x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}()

Nadav Amit reported that commit:

b59167ac7baf ("x86/percpu: Fix this_cpu_read()")

added a bunch of constraints to all sorts of code; and while some of
that was correct and desired, some of that seems superfluous.

The thing is, the this_cpu_*() operations are defined IRQ-safe, this
means the values are subject to change from IRQs, and thus must be
reloaded.

Also, the generic form:

local_irq_save()
__this_cpu_read()
local_irq_restore()

would not allow the re-use of previous values; if by nothing else,
then the barrier()s implied by local_irq_*().

Which raises the point that percpu_from_op() and the others also need
that volatile.

OTOH __this_cpu_*() operations are not IRQ-safe and assume external
preempt/IRQ disabling and could thus be allowed more room for
optimization.

This makes the this_cpu_*() vs __this_cpu_*() behaviour more
consistent with other architectures.

$ ./compare.sh defconfig-build defconfig-build1 vmlinux.o
x86_pmu_cancel_txn 80 71 -9,+0
__text_poke 919 964 +45,+0
do_user_addr_fault 1082 1058 -24,+0
__do_page_fault 1194 1178 -16,+0
do_exit 2995 3027 -43,+75
process_one_work 1008 989 -67,+48
finish_task_switch 524 505 -19,+0
__schedule_bug 103 98 -59,+54
__schedule_bug 103 98 -59,+54
__sched_setscheduler 2015 2030 +15,+0
freeze_processes 203 230 +31,-4
rcu_gp_kthread_wake 106 99 -7,+0
rcu_core 1841 1834 -7,+0
call_timer_fn 298 286 -12,+0
can_stop_idle_tick 146 139 -31,+24
perf_pending_event 253 239 -14,+0
shmem_alloc_page 209 213 +4,+0
__alloc_pages_slowpath 3284 3269 -15,+0
umount_tree 671 694 +23,+0
advance_transaction 803 798 -5,+0
con_put_char 71 51 -20,+0
xhci_urb_enqueue 1302 1295 -7,+0
xhci_urb_enqueue 1302 1295 -7,+0
tcp_sacktag_write_queue 2130 2075 -55,+0
tcp_try_undo_loss 229 208 -21,+0
tcp_v4_inbound_md5_hash 438 411 -31,+4
tcp_v4_inbound_md5_hash 438 411 -31,+4
tcp_v6_inbound_md5_hash 469 411 -33,-25
tcp_v6_inbound_md5_hash 469 411 -33,-25
restricted_pointer 434 420 -14,+0
irq_exit 162 154 -8,+0
get_perf_callchain 638 624 -14,+0
rt_mutex_trylock 169 156 -13,+0
avc_has_extended_perms 1092 1089 -3,+0
avc_has_perm_noaudit 309 306 -3,+0
__perf_sw_event 138 122 -16,+0
perf_swevent_get_recursion_context 116 102 -14,+0
__local_bh_enable_ip 93 72 -21,+0
xfrm_input 4175 4161 -14,+0
avc_has_perm 446 443 -3,+0
vm_events_fold_cpu 57 56 -1,+0
vfree 68 61 -7,+0
freeze_processes 203 230 +31,-4
_local_bh_enable 44 30 -14,+0
ip_do_fragment 1982 1944 -38,+0
do_exit 2995 3027 -43,+75
__do_softirq 742 724 -18,+0
cpu_init 1510 1489 -21,+0
account_system_time 80 79 -1,+0
total 12985281 12984819 -742,+280

Reported-by: Nadav Amit <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/include/asm/percpu.h

···
  * don't give an lvalue though). */
 extern void __bad_percpu_size(void);
 
-#define percpu_to_op(op, var, val)			\
+#define percpu_to_op(qual, op, var, val)		\
 do {							\
 	typedef typeof(var) pto_T__;			\
 	if (0) {					\
···
 	}						\
 	switch (sizeof(var)) {				\
 	case 1:						\
-		asm(op "b %1,"__percpu_arg(0)		\
+		asm qual (op "b %1,"__percpu_arg(0)	\
 		    : "+m" (var)			\
 		    : "qi" ((pto_T__)(val)));		\
 		break;					\
 	case 2:						\
-		asm(op "w %1,"__percpu_arg(0)		\
+		asm qual (op "w %1,"__percpu_arg(0)	\
 		    : "+m" (var)			\
 		    : "ri" ((pto_T__)(val)));		\
 		break;					\
 	case 4:						\
-		asm(op "l %1,"__percpu_arg(0)		\
+		asm qual (op "l %1,"__percpu_arg(0)	\
 		    : "+m" (var)			\
 		    : "ri" ((pto_T__)(val)));		\
 		break;					\
 	case 8:						\
-		asm(op "q %1,"__percpu_arg(0)		\
+		asm qual (op "q %1,"__percpu_arg(0)	\
 		    : "+m" (var)			\
 		    : "re" ((pto_T__)(val)));		\
 		break;					\
···
  * Generate a percpu add to memory instruction and optimize code
  * if one is added or subtracted.
  */
-#define percpu_add_op(var, val)						\
+#define percpu_add_op(qual, var, val)					\
 do {									\
 	typedef typeof(var) pao_T__;					\
 	const int pao_ID__ = (__builtin_constant_p(val) &&		\
···
 	switch (sizeof(var)) {						\
 	case 1:								\
 		if (pao_ID__ == 1)					\
-			asm("incb "__percpu_arg(0) : "+m" (var));	\
+			asm qual ("incb "__percpu_arg(0) : "+m" (var));	\
 		else if (pao_ID__ == -1)				\
-			asm("decb "__percpu_arg(0) : "+m" (var));	\
+			asm qual ("decb "__percpu_arg(0) : "+m" (var));	\
 		else							\
-			asm("addb %1, "__percpu_arg(0)			\
+			asm qual ("addb %1, "__percpu_arg(0)		\
 			    : "+m" (var)				\
 			    : "qi" ((pao_T__)(val)));			\
 		break;							\
 	case 2:								\
 		if (pao_ID__ == 1)					\
-			asm("incw "__percpu_arg(0) : "+m" (var));	\
+			asm qual ("incw "__percpu_arg(0) : "+m" (var));	\
 		else if (pao_ID__ == -1)				\
-			asm("decw "__percpu_arg(0) : "+m" (var));	\
+			asm qual ("decw "__percpu_arg(0) : "+m" (var));	\
 		else							\
-			asm("addw %1, "__percpu_arg(0)			\
+			asm qual ("addw %1, "__percpu_arg(0)		\
 			    : "+m" (var)				\
 			    : "ri" ((pao_T__)(val)));			\
 		break;							\
 	case 4:								\
 		if (pao_ID__ == 1)					\
-			asm("incl "__percpu_arg(0) : "+m" (var));	\
+			asm qual ("incl "__percpu_arg(0) : "+m" (var));	\
 		else if (pao_ID__ == -1)				\
-			asm("decl "__percpu_arg(0) : "+m" (var));	\
+			asm qual ("decl "__percpu_arg(0) : "+m" (var));	\
 		else							\
-			asm("addl %1, "__percpu_arg(0)			\
+			asm qual ("addl %1, "__percpu_arg(0)		\
 			    : "+m" (var)				\
 			    : "ri" ((pao_T__)(val)));			\
 		break;							\
 	case 8:								\
 		if (pao_ID__ == 1)					\
-			asm("incq "__percpu_arg(0) : "+m" (var));	\
+			asm qual ("incq "__percpu_arg(0) : "+m" (var));	\
 		else if (pao_ID__ == -1)				\
-			asm("decq "__percpu_arg(0) : "+m" (var));	\
+			asm qual ("decq "__percpu_arg(0) : "+m" (var));	\
 		else							\
-			asm("addq %1, "__percpu_arg(0)			\
+			asm qual ("addq %1, "__percpu_arg(0)		\
 			    : "+m" (var)				\
 			    : "re" ((pao_T__)(val)));			\
 		break;							\
···
 	}								\
 } while (0)
 
-#define percpu_from_op(op, var)				\
+#define percpu_from_op(qual, op, var)			\
 ({							\
 	typeof(var) pfo_ret__;				\
 	switch (sizeof(var)) {				\
 	case 1:						\
-		asm volatile(op "b "__percpu_arg(1)",%0"\
+		asm qual (op "b "__percpu_arg(1)",%0"	\
 		    : "=q" (pfo_ret__)			\
 		    : "m" (var));			\
 		break;					\
 	case 2:						\
-		asm volatile(op "w "__percpu_arg(1)",%0"\
+		asm qual (op "w "__percpu_arg(1)",%0"	\
 		    : "=r" (pfo_ret__)			\
 		    : "m" (var));			\
 		break;					\
 	case 4:						\
-		asm volatile(op "l "__percpu_arg(1)",%0"\
+		asm qual (op "l "__percpu_arg(1)",%0"	\
 		    : "=r" (pfo_ret__)			\
 		    : "m" (var));			\
 		break;					\
 	case 8:						\
-		asm volatile(op "q "__percpu_arg(1)",%0"\
+		asm qual (op "q "__percpu_arg(1)",%0"	\
 		    : "=r" (pfo_ret__)			\
 		    : "m" (var));			\
 		break;					\
···
 	pfo_ret__;					\
 })
 
-#define percpu_unary_op(op, var)			\
+#define percpu_unary_op(qual, op, var)			\
 ({							\
 	switch (sizeof(var)) {				\
 	case 1:						\
-		asm(op "b "__percpu_arg(0)		\
+		asm qual (op "b "__percpu_arg(0)	\
 		    : "+m" (var));			\
 		break;					\
 	case 2:						\
-		asm(op "w "__percpu_arg(0)		\
+		asm qual (op "w "__percpu_arg(0)	\
 		    : "+m" (var));			\
 		break;					\
 	case 4:						\
-		asm(op "l "__percpu_arg(0)		\
+		asm qual (op "l "__percpu_arg(0)	\
 		    : "+m" (var));			\
 		break;					\
 	case 8:						\
-		asm(op "q "__percpu_arg(0)		\
+		asm qual (op "q "__percpu_arg(0)	\
 		    : "+m" (var));			\
 		break;					\
 	default: __bad_percpu_size();			\
···
 /*
  * Add return operation
  */
-#define percpu_add_return_op(var, val)					\
+#define percpu_add_return_op(qual, var, val)				\
 ({									\
 	typeof(var) paro_ret__ = val;					\
 	switch (sizeof(var)) {						\
 	case 1:								\
-		asm("xaddb %0, "__percpu_arg(1)				\
+		asm qual ("xaddb %0, "__percpu_arg(1)			\
 			    : "+q" (paro_ret__), "+m" (var)		\
 			    : : "memory");				\
 		break;							\
 	case 2:								\
-		asm("xaddw %0, "__percpu_arg(1)				\
+		asm qual ("xaddw %0, "__percpu_arg(1)			\
 			    : "+r" (paro_ret__), "+m" (var)		\
 			    : : "memory");				\
 		break;							\
 	case 4:								\
-		asm("xaddl %0, "__percpu_arg(1)				\
+		asm qual ("xaddl %0, "__percpu_arg(1)			\
 			    : "+r" (paro_ret__), "+m" (var)		\
 			    : : "memory");				\
 		break;							\
 	case 8:								\
-		asm("xaddq %0, "__percpu_arg(1)				\
+		asm qual ("xaddq %0, "__percpu_arg(1)			\
 			    : "+re" (paro_ret__), "+m" (var)		\
 			    : : "memory");				\
 		break;							\
···
  * expensive due to the implied lock prefix.  The processor cannot prefetch
  * cachelines if xchg is used.
  */
-#define percpu_xchg_op(var, nval)					\
+#define percpu_xchg_op(qual, var, nval)					\
 ({									\
 	typeof(var) pxo_ret__;						\
 	typeof(var) pxo_new__ = (nval);					\
 	switch (sizeof(var)) {						\
 	case 1:								\
-		asm("\n\tmov "__percpu_arg(1)",%%al"			\
+		asm qual ("\n\tmov "__percpu_arg(1)",%%al"		\
 		    "\n1:\tcmpxchgb %2, "__percpu_arg(1)		\
 		    "\n\tjnz 1b"					\
 			    : "=&a" (pxo_ret__), "+m" (var)		\
···
 			    : "memory");				\
 		break;							\
 	case 2:								\
-		asm("\n\tmov "__percpu_arg(1)",%%ax"			\
+		asm qual ("\n\tmov "__percpu_arg(1)",%%ax"		\
 		    "\n1:\tcmpxchgw %2, "__percpu_arg(1)		\
 		    "\n\tjnz 1b"					\
 			    : "=&a" (pxo_ret__), "+m" (var)		\
···
 			    : "memory");				\
 		break;							\
 	case 4:								\
-		asm("\n\tmov "__percpu_arg(1)",%%eax"			\
+		asm qual ("\n\tmov "__percpu_arg(1)",%%eax"		\
 		    "\n1:\tcmpxchgl %2, "__percpu_arg(1)		\
 		    "\n\tjnz 1b"					\
 			    : "=&a" (pxo_ret__), "+m" (var)		\
···
 			    : "memory");				\
 		break;							\
 	case 8:								\
-		asm("\n\tmov "__percpu_arg(1)",%%rax"			\
+		asm qual ("\n\tmov "__percpu_arg(1)",%%rax"		\
 		    "\n1:\tcmpxchgq %2, "__percpu_arg(1)		\
 		    "\n\tjnz 1b"					\
 			    : "=&a" (pxo_ret__), "+m" (var)		\
···
  * cmpxchg has no such implied lock semantics as a result it is much
  * more efficient for cpu local operations.
  */
-#define percpu_cmpxchg_op(var, oval, nval)				\
+#define percpu_cmpxchg_op(qual, var, oval, nval)			\
 ({									\
 	typeof(var) pco_ret__;						\
 	typeof(var) pco_old__ = (oval);					\
 	typeof(var) pco_new__ = (nval);					\
 	switch (sizeof(var)) {						\
 	case 1:								\
-		asm("cmpxchgb %2, "__percpu_arg(1)			\
+		asm qual ("cmpxchgb %2, "__percpu_arg(1)		\
 			    : "=a" (pco_ret__), "+m" (var)		\
 			    : "q" (pco_new__), "0" (pco_old__)		\
 			    : "memory");				\
 		break;							\
 	case 2:								\
-		asm("cmpxchgw %2, "__percpu_arg(1)			\
+		asm qual ("cmpxchgw %2, "__percpu_arg(1)		\
 			    : "=a" (pco_ret__), "+m" (var)		\
 			    : "r" (pco_new__), "0" (pco_old__)		\
 			    : "memory");				\
 		break;							\
 	case 4:								\
-		asm("cmpxchgl %2, "__percpu_arg(1)			\
+		asm qual ("cmpxchgl %2, "__percpu_arg(1)		\
 			    : "=a" (pco_ret__), "+m" (var)		\
 			    : "r" (pco_new__), "0" (pco_old__)		\
 			    : "memory");				\
 		break;							\
 	case 8:								\
-		asm("cmpxchgq %2, "__percpu_arg(1)			\
+		asm qual ("cmpxchgq %2, "__percpu_arg(1)		\
 			    : "=a" (pco_ret__), "+m" (var)		\
 			    : "r" (pco_new__), "0" (pco_old__)		\
 			    : "memory");				\
···
  */
 #define this_cpu_read_stable(var)	percpu_stable_op("mov", var)
 
-#define raw_cpu_read_1(pcp)		percpu_from_op("mov", pcp)
-#define raw_cpu_read_2(pcp)		percpu_from_op("mov", pcp)
-#define raw_cpu_read_4(pcp)		percpu_from_op("mov", pcp)
+#define raw_cpu_read_1(pcp)		percpu_from_op(, "mov", pcp)
+#define raw_cpu_read_2(pcp)		percpu_from_op(, "mov", pcp)
+#define raw_cpu_read_4(pcp)		percpu_from_op(, "mov", pcp)
 
-#define raw_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
-#define raw_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
-#define raw_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
-#define raw_cpu_add_1(pcp, val)		percpu_add_op((pcp), val)
-#define raw_cpu_add_2(pcp, val)		percpu_add_op((pcp), val)
-#define raw_cpu_add_4(pcp, val)		percpu_add_op((pcp), val)
-#define raw_cpu_and_1(pcp, val)		percpu_to_op("and", (pcp), val)
-#define raw_cpu_and_2(pcp, val)		percpu_to_op("and", (pcp), val)
-#define raw_cpu_and_4(pcp, val)		percpu_to_op("and", (pcp), val)
-#define raw_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
-#define raw_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
-#define raw_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
-#define raw_cpu_xchg_1(pcp, val)	percpu_xchg_op(pcp, val)
-#define raw_cpu_xchg_2(pcp, val)	percpu_xchg_op(pcp, val)
-#define raw_cpu_xchg_4(pcp, val)	percpu_xchg_op(pcp, val)
+#define raw_cpu_write_1(pcp, val)	percpu_to_op(, "mov", (pcp), val)
+#define raw_cpu_write_2(pcp, val)	percpu_to_op(, "mov", (pcp), val)
+#define raw_cpu_write_4(pcp, val)	percpu_to_op(, "mov", (pcp), val)
+#define raw_cpu_add_1(pcp, val)		percpu_add_op(, (pcp), val)
+#define raw_cpu_add_2(pcp, val)		percpu_add_op(, (pcp), val)
+#define raw_cpu_add_4(pcp, val)		percpu_add_op(, (pcp), val)
+#define raw_cpu_and_1(pcp, val)		percpu_to_op(, "and", (pcp), val)
+#define raw_cpu_and_2(pcp, val)		percpu_to_op(, "and", (pcp), val)
+#define raw_cpu_and_4(pcp, val)		percpu_to_op(, "and", (pcp), val)
+#define raw_cpu_or_1(pcp, val)		percpu_to_op(, "or", (pcp), val)
+#define raw_cpu_or_2(pcp, val)		percpu_to_op(, "or", (pcp), val)
+#define raw_cpu_or_4(pcp, val)		percpu_to_op(, "or", (pcp), val)
+#define raw_cpu_xchg_1(pcp, val)	percpu_xchg_op(, pcp, val)
+#define raw_cpu_xchg_2(pcp, val)	percpu_xchg_op(, pcp, val)
+#define raw_cpu_xchg_4(pcp, val)	percpu_xchg_op(, pcp, val)
 
-#define this_cpu_read_1(pcp)		percpu_from_op("mov", pcp)
-#define this_cpu_read_2(pcp)		percpu_from_op("mov", pcp)
-#define this_cpu_read_4(pcp)		percpu_from_op("mov", pcp)
-#define this_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
-#define this_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
-#define this_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
-#define this_cpu_add_1(pcp, val)	percpu_add_op((pcp), val)
-#define this_cpu_add_2(pcp, val)	percpu_add_op((pcp), val)
-#define this_cpu_add_4(pcp, val)	percpu_add_op((pcp), val)
-#define this_cpu_and_1(pcp, val)	percpu_to_op("and", (pcp), val)
-#define this_cpu_and_2(pcp, val)	percpu_to_op("and", (pcp), val)
-#define this_cpu_and_4(pcp, val)	percpu_to_op("and", (pcp), val)
-#define this_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
-#define this_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
-#define this_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
-#define this_cpu_xchg_1(pcp, nval)	percpu_xchg_op(pcp, nval)
-#define this_cpu_xchg_2(pcp, nval)	percpu_xchg_op(pcp, nval)
-#define this_cpu_xchg_4(pcp, nval)	percpu_xchg_op(pcp, nval)
+#define this_cpu_read_1(pcp)		percpu_from_op(volatile, "mov", pcp)
+#define this_cpu_read_2(pcp)		percpu_from_op(volatile, "mov", pcp)
+#define this_cpu_read_4(pcp)		percpu_from_op(volatile, "mov", pcp)
+#define this_cpu_write_1(pcp, val)	percpu_to_op(volatile, "mov", (pcp), val)
+#define this_cpu_write_2(pcp, val)	percpu_to_op(volatile, "mov", (pcp), val)
+#define this_cpu_write_4(pcp, val)	percpu_to_op(volatile, "mov", (pcp), val)
+#define this_cpu_add_1(pcp, val)	percpu_add_op(volatile, (pcp), val)
+#define this_cpu_add_2(pcp, val)	percpu_add_op(volatile, (pcp), val)
+#define this_cpu_add_4(pcp, val)	percpu_add_op(volatile, (pcp), val)
+#define this_cpu_and_1(pcp, val)	percpu_to_op(volatile, "and", (pcp), val)
+#define this_cpu_and_2(pcp, val)	percpu_to_op(volatile, "and", (pcp), val)
+#define this_cpu_and_4(pcp, val)	percpu_to_op(volatile, "and", (pcp), val)
+#define this_cpu_or_1(pcp, val)		percpu_to_op(volatile, "or", (pcp), val)
+#define this_cpu_or_2(pcp, val)		percpu_to_op(volatile, "or", (pcp), val)
+#define this_cpu_or_4(pcp, val)		percpu_to_op(volatile, "or", (pcp), val)
+#define this_cpu_xchg_1(pcp, nval)	percpu_xchg_op(volatile, pcp, nval)
+#define this_cpu_xchg_2(pcp, nval)	percpu_xchg_op(volatile, pcp, nval)
+#define this_cpu_xchg_4(pcp, nval)	percpu_xchg_op(volatile, pcp, nval)
 
-#define raw_cpu_add_return_1(pcp, val)		percpu_add_return_op(pcp, val)
-#define raw_cpu_add_return_2(pcp, val)		percpu_add_return_op(pcp, val)
-#define raw_cpu_add_return_4(pcp, val)		percpu_add_return_op(pcp, val)
-#define raw_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
-#define raw_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
-#define raw_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
+#define raw_cpu_add_return_1(pcp, val)		percpu_add_return_op(, pcp, val)
+#define raw_cpu_add_return_2(pcp, val)		percpu_add_return_op(, pcp, val)
+#define raw_cpu_add_return_4(pcp, val)		percpu_add_return_op(, pcp, val)
+#define raw_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(, pcp, oval, nval)
+#define raw_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(, pcp, oval, nval)
+#define raw_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(, pcp, oval, nval)
 
-#define this_cpu_add_return_1(pcp, val)		percpu_add_return_op(pcp, val)
-#define this_cpu_add_return_2(pcp, val)		percpu_add_return_op(pcp, val)
-#define this_cpu_add_return_4(pcp, val)		percpu_add_return_op(pcp, val)
-#define this_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
-#define this_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
-#define this_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
+#define this_cpu_add_return_1(pcp, val)		percpu_add_return_op(volatile, pcp, val)
+#define this_cpu_add_return_2(pcp, val)		percpu_add_return_op(volatile, pcp, val)
+#define this_cpu_add_return_4(pcp, val)		percpu_add_return_op(volatile, pcp, val)
+#define this_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(volatile, pcp, oval, nval)
+#define this_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(volatile, pcp, oval, nval)
+#define this_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(volatile, pcp, oval, nval)
 
 #ifdef CONFIG_X86_CMPXCHG64
 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2)		\
···
  * 32 bit must fall back to generic operations.
  */
 #ifdef CONFIG_X86_64
-#define raw_cpu_read_8(pcp)			percpu_from_op("mov", pcp)
-#define raw_cpu_write_8(pcp, val)		percpu_to_op("mov", (pcp), val)
-#define raw_cpu_add_8(pcp, val)			percpu_add_op((pcp), val)
-#define raw_cpu_and_8(pcp, val)			percpu_to_op("and", (pcp), val)
-#define raw_cpu_or_8(pcp, val)			percpu_to_op("or", (pcp), val)
-#define raw_cpu_add_return_8(pcp, val)		percpu_add_return_op(pcp, val)
-#define raw_cpu_xchg_8(pcp, nval)		percpu_xchg_op(pcp, nval)
-#define raw_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
+#define raw_cpu_read_8(pcp)			percpu_from_op(, "mov", pcp)
+#define raw_cpu_write_8(pcp, val)		percpu_to_op(, "mov", (pcp), val)
+#define raw_cpu_add_8(pcp, val)			percpu_add_op(, (pcp), val)
+#define raw_cpu_and_8(pcp, val)			percpu_to_op(, "and", (pcp), val)
+#define raw_cpu_or_8(pcp, val)			percpu_to_op(, "or", (pcp), val)
+#define raw_cpu_add_return_8(pcp, val)		percpu_add_return_op(, pcp, val)
+#define raw_cpu_xchg_8(pcp, nval)		percpu_xchg_op(, pcp, nval)
+#define raw_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(, pcp, oval, nval)
 
-#define this_cpu_read_8(pcp)			percpu_from_op("mov", pcp)
-#define this_cpu_write_8(pcp, val)		percpu_to_op("mov", (pcp), val)
-#define this_cpu_add_8(pcp, val)		percpu_add_op((pcp), val)
-#define this_cpu_and_8(pcp, val)		percpu_to_op("and", (pcp), val)
-#define this_cpu_or_8(pcp, val)			percpu_to_op("or", (pcp), val)
-#define this_cpu_add_return_8(pcp, val)		percpu_add_return_op(pcp, val)
-#define this_cpu_xchg_8(pcp, nval)		percpu_xchg_op(pcp, nval)
-#define this_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
+#define this_cpu_read_8(pcp)			percpu_from_op(volatile, "mov", pcp)
+#define this_cpu_write_8(pcp, val)		percpu_to_op(volatile, "mov", (pcp), val)
+#define this_cpu_add_8(pcp, val)		percpu_add_op(volatile, (pcp), val)
+#define this_cpu_and_8(pcp, val)		percpu_to_op(volatile, "and", (pcp), val)
+#define this_cpu_or_8(pcp, val)			percpu_to_op(volatile, "or", (pcp), val)
+#define this_cpu_add_return_8(pcp, val)		percpu_add_return_op(volatile, pcp, val)
+#define this_cpu_xchg_8(pcp, nval)		percpu_xchg_op(volatile, pcp, nval)
+#define this_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(volatile, pcp, oval, nval)
 
 /*
  * Pretty complex macro to generate cmpxchg16 instruction.  The instruction