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s390: remove superfluous tpi from wait_cons_dev

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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>
This commit is contained in:
Martin Schwidefsky 2012-05-09 16:27:36 +02:00
parent 0de9db37f0
commit b603d258a4
1 changed files with 20 additions and 55 deletions
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75
drivers/s390/cio/cio.c
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@ -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;
}
irq_context = in_interrupt();
if (!irq_context)
local_bh_disable();
irq_enter();
spin_lock(sch->lock);
return;
memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
/* Call interrupt handler with updated status. */
irq_context = in_interrupt();
if (!irq_context) {
local_bh_disable();
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