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s390: assume stckf is always present

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With z10 as minimum supported machine generation the store-clock-fast
facility (25) is always present and checked in als code.
Drop alternatives and always use stckf.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Vasily Gorbik 2022-02-25 10:38:23 +01:00
parent bedc96698f
commit 10bc15ba3a
2 changed files with 9 additions and 15 deletions
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11
arch/s390/kernel/entry.S
View File

@ -98,11 +98,6 @@ _LPP_OFFSET = __LC_LPP
#endif
.endm
.macro STCK savearea
ALTERNATIVE ".insn s,0xb2050000,\savearea", \
".insn s,0xb27c0000,\savearea", 25
.endm
/*
* The TSTMSK macro generates a test-under-mask instruction by
* calculating the memory offset for the specified mask value.
@ -442,7 +437,7 @@ ENDPROC(pgm_check_handler)
*/
.macro INT_HANDLER name,lc_old_psw,handler
ENTRY(\name)
STCK __LC_INT_CLOCK
stckf __LC_INT_CLOCK
stpt __LC_SYS_ENTER_TIMER
STBEAR __LC_LAST_BREAK
BPOFF
@ -514,7 +509,7 @@ ENTRY(psw_idle)
.Lpsw_idle_stcctm:
oi __LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
BPON
STCK __CLOCK_IDLE_ENTER(%r2)
stckf __CLOCK_IDLE_ENTER(%r2)
stpt __TIMER_IDLE_ENTER(%r2)
lpswe __SF_EMPTY(%r15)
.globl psw_idle_exit
@ -526,7 +521,7 @@ ENDPROC(psw_idle)
* Machine check handler routines
*/
ENTRY(mcck_int_handler)
STCK __LC_MCCK_CLOCK
stckf __LC_MCCK_CLOCK
BPOFF
la %r1,4095 # validate r1
spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # validate cpu timer

13
arch/s390/kernel/vtime.c
View File

@ -128,13 +128,12 @@ static int do_account_vtime(struct task_struct *tsk)
timer = S390_lowcore.last_update_timer;
clock = S390_lowcore.last_update_clock;
/* Use STORE CLOCK by default, STORE CLOCK FAST if available. */
alternative_io("stpt %0\n .insn s,0xb2050000,%1\n",
"stpt %0\n .insn s,0xb27c0000,%1\n",
25,
ASM_OUTPUT2("=Q" (S390_lowcore.last_update_timer),
"=Q" (S390_lowcore.last_update_clock)),
ASM_NO_INPUT_CLOBBER("cc"));
asm volatile(
" stpt %0\n" /* Store current cpu timer value */
" stckf %1" /* Store current tod clock value */
: "=Q" (S390_lowcore.last_update_timer),
"=Q" (S390_lowcore.last_update_clock)
: : "cc");
clock = S390_lowcore.last_update_clock - clock;
timer -= S390_lowcore.last_update_timer;