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>

4 files changed, 17 insertions, 21 deletions

diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index b21e46e5d4b8..7244e1f64126 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -82,7 +82,6 @@ extern unsigned int user_mode;
 #define MACHINE_FLAG_LPAR       (1UL << 12)
 #define MACHINE_FLAG_SPP        (1UL << 13)
 #define MACHINE_FLAG_TOPOLOGY   (1UL << 14)
-#define MACHINE_FLAG_STCKF      (1UL << 15)
 
 #define MACHINE_IS_VM           (S390_lowcore.machine_flags & MACHINE_FLAG_VM)
 #define MACHINE_IS_KVM          (S390_lowcore.machine_flags & MACHINE_FLAG_KVM)
@@ -101,7 +100,6 @@ extern unsigned int user_mode;
 #define MACHINE_HAS_PFMF        (0)
 #define MACHINE_HAS_SPP         (0)
 #define MACHINE_HAS_TOPOLOGY    (0)
-#define MACHINE_HAS_STCKF       (0)
 #else /* __s390x__ */
 #define MACHINE_HAS_IEEE        (1)
 #define MACHINE_HAS_CSP         (1)
@@ -113,7 +111,6 @@ extern unsigned int user_mode;
 #define MACHINE_HAS_PFMF        (S390_lowcore.machine_flags & MACHINE_FLAG_PFMF)
 #define MACHINE_HAS_SPP         (S390_lowcore.machine_flags & MACHINE_FLAG_SPP)
 #define MACHINE_HAS_TOPOLOGY    (S390_lowcore.machine_flags & MACHINE_FLAG_TOPOLOGY)
-#define MACHINE_HAS_STCKF       (S390_lowcore.machine_flags & MACHINE_FLAG_STCKF)
 #endif /* __s390x__ */
 
 #define ZFCPDUMP_HSA_SIZE       (32UL<<20)
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];
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 9475e682727f..d84181f1f5e8 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -374,8 +374,6 @@ static __init void detect_machine_facilities(void)
                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
         if (test_facility(40))
                 S390_lowcore.machine_flags |= MACHINE_FLAG_SPP;
-        if (test_facility(25))
-                S390_lowcore.machine_flags |= MACHINE_FLAG_STCKF;
 #endif
 }
 
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 3a633af72bae..444fd72e0787 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -148,6 +148,14 @@ _TIF_EXIT_SIE = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING)
         ssm     __LC_RETURN_PSW
         .endm
 
+        .macro STCK savearea
+#if defined(CONFIG_64BIT) && !defined(CONFIG_MARCH_Z900) && !defined(CONFIG_MARCH_Z990)
+        .insn   s,0xb27c0000,\savearea          # store clock fast
+#else
+        .insn   s,0xb2050000,\savearea          # store clock
+#endif
+        .endm
+
         .section .kprobes.text, "ax"
 
 /*
@@ -458,7 +466,7 @@ pgm_svcper:
  * IO interrupt handler routine
  */
 ENTRY(io_int_handler)
-        stck    __LC_INT_CLOCK
+        STCK    __LC_INT_CLOCK
         stpt    __LC_ASYNC_ENTER_TIMER
         stmg    %r8,%r15,__LC_SAVE_AREA_ASYNC
         lg      %r10,__LC_LAST_BREAK
@@ -604,7 +612,7 @@ io_notify_resume:
  * External interrupt handler routine
  */
 ENTRY(ext_int_handler)
-        stck    __LC_INT_CLOCK
+        STCK    __LC_INT_CLOCK
         stpt    __LC_ASYNC_ENTER_TIMER
         stmg    %r8,%r15,__LC_SAVE_AREA_ASYNC
         lg      %r10,__LC_LAST_BREAK
@@ -639,7 +647,7 @@ ENTRY(psw_idle)
         larl    %r1,psw_idle_lpsw+4
         stg     %r1,__SF_EMPTY+8(%r15)
         larl    %r1,.Lvtimer_max
-        stck    __IDLE_ENTER(%r2)
+        STCK    __IDLE_ENTER(%r2)
         ltr     %r5,%r5
         stpt    __VQ_IDLE_ENTER(%r3)
         jz      psw_idle_lpsw
@@ -655,7 +663,7 @@ __critical_end:
  * Machine check handler routines
  */
 ENTRY(mcck_int_handler)
-        stck    __LC_MCCK_CLOCK
+        STCK    __LC_MCCK_CLOCK
         la      %r1,4095                # revalidate r1
         spt     __LC_CPU_TIMER_SAVE_AREA-4095(%r1)      # revalidate cpu timer
         lmg     %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs