From 27f6b416626a240e1b46f646d2e0c5266f4eac95 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 20 Jul 2012 11:15:08 +0200 Subject: s390/vtimer: rework virtual timer interface The current virtual timer interface is inherently per-cpu and hard to use. The sole user of the interface is appldata which uses it to execute a function after a specific amount of cputime has been used over all cpus. Rework the virtual timer interface to hook into the cputime accounting. This makes the interface independent from the CPU timer interrupts, and makes the virtual timers global as opposed to per-cpu. Overall the code is greatly simplified. The downside is that the accuracy is not as good as the original implementation, but it is still good enough for appldata. Reviewed-by: Jan Glauber Reviewed-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry.S | 37 ++++++++++++++----------------------- 1 file changed, 14 insertions(+), 23 deletions(-) (limited to 'arch/s390/kernel/entry.S') diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 2c0eff488875..870bad6d56fc 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -616,17 +616,13 @@ ext_skip: * Load idle PSW. The second "half" of this function is in cleanup_idle. */ ENTRY(psw_idle) - st %r4,__SF_EMPTY(%r15) + st %r3,__SF_EMPTY(%r15) basr %r1,0 la %r1,psw_idle_lpsw+4-.(%r1) st %r1,__SF_EMPTY+4(%r15) oi __SF_EMPTY+4(%r15),0x80 - la %r1,.Lvtimer_max-psw_idle_lpsw-4(%r1) - stck __IDLE_ENTER(%r2) - ltr %r5,%r5 - stpt __VQ_IDLE_ENTER(%r3) - jz psw_idle_lpsw - spt 0(%r1) + stck __CLOCK_IDLE_ENTER(%r2) + stpt __TIMER_IDLE_ENTER(%r2) psw_idle_lpsw: lpsw __SF_EMPTY(%r15) br %r14 @@ -885,33 +881,28 @@ cleanup_io_restore_insn: cleanup_idle: # copy interrupt clock & cpu timer - mvc __IDLE_EXIT(8,%r2),__LC_INT_CLOCK - mvc __VQ_IDLE_EXIT(8,%r3),__LC_ASYNC_ENTER_TIMER + mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK + mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER chi %r11,__LC_SAVE_AREA_ASYNC je 0f - mvc __IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK - mvc __VQ_IDLE_EXIT(8,%r3),__LC_MCCK_ENTER_TIMER + mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK + mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER 0: # check if stck has been executed cl %r9,BASED(cleanup_idle_insn) jhe 1f - mvc __IDLE_ENTER(8,%r2),__IDLE_EXIT(%r2) - mvc __VQ_IDLE_ENTER(8,%r3),__VQ_IDLE_EXIT(%r3) - j 2f -1: # check if the cpu timer has been reprogrammed - ltr %r5,%r5 - jz 2f - spt __VQ_IDLE_ENTER(%r3) -2: # account system time going idle + mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2) + mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r3) +1: # account system time going idle lm %r9,%r10,__LC_STEAL_TIMER - ADD64 %r9,%r10,__IDLE_ENTER(%r2) + ADD64 %r9,%r10,__CLOCK_IDLE_ENTER(%r2) SUB64 %r9,%r10,__LC_LAST_UPDATE_CLOCK stm %r9,%r10,__LC_STEAL_TIMER - mvc __LC_LAST_UPDATE_CLOCK(8),__IDLE_EXIT(%r2) + mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2) lm %r9,%r10,__LC_SYSTEM_TIMER ADD64 %r9,%r10,__LC_LAST_UPDATE_TIMER - SUB64 %r9,%r10,__VQ_IDLE_ENTER(%r3) + SUB64 %r9,%r10,__TIMER_IDLE_ENTER(%r2) stm %r9,%r10,__LC_SYSTEM_TIMER - mvc __LC_LAST_UPDATE_TIMER(8),__VQ_IDLE_EXIT(%r3) + mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2) # prepare return psw n %r8,BASED(cleanup_idle_wait) # clear wait state bit l %r9,24(%r11) # return from psw_idle -- cgit v1.2.3