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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2013-08-23 12:45:58 (GMT)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-08-28 07:19:23 (GMT)
commit0587d409ec53312f735d2004d5f47f8effee1ea9 (patch)
tree7ab956aaf3d7d238f8bd40a8f50d60302cb3363a
parent6b169ac9b4342ff3a1499bdeb7596aa4f1bc401b (diff)
downloadlinux-0587d409ec53312f735d2004d5f47f8effee1ea9.tar.xz
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 <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/kernel/entry.S4
-rw-r--r--arch/s390/kernel/entry64.S2
-rw-r--r--arch/s390/kernel/process.c1
-rw-r--r--arch/s390/kernel/time.c1
-rw-r--r--arch/s390/lib/delay.c2
5 files changed, 4 insertions, 6 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 5ca70b4..cc30d1f 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 980c7aa..2b2188b 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 2bc3edd..c5dbb33 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 876546b..064c308 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 c61b9fa..57c87d7 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);