From 0587d409ec53312f735d2004d5f47f8effee1ea9 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 23 Aug 2013 14:45:58 +0200 Subject: [PATCH] s390/time: return with irqs disabled from psw_idle Modify the psw_idle waiting logic in entry[64].S to return with interrupts disabled. This avoids potential issues with udelay and interrupt loops as interrupts are not reenabled after clock comparator interrupts. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry.S | 4 ++-- arch/s390/kernel/entry64.S | 2 +- arch/s390/kernel/process.c | 1 + arch/s390/kernel/time.c | 1 - arch/s390/lib/delay.c | 2 -- 5 files changed, 4 insertions(+), 6 deletions(-) diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 5ca70b4b72cb..cc30d1fb000c 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -886,13 +886,13 @@ cleanup_idle: stm %r9,%r10,__LC_SYSTEM_TIMER mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2) # prepare return psw - n %r8,BASED(cleanup_idle_wait) # clear wait state bit + n %r8,BASED(cleanup_idle_wait) # clear irq & wait state bits l %r9,24(%r11) # return from psw_idle br %r14 cleanup_idle_insn: .long psw_idle_lpsw + 0x80000000 cleanup_idle_wait: - .long 0xfffdffff + .long 0xfcfdffff /* * Integer constants diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index 980c7aa1cc5c..2b2188b97c6a 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -929,7 +929,7 @@ cleanup_idle: stg %r9,__LC_SYSTEM_TIMER mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2) # prepare return psw - nihh %r8,0xfffd # clear wait state bit + nihh %r8,0xfcfd # clear irq & wait state bits lg %r9,48(%r11) # return from psw_idle br %r14 cleanup_idle_insn: diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 2bc3eddae34a..c5dbb335716d 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -71,6 +71,7 @@ void arch_cpu_idle(void) } /* Halt the cpu and keep track of cpu time accounting. */ vtime_stop_cpu(); + local_irq_enable(); } void arch_cpu_idle_exit(void) diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index 876546b9cfa1..064c3082ab33 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -92,7 +92,6 @@ void clock_comparator_work(void) struct clock_event_device *cd; S390_lowcore.clock_comparator = -1ULL; - set_clock_comparator(S390_lowcore.clock_comparator); cd = &__get_cpu_var(comparators); cd->event_handler(cd); } diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c index c61b9fad43cc..57c87d7d7ede 100644 --- a/arch/s390/lib/delay.c +++ b/arch/s390/lib/delay.c @@ -44,7 +44,6 @@ static void __udelay_disabled(unsigned long long usecs) do { set_clock_comparator(end); vtime_stop_cpu(); - local_irq_disable(); } while (get_tod_clock() < end); lockdep_on(); __ctl_load(cr0, 0, 0); @@ -64,7 +63,6 @@ static void __udelay_enabled(unsigned long long usecs) set_clock_comparator(end); } vtime_stop_cpu(); - local_irq_disable(); if (clock_saved) local_tick_enable(clock_saved); } while (get_tod_clock() < end); -- 2.45.2