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path: root/drivers/s390/cio/device.c
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Diffstat (limited to 'drivers/s390/cio/device.c')
-rw-r--r--drivers/s390/cio/device.c237
1 files changed, 158 insertions, 79 deletions
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 4e4008325e28..23d5752349b5 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -376,19 +376,23 @@ int ccw_device_set_offline(struct ccw_device *cdev)
dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
}
spin_unlock_irq(cdev->ccwlock);
+ /* Give up reference from ccw_device_set_online(). */
+ put_device(&cdev->dev);
return ret;
}
spin_unlock_irq(cdev->ccwlock);
- if (ret == 0)
+ if (ret == 0) {
wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
- else {
+ /* Give up reference from ccw_device_set_online(). */
+ put_device(&cdev->dev);
+ } else {
CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
"device 0.%x.%04x\n",
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
cdev->online = 1;
}
- return ret;
+ return ret;
}
/**
@@ -411,6 +415,9 @@ int ccw_device_set_online(struct ccw_device *cdev)
return -ENODEV;
if (cdev->online || !cdev->drv)
return -EINVAL;
+ /* Hold on to an extra reference while device is online. */
+ if (!get_device(&cdev->dev))
+ return -ENODEV;
spin_lock_irq(cdev->ccwlock);
ret = ccw_device_online(cdev);
@@ -422,10 +429,15 @@ int ccw_device_set_online(struct ccw_device *cdev)
"device 0.%x.%04x\n",
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
+ /* Give up online reference since onlining failed. */
+ put_device(&cdev->dev);
return ret;
}
- if (cdev->private->state != DEV_STATE_ONLINE)
+ if (cdev->private->state != DEV_STATE_ONLINE) {
+ /* Give up online reference since onlining failed. */
+ put_device(&cdev->dev);
return -ENODEV;
+ }
if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
cdev->online = 1;
return 0;
@@ -440,6 +452,8 @@ int ccw_device_set_online(struct ccw_device *cdev)
"device 0.%x.%04x\n",
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
+ /* Give up online reference since onlining failed. */
+ put_device(&cdev->dev);
return (ret == 0) ? -ENODEV : ret;
}
@@ -704,6 +718,8 @@ ccw_device_release(struct device *dev)
struct ccw_device *cdev;
cdev = to_ccwdev(dev);
+ /* Release reference of parent subchannel. */
+ put_device(cdev->dev.parent);
kfree(cdev->private);
kfree(cdev);
}
@@ -735,8 +751,8 @@ static int io_subchannel_initialize_dev(struct subchannel *sch,
/* Do first half of device_register. */
device_initialize(&cdev->dev);
if (!get_device(&sch->dev)) {
- if (cdev->dev.release)
- cdev->dev.release(&cdev->dev);
+ /* Release reference from device_initialize(). */
+ put_device(&cdev->dev);
return -ENODEV;
}
return 0;
@@ -778,37 +794,55 @@ static void sch_attach_disconnected_device(struct subchannel *sch,
struct subchannel *other_sch;
int ret;
- other_sch = to_subchannel(get_device(cdev->dev.parent));
+ /* Get reference for new parent. */
+ if (!get_device(&sch->dev))
+ return;
+ other_sch = to_subchannel(cdev->dev.parent);
+ /* Note: device_move() changes cdev->dev.parent */
ret = device_move(&cdev->dev, &sch->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
"(ret=%d)!\n", cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
- put_device(&other_sch->dev);
+ /* Put reference for new parent. */
+ put_device(&sch->dev);
return;
}
sch_set_cdev(other_sch, NULL);
/* No need to keep a subchannel without ccw device around. */
css_sch_device_unregister(other_sch);
- put_device(&other_sch->dev);
sch_attach_device(sch, cdev);
+ /* Put reference for old parent. */
+ put_device(&other_sch->dev);
}
static void sch_attach_orphaned_device(struct subchannel *sch,
struct ccw_device *cdev)
{
int ret;
+ struct subchannel *pseudo_sch;
- /* Try to move the ccw device to its new subchannel. */
+ /* Get reference for new parent. */
+ if (!get_device(&sch->dev))
+ return;
+ pseudo_sch = to_subchannel(cdev->dev.parent);
+ /*
+ * Try to move the ccw device to its new subchannel.
+ * Note: device_move() changes cdev->dev.parent
+ */
ret = device_move(&cdev->dev, &sch->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
"failed (ret=%d)!\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
+ /* Put reference for new parent. */
+ put_device(&sch->dev);
return;
}
sch_attach_device(sch, cdev);
+ /* Put reference on pseudo subchannel. */
+ put_device(&pseudo_sch->dev);
}
static void sch_create_and_recog_new_device(struct subchannel *sch)
@@ -830,9 +864,11 @@ static void sch_create_and_recog_new_device(struct subchannel *sch)
spin_lock_irq(sch->lock);
sch_set_cdev(sch, NULL);
spin_unlock_irq(sch->lock);
- if (cdev->dev.release)
- cdev->dev.release(&cdev->dev);
css_sch_device_unregister(sch);
+ /* Put reference from io_subchannel_create_ccwdev(). */
+ put_device(&sch->dev);
+ /* Give up initial reference. */
+ put_device(&cdev->dev);
}
}
@@ -854,15 +890,20 @@ void ccw_device_move_to_orphanage(struct work_struct *work)
dev_id.devno = sch->schib.pmcw.dev;
dev_id.ssid = sch->schid.ssid;
+ /* Increase refcount for pseudo subchannel. */
+ get_device(&css->pseudo_subchannel->dev);
/*
* Move the orphaned ccw device to the orphanage so the replacing
* ccw device can take its place on the subchannel.
+ * Note: device_move() changes cdev->dev.parent
*/
ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
"(ret=%d)!\n", cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
+ /* Decrease refcount for pseudo subchannel again. */
+ put_device(&css->pseudo_subchannel->dev);
return;
}
cdev->ccwlock = css->pseudo_subchannel->lock;
@@ -875,17 +916,23 @@ void ccw_device_move_to_orphanage(struct work_struct *work)
if (replacing_cdev) {
sch_attach_disconnected_device(sch, replacing_cdev);
/* Release reference from get_disc_ccwdev_by_dev_id() */
- put_device(&cdev->dev);
+ put_device(&replacing_cdev->dev);
+ /* Release reference of subchannel from old cdev. */
+ put_device(&sch->dev);
return;
}
replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
if (replacing_cdev) {
sch_attach_orphaned_device(sch, replacing_cdev);
/* Release reference from get_orphaned_ccwdev_by_dev_id() */
- put_device(&cdev->dev);
+ put_device(&replacing_cdev->dev);
+ /* Release reference of subchannel from old cdev. */
+ put_device(&sch->dev);
return;
}
sch_create_and_recog_new_device(sch);
+ /* Release reference of subchannel from old cdev. */
+ put_device(&sch->dev);
}
/*
@@ -903,6 +950,14 @@ io_subchannel_register(struct work_struct *work)
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
sch = to_subchannel(cdev->dev.parent);
+ /*
+ * Check if subchannel is still registered. It may have become
+ * unregistered if a machine check hit us after finishing
+ * device recognition but before the register work could be
+ * queued.
+ */
+ if (!device_is_registered(&sch->dev))
+ goto out_err;
css_update_ssd_info(sch);
/*
* io_subchannel_register() will also be called after device
@@ -910,7 +965,7 @@ io_subchannel_register(struct work_struct *work)
* be registered). We need to reprobe since we may now have sense id
* information.
*/
- if (klist_node_attached(&cdev->dev.knode_parent)) {
+ if (device_is_registered(&cdev->dev)) {
if (!cdev->drv) {
ret = device_reprobe(&cdev->dev);
if (ret)
@@ -934,22 +989,19 @@ io_subchannel_register(struct work_struct *work)
CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
- put_device(&cdev->dev);
spin_lock_irqsave(sch->lock, flags);
sch_set_cdev(sch, NULL);
spin_unlock_irqrestore(sch->lock, flags);
- kfree (cdev->private);
- kfree (cdev);
- put_device(&sch->dev);
- if (atomic_dec_and_test(&ccw_device_init_count))
- wake_up(&ccw_device_init_wq);
- return;
+ /* Release initial device reference. */
+ put_device(&cdev->dev);
+ goto out_err;
}
- put_device(&cdev->dev);
out:
cdev->private->flags.recog_done = 1;
- put_device(&sch->dev);
wake_up(&cdev->private->wait_q);
+out_err:
+ /* Release reference for workqueue processing. */
+ put_device(&cdev->dev);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
}
@@ -968,8 +1020,8 @@ static void ccw_device_call_sch_unregister(struct work_struct *work)
sch = to_subchannel(cdev->dev.parent);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
- sch->schib.pmcw.intparm = 0;
- cio_modify(sch);
+ sch->config.intparm = 0;
+ cio_commit_config(sch);
/* Release cdev reference for workqueue processing.*/
put_device(&cdev->dev);
/* Release subchannel reference for local processing. */
@@ -998,8 +1050,6 @@ io_subchannel_recog_done(struct ccw_device *cdev)
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_call_sch_unregister);
queue_work(slow_path_wq, &cdev->private->kick_work);
- /* Release subchannel reference for asynchronous recognition. */
- put_device(&sch->dev);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
break;
@@ -1070,10 +1120,15 @@ static void ccw_device_move_to_sch(struct work_struct *work)
priv = container_of(work, struct ccw_device_private, kick_work);
sch = priv->sch;
cdev = priv->cdev;
- former_parent = ccw_device_is_orphan(cdev) ?
- NULL : to_subchannel(get_device(cdev->dev.parent));
+ former_parent = to_subchannel(cdev->dev.parent);
+ /* Get reference for new parent. */
+ if (!get_device(&sch->dev))
+ return;
mutex_lock(&sch->reg_mutex);
- /* Try to move the ccw device to its new subchannel. */
+ /*
+ * Try to move the ccw device to its new subchannel.
+ * Note: device_move() changes cdev->dev.parent
+ */
rc = device_move(&cdev->dev, &sch->dev);
mutex_unlock(&sch->reg_mutex);
if (rc) {
@@ -1083,21 +1138,23 @@ static void ccw_device_move_to_sch(struct work_struct *work)
cdev->private->dev_id.devno, sch->schid.ssid,
sch->schid.sch_no, rc);
css_sch_device_unregister(sch);
+ /* Put reference for new parent again. */
+ put_device(&sch->dev);
goto out;
}
- if (former_parent) {
+ if (!sch_is_pseudo_sch(former_parent)) {
spin_lock_irq(former_parent->lock);
sch_set_cdev(former_parent, NULL);
spin_unlock_irq(former_parent->lock);
css_sch_device_unregister(former_parent);
/* Reset intparm to zeroes. */
- former_parent->schib.pmcw.intparm = 0;
- cio_modify(former_parent);
+ former_parent->config.intparm = 0;
+ cio_commit_config(former_parent);
}
sch_attach_device(sch, cdev);
out:
- if (former_parent)
- put_device(&former_parent->dev);
+ /* Put reference for old parent. */
+ put_device(&former_parent->dev);
put_device(&cdev->dev);
}
@@ -1113,6 +1170,15 @@ static void io_subchannel_irq(struct subchannel *sch)
dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
}
+void io_subchannel_init_config(struct subchannel *sch)
+{
+ memset(&sch->config, 0, sizeof(sch->config));
+ sch->config.csense = 1;
+ /* Use subchannel mp mode when there is more than 1 installed CHPID. */
+ if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0)
+ sch->config.mp = 1;
+}
+
static void io_subchannel_init_fields(struct subchannel *sch)
{
if (cio_is_console(sch->schid))
@@ -1127,18 +1193,34 @@ static void io_subchannel_init_fields(struct subchannel *sch)
sch->schib.pmcw.dev, sch->schid.ssid,
sch->schid.sch_no, sch->schib.pmcw.pim,
sch->schib.pmcw.pam, sch->schib.pmcw.pom);
- /* Initially set up some fields in the pmcw. */
- sch->schib.pmcw.ena = 0;
- sch->schib.pmcw.csense = 1; /* concurrent sense */
- if ((sch->lpm & (sch->lpm - 1)) != 0)
- sch->schib.pmcw.mp = 1; /* multipath mode */
- /* clean up possible residual cmf stuff */
- sch->schib.pmcw.mme = 0;
- sch->schib.pmcw.mbfc = 0;
- sch->schib.pmcw.mbi = 0;
- sch->schib.mba = 0;
+
+ io_subchannel_init_config(sch);
}
+static void io_subchannel_do_unreg(struct work_struct *work)
+{
+ struct subchannel *sch;
+
+ sch = container_of(work, struct subchannel, work);
+ css_sch_device_unregister(sch);
+ /* Reset intparm to zeroes. */
+ sch->config.intparm = 0;
+ cio_commit_config(sch);
+ put_device(&sch->dev);
+}
+
+/* Schedule unregister if we have no cdev. */
+static void io_subchannel_schedule_removal(struct subchannel *sch)
+{
+ get_device(&sch->dev);
+ INIT_WORK(&sch->work, io_subchannel_do_unreg);
+ queue_work(slow_path_wq, &sch->work);
+}
+
+/*
+ * Note: We always return 0 so that we bind to the device even on error.
+ * This is needed so that our remove function is called on unregister.
+ */
static int io_subchannel_probe(struct subchannel *sch)
{
struct ccw_device *cdev;
@@ -1168,9 +1250,8 @@ static int io_subchannel_probe(struct subchannel *sch)
ccw_device_register(cdev);
/*
* Check if the device is already online. If it is
- * the reference count needs to be corrected
- * (see ccw_device_online and css_init_done for the
- * ugly details).
+ * the reference count needs to be corrected since we
+ * didn't obtain a reference in ccw_device_set_online.
*/
if (cdev->private->state != DEV_STATE_NOT_OPER &&
cdev->private->state != DEV_STATE_OFFLINE &&
@@ -1179,23 +1260,24 @@ static int io_subchannel_probe(struct subchannel *sch)
return 0;
}
io_subchannel_init_fields(sch);
- /*
- * First check if a fitting device may be found amongst the
- * disconnected devices or in the orphanage.
- */
- dev_id.devno = sch->schib.pmcw.dev;
- dev_id.ssid = sch->schid.ssid;
+ rc = cio_commit_config(sch);
+ if (rc)
+ goto out_schedule;
rc = sysfs_create_group(&sch->dev.kobj,
&io_subchannel_attr_group);
if (rc)
- return rc;
+ goto out_schedule;
/* Allocate I/O subchannel private data. */
sch->private = kzalloc(sizeof(struct io_subchannel_private),
GFP_KERNEL | GFP_DMA);
- if (!sch->private) {
- rc = -ENOMEM;
+ if (!sch->private)
goto out_err;
- }
+ /*
+ * First check if a fitting device may be found amongst the
+ * disconnected devices or in the orphanage.
+ */
+ dev_id.devno = sch->schib.pmcw.dev;
+ dev_id.ssid = sch->schid.ssid;
cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
if (!cdev)
cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
@@ -1213,24 +1295,21 @@ static int io_subchannel_probe(struct subchannel *sch)
return 0;
}
cdev = io_subchannel_create_ccwdev(sch);
- if (IS_ERR(cdev)) {
- rc = PTR_ERR(cdev);
+ if (IS_ERR(cdev))
goto out_err;
- }
rc = io_subchannel_recog(cdev, sch);
if (rc) {
spin_lock_irqsave(sch->lock, flags);
- sch_set_cdev(sch, NULL);
+ io_subchannel_recog_done(cdev);
spin_unlock_irqrestore(sch->lock, flags);
- if (cdev->dev.release)
- cdev->dev.release(&cdev->dev);
- goto out_err;
}
return 0;
out_err:
kfree(sch->private);
sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
- return rc;
+out_schedule:
+ io_subchannel_schedule_removal(sch);
+ return 0;
}
static int
@@ -1275,10 +1354,7 @@ static void io_subchannel_verify(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)
+ if (cio_update_schib(sch))
return 0;
if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
return 1;
@@ -1347,15 +1423,13 @@ static int io_subchannel_chp_event(struct subchannel *sch,
io_subchannel_verify(sch);
break;
case CHP_OFFLINE:
- if (stsch(sch->schid, &sch->schib))
- return -ENXIO;
- if (!css_sch_is_valid(&sch->schib))
+ if (cio_update_schib(sch))
return -ENODEV;
io_subchannel_terminate_path(sch, mask);
break;
case CHP_ONLINE:
- if (stsch(sch->schid, &sch->schib))
- return -ENXIO;
+ if (cio_update_schib(sch))
+ return -ENODEV;
sch->lpm |= mask & sch->opm;
io_subchannel_verify(sch);
break;
@@ -1610,8 +1684,8 @@ static int io_subchannel_sch_event(struct subchannel *sch, int slow)
spin_lock_irqsave(sch->lock, flags);
/* Reset intparm to zeroes. */
- sch->schib.pmcw.intparm = 0;
- cio_modify(sch);
+ sch->config.intparm = 0;
+ cio_commit_config(sch);
break;
case REPROBE:
ccw_device_trigger_reprobe(cdev);
@@ -1652,6 +1726,9 @@ static int ccw_device_console_enable(struct ccw_device *cdev,
sch->private = cio_get_console_priv();
memset(sch->private, 0, sizeof(struct io_subchannel_private));
io_subchannel_init_fields(sch);
+ rc = cio_commit_config(sch);
+ if (rc)
+ return rc;
sch->driver = &io_subchannel_driver;
/* Initialize the ccw_device structure. */
cdev->dev.parent= &sch->dev;
@@ -1723,7 +1800,7 @@ __ccwdev_check_busid(struct device *dev, void *id)
bus_id = id;
- return (strncmp(bus_id, dev_name(dev), BUS_ID_SIZE) == 0);
+ return (strcmp(bus_id, dev_name(dev)) == 0);
}
@@ -1806,6 +1883,8 @@ ccw_device_remove (struct device *dev)
"device 0.%x.%04x\n",
ret, cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
+ /* Give up reference obtained in ccw_device_set_online(). */
+ put_device(&cdev->dev);
}
ccw_device_set_timeout(cdev, 0);
cdev->drv = NULL;