From 4c1051e37a0e2a941115c6fb7ba08c318f25a0f9 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Sun, 11 Mar 2012 11:59:27 -0400 Subject: [S390] rework idle code Whenever the cpu loads an enabled wait PSW it will appear as idle to the underlying host system. The code in default_idle calls vtime_stop_cpu which does the necessary voodoo to get the cpu time accounting right. The udelay code just loads an enabled wait PSW. To correct this rework the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts to entry[64].S, vtime_stop_cpu can now be called from anywhere and vtime_start_cpu is gone. The correction of the cpu time during wakeup from an enabled wait PSW is done with a critical section in entry[64].S. As vtime_start_cpu is gone, s390_idle_check can be removed as well. Signed-off-by: Martin Schwidefsky --- arch/s390/lib/delay.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) (limited to 'arch/s390/lib') diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c index db92f044024c..9f1f71e85778 100644 --- a/arch/s390/lib/delay.c +++ b/arch/s390/lib/delay.c @@ -13,6 +13,7 @@ #include #include #include +#include void __delay(unsigned long loops) { @@ -28,36 +29,33 @@ void __delay(unsigned long loops) static void __udelay_disabled(unsigned long long usecs) { - unsigned long mask, cr0, cr0_saved; - u64 clock_saved; - u64 end; + unsigned long cr0, cr6, new; + u64 clock_saved, end; - mask = psw_kernel_bits | PSW_MASK_DAT | PSW_MASK_WAIT | - PSW_MASK_EXT | PSW_MASK_MCHECK; end = get_clock() + (usecs << 12); clock_saved = local_tick_disable(); - __ctl_store(cr0_saved, 0, 0); - cr0 = (cr0_saved & 0xffff00e0) | 0x00000800; - __ctl_load(cr0 , 0, 0); + __ctl_store(cr0, 0, 0); + __ctl_store(cr6, 6, 6); + new = (cr0 & 0xffff00e0) | 0x00000800; + __ctl_load(new , 0, 0); + new = 0; + __ctl_load(new, 6, 6); lockdep_off(); do { set_clock_comparator(end); - trace_hardirqs_on(); - __load_psw_mask(mask); + vtime_stop_cpu(); local_irq_disable(); } while (get_clock() < end); lockdep_on(); - __ctl_load(cr0_saved, 0, 0); + __ctl_load(cr0, 0, 0); + __ctl_load(cr6, 6, 6); local_tick_enable(clock_saved); } static void __udelay_enabled(unsigned long long usecs) { - unsigned long mask; - u64 clock_saved; - u64 end; + u64 clock_saved, end; - mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_EXT | PSW_MASK_IO; end = get_clock() + (usecs << 12); do { clock_saved = 0; @@ -65,8 +63,7 @@ static void __udelay_enabled(unsigned long long usecs) clock_saved = local_tick_disable(); set_clock_comparator(end); } - trace_hardirqs_on(); - __load_psw_mask(mask); + vtime_stop_cpu(); local_irq_disable(); if (clock_saved) local_tick_enable(clock_saved); -- cgit v1.2.3