diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a98070fe7f14..2c3bdce15134 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1889,8 +1889,9 @@ config XEN_DOM0
 
 config XEN
 	bool "Xen guest support on ARM (EXPERIMENTAL)"
-	depends on ARM && OF
+	depends on ARM && AEABI && OF
 	depends on CPU_V7 && !CPU_V6
+	depends on !GENERIC_ATOMIC64
 	help
 	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
 
diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h
index 5c27696de14f..8b1f37bfeeec 100644
--- a/arch/arm/include/asm/xen/events.h
+++ b/arch/arm/include/asm/xen/events.h
@@ -2,6 +2,7 @@
 #define _ASM_ARM_XEN_EVENTS_H
 
 #include <asm/ptrace.h>
+#include <asm/atomic.h>
 
 enum ipi_vector {
 	XEN_PLACEHOLDER_VECTOR,
@@ -15,26 +16,8 @@ static inline int xen_irqs_disabled(struct pt_regs *regs)
 	return raw_irqs_disabled_flags(regs->ARM_cpsr);
 }
 
-/*
- * We cannot use xchg because it does not support 8-byte
- * values. However it is safe to use {ldr,dtd}exd directly because all
- * platforms which Xen can run on support those instructions.
- */
-static inline xen_ulong_t xchg_xen_ulong(xen_ulong_t *ptr, xen_ulong_t val)
-{
-	xen_ulong_t oldval;
-	unsigned int tmp;
-
-	wmb();
-	asm volatile("@ xchg_xen_ulong\n"
-		"1:     ldrexd  %0, %H0, [%3]\n"
-		"       strexd  %1, %2, %H2, [%3]\n"
-		"       teq     %1, #0\n"
-		"       bne     1b"
-		: "=&r" (oldval), "=&r" (tmp)
-		: "r" (val), "r" (ptr)
-		: "memory", "cc");
-	return oldval;
-}
+#define xchg_xen_ulong(ptr, val) atomic64_xchg(container_of((ptr),	\
+							    atomic64_t,	\
+							    counter), (val))
 
 #endif /* _ASM_ARM_XEN_EVENTS_H */
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 53e7ac9403a7..e854582f29a6 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -465,7 +465,7 @@ static int acpi_processor_get_performance_states(struct acpi_processor *pr)
 	return result;
 }
 
-static int acpi_processor_get_performance_info(struct acpi_processor *pr)
+int acpi_processor_get_performance_info(struct acpi_processor *pr)
 {
 	int result = 0;
 	acpi_status status = AE_OK;
@@ -509,7 +509,7 @@ static int acpi_processor_get_performance_info(struct acpi_processor *pr)
 #endif
 	return result;
 }
-
+EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info);
 int acpi_processor_notify_smm(struct module *calling_module)
 {
 	acpi_status status;
diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c
index 316df65163cf..f3278a6603ca 100644
--- a/drivers/xen/xen-acpi-processor.c
+++ b/drivers/xen/xen-acpi-processor.c
@@ -500,16 +500,16 @@ static int __init xen_acpi_processor_init(void)
 	(void)acpi_processor_preregister_performance(acpi_perf_data);
 
 	for_each_possible_cpu(i) {
+		struct acpi_processor *pr;
 		struct acpi_processor_performance *perf;
 
+		pr = per_cpu(processors, i);
 		perf = per_cpu_ptr(acpi_perf_data, i);
-		rc = acpi_processor_register_performance(perf, i);
+		pr->performance = perf;
+		rc = acpi_processor_get_performance_info(pr);
 		if (rc)
 			goto err_out;
 	}
-	rc = acpi_processor_notify_smm(THIS_MODULE);
-	if (rc)
-		goto err_unregister;
 
 	for_each_possible_cpu(i) {
 		struct acpi_processor *_pr;
diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index 37c1f825f513..b98cf0c35725 100644
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -113,7 +113,8 @@ void xen_pcibk_reset_device(struct pci_dev *dev)
 		if (dev->msi_enabled)
 			pci_disable_msi(dev);
 #endif
-		pci_disable_device(dev);
+		if (pci_is_enabled(dev))
+			pci_disable_device(dev);
 
 		pci_write_config_word(dev, PCI_COMMAND, 0);
 
diff --git a/drivers/xen/xen-stub.c b/drivers/xen/xen-stub.c
index d85e411cbf89..bbef194c5b01 100644
--- a/drivers/xen/xen-stub.c
+++ b/drivers/xen/xen-stub.c
@@ -25,7 +25,6 @@
 #include <linux/export.h>
 #include <linux/types.h>
 #include <linux/acpi.h>
-#include <acpi/acpi_drivers.h>
 #include <xen/acpi.h>
 
 #ifdef CONFIG_ACPI
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 555d0337ad95..b327b5a9296d 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -235,6 +235,9 @@ extern void acpi_processor_unregister_performance(struct
          if a _PPC object exists, rmmod is disallowed then */
 int acpi_processor_notify_smm(struct module *calling_module);
 
+/* parsing the _P* objects. */
+extern int acpi_processor_get_performance_info(struct acpi_processor *pr);
+
 /* for communication between multiple parts of the processor kernel module */
 DECLARE_PER_CPU(struct acpi_processor *, processors);
 extern struct acpi_processor_errata errata;