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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2017-09-07 17:03:19 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2018-10-09 11:20:56 +0200
commitff340d2472ec7618443913928af9fb85a7009270 (patch)
treef0228c89cf80d5fc617bf7f7fea79f2c610afa1f /arch/s390/include/asm/processor.h
parentinit: add arch_call_rest_init to allow stack switching (diff)
downloadlinux-dev-ff340d2472ec7618443913928af9fb85a7009270.tar.xz
linux-dev-ff340d2472ec7618443913928af9fb85a7009270.zip
s390: add stack switch helper
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/processor.h')
-rw-r--r--arch/s390/include/asm/processor.h49
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.
*/