s390/time: always use stckf instead of stck if available

The store clock fast instruction saves a couple of instructions compared
to the store clock instruction. Always use stckf instead of stck if it
is available.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 5 insertions, 12 deletions

diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h
index c447a27a7fdb..72eaa8511a4f 100644
--- a/arch/s390/include/asm/timex.h
+++ b/arch/s390/include/asm/timex.h
@@ -73,11 +73,15 @@ static inline void local_tick_enable(unsigned long long comp)
 
 typedef unsigned long long cycles_t;
 
-static inline unsigned long long get_clock (void)
+static inline unsigned long long get_clock(void)
 {
 	unsigned long long clk;
 
+#if defined(CONFIG_64BIT) && !defined(CONFIG_MARCH_Z900) && !defined(CONFIG_MARCH_Z990)
+	asm volatile(".insn s,0xb27c0000,%0" : "=Q" (clk) : : "cc");
+#else
 	asm volatile("stck %0" : "=Q" (clk) : : "cc");
+#endif
 	return clk;
 }
 
@@ -86,17 +90,6 @@ static inline void get_clock_ext(char *clk)
 	asm volatile("stcke %0" : "=Q" (*clk) : : "cc");
 }
 
-static inline unsigned long long get_clock_fast(void)
-{
-	unsigned long long clk;
-
-	if (MACHINE_HAS_STCKF)
-		asm volatile(".insn	s,0xb27c0000,%0" : "=Q" (clk) : : "cc");
-	else
-		clk = get_clock();
-	return clk;
-}
-
 static inline unsigned long long get_clock_xt(void)
 {
 	unsigned char clk[16];