xen: arm: enable balloon driver

The code is now in a state where can just enable it.

Drop the *_xenballloned_pages duplicates since these are now supplied
by the balloon code.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/arm/xen/enlighten.c

@@ -8,6 +8,7 @@
 #include <xen/features.h>
 #include <xen/platform_pci.h>
 #include <xen/xenbus.h>
+#include <xen/page.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <linux/interrupt.h>
@@ -29,6 +30,10 @@ struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
 
 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
 
+/* These are unused until we support booting "pre-ballooned" */
+unsigned long xen_released_pages;
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
+
 /* TODO: to be removed */
 __read_mostly int xen_have_vector_callback;
 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
@@ -148,21 +153,3 @@ static int __init xen_init_events(void)
 	return 0;
 }
 postcore_initcall(xen_init_events);
-
-/* XXX: only until balloon is properly working */
-int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem)
-{
-	*pages = alloc_pages(highmem ? GFP_HIGHUSER : GFP_KERNEL,
-			get_order(nr_pages));
-	if (*pages == NULL)
-		return -ENOMEM;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(alloc_xenballooned_pages);
-
-void free_xenballooned_pages(int nr_pages, struct page **pages)
-{
-	kfree(*pages);
-	*pages = NULL;
-}
-EXPORT_SYMBOL_GPL(free_xenballooned_pages);

drivers/xen/Makefile

 ifneq ($(CONFIG_ARM),y)
-obj-y	+= manage.o balloon.o
+obj-y	+= manage.o
 obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
 endif
-obj-y	+= grant-table.o features.o events.o
+obj-y	+= grant-table.o features.o events.o balloon.o
 obj-y	+= xenbus/
 
 nostackp := $(call cc-option, -fno-stack-protector)