From b603d258a43b4e7339660bdd3b5c25eacd603e54 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 9 May 2012 16:27:36 +0200 Subject: [PATCH] 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 --- drivers/s390/cio/cio.c | 73 +++++++++++------------------------------- 1 file changed, 19 insertions(+), 54 deletions(-) diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c index a49c46c91983..a6ddaed8793d 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 -- 2.20.1