.mmu_update_histo, 20);
-
-	debugfs_create_u32("set_pte_at", 0444, d_mmu_debug, &mmu_stats.set_pte_at);
-	debugfs_create_u32("set_pte_at_batched", 0444, d_mmu_debug,
-			   &mmu_stats.set_pte_at_batched);
-	debugfs_create_u32("set_pte_at_current", 0444, d_mmu_debug,
-			   &mmu_stats.set_pte_at_current);
-	debugfs_create_u32("set_pte_at_kernel", 0444, d_mmu_debug,
-			   &mmu_stats.set_pte_at_kernel);
-
-	debugfs_create_u32("prot_commit", 0444, d_mmu_debug, &mmu_stats.prot_commit);
-	debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
-			   &mmu_stats.prot_commit_batched);
-
-	debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops);
-	return 0;
-}
-fs_initcall(xen_mmu_debugfs);
-
-#endif	/* CONFIG_XEN_DEBUG_FS */
+#endif /* CONFIG_XEN_DEBUG_FS */
diff --git a/arch/x86/xen/mmu.h b/arch/x86/xen/mmu.h
index 537bb9aab77..73809bb951b 100644
--- a/arch/x86/xen/mmu.h
+++ b/arch/x86/xen/mmu.h
@@ -15,43 +15,6 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
 
 void set_pte_mfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);
 
-
-void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next);
-void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm);
-void xen_exit_mmap(struct mm_struct *mm);
-
-pteval_t xen_pte_val(pte_t);
-pmdval_t xen_pmd_val(pmd_t);
-pgdval_t xen_pgd_val(pgd_t);
-
-pte_t xen_make_pte(pteval_t);
-pmd_t xen_make_pmd(pmdval_t);
-pgd_t xen_make_pgd(pgdval_t);
-
-void xen_set_pte(pte_t *ptep, pte_t pteval);
-void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
-		    pte_t *ptep, pte_t pteval);
-
-#ifdef CONFIG_X86_PAE
-void xen_set_pte_atomic(pte_t *ptep, pte_t pte);
-void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
-void xen_pmd_clear(pmd_t *pmdp);
-#endif	/* CONFIG_X86_PAE */
-
-void xen_set_pmd(pmd_t *pmdp, pmd_t pmdval);
-void xen_set_pud(pud_t *ptr, pud_t val);
-void xen_set_pmd_hyper(pmd_t *pmdp, pmd_t pmdval);
-void xen_set_pud_hyper(pud_t *ptr, pud_t val);
-
-#if PAGETABLE_LEVELS == 4
-pudval_t xen_pud_val(pud_t pud);
-pud_t xen_make_pud(pudval_t pudval);
-void xen_set_pgd(pgd_t *pgdp, pgd_t pgd);
-void xen_set_pgd_hyper(pgd_t *pgdp, pgd_t pgd);
-#endif
-
-pgd_t *xen_get_user_pgd(pgd_t *pgd);
-
 pte_t xen_ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 void  xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
 				  pte_t *ptep, pte_t pte);
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 141eb0de8b0..58efeb9d544 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -522,11 +522,20 @@ static bool __init __early_alloc_p2m(unsigned long pfn)
 	/* Boundary cross-over for the edges: */
 	if (idx) {
 		unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);
+		unsigned long *mid_mfn_p;
 
 		p2m_init(p2m);
 
 		p2m_top[topidx][mididx] = p2m;
 
+		/* For save/restore we need to MFN of the P2M saved */
+		
+		mid_mfn_p = p2m_top_mfn_p[topidx];
+		WARN(mid_mfn_p[mididx] != virt_to_mfn(p2m_missing),
+			"P2M_TOP_P[%d][%d] != MFN of p2m_missing!\n",
+			topidx, mididx);
+		mid_mfn_p[mididx] = virt_to_mfn(p2m);
+
 	}
 	return idx != 0;
 }
@@ -549,12 +558,29 @@ unsigned long __init set_phys_range_identity(unsigned long pfn_s,
 		pfn += P2M_MID_PER_PAGE * P2M_PER_PAGE)
 	{
 		unsigned topidx = p2m_top_index(pfn);
-		if (p2m_top[topidx] == p2m_mid_missing) {
-			unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
+		unsigned long *mid_mfn_p;
+		unsigned long **mid;
+
+		mid = p2m_top[topidx];
+		mid_mfn_p = p2m_top_mfn_p[topidx];
+		if (mid == p2m_mid_missing) {
+			mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
 
 			p2m_mid_init(mid);
 
 			p2m_top[topidx] = mid;
+
+			BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
+		}
+		/* And the save/restore P2M tables.. */
+		if (mid_mfn_p == p2m_mid_missing_mfn) {
+			mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
+			p2m_mid_mfn_init(mid_mfn_p);
+
+			p2m_top_mfn_p[topidx] = mid_mfn_p;
+			p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
+			/* Note: we don't set mid_mfn_p[midix] here,
+		 	 * look in __early_alloc_p2m */
 		}
 	}
 
@@ -650,7 +676,7 @@ static unsigned long mfn_hash(unsigned long mfn)
 }
 
 /* Add an MFN override for a particular page */
-int m2p_add_override(unsigned long mfn, struct page *page)
+int m2p_add_override(unsigned long mfn, struct page *page, bool clear_pte)
 {
 	unsigned long flags;
 	unsigned long pfn;
@@ -662,7 +688,6 @@ int m2p_add_override(unsigned long mfn, struct page *page)
 	if (!PageHighMem(page)) {
 		address = (unsigned long)__va(pfn << PAGE_SHIFT);
 		ptep = lookup_address(address, &level);
-
 		if (WARN(ptep == NULL || level != PG_LEVEL_4K,
 					"m2p_add_override: pfn %lx not mapped", pfn))
 			return -EINVAL;
@@ -674,18 +699,17 @@ int m2p_add_override(unsigned long mfn, struct page *page)
 	if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
 		return -ENOMEM;
 
-	if (!PageHighMem(page))
+	if (clear_pte && !PageHighMem(page))
 		/* Just zap old mapping for now */
 		pte_clear(&init_mm, address, ptep);
-
 	spin_lock_irqsave(&m2p_override_lock, flags);
 	list_add(&page->lru,  &m2p_overrides[mfn_hash(mfn)]);
 	spin_unlock_irqrestore(&m2p_override_lock, flags);
 
 	return 0;
 }
-
-int m2p_remove_override(struct page *page)
+EXPORT_SYMBOL_GPL(m2p_add_override);
+int m2p_remove_override(struct page *page, bool clear_pte)
 {
 	unsigned long flags;
 	unsigned long mfn;
@@ -713,7 +737,7 @@ int m2p_remove_override(struct page *page)
 	spin_unlock_irqrestore(&m2p_override_lock, flags);
 	set_phys_to_machine(pfn, page->index);
 
-	if (!PageHighMem(page))
+	if (clear_pte && !PageHighMem(page))
 		set_pte_at(&init_mm, address, ptep,
 				pfn_pte(pfn, PAGE_KERNEL));
 		/* No tlb flush necessary because the caller already
@@ -721,6 +745,7 @@ int m2p_remove_override(struct page *page)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(m2p_remove_override);
 
 struct page *m2p_find_override(unsigned long mfn)
 {
diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index bfd0632fe65..b480d4207a4 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -36,7 +36,7 @@ int __init pci_xen_swiotlb_detect(void)
 
 	/* If running as PV guest, either iommu=soft, or swiotlb=force will
 	 * activate this IOMMU. If running as PV privileged, activate it
-	 * irregardlesss.
+	 * irregardless.
 	 */
 	if ((xen_initial_domain() || swiotlb || swiotlb_force) &&
 	    (xen_pv_domain()))
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 90bac0aac3a..be1a464f6d6 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -50,7 +50,7 @@ phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
  */
 #define EXTRA_MEM_RATIO		(10)
 
-static __init void xen_add_extra_mem(unsigned long pages)
+static void __init xen_add_extra_mem(unsigned long pages)
 {
 	unsigned long pfn;
 
@@ -166,7 +166,7 @@ static unsigned long __init xen_set_identity(const struct e820entry *list,
 		if (last > end)
 			continue;
 
-		if (entry->type == E820_RAM) {
+		if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) {
 			if (start > start_pci)
 				identity += set_phys_range_identity(
 						PFN_UP(start_pci), PFN_DOWN(start));
@@ -227,7 +227,11 @@ char * __init xen_memory_setup(void)
 
 	memcpy(map_raw, map, sizeof(map));
 	e820.nr_map = 0;
+#ifdef CONFIG_X86_32
+	xen_extra_mem_start = mem_end;
+#else
 	xen_extra_mem_start = max((1ULL << 32), mem_end);
+#endif
 	for (i = 0; i < memmap.nr_entries; i++) {
 		unsigned long long end;
 
@@ -336,7 +340,7 @@ static void __init fiddle_vdso(void)
 #endif
 }
 
-static __cpuinit int register_callback(unsigned type, const void *func)
+static int __cpuinit register_callback(unsigned type, const void *func)
 {
 	struct callback_register callback = {
 		.type = type,
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 30612441ed9..41038c01de4 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -46,18 +46,17 @@ static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
 
 /*
- * Reschedule call back. Nothing to do,
- * all the work is done automatically when
- * we return from the interrupt.
+ * Reschedule call back.
  */
 static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
 {
 	inc_irq_stat(irq_resched_count);
+	scheduler_ipi();
 
 	return IRQ_HANDLED;
 }
 
-static __cpuinit void cpu_bringup(void)
+static void __cpuinit cpu_bringup(void)
 {
 	int cpu = smp_processor_id();
 
@@ -85,7 +84,7 @@ static __cpuinit void cpu_bringup(void)
 	wmb();			/* make sure everything is out */
 }
 
-static __cpuinit void cpu_bringup_and_idle(void)
+static void __cpuinit cpu_bringup_and_idle(void)
 {
 	cpu_bringup();
 	cpu_idle();
@@ -242,7 +241,7 @@ static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
 	}
 }
 
-static __cpuinit int
+static int __cpuinit
 cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 {
 	struct vcpu_guest_context *ctxt;
@@ -486,7 +485,7 @@ static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static const struct smp_ops xen_smp_ops __initdata = {
+static const struct smp_ops xen_smp_ops __initconst = {
 	.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
 	.smp_prepare_cpus = xen_smp_prepare_cpus,
 	.smp_cpus_done = xen_smp_cpus_done,
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 2e2d370a47b..5158c505bef 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -26,8 +26,6 @@
 
 #include "xen-ops.h"
 
-#define XEN_SHIFT 22
-
 /* Xen may fire a timer up to this many ns early */
 #define TIMER_SLOP	100000
 #define NS_PER_TICK	(1000000000LL / HZ)
@@ -211,8 +209,6 @@ static struct clocksource xen_clocksource __read_mostly = {
 	.rating = 400,
 	.read = xen_clocksource_get_cycles,
 	.mask = ~0,
-	.mult = 1<<XEN_SHIFT,		/* time directly in nanoseconds */
-	.shift = XEN_SHIFT,
 	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
@@ -439,16 +435,16 @@ void xen_timer_resume(void)
 	}
 }
 
-static const struct pv_time_ops xen_time_ops __initdata = {
+static const struct pv_time_ops xen_time_ops __initconst = {
 	.sched_clock = xen_clocksource_read,
 };
 
-static __init void xen_time_init(void)
+static void __init xen_time_init(void)
 {
 	int cpu = smp_processor_id();
 	struct timespec tp;
 
-	clocksource_register(&xen_clocksource);
+	clocksource_register_hz(&xen_clocksource, NSEC_PER_SEC);
 
 	if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL) == 0) {
 		/* Successfully turned off 100Hz tick, so we have the
@@ -468,7 +464,7 @@ static __init void xen_time_init(void)
 	xen_setup_cpu_clockevents();
 }
 
-__init void xen_init_time_ops(void)
+void __init xen_init_time_ops(void)
 {
 	pv_time_ops = xen_time_ops;
 
@@ -490,7 +486,7 @@ static void xen_hvm_setup_cpu_clockevents(void)
 	xen_setup_cpu_clockevents();
 }
 
-__init void xen_hvm_init_time_ops(void)
+void __init xen_hvm_init_time_ops(void)
 {
 	/* vector callback is needed otherwise we cannot receive interrupts
 	 * on cpu > 0 and at this point we don't know how many cpus are
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 3112f55638c..97dfdc8757b 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -74,7 +74,7 @@ static inline void xen_hvm_smp_init(void) {}
 
 #ifdef CONFIG_PARAVIRT_SPINLOCKS
 void __init xen_init_spinlocks(void);
-__cpuinit void xen_init_lock_cpu(int cpu);
+void __cpuinit xen_init_lock_cpu(int cpu);
 void xen_uninit_lock_cpu(int cpu);
 #else
 static inline void xen_init_spinlocks(void)