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authorHeiko Carstens <heiko.carstens@de.ibm.com>2008-08-01 10:39:11 -0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-08-01 10:39:30 -0400
commit934b2857cc576ae53c92a66e63fce7ddcfa74691 (patch)
tree4a8e261d16739624bb91ed9f56062ec5f7401227 /drivers/s390/char
parent3a95e8eb34f595a0144adb6e5513d456319bd8a5 (diff)
[S390] nohz/sclp: disable timer on synchronous waits.
sclp_sync_wait wait synchronously for an sclp interrupt and disables timer interrupts. However on the irq enter paths there is an extra check if a timer interrupt would be due and calls the timer callback. This would schedule softirqs in the wrong context. So introduce local_tick_enable/disable which prevents this. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/char')
-rw-r--r--drivers/s390/char/sclp.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 3c8b25e6c345..1fd8f2193ed8 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -399,6 +399,7 @@ sclp_tod_from_jiffies(unsigned long jiffies)
399void 399void
400sclp_sync_wait(void) 400sclp_sync_wait(void)
401{ 401{
402 unsigned long long old_tick;
402 unsigned long flags; 403 unsigned long flags;
403 unsigned long cr0, cr0_sync; 404 unsigned long cr0, cr0_sync;
404 u64 timeout; 405 u64 timeout;
@@ -419,11 +420,12 @@ sclp_sync_wait(void)
419 if (!irq_context) 420 if (!irq_context)
420 local_bh_disable(); 421 local_bh_disable();
421 /* Enable service-signal interruption, disable timer interrupts */ 422 /* Enable service-signal interruption, disable timer interrupts */
423 old_tick = local_tick_disable();
422 trace_hardirqs_on(); 424 trace_hardirqs_on();
423 __ctl_store(cr0, 0, 0); 425 __ctl_store(cr0, 0, 0);
424 cr0_sync = cr0; 426 cr0_sync = cr0;
427 cr0_sync &= 0xffff00a0;
425 cr0_sync |= 0x00000200; 428 cr0_sync |= 0x00000200;
426 cr0_sync &= 0xFFFFF3AC;
427 __ctl_load(cr0_sync, 0, 0); 429 __ctl_load(cr0_sync, 0, 0);
428 __raw_local_irq_stosm(0x01); 430 __raw_local_irq_stosm(0x01);
429 /* Loop until driver state indicates finished request */ 431 /* Loop until driver state indicates finished request */
@@ -439,9 +441,9 @@ sclp_sync_wait(void)
439 __ctl_load(cr0, 0, 0); 441 __ctl_load(cr0, 0, 0);
440 if (!irq_context) 442 if (!irq_context)
441 _local_bh_enable(); 443 _local_bh_enable();
444 local_tick_enable(old_tick);
442 local_irq_restore(flags); 445 local_irq_restore(flags);
443} 446}
444
445EXPORT_SYMBOL(sclp_sync_wait); 447EXPORT_SYMBOL(sclp_sync_wait);
446 448
447/* Dispatch changes in send and receive mask to registered listeners. */ 449/* Dispatch changes in send and receive mask to registered listeners. */