From c820de39bd083222f5be2563181c87493e436f7c Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Mon, 14 Jul 2008 09:58:45 +0200 Subject: [S390] cio: Rework css driver. Rework the css driver methods to provide sane callbacks for subchannels of all types. As a bonus, this cleans up and simplyfies the machine check handling for I/O subchannels a lot. Signed-off-by: Cornelia Huck Signed-off-by: Martin Schwidefsky Signed-off-by: Heiko Carstens --- drivers/s390/cio/css.c | 123 +++++++------------------------------------------ 1 file changed, 16 insertions(+), 107 deletions(-) (limited to 'drivers/s390/cio/css.c') diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index 53e7496..0205665 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -283,7 +283,7 @@ static int css_register_subchannel(struct subchannel *sch) return ret; } -static int css_probe_device(struct subchannel_id schid) +int css_probe_device(struct subchannel_id schid) { int ret; struct subchannel *sch; @@ -330,112 +330,6 @@ int css_sch_is_valid(struct schib *schib) } EXPORT_SYMBOL_GPL(css_sch_is_valid); -static int css_get_subchannel_status(struct subchannel *sch) -{ - struct schib schib; - - if (stsch(sch->schid, &schib)) - return CIO_GONE; - if (!css_sch_is_valid(&schib)) - return CIO_GONE; - if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev)) - return CIO_REVALIDATE; - if (!sch->lpm) - return CIO_NO_PATH; - return CIO_OPER; -} - -static int css_evaluate_known_subchannel(struct subchannel *sch, int slow) -{ - int event, ret, disc; - unsigned long flags; - enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE } action; - - spin_lock_irqsave(sch->lock, flags); - disc = device_is_disconnected(sch); - if (disc && slow) { - /* Disconnected devices are evaluated directly only.*/ - spin_unlock_irqrestore(sch->lock, flags); - return 0; - } - /* No interrupt after machine check - kill pending timers. */ - device_kill_pending_timer(sch); - if (!disc && !slow) { - /* Non-disconnected devices are evaluated on the slow path. */ - spin_unlock_irqrestore(sch->lock, flags); - return -EAGAIN; - } - event = css_get_subchannel_status(sch); - CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n", - sch->schid.ssid, sch->schid.sch_no, event, - disc ? "disconnected" : "normal", - slow ? "slow" : "fast"); - /* Analyze subchannel status. */ - action = NONE; - switch (event) { - case CIO_NO_PATH: - if (disc) { - /* Check if paths have become available. */ - action = REPROBE; - break; - } - /* fall through */ - case CIO_GONE: - /* Prevent unwanted effects when opening lock. */ - cio_disable_subchannel(sch); - device_set_disconnected(sch); - /* Ask driver what to do with device. */ - action = UNREGISTER; - if (sch->driver && sch->driver->notify) { - spin_unlock_irqrestore(sch->lock, flags); - ret = sch->driver->notify(sch, event); - spin_lock_irqsave(sch->lock, flags); - if (ret) - action = NONE; - } - break; - case CIO_REVALIDATE: - /* Device will be removed, so no notify necessary. */ - if (disc) - /* Reprobe because immediate unregister might block. */ - action = REPROBE; - else - action = UNREGISTER_PROBE; - break; - case CIO_OPER: - if (disc) - /* Get device operational again. */ - action = REPROBE; - break; - } - /* Perform action. */ - ret = 0; - switch (action) { - case UNREGISTER: - case UNREGISTER_PROBE: - /* Unregister device (will use subchannel lock). */ - spin_unlock_irqrestore(sch->lock, flags); - css_sch_device_unregister(sch); - spin_lock_irqsave(sch->lock, flags); - - /* Reset intparm to zeroes. */ - sch->schib.pmcw.intparm = 0; - cio_modify(sch); - break; - case REPROBE: - device_trigger_reprobe(sch); - break; - default: - break; - } - spin_unlock_irqrestore(sch->lock, flags); - /* Probe if necessary. */ - if (action == UNREGISTER_PROBE) - ret = css_probe_device(sch->schid); - - return ret; -} - static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow) { struct schib schib; @@ -454,6 +348,21 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow) return css_probe_device(schid); } +static int css_evaluate_known_subchannel(struct subchannel *sch, int slow) +{ + int ret = 0; + + if (sch->driver) { + if (sch->driver->sch_event) + ret = sch->driver->sch_event(sch, slow); + else + dev_dbg(&sch->dev, + "Got subchannel machine check but " + "no sch_event handler provided.\n"); + } + return ret; +} + static void css_evaluate_subchannel(struct subchannel_id schid, int slow) { struct subchannel *sch; -- cgit v1.1