Commit 10bc15ba authored by Vasily Gorbik's avatar Vasily Gorbik
Browse files

s390: assume stckf is always present 



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: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent bedc9669

arch/s390/kernel/entry.S

+3 −8
Original line number Diff line number Diff line
@@ -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

arch/s390/kernel/vtime.c

+6 −7
Original line number Diff line number Diff line
@@ -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;