[S390] prevent softirqs if delay is called disabled

The new delay implementation uses the clock comparator and an external
interrupt even if it is called disabled for interrupts. To do this
all external interrupt source except clock comparator are switched of
before enabling external interrupts. The external interrupt at the
end of the delay period may not execute softirqs or we can end up in a
dead-lock.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c
index 02854449b74ba64dea7230b606f72b63c3890218..70f2a862b670649e296d1c6e5277f01241161a11 100644 (file)
--- a/arch/s390/lib/delay.c
+++ b/arch/s390/lib/delay.c
@@ -15,6 +15,7 @@
 #include <linux/delay.h>
 #include <linux/timex.h>
 #include <linux/irqflags.h>
+#include <linux/interrupt.h>
 
 void __delay(unsigned long loops)
 {
@@ -35,7 +36,11 @@ void __udelay(unsigned long usecs)
 {
        u64 end, time, jiffy_timer = 0;
        unsigned long flags, cr0, mask, dummy;
+       int irq_context;
 
+       irq_context = in_interrupt();
+       if (!irq_context)
+               local_bh_disable();
        local_irq_save(flags);
        if (raw_irqs_disabled_flags(flags)) {
                jiffy_timer = S390_lowcore.jiffy_timer;
@@ -62,6 +67,8 @@ void __udelay(unsigned long usecs)
                __ctl_load(cr0, 0, 0);
                S390_lowcore.jiffy_timer = jiffy_timer;
        }
+       if (!irq_context)
+               _local_bh_enable();
        set_clock_comparator(S390_lowcore.jiffy_timer);
        local_irq_restore(flags);
 }