diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 3788f4649db4..7e172955ee57 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -273,34 +273,34 @@ do {									\
 	typeof(var) pxo_new__ = (nval);					\
 	switch (sizeof(var)) {						\
 	case 1:								\
-		asm("\n1:mov "__percpu_arg(1)",%%al"			\
-		    "\n\tcmpxchgb %2, "__percpu_arg(1)			\
+		asm("\n\tmov "__percpu_arg(1)",%%al"			\
+		    "\n1:\tcmpxchgb %2, "__percpu_arg(1)		\
 		    "\n\tjnz 1b"					\
-			    : "=a" (pxo_ret__), "+m" (var)		\
+			    : "=&a" (pxo_ret__), "+m" (var)		\
 			    : "q" (pxo_new__)				\
 			    : "memory");				\
 		break;							\
 	case 2:								\
-		asm("\n1:mov "__percpu_arg(1)",%%ax"			\
-		    "\n\tcmpxchgw %2, "__percpu_arg(1)			\
+		asm("\n\tmov "__percpu_arg(1)",%%ax"			\
+		    "\n1:\tcmpxchgw %2, "__percpu_arg(1)		\
 		    "\n\tjnz 1b"					\
-			    : "=a" (pxo_ret__), "+m" (var)		\
+			    : "=&a" (pxo_ret__), "+m" (var)		\
 			    : "r" (pxo_new__)				\
 			    : "memory");				\
 		break;							\
 	case 4:								\
-		asm("\n1:mov "__percpu_arg(1)",%%eax"			\
-		    "\n\tcmpxchgl %2, "__percpu_arg(1)			\
+		asm("\n\tmov "__percpu_arg(1)",%%eax"			\
+		    "\n1:\tcmpxchgl %2, "__percpu_arg(1)		\
 		    "\n\tjnz 1b"					\
-			    : "=a" (pxo_ret__), "+m" (var)		\
+			    : "=&a" (pxo_ret__), "+m" (var)		\
 			    : "r" (pxo_new__)				\
 			    : "memory");				\
 		break;							\
 	case 8:								\
-		asm("\n1:mov "__percpu_arg(1)",%%rax"			\
-		    "\n\tcmpxchgq %2, "__percpu_arg(1)			\
+		asm("\n\tmov "__percpu_arg(1)",%%rax"			\
+		    "\n1:\tcmpxchgq %2, "__percpu_arg(1)		\
 		    "\n\tjnz 1b"					\
-			    : "=a" (pxo_ret__), "+m" (var)		\
+			    : "=&a" (pxo_ret__), "+m" (var)		\
 			    : "r" (pxo_new__)				\
 			    : "memory");				\
 		break;							\
diff --git a/arch/x86/include/asm/system_64.h b/arch/x86/include/asm/system_64.h
deleted file mode 100644
index 1159e091ad09..000000000000
--- a/arch/x86/include/asm/system_64.h
+++ /dev/null
@@ -1,22 +0,0 @@
-#ifndef _ASM_X86_SYSTEM_64_H
-#define _ASM_X86_SYSTEM_64_H
-
-#include <asm/segment.h>
-#include <asm/cmpxchg.h>
-
-
-static inline unsigned long read_cr8(void)
-{
-	unsigned long cr8;
-	asm volatile("movq %%cr8,%0" : "=r" (cr8));
-	return cr8;
-}
-
-static inline void write_cr8(unsigned long val)
-{
-	asm volatile("movq %0,%%cr8" :: "r" (val) : "memory");
-}
-
-#include <linux/irqflags.h>
-
-#endif /* _ASM_X86_SYSTEM_64_H */
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 64101335de19..a6b6fcf7f0ae 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -149,13 +149,13 @@ void dump_trace(struct task_struct *task,
 	unsigned used = 0;
 	struct thread_info *tinfo;
 	int graph = 0;
+	unsigned long dummy;
 	unsigned long bp;
 
 	if (!task)
 		task = current;
 
 	if (!stack) {
-		unsigned long dummy;
 		stack = &dummy;
 		if (task && task != current)
 			stack = (unsigned long *)task->thread.sp;