1 files changed, 49 insertions, 0 deletions

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 7f2953c15c37..43494a014d5b 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -250,6 +250,55 @@ static inline unsigned short stap(void)
         return cpu_address;
 }
 
+#define CALL_ARGS_0()                                                   \
+        register unsigned long r2 asm("2")
+#define CALL_ARGS_1(arg1)                                               \
+        register unsigned long r2 asm("2") = (unsigned long)(arg1)
+#define CALL_ARGS_2(arg1, arg2)                                         \
+        CALL_ARGS_1(arg1);                                              \
+        register unsigned long r3 asm("3") = (unsigned long)(arg2)
+#define CALL_ARGS_3(arg1, arg2, arg3)                                   \
+        CALL_ARGS_2(arg1, arg2);                                        \
+        register unsigned long r4 asm("4") = (unsigned long)(arg3)
+#define CALL_ARGS_4(arg1, arg2, arg3, arg4)                             \
+        CALL_ARGS_3(arg1, arg2, arg3);                                  \
+        register unsigned long r4 asm("5") = (unsigned long)(arg4)
+#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5)                       \
+        CALL_ARGS_4(arg1, arg2, arg3, arg4);                            \
+        register unsigned long r4 asm("6") = (unsigned long)(arg5)
+
+#define CALL_FMT_0
+#define CALL_FMT_1 CALL_FMT_0, "0" (r2)
+#define CALL_FMT_2 CALL_FMT_1, "d" (r3)
+#define CALL_FMT_3 CALL_FMT_2, "d" (r4)
+#define CALL_FMT_4 CALL_FMT_3, "d" (r5)
+#define CALL_FMT_5 CALL_FMT_4, "d" (r6)
+
+#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
+#define CALL_CLOBBER_4 CALL_CLOBBER_5
+#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
+#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
+#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
+#define CALL_CLOBBER_0 CALL_CLOBBER_1
+
+#define CALL_ON_STACK(fn, stack, nr, args...)                           \
+({                                                                      \
+        CALL_ARGS_##nr(args);                                           \
+        unsigned long prev;                                             \
+                                                                        \
+        asm volatile(                                                   \
+                "       la      %[_prev],0(15)\n"                       \
+                "       la      15,0(%[_stack])\n"                      \
+                "       stg     %[_prev],%[_bc](15)\n"                  \
+                "       brasl   14,%[_fn]\n"                            \
+                "       la      15,0(%[_prev])\n"                       \
+                : "+&d" (r2), [_prev] "=&a" (prev)                      \
+                : [_stack] "a" (stack),                                 \
+                  [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
+                  [_fn] "X" (fn) CALL_FMT_##nr : CALL_CLOBBER_##nr);    \
+        r2;                                                             \
+})
+
 /*
  * Give up the time slice of the virtual PU.
  */