Merge branch 'linus' into sched/core

Merge reason: we want to queue up dependent cleanup

Signed-off-by: Ingo Molnar <mingo@elte.hu>

7 files changed, 203 insertions, 126 deletions

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index eb8a78d77d9d..533a199e7a3f 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -8,9 +8,12 @@ obj-$(CONFIG_BLOCK)		+= biomerge.o
 obj-$(CONFIG_HOTPLUG_CPU)	+= cpu_hotplug.o
 obj-$(CONFIG_XEN_XENCOMM)	+= xencomm.o
 obj-$(CONFIG_XEN_BALLOON)	+= balloon.o
-obj-$(CONFIG_XEN_DEV_EVTCHN)	+= evtchn.o
+obj-$(CONFIG_XEN_DEV_EVTCHN)	+= xen-evtchn.o
 obj-$(CONFIG_XENFS)		+= xenfs/
 obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
 obj-$(CONFIG_XEN_PLATFORM_PCI)	+= platform-pci.o
 obj-$(CONFIG_SWIOTLB_XEN)	+= swiotlb-xen.o
 obj-$(CONFIG_XEN_DOM0)		+= pci.o
+
+xen-evtchn-y			:= evtchn.o
+
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 500290b150bb..43f9f02c7db0 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -50,6 +50,7 @@
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
 #include <asm/tlb.h>
+#include <asm/e820.h>
 
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
@@ -119,7 +120,7 @@ static void scrub_page(struct page *page)
 }
 
 /* balloon_append: add the given page to the balloon. */
-static void balloon_append(struct page *page)
+static void __balloon_append(struct page *page)
 {
 	/* Lowmem is re-populated first, so highmem pages go at list tail. */
 	if (PageHighMem(page)) {
@@ -130,7 +131,11 @@ static void balloon_append(struct page *page)
 		list_add(&page->lru, &ballooned_pages);
 		balloon_stats.balloon_low++;
 	}
+}
 
+static void balloon_append(struct page *page)
+{
+	__balloon_append(page);
 	totalram_pages--;
 }
 
@@ -191,7 +196,7 @@ static unsigned long current_target(void)
 
 static int increase_reservation(unsigned long nr_pages)
 {
-	unsigned long  pfn, i, flags;
+	unsigned long  pfn, i;
 	struct page   *page;
 	long           rc;
 	struct xen_memory_reservation reservation = {
@@ -203,8 +208,6 @@ static int increase_reservation(unsigned long nr_pages)
 	if (nr_pages > ARRAY_SIZE(frame_list))
 		nr_pages = ARRAY_SIZE(frame_list);
 
-	spin_lock_irqsave(&xen_reservation_lock, flags);
-
 	page = balloon_first_page();
 	for (i = 0; i < nr_pages; i++) {
 		BUG_ON(page == NULL);
@@ -247,14 +250,12 @@ static int increase_reservation(unsigned long nr_pages)
 	balloon_stats.current_pages += rc;
 
  out:
-	spin_unlock_irqrestore(&xen_reservation_lock, flags);
-
 	return rc < 0 ? rc : rc != nr_pages;
 }
 
 static int decrease_reservation(unsigned long nr_pages)
 {
-	unsigned long  pfn, i, flags;
+	unsigned long  pfn, i;
 	struct page   *page;
 	int            need_sleep = 0;
 	int ret;
@@ -292,8 +293,6 @@ static int decrease_reservation(unsigned long nr_pages)
 	kmap_flush_unused();
 	flush_tlb_all();
 
-	spin_lock_irqsave(&xen_reservation_lock, flags);
-
 	/* No more mappings: invalidate P2M and add to balloon. */
 	for (i = 0; i < nr_pages; i++) {
 		pfn = mfn_to_pfn(frame_list[i]);
@@ -308,8 +307,6 @@ static int decrease_reservation(unsigned long nr_pages)
 
 	balloon_stats.current_pages -= nr_pages;
 
-	spin_unlock_irqrestore(&xen_reservation_lock, flags);
-
 	return need_sleep;
 }
 
@@ -395,7 +392,7 @@ static struct notifier_block xenstore_notifier;
 
 static int __init balloon_init(void)
 {
-	unsigned long pfn;
+	unsigned long pfn, extra_pfn_end;
 	struct page *page;
 
 	if (!xen_pv_domain())
@@ -415,11 +412,24 @@ static int __init balloon_init(void)
 
 	register_balloon(&balloon_sysdev);
 
-	/* Initialise the balloon with excess memory space. */
-	for (pfn = xen_start_info->nr_pages; pfn < max_pfn; pfn++) {
+	/*
+	 * Initialise the balloon with excess memory space.  We need
+	 * to make sure we don't add memory which doesn't exist or
+	 * logically exist.  The E820 map can be trimmed to be smaller
+	 * than the amount of physical memory due to the mem= command
+	 * line parameter.  And if this is a 32-bit non-HIGHMEM kernel
+	 * on a system with memory which requires highmem to access,
+	 * don't try to use it.
+	 */
+	extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()),
+			    (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size));
+	for (pfn = PFN_UP(xen_extra_mem_start);
+	     pfn < extra_pfn_end;
+	     pfn++) {
 		page = pfn_to_page(pfn);
-		if (!PageReserved(page))
-			balloon_append(page);
+		/* totalram_pages doesn't include the boot-time
+		   balloon extension, so don't subtract from it. */
+		__balloon_append(page);
 	}
 
 	target_watch.callback = watch_target;
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 321a0c8346e5..31af0ac31a98 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -105,7 +105,6 @@ struct irq_info
 
 static struct irq_info *irq_info;
 static int *pirq_to_irq;
-static int nr_pirqs;
 
 static int *evtchn_to_irq;
 struct cpu_evtchn_s {
@@ -278,17 +277,17 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 	cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu));
 #endif
 
-	__clear_bit(chn, cpu_evtchn_mask(cpu_from_irq(irq)));
-	__set_bit(chn, cpu_evtchn_mask(cpu));
+	clear_bit(chn, cpu_evtchn_mask(cpu_from_irq(irq)));
+	set_bit(chn, cpu_evtchn_mask(cpu));
 
 	irq_info[irq].cpu = cpu;
 }
 
 static void init_evtchn_cpu_bindings(void)
 {
+	int i;
 #ifdef CONFIG_SMP
 	struct irq_desc *desc;
-	int i;
 
 	/* By default all event channels notify CPU#0. */
 	for_each_irq_desc(i, desc) {
@@ -296,7 +295,10 @@ static void init_evtchn_cpu_bindings(void)
 	}
 #endif
 
-	memset(cpu_evtchn_mask(0), ~0, sizeof(struct cpu_evtchn_s));
+	for_each_possible_cpu(i)
+		memset(cpu_evtchn_mask(i),
+		       (i == 0) ? ~0 : 0, sizeof(struct cpu_evtchn_s));
+
 }
 
 static inline void clear_evtchn(int port)
@@ -382,12 +384,17 @@ static int get_nr_hw_irqs(void)
 	return ret;
 }
 
-/* callers of this function should make sure that PHYSDEVOP_get_nr_pirqs
- * succeeded otherwise nr_pirqs won't hold the right value */
-static int find_unbound_pirq(void)
+static int find_unbound_pirq(int type)
 {
-	int i;
-	for (i = nr_pirqs-1; i >= 0; i--) {
+	int rc, i;
+	struct physdev_get_free_pirq op_get_free_pirq;
+	op_get_free_pirq.type = type;
+
+	rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
+	if (!rc)
+		return op_get_free_pirq.pirq;
+
+	for (i = 0; i < nr_irqs; i++) {
 		if (pirq_to_irq[i] < 0)
 			return i;
 	}
@@ -420,7 +427,7 @@ static int find_unbound_irq(void)
 	if (irq == start)
 		goto no_irqs;
 
-	res = irq_alloc_desc_at(irq, 0);
+	res = irq_alloc_desc_at(irq, -1);
 
 	if (WARN_ON(res != irq))
 		return -1;
@@ -608,10 +615,10 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
 
 	spin_lock(&irq_mapping_update_lock);
 
-	if ((pirq > nr_pirqs) || (gsi > nr_irqs)) {
+	if ((pirq > nr_irqs) || (gsi > nr_irqs)) {
 		printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n",
-			pirq > nr_pirqs ? "nr_pirqs" :"",
-			gsi > nr_irqs ? "nr_irqs" : "");
+			pirq > nr_irqs ? "pirq" :"",
+			gsi > nr_irqs ? "gsi" : "");
 		goto out;
 	}
 
@@ -627,7 +634,7 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
 	if (identity_mapped_irq(gsi) || (!xen_initial_domain() &&
 				xen_pv_domain())) {
 		irq = gsi;
-		irq_alloc_desc_at(irq, 0);
+		irq_alloc_desc_at(irq, -1);
 	} else
 		irq = find_unbound_irq();
 
@@ -661,17 +668,21 @@ out:
 #include <linux/msi.h>
 #include "../pci/msi.h"
 
-void xen_allocate_pirq_msi(char *name, int *irq, int *pirq)
+void xen_allocate_pirq_msi(char *name, int *irq, int *pirq, int alloc)
 {
 	spin_lock(&irq_mapping_update_lock);
 
-	*irq = find_unbound_irq();
-	if (*irq == -1)
-		goto out;
+	if (alloc & XEN_ALLOC_IRQ) {
+		*irq = find_unbound_irq();
+		if (*irq == -1)
+			goto out;
+	}
 
-	*pirq = find_unbound_pirq();
-	if (*pirq == -1)
-		goto out;
+	if (alloc & XEN_ALLOC_PIRQ) {
+		*pirq = find_unbound_pirq(MAP_PIRQ_TYPE_MSI);
+		if (*pirq == -1)
+			goto out;
+	}
 
 	set_irq_chip_and_handler_name(*irq, &xen_pirq_chip,
 				      handle_level_irq, name);
@@ -752,13 +763,14 @@ int xen_destroy_irq(int irq)
 		goto out;
 
 	if (xen_initial_domain()) {
-		unmap_irq.pirq = info->u.pirq.gsi;
+		unmap_irq.pirq = info->u.pirq.pirq;
 		unmap_irq.domid = DOMID_SELF;
 		rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 		if (rc) {
 			printk(KERN_WARNING "unmap irq failed %d\n", rc);
 			goto out;
 		}
+		pirq_to_irq[info->u.pirq.pirq] = -1;
 	}
 	irq_info[irq] = mk_unbound_info();
 
@@ -779,6 +791,11 @@ int xen_gsi_from_irq(unsigned irq)
 	return gsi_from_irq(irq);
 }
 
+int xen_irq_from_pirq(unsigned pirq)
+{
+	return pirq_to_irq[pirq];
+}
+
 int bind_evtchn_to_irq(unsigned int evtchn)
 {
 	int irq;
@@ -1276,6 +1293,42 @@ static int retrigger_dynirq(unsigned int irq)
 	return ret;
 }
 
+static void restore_cpu_pirqs(void)
+{
+	int pirq, rc, irq, gsi;
+	struct physdev_map_pirq map_irq;
+
+	for (pirq = 0; pirq < nr_irqs; pirq++) {
+		irq = pirq_to_irq[pirq];
+		if (irq == -1)
+			continue;
+
+		/* save/restore of PT devices doesn't work, so at this point the
+		 * only devices present are GSI based emulated devices */
+		gsi = gsi_from_irq(irq);
+		if (!gsi)
+			continue;
+
+		map_irq.domid = DOMID_SELF;
+		map_irq.type = MAP_PIRQ_TYPE_GSI;
+		map_irq.index = gsi;
+		map_irq.pirq = pirq;
+
+		rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
+		if (rc) {
+			printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
+					gsi, irq, pirq, rc);
+			irq_info[irq] = mk_unbound_info();
+			pirq_to_irq[pirq] = -1;
+			continue;
+		}
+
+		printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
+
+		startup_pirq(irq);
+	}
+}
+
 static void restore_cpu_virqs(unsigned int cpu)
 {
 	struct evtchn_bind_virq bind_virq;
@@ -1419,6 +1472,8 @@ void xen_irq_resume(void)
 
 		unmask_evtchn(evtchn);
 	}
+
+	restore_cpu_pirqs();
 }
 
 static struct irq_chip xen_dynamic_chip __read_mostly = {
@@ -1503,26 +1558,17 @@ void xen_callback_vector(void) {}
 
 void __init xen_init_IRQ(void)
 {
-	int i, rc;
-	struct physdev_nr_pirqs op_nr_pirqs;
+	int i;
 
 	cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s),
 				    GFP_KERNEL);
 	irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL);
 
-	rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_nr_pirqs, &op_nr_pirqs);
-	if (rc < 0) {
-		nr_pirqs = nr_irqs;
-		if (rc != -ENOSYS)
-			printk(KERN_WARNING "PHYSDEVOP_get_nr_pirqs returned rc=%d\n", rc);
-	} else {
-		if (xen_pv_domain() && !xen_initial_domain())
-			nr_pirqs = max((int)op_nr_pirqs.nr_pirqs, nr_irqs);
-		else
-			nr_pirqs = op_nr_pirqs.nr_pirqs;
-	}
-	pirq_to_irq = kcalloc(nr_pirqs, sizeof(*pirq_to_irq), GFP_KERNEL);
-	for (i = 0; i < nr_pirqs; i++)
+	/* We are using nr_irqs as the maximum number of pirq available but
+	 * that number is actually chosen by Xen and we don't know exactly
+	 * what it is. Be careful choosing high pirq numbers. */
+	pirq_to_irq = kcalloc(nr_irqs, sizeof(*pirq_to_irq), GFP_KERNEL);
+	for (i = 0; i < nr_irqs; i++)
 		pirq_to_irq[i] = -1;
 
 	evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index fec6ba3c08a8..ef11daf0cafe 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -69,20 +69,51 @@ struct per_user_data {
 	const char *name;
 };
 
-/* Who's bound to each port? */
-static struct per_user_data *port_user[NR_EVENT_CHANNELS];
+/*
+ * Who's bound to each port?  This is logically an array of struct
+ * per_user_data *, but we encode the current enabled-state in bit 0.
+ */
+static unsigned long *port_user;
 static DEFINE_SPINLOCK(port_user_lock); /* protects port_user[] and ring_prod */
 
-irqreturn_t evtchn_interrupt(int irq, void *data)
+static inline struct per_user_data *get_port_user(unsigned port)
+{
+	return (struct per_user_data *)(port_user[port] & ~1);
+}
+
+static inline void set_port_user(unsigned port, struct per_user_data *u)
+{
+	port_user[port] = (unsigned long)u;
+}
+
+static inline bool get_port_enabled(unsigned port)
+{
+	return port_user[port] & 1;
+}
+
+static inline void set_port_enabled(unsigned port, bool enabled)
+{
+	if (enabled)
+		port_user[port] |= 1;
+	else
+		port_user[port] &= ~1;
+}
+
+static irqreturn_t evtchn_interrupt(int irq, void *data)
 {
 	unsigned int port = (unsigned long)data;
 	struct per_user_data *u;
 
 	spin_lock(&port_user_lock);
 
-	u = port_user[port];
+	u = get_port_user(port);
+
+	WARN(!get_port_enabled(port),
+	     "Interrupt for port %d, but apparently not enabled; per-user %p\n",
+	     port, u);
 
 	disable_irq_nosync(irq);
+	set_port_enabled(port, false);
 
 	if ((u->ring_prod - u->ring_cons) < EVTCHN_RING_SIZE) {
 		u->ring[EVTCHN_RING_MASK(u->ring_prod)] = port;
@@ -92,9 +123,8 @@ irqreturn_t evtchn_interrupt(int irq, void *data)
 			kill_fasync(&u->evtchn_async_queue,
 				    SIGIO, POLL_IN);
 		}
-	} else {
+	} else
 		u->ring_overflow = 1;
-	}
 
 	spin_unlock(&port_user_lock);
 
@@ -198,9 +228,18 @@ static ssize_t evtchn_write(struct file *file, const char __user *buf,
 		goto out;
 
 	spin_lock_irq(&port_user_lock);
-	for (i = 0; i < (count/sizeof(evtchn_port_t)); i++)
-		if ((kbuf[i] < NR_EVENT_CHANNELS) && (port_user[kbuf[i]] == u))
-			enable_irq(irq_from_evtchn(kbuf[i]));
+
+	for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) {
+		unsigned port = kbuf[i];
+
+		if (port < NR_EVENT_CHANNELS &&
+		    get_port_user(port) == u &&
+		    !get_port_enabled(port)) {
+			set_port_enabled(port, true);
+			enable_irq(irq_from_evtchn(port));
+		}
+	}
+
 	spin_unlock_irq(&port_user_lock);
 
 	rc = count;
@@ -222,8 +261,9 @@ static int evtchn_bind_to_user(struct per_user_data *u, int port)
 	 * interrupt handler yet, and our caller has already
 	 * serialized bind operations.)
 	 */
-	BUG_ON(port_user[port] != NULL);
-	port_user[port] = u;
+	BUG_ON(get_port_user(port) != NULL);
+	set_port_user(port, u);
+	set_port_enabled(port, true); /* start enabled */
 
 	rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, IRQF_DISABLED,
 				       u->name, (void *)(unsigned long)port);
@@ -239,10 +279,7 @@ static void evtchn_unbind_from_user(struct per_user_data *u, int port)
 
 	unbind_from_irqhandler(irq, (void *)(unsigned long)port);
 
-	/* make sure we unbind the irq handler before clearing the port */
-	barrier();
-
-	port_user[port] = NULL;
+	set_port_user(port, NULL);
 }
 
 static long evtchn_ioctl(struct file *file,
@@ -333,15 +370,17 @@ static long evtchn_ioctl(struct file *file,
 		spin_lock_irq(&port_user_lock);
 
 		rc = -ENOTCONN;
-		if (port_user[unbind.port] != u) {
+		if (get_port_user(unbind.port) != u) {
 			spin_unlock_irq(&port_user_lock);
 			break;
 		}
 
-		evtchn_unbind_from_user(u, unbind.port);
+		disable_irq(irq_from_evtchn(unbind.port));
 
 		spin_unlock_irq(&port_user_lock);
 
+		evtchn_unbind_from_user(u, unbind.port);
+
 		rc = 0;
 		break;
 	}
@@ -355,7 +394,7 @@ static long evtchn_ioctl(struct file *file,
 
 		if (notify.port >= NR_EVENT_CHANNELS) {
 			rc = -EINVAL;
-		} else if (port_user[notify.port] != u) {
+		} else if (get_port_user(notify.port) != u) {
 			rc = -ENOTCONN;
 		} else {
 			notify_remote_via_evtchn(notify.port);
@@ -431,7 +470,7 @@ static int evtchn_open(struct inode *inode, struct file *filp)
 
 	filp->private_data = u;
 
-	return 0;
+	return nonseekable_open(inode, filp);;
 }
 
 static int evtchn_release(struct inode *inode, struct file *filp)
@@ -444,14 +483,21 @@ static int evtchn_release(struct inode *inode, struct file *filp)
 	free_page((unsigned long)u->ring);
 
 	for (i = 0; i < NR_EVENT_CHANNELS; i++) {
-		if (port_user[i] != u)
+		if (get_port_user(i) != u)
 			continue;
 
-		evtchn_unbind_from_user(port_user[i], i);
+		disable_irq(irq_from_evtchn(i));
 	}
 
 	spin_unlock_irq(&port_user_lock);
 
+	for (i = 0; i < NR_EVENT_CHANNELS; i++) {
+		if (get_port_user(i) != u)
+			continue;
+
+		evtchn_unbind_from_user(get_port_user(i), i);
+	}
+
 	kfree(u->name);
 	kfree(u);
 
@@ -467,12 +513,12 @@ static const struct file_operations evtchn_fops = {
 	.fasync  = evtchn_fasync,
 	.open    = evtchn_open,
 	.release = evtchn_release,
-	.llseek = noop_llseek,
+	.llseek	 = no_llseek,
 };
 
 static struct miscdevice evtchn_miscdev = {
 	.minor        = MISC_DYNAMIC_MINOR,
-	.name         = "evtchn",
+	.name         = "xen/evtchn",
 	.fops         = &evtchn_fops,
 };
 static int __init evtchn_init(void)
@@ -482,8 +528,11 @@ static int __init evtchn_init(void)
 	if (!xen_domain())
 		return -ENODEV;
 
+	port_user = kcalloc(NR_EVENT_CHANNELS, sizeof(*port_user), GFP_KERNEL);
+	if (port_user == NULL)
+		return -ENOMEM;
+
 	spin_lock_init(&port_user_lock);
-	memset(port_user, 0, sizeof(port_user));
 
 	/* Create '/dev/misc/evtchn'. */
 	err = misc_register(&evtchn_miscdev);
@@ -499,6 +548,9 @@ static int __init evtchn_init(void)
 
 static void __exit evtchn_cleanup(void)
 {
+	kfree(port_user);
+	port_user = NULL;
+
 	misc_deregister(&evtchn_miscdev);
 }
 
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index ef9c7db52077..db8c4c4ac880 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -49,6 +49,7 @@ static int xen_hvm_suspend(void *data)
 
 	if (!*cancelled) {
 		xen_irq_resume();
+		xen_console_resume();
 		xen_timer_resume();
 	}
 
diff --git a/drivers/xen/xenfs/privcmd.c b/drivers/xen/xenfs/privcmd.c
index 0f5d4162b22d..dbd3b16fd131 100644
--- a/drivers/xen/xenfs/privcmd.c
+++ b/drivers/xen/xenfs/privcmd.c
@@ -265,9 +265,7 @@ static int mmap_return_errors(void *data, void *state)
 	xen_pfn_t *mfnp = data;
 	struct mmap_batch_state *st = state;
 
-	put_user(*mfnp, st->user++);
-
-	return 0;
+	return put_user(*mfnp, st->user++);
 }
 
 static struct vm_operations_struct privcmd_vm_ops;
@@ -322,10 +320,8 @@ static long privcmd_ioctl_mmap_batch(void __user *udata)
 	up_write(&mm->mmap_sem);
 
 	if (state.err > 0) {
-		ret = 0;
-
 		state.user = m.arr;
-		traverse_pages(m.num, sizeof(xen_pfn_t),
+		ret = traverse_pages(m.num, sizeof(xen_pfn_t),
 			       &pagelist,
 			       mmap_return_errors, &state);
 	}
@@ -383,8 +379,9 @@ static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
 	if (xen_feature(XENFEAT_auto_translated_physmap))
 		return -ENOSYS;
 
-	/* DONTCOPY is essential for Xen as copy_page_range is broken. */
-	vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY;
+	/* DONTCOPY is essential for Xen because copy_page_range doesn't know
+	 * how to recreate these mappings */
+	vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
 	vma->vm_ops = &privcmd_vm_ops;
 	vma->vm_private_data = NULL;
 
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index f6339d11d59c..1aa389719846 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -12,8 +12,6 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/magic.h>
-#include <linux/mm.h>
-#include <linux/backing-dev.h>
 
 #include <xen/xen.h>
 
@@ -24,28 +22,12 @@
 MODULE_DESCRIPTION("Xen filesystem");
 MODULE_LICENSE("GPL");
 
-static int xenfs_set_page_dirty(struct page *page)
-{
-	return !TestSetPageDirty(page);
-}
-
-static const struct address_space_operations xenfs_aops = {
-	.set_page_dirty = xenfs_set_page_dirty,
-};
-
-static struct backing_dev_info xenfs_backing_dev_info = {
-	.ra_pages	= 0,	/* No readahead */
-	.capabilities	= BDI_CAP_NO_ACCT_AND_WRITEBACK,
-};
-
 static struct inode *xenfs_make_inode(struct super_block *sb, int mode)
 {
 	struct inode *ret = new_inode(sb);
 
 	if (ret) {
 		ret->i_mode = mode;
-		ret->i_mapping->a_ops = &xenfs_aops;
-		ret->i_mapping->backing_dev_info = &xenfs_backing_dev_info;
 		ret->i_uid = ret->i_gid = 0;
 		ret->i_blocks = 0;
 		ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
@@ -121,9 +103,9 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
 	return rc;
 }
 
-static int xenfs_mount(struct file_system_type *fs_type,
-			int flags, const char *dev_name,
-			void *data)
+static struct dentry *xenfs_mount(struct file_system_type *fs_type,
+				  int flags, const char *dev_name,
+				  void *data)
 {
 	return mount_single(fs_type, flags, data, xenfs_fill_super);
 }
@@ -137,25 +119,11 @@ static struct file_system_type xenfs_type = {
 
 static int __init xenfs_init(void)
 {
-	int err;
-	if (!xen_domain()) {
-		printk(KERN_INFO "xenfs: not registering filesystem on non-xen platform\n");
-		return 0;
-	}
-
-	err = register_filesystem(&xenfs_type);
-	if (err) {
-		printk(KERN_ERR "xenfs: Unable to register filesystem!\n");
-		goto out;
-	}
-
-	err = bdi_init(&xenfs_backing_dev_info);
-	if (err)
-		unregister_filesystem(&xenfs_type);
-
- out:
+	if (xen_domain())
+		return register_filesystem(&xenfs_type);
 
-	return err;
+	printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n");
+	return 0;
 }
 
 static void __exit xenfs_exit(void)