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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2012-05-09 16:27:36 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-05-16 14:42:38 +0200
commitb603d258a43b4e7339660bdd3b5c25eacd603e54 (patch)
treed6bf2fb403540be8e48e22dc85fb5587d7567d9e /drivers/s390/cio/cio.c
parent0de9db37f0dff3bda21b3650ba60a21d3fe70df2 (diff)
downloadop-kernel-dev-b603d258a43b4e7339660bdd3b5c25eacd603e54.zip
op-kernel-dev-b603d258a43b4e7339660bdd3b5c25eacd603e54.tar.gz
s390: remove superfluous tpi from wait_cons_dev
wait_cons_dev waits for a particular subchannel to complete an I/O. It is not necessary to use tpi to get the subchannel id as it is already known. This avoids changes to the interrupt subclass mask and allows to remove the lock & unlock of the subchannel lock. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio/cio.c')
-rw-r--r--drivers/s390/cio/cio.c73
1 files changed, 19 insertions, 54 deletions
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index a49c46c..a6ddaed 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -656,51 +656,34 @@ static struct io_subchannel_private console_priv;
static int console_subchannel_in_use;
/*
- * Use cio_tpi to get a pending interrupt and call the interrupt handler.
- * Return non-zero if an interrupt was processed, zero otherwise.
+ * Use cio_tsch to update the subchannel status and call the interrupt handler
+ * if status had been pending. Called with the console_subchannel lock.
*/
-static int cio_tpi(void)
+static void cio_tsch(struct subchannel *sch)
{
- struct tpi_info *tpi_info;
- struct subchannel *sch;
struct irb *irb;
int irq_context;
- tpi_info = (struct tpi_info *)&S390_lowcore.subchannel_id;
- if (tpi(NULL) != 1)
- return 0;
- kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
- if (tpi_info->adapter_IO) {
- do_adapter_IO(tpi_info->isc);
- return 1;
- }
irb = (struct irb *)&S390_lowcore.irb;
/* Store interrupt response block to lowcore. */
- if (tsch(tpi_info->schid, irb) != 0) {
+ if (tsch(sch->schid, irb) != 0)
/* Not status pending or not operational. */
- kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
- return 1;
- }
- sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
- if (!sch) {
- kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
- return 1;
- }
+ return;
+ memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
+ /* Call interrupt handler with updated status. */
irq_context = in_interrupt();
- if (!irq_context)
+ if (!irq_context) {
local_bh_disable();
- irq_enter();
- spin_lock(sch->lock);
- memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
+ irq_enter();
+ }
if (sch->driver && sch->driver->irq)
sch->driver->irq(sch);
else
kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
- spin_unlock(sch->lock);
- irq_exit();
- if (!irq_context)
+ if (!irq_context) {
+ irq_exit();
_local_bh_enable();
- return 1;
+ }
}
void *cio_get_console_priv(void)
@@ -712,34 +695,16 @@ void *cio_get_console_priv(void)
* busy wait for the next interrupt on the console
*/
void wait_cons_dev(void)
- __releases(console_subchannel.lock)
- __acquires(console_subchannel.lock)
{
- unsigned long cr6 __attribute__ ((aligned (8)));
- unsigned long save_cr6 __attribute__ ((aligned (8)));
-
- /*
- * before entering the spinlock we may already have
- * processed the interrupt on a different CPU...
- */
if (!console_subchannel_in_use)
return;
- /* disable all but the console isc */
- __ctl_store (save_cr6, 6, 6);
- cr6 = 1UL << (31 - CONSOLE_ISC);
- __ctl_load (cr6, 6, 6);
-
- do {
- spin_unlock(console_subchannel.lock);
- if (!cio_tpi())
- cpu_relax();
- spin_lock(console_subchannel.lock);
- } while (console_subchannel.schib.scsw.cmd.actl != 0);
- /*
- * restore previous isc value
- */
- __ctl_load (save_cr6, 6, 6);
+ while (1) {
+ cio_tsch(&console_subchannel);
+ if (console_subchannel.schib.scsw.cmd.actl == 0)
+ break;
+ udelay_simple(100);
+ }
}
static int
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