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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2008-08-01 16:39:11 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-08-01 16:39:30 +0200 |
| commit | 934b2857cc576ae53c92a66e63fce7ddcfa74691 (patch) | |
| tree | 4a8e261d16739624bb91ed9f56062ec5f7401227 /drivers/s390 | |
| parent | 3a95e8eb34f595a0144adb6e5513d456319bd8a5 (diff) | |
| download | linux-934b2857cc576ae53c92a66e63fce7ddcfa74691.tar.gz linux-934b2857cc576ae53c92a66e63fce7ddcfa74691.tar.bz2 linux-934b2857cc576ae53c92a66e63fce7ddcfa74691.zip | |
[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')
| -rw-r--r-- | drivers/s390/char/sclp.c | 6 |
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) void sclp_sync_wait(void) { + unsigned long long old_tick; unsigned long flags; unsigned long cr0, cr0_sync; u64 timeout; @@ -419,11 +420,12 @@ sclp_sync_wait(void) if (!irq_context) local_bh_disable(); /* Enable service-signal interruption, disable timer interrupts */ + old_tick = local_tick_disable(); trace_hardirqs_on(); __ctl_store(cr0, 0, 0); cr0_sync = cr0; + cr0_sync &= 0xffff00a0; cr0_sync |= 0x00000200; - cr0_sync &= 0xFFFFF3AC; __ctl_load(cr0_sync, 0, 0); __raw_local_irq_stosm(0x01); /* Loop until driver state indicates finished request */ @@ -439,9 +441,9 @@ sclp_sync_wait(void) __ctl_load(cr0, 0, 0); if (!irq_context) _local_bh_enable(); + local_tick_enable(old_tick); local_irq_restore(flags); } - EXPORT_SYMBOL(sclp_sync_wait); /* Dispatch changes in send and receive mask to registered listeners. */ |