[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 <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 23b129f..9281b25 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -2,8 +2,7 @@
* drivers/s390/cio/device.c
* bus driver for ccw devices
*
- * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- * IBM Corporation
+ * Copyright IBM Corp. 2002,2008
* Author(s): Arnd Bergmann (arndb@de.ibm.com)
* Cornelia Huck (cornelia.huck@de.ibm.com)
* Martin Schwidefsky (schwidefsky@de.ibm.com)
@@ -126,19 +125,17 @@
static void io_subchannel_irq(struct subchannel *);
static int io_subchannel_probe(struct subchannel *);
static int io_subchannel_remove(struct subchannel *);
-static int io_subchannel_notify(struct subchannel *, int);
-static void io_subchannel_verify(struct subchannel *);
-static void io_subchannel_ioterm(struct subchannel *);
static void io_subchannel_shutdown(struct subchannel *);
+static int io_subchannel_sch_event(struct subchannel *, int);
+static int io_subchannel_chp_event(struct subchannel *, void *, int);
static struct css_driver io_subchannel_driver = {
.owner = THIS_MODULE,
.subchannel_type = SUBCHANNEL_TYPE_IO,
.name = "io_subchannel",
.irq = io_subchannel_irq,
- .notify = io_subchannel_notify,
- .verify = io_subchannel_verify,
- .termination = io_subchannel_ioterm,
+ .sch_event = io_subchannel_sch_event,
+ .chp_event = io_subchannel_chp_event,
.probe = io_subchannel_probe,
.remove = io_subchannel_remove,
.shutdown = io_subchannel_shutdown,
@@ -786,7 +783,7 @@
sch_set_cdev(sch, cdev);
cdev->private->schid = sch->schid;
cdev->ccwlock = sch->lock;
- device_trigger_reprobe(sch);
+ ccw_device_trigger_reprobe(cdev);
spin_unlock_irq(sch->lock);
}
@@ -1265,11 +1262,7 @@
cdev = sch_get_cdev(sch);
if (!cdev)
return 0;
- if (!cdev->drv)
- return 0;
- if (!cdev->online)
- return 0;
- return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
+ return ccw_device_notify(cdev, event);
}
static void io_subchannel_verify(struct subchannel *sch)
@@ -1281,20 +1274,96 @@
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
}
-static void io_subchannel_ioterm(struct subchannel *sch)
+static int check_for_io_on_path(struct subchannel *sch, int mask)
+{
+ int cc;
+
+ cc = stsch(sch->schid, &sch->schib);
+ if (cc)
+ return 0;
+ if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == mask)
+ return 1;
+ return 0;
+}
+
+static void terminate_internal_io(struct subchannel *sch,
+ struct ccw_device *cdev)
+{
+ if (cio_clear(sch)) {
+ /* Recheck device in case clear failed. */
+ sch->lpm = 0;
+ if (cdev->online)
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+ else
+ css_schedule_eval(sch->schid);
+ return;
+ }
+ cdev->private->state = DEV_STATE_CLEAR_VERIFY;
+ /* Request retry of internal operation. */
+ cdev->private->flags.intretry = 1;
+ /* Call handler. */
+ if (cdev->handler)
+ cdev->handler(cdev, cdev->private->intparm,
+ ERR_PTR(-EIO));
+}
+
+static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
{
struct ccw_device *cdev;
cdev = sch_get_cdev(sch);
if (!cdev)
return;
- /* Internal I/O will be retried by the interrupt handler. */
- if (cdev->private->flags.intretry)
- return;
- cdev->private->state = DEV_STATE_CLEAR_VERIFY;
- if (cdev->handler)
- cdev->handler(cdev, cdev->private->intparm,
- ERR_PTR(-EIO));
+ if (check_for_io_on_path(sch, mask)) {
+ if (cdev->private->state == DEV_STATE_ONLINE)
+ ccw_device_kill_io(cdev);
+ else {
+ terminate_internal_io(sch, cdev);
+ /* Re-start path verification. */
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+ }
+ } else
+ /* trigger path verification. */
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+
+}
+
+static int io_subchannel_chp_event(struct subchannel *sch, void *data,
+ int event)
+{
+ int mask;
+ struct res_acc_data *res_data;
+
+ res_data = data;
+ mask = chp_ssd_get_mask(&sch->ssd_info, res_data);
+ if (!mask)
+ return 0;
+ switch (event) {
+ case CHP_VARY_OFF:
+ sch->opm &= ~mask;
+ sch->lpm &= ~mask;
+ io_subchannel_terminate_path(sch, mask);
+ break;
+ case CHP_VARY_ON:
+ sch->opm |= mask;
+ sch->lpm |= mask;
+ io_subchannel_verify(sch);
+ break;
+ case CHP_OFFLINE:
+ if (stsch(sch->schid, &sch->schib))
+ return -ENXIO;
+ if (!css_sch_is_valid(&sch->schib))
+ return -ENODEV;
+ io_subchannel_terminate_path(sch, mask);
+ break;
+ case CHP_ONLINE:
+ if (stsch(sch->schid, &sch->schib))
+ return -ENXIO;
+ sch->lpm |= mask & sch->opm;
+ io_subchannel_verify(sch);
+ break;
+ }
+ return 0;
}
static void
@@ -1326,6 +1395,195 @@
cio_disable_subchannel(sch);
}
+static int io_subchannel_get_status(struct subchannel *sch)
+{
+ struct schib schib;
+
+ if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
+ 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 device_is_disconnected(struct ccw_device *cdev)
+{
+ if (!cdev)
+ return 0;
+ return (cdev->private->state == DEV_STATE_DISCONNECTED ||
+ cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
+}
+
+static int recovery_check(struct device *dev, void *data)
+{
+ struct ccw_device *cdev = to_ccwdev(dev);
+ int *redo = data;
+
+ spin_lock_irq(cdev->ccwlock);
+ switch (cdev->private->state) {
+ case DEV_STATE_DISCONNECTED:
+ CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
+ cdev->private->dev_id.ssid,
+ cdev->private->dev_id.devno);
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+ *redo = 1;
+ break;
+ case DEV_STATE_DISCONNECTED_SENSE_ID:
+ *redo = 1;
+ break;
+ }
+ spin_unlock_irq(cdev->ccwlock);
+
+ return 0;
+}
+
+static void recovery_work_func(struct work_struct *unused)
+{
+ int redo = 0;
+
+ bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
+ if (redo) {
+ spin_lock_irq(&recovery_lock);
+ if (!timer_pending(&recovery_timer)) {
+ if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
+ recovery_phase++;
+ mod_timer(&recovery_timer, jiffies +
+ recovery_delay[recovery_phase] * HZ);
+ }
+ spin_unlock_irq(&recovery_lock);
+ } else
+ CIO_MSG_EVENT(4, "recovery: end\n");
+}
+
+static DECLARE_WORK(recovery_work, recovery_work_func);
+
+static void recovery_func(unsigned long data)
+{
+ /*
+ * We can't do our recovery in softirq context and it's not
+ * performance critical, so we schedule it.
+ */
+ schedule_work(&recovery_work);
+}
+
+static void ccw_device_schedule_recovery(void)
+{
+ unsigned long flags;
+
+ CIO_MSG_EVENT(4, "recovery: schedule\n");
+ spin_lock_irqsave(&recovery_lock, flags);
+ if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
+ recovery_phase = 0;
+ mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
+ }
+ spin_unlock_irqrestore(&recovery_lock, flags);
+}
+
+static void device_set_disconnected(struct ccw_device *cdev)
+{
+ if (!cdev)
+ return;
+ ccw_device_set_timeout(cdev, 0);
+ cdev->private->flags.fake_irb = 0;
+ cdev->private->state = DEV_STATE_DISCONNECTED;
+ if (cdev->online)
+ ccw_device_schedule_recovery();
+}
+
+static int io_subchannel_sch_event(struct subchannel *sch, int slow)
+{
+ int event, ret, disc;
+ unsigned long flags;
+ enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE } action;
+ struct ccw_device *cdev;
+
+ spin_lock_irqsave(sch->lock, flags);
+ cdev = sch_get_cdev(sch);
+ disc = device_is_disconnected(cdev);
+ 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. */
+ if (cdev)
+ ccw_device_set_timeout(cdev, 0);
+ if (!disc && !slow) {
+ /* Non-disconnected devices are evaluated on the slow path. */
+ spin_unlock_irqrestore(sch->lock, flags);
+ return -EAGAIN;
+ }
+ event = io_subchannel_get_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(cdev);
+ /* Ask driver what to do with device. */
+ action = UNREGISTER;
+ spin_unlock_irqrestore(sch->lock, flags);
+ ret = io_subchannel_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:
+ ccw_device_trigger_reprobe(cdev);
+ break;
+ default:
+ break;
+ }
+ spin_unlock_irqrestore(sch->lock, flags);
+ /* Probe if necessary. */
+ if (action == UNREGISTER_PROBE)
+ ret = css_probe_device(sch->schid);
+
+ return ret;
+}
+
#ifdef CONFIG_CCW_CONSOLE
static struct ccw_device console_cdev;
static struct ccw_device_private console_private;
@@ -1558,71 +1816,6 @@
return sch->schid;
}
-static int recovery_check(struct device *dev, void *data)
-{
- struct ccw_device *cdev = to_ccwdev(dev);
- int *redo = data;
-
- spin_lock_irq(cdev->ccwlock);
- switch (cdev->private->state) {
- case DEV_STATE_DISCONNECTED:
- CIO_MSG_EVENT(4, "recovery: trigger 0.%x.%04x\n",
- cdev->private->dev_id.ssid,
- cdev->private->dev_id.devno);
- dev_fsm_event(cdev, DEV_EVENT_VERIFY);
- *redo = 1;
- break;
- case DEV_STATE_DISCONNECTED_SENSE_ID:
- *redo = 1;
- break;
- }
- spin_unlock_irq(cdev->ccwlock);
-
- return 0;
-}
-
-static void recovery_work_func(struct work_struct *unused)
-{
- int redo = 0;
-
- bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
- if (redo) {
- spin_lock_irq(&recovery_lock);
- if (!timer_pending(&recovery_timer)) {
- if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
- recovery_phase++;
- mod_timer(&recovery_timer, jiffies +
- recovery_delay[recovery_phase] * HZ);
- }
- spin_unlock_irq(&recovery_lock);
- } else
- CIO_MSG_EVENT(4, "recovery: end\n");
-}
-
-static DECLARE_WORK(recovery_work, recovery_work_func);
-
-static void recovery_func(unsigned long data)
-{
- /*
- * We can't do our recovery in softirq context and it's not
- * performance critical, so we schedule it.
- */
- schedule_work(&recovery_work);
-}
-
-void ccw_device_schedule_recovery(void)
-{
- unsigned long flags;
-
- CIO_MSG_EVENT(4, "recovery: schedule\n");
- spin_lock_irqsave(&recovery_lock, flags);
- if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
- recovery_phase = 0;
- mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
- }
- spin_unlock_irqrestore(&recovery_lock, flags);
-}
-
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccw_device_set_online);
EXPORT_SYMBOL(ccw_device_set_offline);