/*
- * drivers/s390/cio/css.c
- * driver for channel subsystem
+ * driver for channel subsystem
*
- * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- * IBM Corporation
- * Author(s): Arnd Bergmann (arndb@de.ibm.com)
- * Cornelia Huck (cornelia.huck@de.ibm.com)
+ * Copyright IBM Corp. 2002, 2009
+ *
+ * Author(s): Arnd Bergmann (arndb@de.ibm.com)
+ * Cornelia Huck (cornelia.huck@de.ibm.com)
*/
+
+#define KMSG_COMPONENT "cio"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/list.h>
+#include <linux/reboot.h>
+#include <linux/suspend.h>
+#include <linux/proc_fs.h>
+#include <asm/isc.h>
+#include <asm/crw.h>
#include "css.h"
#include "cio.h"
#include "ioasm.h"
#include "chsc.h"
#include "device.h"
+#include "idset.h"
+#include "chp.h"
-int need_rescan = 0;
int css_init_done = 0;
-static int need_reprobe = 0;
-static int max_ssid = 0;
-
-struct channel_subsystem *css[__MAX_CSSID + 1];
+int max_ssid;
-int css_characteristics_avail = 0;
+struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
-inline int
+int
for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
{
struct subchannel_id schid;
return ret;
}
+struct cb_data {
+ void *data;
+ struct idset *set;
+ int (*fn_known_sch)(struct subchannel *, void *);
+ int (*fn_unknown_sch)(struct subchannel_id, void *);
+};
+
+static int call_fn_known_sch(struct device *dev, void *data)
+{
+ struct subchannel *sch = to_subchannel(dev);
+ struct cb_data *cb = data;
+ int rc = 0;
+
+ idset_sch_del(cb->set, sch->schid);
+ if (cb->fn_known_sch)
+ rc = cb->fn_known_sch(sch, cb->data);
+ return rc;
+}
+
+static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
+{
+ struct cb_data *cb = data;
+ int rc = 0;
+
+ if (idset_sch_contains(cb->set, schid))
+ rc = cb->fn_unknown_sch(schid, cb->data);
+ return rc;
+}
+
+static int call_fn_all_sch(struct subchannel_id schid, void *data)
+{
+ struct cb_data *cb = data;
+ struct subchannel *sch;
+ int rc = 0;
+
+ sch = get_subchannel_by_schid(schid);
+ if (sch) {
+ if (cb->fn_known_sch)
+ rc = cb->fn_known_sch(sch, cb->data);
+ put_device(&sch->dev);
+ } else {
+ if (cb->fn_unknown_sch)
+ rc = cb->fn_unknown_sch(schid, cb->data);
+ }
+
+ return rc;
+}
+
+int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
+ int (*fn_unknown)(struct subchannel_id,
+ void *), void *data)
+{
+ struct cb_data cb;
+ int rc;
+
+ cb.data = data;
+ cb.fn_known_sch = fn_known;
+ cb.fn_unknown_sch = fn_unknown;
+
+ cb.set = idset_sch_new();
+ if (!cb.set)
+ /* fall back to brute force scanning in case of oom */
+ return for_each_subchannel(call_fn_all_sch, &cb);
+
+ idset_fill(cb.set);
+
+ /* Process registered subchannels. */
+ rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
+ if (rc)
+ goto out;
+ /* Process unregistered subchannels. */
+ if (fn_unknown)
+ rc = for_each_subchannel(call_fn_unknown_sch, &cb);
+out:
+ idset_free(cb.set);
+
+ return rc;
+}
+
+static void css_sch_todo(struct work_struct *work);
+
static struct subchannel *
css_alloc_subchannel(struct subchannel_id schid)
{
kfree(sch);
return ERR_PTR(ret);
}
-
- if (sch->st != SUBCHANNEL_TYPE_IO) {
- /* For now we ignore all non-io subchannels. */
- kfree(sch);
- return ERR_PTR(-EINVAL);
- }
-
- /*
- * Set intparm to subchannel address.
- * This is fine even on 64bit since the subchannel is always located
- * under 2G.
- */
- sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
- ret = cio_modify(sch);
- if (ret) {
- kfree(sch);
- return ERR_PTR(ret);
- }
+ INIT_WORK(&sch->todo_work, css_sch_todo);
return sch;
}
static void
-css_free_subchannel(struct subchannel *sch)
-{
- if (sch) {
- /* Reset intparm to zeroes. */
- sch->schib.pmcw.intparm = 0;
- cio_modify(sch);
- kfree(sch);
- }
-
-}
-
-static void
css_subchannel_release(struct device *dev)
{
struct subchannel *sch;
sch = to_subchannel(dev);
- if (!cio_is_console(sch->schid))
+ if (!cio_is_console(sch->schid)) {
+ /* Reset intparm to zeroes. */
+ sch->config.intparm = 0;
+ cio_commit_config(sch);
+ kfree(sch->lock);
kfree(sch);
+ }
}
-extern int css_get_ssd_info(struct subchannel *sch);
-
-
-int css_sch_device_register(struct subchannel *sch)
+static int css_sch_device_register(struct subchannel *sch)
{
int ret;
mutex_lock(&sch->reg_mutex);
+ dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
+ sch->schid.sch_no);
ret = device_register(&sch->dev);
mutex_unlock(&sch->reg_mutex);
return ret;
}
+/**
+ * css_sch_device_unregister - unregister a subchannel
+ * @sch: subchannel to be unregistered
+ */
void css_sch_device_unregister(struct subchannel *sch)
{
mutex_lock(&sch->reg_mutex);
- device_unregister(&sch->dev);
+ if (device_is_registered(&sch->dev))
+ device_unregister(&sch->dev);
mutex_unlock(&sch->reg_mutex);
}
+EXPORT_SYMBOL_GPL(css_sch_device_unregister);
-static int
-css_register_subchannel(struct subchannel *sch)
+static void css_sch_todo(struct work_struct *work)
+{
+ struct subchannel *sch;
+ enum sch_todo todo;
+
+ sch = container_of(work, struct subchannel, todo_work);
+ /* Find out todo. */
+ spin_lock_irq(sch->lock);
+ todo = sch->todo;
+ CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
+ sch->schid.sch_no, todo);
+ sch->todo = SCH_TODO_NOTHING;
+ spin_unlock_irq(sch->lock);
+ /* Perform todo. */
+ if (todo == SCH_TODO_UNREG)
+ css_sch_device_unregister(sch);
+ /* Release workqueue ref. */
+ put_device(&sch->dev);
+}
+
+/**
+ * css_sched_sch_todo - schedule a subchannel operation
+ * @sch: subchannel
+ * @todo: todo
+ *
+ * Schedule the operation identified by @todo to be performed on the slow path
+ * workqueue. Do nothing if another operation with higher priority is already
+ * scheduled. Needs to be called with subchannel lock held.
+ */
+void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
+{
+ CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
+ sch->schid.ssid, sch->schid.sch_no, todo);
+ if (sch->todo >= todo)
+ return;
+ /* Get workqueue ref. */
+ if (!get_device(&sch->dev))
+ return;
+ sch->todo = todo;
+ if (!queue_work(cio_work_q, &sch->todo_work)) {
+ /* Already queued, release workqueue ref. */
+ put_device(&sch->dev);
+ }
+}
+
+static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
+{
+ int i;
+ int mask;
+
+ memset(ssd, 0, sizeof(struct chsc_ssd_info));
+ ssd->path_mask = pmcw->pim;
+ for (i = 0; i < 8; i++) {
+ mask = 0x80 >> i;
+ if (pmcw->pim & mask) {
+ chp_id_init(&ssd->chpid[i]);
+ ssd->chpid[i].id = pmcw->chpid[i];
+ }
+ }
+}
+
+static void ssd_register_chpids(struct chsc_ssd_info *ssd)
+{
+ int i;
+ int mask;
+
+ for (i = 0; i < 8; i++) {
+ mask = 0x80 >> i;
+ if (ssd->path_mask & mask)
+ if (!chp_is_registered(ssd->chpid[i]))
+ chp_new(ssd->chpid[i]);
+ }
+}
+
+void css_update_ssd_info(struct subchannel *sch)
+{
+ int ret;
+
+ if (cio_is_console(sch->schid)) {
+ /* Console is initialized too early for functions requiring
+ * memory allocation. */
+ ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
+ } else {
+ ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
+ if (ret)
+ ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
+ ssd_register_chpids(&sch->ssd_info);
+ }
+}
+
+static ssize_t type_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct subchannel *sch = to_subchannel(dev);
+
+ return sprintf(buf, "%01x\n", sch->st);
+}
+
+static DEVICE_ATTR(type, 0444, type_show, NULL);
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct subchannel *sch = to_subchannel(dev);
+
+ return sprintf(buf, "css:t%01X\n", sch->st);
+}
+
+static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
+
+static struct attribute *subch_attrs[] = {
+ &dev_attr_type.attr,
+ &dev_attr_modalias.attr,
+ NULL,
+};
+
+static struct attribute_group subch_attr_group = {
+ .attrs = subch_attrs,
+};
+
+static const struct attribute_group *default_subch_attr_groups[] = {
+ &subch_attr_group,
+ NULL,
+};
+
+static int css_register_subchannel(struct subchannel *sch)
{
int ret;
/* Initialize the subchannel structure */
- sch->dev.parent = &css[0]->device;
+ sch->dev.parent = &channel_subsystems[0]->device;
sch->dev.bus = &css_bus_type;
sch->dev.release = &css_subchannel_release;
-
+ sch->dev.groups = default_subch_attr_groups;
+ /*
+ * We don't want to generate uevents for I/O subchannels that don't
+ * have a working ccw device behind them since they will be
+ * unregistered before they can be used anyway, so we delay the add
+ * uevent until after device recognition was successful.
+ * Note that we suppress the uevent for all subchannel types;
+ * the subchannel driver can decide itself when it wants to inform
+ * userspace of its existence.
+ */
+ dev_set_uevent_suppress(&sch->dev, 1);
+ css_update_ssd_info(sch);
/* make it known to the system */
ret = css_sch_device_register(sch);
- if (ret)
- printk (KERN_WARNING "%s: could not register %s\n",
- __func__, sch->dev.bus_id);
- else
- css_get_ssd_info(sch);
+ if (ret) {
+ CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
+ sch->schid.ssid, sch->schid.sch_no, ret);
+ return ret;
+ }
+ if (!sch->driver) {
+ /*
+ * No driver matched. Generate the uevent now so that
+ * a fitting driver module may be loaded based on the
+ * modalias.
+ */
+ dev_set_uevent_suppress(&sch->dev, 0);
+ kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
+ }
return ret;
}
-int
-css_probe_device(struct subchannel_id schid)
+int css_probe_device(struct subchannel_id schid)
{
int ret;
struct subchannel *sch;
- sch = css_alloc_subchannel(schid);
- if (IS_ERR(sch))
- return PTR_ERR(sch);
+ if (cio_is_console(schid))
+ sch = cio_get_console_subchannel();
+ else {
+ sch = css_alloc_subchannel(schid);
+ if (IS_ERR(sch))
+ return PTR_ERR(sch);
+ }
ret = css_register_subchannel(sch);
- if (ret)
- css_free_subchannel(sch);
+ if (ret) {
+ if (!cio_is_console(schid))
+ put_device(&sch->dev);
+ }
return ret;
}
return dev ? to_subchannel(dev) : NULL;
}
-static inline int css_get_subchannel_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 css_evaluate_known_subchannel(struct subchannel *sch, int slow)
+/**
+ * css_sch_is_valid() - check if a subchannel is valid
+ * @schib: subchannel information block for the subchannel
+ */
+int css_sch_is_valid(struct schib *schib)
{
- 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);
+ if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
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->dev, 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;
+ if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
+ return 0;
+ return 1;
}
+EXPORT_SYMBOL_GPL(css_sch_is_valid);
static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
{
/* Will be done on the slow path. */
return -EAGAIN;
}
- if (stsch(schid, &schib) || !schib.pmcw.dnv) {
+ if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
/* Unusable - ignore. */
return 0;
}
- CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
- "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
+ CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
+ schid.sch_no);
return css_probe_device(schid);
}
-static int css_evaluate_subchannel(struct subchannel_id schid, int slow)
+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");
+ }
+ if (ret != 0 && ret != -EAGAIN) {
+ CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
+ sch->schid.ssid, sch->schid.sch_no, ret);
+ }
+ return ret;
+}
+
+static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
{
struct subchannel *sch;
int ret;
put_device(&sch->dev);
} else
ret = css_evaluate_new_subchannel(schid, slow);
-
- return ret;
+ if (ret == -EAGAIN)
+ css_schedule_eval(schid);
}
-static int
-css_rescan_devices(struct subchannel_id schid, void *data)
+static struct idset *slow_subchannel_set;
+static spinlock_t slow_subchannel_lock;
+static wait_queue_head_t css_eval_wq;
+static atomic_t css_eval_scheduled;
+
+static int __init slow_subchannel_init(void)
{
- return css_evaluate_subchannel(schid, 1);
+ spin_lock_init(&slow_subchannel_lock);
+ atomic_set(&css_eval_scheduled, 0);
+ init_waitqueue_head(&css_eval_wq);
+ slow_subchannel_set = idset_sch_new();
+ if (!slow_subchannel_set) {
+ CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
+ return -ENOMEM;
+ }
+ return 0;
}
-struct slow_subchannel {
- struct list_head slow_list;
- struct subchannel_id schid;
-};
+static int slow_eval_known_fn(struct subchannel *sch, void *data)
+{
+ int eval;
+ int rc;
-static LIST_HEAD(slow_subchannels_head);
-static DEFINE_SPINLOCK(slow_subchannel_lock);
+ spin_lock_irq(&slow_subchannel_lock);
+ eval = idset_sch_contains(slow_subchannel_set, sch->schid);
+ idset_sch_del(slow_subchannel_set, sch->schid);
+ spin_unlock_irq(&slow_subchannel_lock);
+ if (eval) {
+ rc = css_evaluate_known_subchannel(sch, 1);
+ if (rc == -EAGAIN)
+ css_schedule_eval(sch->schid);
+ }
+ return 0;
+}
-static void
-css_trigger_slow_path(void)
+static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
{
- CIO_TRACE_EVENT(4, "slowpath");
+ int eval;
+ int rc = 0;
- if (need_rescan) {
- need_rescan = 0;
- for_each_subchannel(css_rescan_devices, NULL);
- return;
+ spin_lock_irq(&slow_subchannel_lock);
+ eval = idset_sch_contains(slow_subchannel_set, schid);
+ idset_sch_del(slow_subchannel_set, schid);
+ spin_unlock_irq(&slow_subchannel_lock);
+ if (eval) {
+ rc = css_evaluate_new_subchannel(schid, 1);
+ switch (rc) {
+ case -EAGAIN:
+ css_schedule_eval(schid);
+ rc = 0;
+ break;
+ case -ENXIO:
+ case -ENOMEM:
+ case -EIO:
+ /* These should abort looping */
+ break;
+ default:
+ rc = 0;
+ }
}
+ return rc;
+}
- spin_lock_irq(&slow_subchannel_lock);
- while (!list_empty(&slow_subchannels_head)) {
- struct slow_subchannel *slow_sch =
- list_entry(slow_subchannels_head.next,
- struct slow_subchannel, slow_list);
+static void css_slow_path_func(struct work_struct *unused)
+{
+ unsigned long flags;
- list_del_init(slow_subchannels_head.next);
- spin_unlock_irq(&slow_subchannel_lock);
- css_evaluate_subchannel(slow_sch->schid, 1);
- spin_lock_irq(&slow_subchannel_lock);
- kfree(slow_sch);
+ CIO_TRACE_EVENT(4, "slowpath");
+ for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
+ NULL);
+ spin_lock_irqsave(&slow_subchannel_lock, flags);
+ if (idset_is_empty(slow_subchannel_set)) {
+ atomic_set(&css_eval_scheduled, 0);
+ wake_up(&css_eval_wq);
}
- spin_unlock_irq(&slow_subchannel_lock);
+ spin_unlock_irqrestore(&slow_subchannel_lock, flags);
}
-typedef void (*workfunc)(void *);
-DECLARE_WORK(slow_path_work, (workfunc)css_trigger_slow_path, NULL);
-struct workqueue_struct *slow_path_wq;
+static DECLARE_WORK(slow_path_work, css_slow_path_func);
+struct workqueue_struct *cio_work_q;
-/* Reprobe subchannel if unregistered. */
-static int reprobe_subchannel(struct subchannel_id schid, void *data)
+void css_schedule_eval(struct subchannel_id schid)
{
- struct subchannel *sch;
- int ret;
-
- CIO_DEBUG(KERN_INFO, 6, "cio: reprobe 0.%x.%04x\n",
- schid.ssid, schid.sch_no);
- if (need_reprobe)
- return -EAGAIN;
+ unsigned long flags;
- sch = get_subchannel_by_schid(schid);
- if (sch) {
- /* Already known. */
- put_device(&sch->dev);
- return 0;
- }
+ spin_lock_irqsave(&slow_subchannel_lock, flags);
+ idset_sch_add(slow_subchannel_set, schid);
+ atomic_set(&css_eval_scheduled, 1);
+ queue_work(cio_work_q, &slow_path_work);
+ spin_unlock_irqrestore(&slow_subchannel_lock, flags);
+}
- ret = css_probe_device(schid);
- switch (ret) {
- case 0:
- break;
- case -ENXIO:
- case -ENOMEM:
- /* These should abort looping */
- break;
- default:
- ret = 0;
- }
+void css_schedule_eval_all(void)
+{
+ unsigned long flags;
- return ret;
+ spin_lock_irqsave(&slow_subchannel_lock, flags);
+ idset_fill(slow_subchannel_set);
+ atomic_set(&css_eval_scheduled, 1);
+ queue_work(cio_work_q, &slow_path_work);
+ spin_unlock_irqrestore(&slow_subchannel_lock, flags);
}
-/* Work function used to reprobe all unregistered subchannels. */
-static void reprobe_all(void *data)
+static int __unset_registered(struct device *dev, void *data)
{
- int ret;
+ struct idset *set = data;
+ struct subchannel *sch = to_subchannel(dev);
- CIO_MSG_EVENT(2, "reprobe start\n");
+ idset_sch_del(set, sch->schid);
+ return 0;
+}
- need_reprobe = 0;
- /* Make sure initial subchannel scan is done. */
- wait_event(ccw_device_init_wq,
- atomic_read(&ccw_device_init_count) == 0);
- ret = for_each_subchannel(reprobe_subchannel, NULL);
+void css_schedule_eval_all_unreg(void)
+{
+ unsigned long flags;
+ struct idset *unreg_set;
- CIO_MSG_EVENT(2, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
- need_reprobe);
+ /* Find unregistered subchannels. */
+ unreg_set = idset_sch_new();
+ if (!unreg_set) {
+ /* Fallback. */
+ css_schedule_eval_all();
+ return;
+ }
+ idset_fill(unreg_set);
+ bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
+ /* Apply to slow_subchannel_set. */
+ spin_lock_irqsave(&slow_subchannel_lock, flags);
+ idset_add_set(slow_subchannel_set, unreg_set);
+ atomic_set(&css_eval_scheduled, 1);
+ queue_work(cio_work_q, &slow_path_work);
+ spin_unlock_irqrestore(&slow_subchannel_lock, flags);
+ idset_free(unreg_set);
}
-DECLARE_WORK(css_reprobe_work, reprobe_all, NULL);
+void css_wait_for_slow_path(void)
+{
+ flush_workqueue(cio_work_q);
+}
/* Schedule reprobing of all unregistered subchannels. */
void css_schedule_reprobe(void)
{
- need_reprobe = 1;
- queue_work(ccw_device_work, &css_reprobe_work);
+ css_schedule_eval_all_unreg();
}
-
EXPORT_SYMBOL_GPL(css_schedule_reprobe);
/*
- * Rescan for new devices. FIXME: This is slow.
- * This function is called when we have lost CRWs due to overflows and we have
- * to do subchannel housekeeping.
- */
-void
-css_reiterate_subchannels(void)
-{
- css_clear_subchannel_slow_list();
- need_rescan = 1;
-}
-
-/*
* Called from the machine check handler for subchannel report words.
*/
-int
-css_process_crw(int rsid1, int rsid2)
+static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
{
- int ret;
struct subchannel_id mchk_schid;
- CIO_CRW_EVENT(2, "source is subchannel %04X, subsystem id %x\n",
- rsid1, rsid2);
-
- if (need_rescan)
- /* We need to iterate all subchannels anyway. */
- return -EAGAIN;
-
+ if (overflow) {
+ css_schedule_eval_all();
+ return;
+ }
+ CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
+ "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
+ crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
+ crw0->erc, crw0->rsid);
+ if (crw1)
+ CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
+ "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
+ crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
+ crw1->anc, crw1->erc, crw1->rsid);
init_subchannel_id(&mchk_schid);
- mchk_schid.sch_no = rsid1;
- if (rsid2 != 0)
- mchk_schid.ssid = (rsid2 >> 8) & 3;
+ mchk_schid.sch_no = crw0->rsid;
+ if (crw1)
+ mchk_schid.ssid = (crw1->rsid >> 8) & 3;
- /*
+ /*
* Since we are always presented with IPI in the CRW, we have to
* use stsch() to find out if the subchannel in question has come
* or gone.
*/
- ret = css_evaluate_subchannel(mchk_schid, 0);
- if (ret == -EAGAIN) {
- if (css_enqueue_subchannel_slow(mchk_schid)) {
- css_clear_subchannel_slow_list();
- need_rescan = 1;
- }
- }
- return ret;
-}
-
-static int __init
-__init_channel_subsystem(struct subchannel_id schid, void *data)
-{
- struct subchannel *sch;
- int ret;
-
- if (cio_is_console(schid))
- sch = cio_get_console_subchannel();
- else {
- sch = css_alloc_subchannel(schid);
- if (IS_ERR(sch))
- ret = PTR_ERR(sch);
- else
- ret = 0;
- switch (ret) {
- case 0:
- break;
- case -ENOMEM:
- panic("Out of memory in init_channel_subsystem\n");
- /* -ENXIO: no more subchannels. */
- case -ENXIO:
- return ret;
- /* -EIO: this subchannel set not supported. */
- case -EIO:
- return ret;
- default:
- return 0;
- }
- }
- /*
- * We register ALL valid subchannels in ioinfo, even those
- * that have been present before init_channel_subsystem.
- * These subchannels can't have been registered yet (kmalloc
- * not working) so we do it now. This is true e.g. for the
- * console subchannel.
- */
- css_register_subchannel(sch);
- return 0;
+ css_evaluate_subchannel(mchk_schid, 0);
}
static void __init
css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
{
- if (css_characteristics_avail && css_general_characteristics.mcss) {
+ if (css_general_characteristics.mcss) {
css->global_pgid.pgid_high.ext_cssid.version = 0x80;
css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
} else {
#ifdef CONFIG_SMP
- css->global_pgid.pgid_high.cpu_addr = hard_smp_processor_id();
+ css->global_pgid.pgid_high.cpu_addr = stap();
#else
css->global_pgid.pgid_high.cpu_addr = 0;
#endif
}
- css->global_pgid.cpu_id = ((cpuid_t *) __LC_CPUID)->ident;
- css->global_pgid.cpu_model = ((cpuid_t *) __LC_CPUID)->machine;
+ css->global_pgid.cpu_id = S390_lowcore.cpu_id.ident;
+ css->global_pgid.cpu_model = S390_lowcore.cpu_id.machine;
css->global_pgid.tod_high = tod_high;
}
css = to_css(dev);
mutex_destroy(&css->mutex);
+ if (css->pseudo_subchannel) {
+ /* Implies that it has been generated but never registered. */
+ css_subchannel_release(&css->pseudo_subchannel->dev);
+ css->pseudo_subchannel = NULL;
+ }
kfree(css);
}
char *buf)
{
struct channel_subsystem *css = to_css(dev);
+ int ret;
if (!css)
return 0;
- return sprintf(buf, "%x\n", css->cm_enabled);
+ mutex_lock(&css->mutex);
+ ret = sprintf(buf, "%x\n", css->cm_enabled);
+ mutex_unlock(&css->mutex);
+ return ret;
}
static ssize_t
{
struct channel_subsystem *css = to_css(dev);
int ret;
+ unsigned long val;
- switch (buf[0]) {
- case '0':
+ ret = strict_strtoul(buf, 16, &val);
+ if (ret)
+ return ret;
+ mutex_lock(&css->mutex);
+ switch (val) {
+ case 0:
ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
break;
- case '1':
+ case 1:
ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
break;
default:
ret = -EINVAL;
}
+ mutex_unlock(&css->mutex);
return ret < 0 ? ret : count;
}
static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
-static inline void __init
-setup_css(int nr)
+static int __init setup_css(int nr)
{
u32 tod_high;
+ int ret;
+ struct channel_subsystem *css;
- memset(css[nr], 0, sizeof(struct channel_subsystem));
- mutex_init(&css[nr]->mutex);
- css[nr]->valid = 1;
- css[nr]->cssid = nr;
- sprintf(css[nr]->device.bus_id, "css%x", nr);
- css[nr]->device.release = channel_subsystem_release;
+ css = channel_subsystems[nr];
+ memset(css, 0, sizeof(struct channel_subsystem));
+ css->pseudo_subchannel =
+ kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
+ if (!css->pseudo_subchannel)
+ return -ENOMEM;
+ css->pseudo_subchannel->dev.parent = &css->device;
+ css->pseudo_subchannel->dev.release = css_subchannel_release;
+ dev_set_name(&css->pseudo_subchannel->dev, "defunct");
+ mutex_init(&css->pseudo_subchannel->reg_mutex);
+ ret = cio_create_sch_lock(css->pseudo_subchannel);
+ if (ret) {
+ kfree(css->pseudo_subchannel);
+ return ret;
+ }
+ mutex_init(&css->mutex);
+ css->valid = 1;
+ css->cssid = nr;
+ dev_set_name(&css->device, "css%x", nr);
+ css->device.release = channel_subsystem_release;
tod_high = (u32) (get_clock() >> 32);
- css_generate_pgid(css[nr], tod_high);
+ css_generate_pgid(css, tod_high);
+ return 0;
+}
+
+static int css_reboot_event(struct notifier_block *this,
+ unsigned long event,
+ void *ptr)
+{
+ int ret, i;
+
+ ret = NOTIFY_DONE;
+ for (i = 0; i <= __MAX_CSSID; i++) {
+ struct channel_subsystem *css;
+
+ css = channel_subsystems[i];
+ mutex_lock(&css->mutex);
+ if (css->cm_enabled)
+ if (chsc_secm(css, 0))
+ ret = NOTIFY_BAD;
+ mutex_unlock(&css->mutex);
+ }
+
+ return ret;
}
+static struct notifier_block css_reboot_notifier = {
+ .notifier_call = css_reboot_event,
+};
+
+/*
+ * Since the css devices are neither on a bus nor have a class
+ * nor have a special device type, we cannot stop/restart channel
+ * path measurements via the normal suspend/resume callbacks, but have
+ * to use notifiers.
+ */
+static int css_power_event(struct notifier_block *this, unsigned long event,
+ void *ptr)
+{
+ void *secm_area;
+ int ret, i;
+
+ switch (event) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_SUSPEND_PREPARE:
+ ret = NOTIFY_DONE;
+ for (i = 0; i <= __MAX_CSSID; i++) {
+ struct channel_subsystem *css;
+
+ css = channel_subsystems[i];
+ mutex_lock(&css->mutex);
+ if (!css->cm_enabled) {
+ mutex_unlock(&css->mutex);
+ continue;
+ }
+ secm_area = (void *)get_zeroed_page(GFP_KERNEL |
+ GFP_DMA);
+ if (secm_area) {
+ if (__chsc_do_secm(css, 0, secm_area))
+ ret = NOTIFY_BAD;
+ free_page((unsigned long)secm_area);
+ } else
+ ret = NOTIFY_BAD;
+
+ mutex_unlock(&css->mutex);
+ }
+ break;
+ case PM_POST_HIBERNATION:
+ case PM_POST_SUSPEND:
+ ret = NOTIFY_DONE;
+ for (i = 0; i <= __MAX_CSSID; i++) {
+ struct channel_subsystem *css;
+
+ css = channel_subsystems[i];
+ mutex_lock(&css->mutex);
+ if (!css->cm_enabled) {
+ mutex_unlock(&css->mutex);
+ continue;
+ }
+ secm_area = (void *)get_zeroed_page(GFP_KERNEL |
+ GFP_DMA);
+ if (secm_area) {
+ if (__chsc_do_secm(css, 1, secm_area))
+ ret = NOTIFY_BAD;
+ free_page((unsigned long)secm_area);
+ } else
+ ret = NOTIFY_BAD;
+
+ mutex_unlock(&css->mutex);
+ }
+ /* search for subchannels, which appeared during hibernation */
+ css_schedule_reprobe();
+ break;
+ default:
+ ret = NOTIFY_DONE;
+ }
+ return ret;
+
+}
+static struct notifier_block css_power_notifier = {
+ .notifier_call = css_power_event,
+};
+
/*
* Now that the driver core is running, we can setup our channel subsystem.
* The struct subchannel's are created during probing (except for the
* static console subchannel).
*/
-static int __init
-init_channel_subsystem (void)
+static int __init css_bus_init(void)
{
int ret, i;
- if (chsc_determine_css_characteristics() == 0)
- css_characteristics_avail = 1;
+ ret = chsc_determine_css_characteristics();
+ if (ret == -ENOMEM)
+ goto out;
- if ((ret = bus_register(&css_bus_type)))
+ ret = chsc_alloc_sei_area();
+ if (ret)
goto out;
/* Try to enable MSS. */
ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
- switch (ret) {
- case 0: /* Success. */
- max_ssid = __MAX_SSID;
- break;
- case -ENOMEM:
- goto out_bus;
- default:
+ if (ret)
max_ssid = 0;
- }
+ else /* Success. */
+ max_ssid = __MAX_SSID;
+
+ ret = slow_subchannel_init();
+ if (ret)
+ goto out;
+
+ ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
+ if (ret)
+ goto out;
+
+ if ((ret = bus_register(&css_bus_type)))
+ goto out;
+
/* Setup css structure. */
for (i = 0; i <= __MAX_CSSID; i++) {
- css[i] = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
- if (!css[i]) {
+ struct channel_subsystem *css;
+
+ css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
+ if (!css) {
ret = -ENOMEM;
goto out_unregister;
}
- setup_css(i);
- ret = device_register(&css[i]->device);
- if (ret)
- goto out_free;
- if (css_characteristics_avail &&
- css_chsc_characteristics.secm) {
- ret = device_create_file(&css[i]->device,
+ channel_subsystems[i] = css;
+ ret = setup_css(i);
+ if (ret) {
+ kfree(channel_subsystems[i]);
+ goto out_unregister;
+ }
+ ret = device_register(&css->device);
+ if (ret) {
+ put_device(&css->device);
+ goto out_unregister;
+ }
+ if (css_chsc_characteristics.secm) {
+ ret = device_create_file(&css->device,
&dev_attr_cm_enable);
if (ret)
goto out_device;
}
+ ret = device_register(&css->pseudo_subchannel->dev);
+ if (ret) {
+ put_device(&css->pseudo_subchannel->dev);
+ goto out_file;
+ }
+ }
+ ret = register_reboot_notifier(&css_reboot_notifier);
+ if (ret)
+ goto out_unregister;
+ ret = register_pm_notifier(&css_power_notifier);
+ if (ret) {
+ unregister_reboot_notifier(&css_reboot_notifier);
+ goto out_unregister;
}
css_init_done = 1;
- ctl_set_bit(6, 28);
+ /* Enable default isc for I/O subchannels. */
+ isc_register(IO_SCH_ISC);
- for_each_subchannel(__init_channel_subsystem, NULL);
return 0;
+out_file:
+ if (css_chsc_characteristics.secm)
+ device_remove_file(&channel_subsystems[i]->device,
+ &dev_attr_cm_enable);
out_device:
- device_unregister(&css[i]->device);
-out_free:
- kfree(css[i]);
+ device_unregister(&channel_subsystems[i]->device);
out_unregister:
while (i > 0) {
+ struct channel_subsystem *css;
+
i--;
- if (css_characteristics_avail && css_chsc_characteristics.secm)
- device_remove_file(&css[i]->device,
+ css = channel_subsystems[i];
+ device_unregister(&css->pseudo_subchannel->dev);
+ css->pseudo_subchannel = NULL;
+ if (css_chsc_characteristics.secm)
+ device_remove_file(&css->device,
&dev_attr_cm_enable);
- device_unregister(&css[i]->device);
+ device_unregister(&css->device);
}
-out_bus:
bus_unregister(&css_bus_type);
out:
+ crw_unregister_handler(CRW_RSC_CSS);
+ chsc_free_sei_area();
+ idset_free(slow_subchannel_set);
+ pr_alert("The CSS device driver initialization failed with "
+ "errno=%d\n", ret);
+ return ret;
+}
+
+static void __init css_bus_cleanup(void)
+{
+ struct channel_subsystem *css;
+ int i;
+
+ for (i = 0; i <= __MAX_CSSID; i++) {
+ css = channel_subsystems[i];
+ device_unregister(&css->pseudo_subchannel->dev);
+ css->pseudo_subchannel = NULL;
+ if (css_chsc_characteristics.secm)
+ device_remove_file(&css->device, &dev_attr_cm_enable);
+ device_unregister(&css->device);
+ }
+ bus_unregister(&css_bus_type);
+ crw_unregister_handler(CRW_RSC_CSS);
+ chsc_free_sei_area();
+ idset_free(slow_subchannel_set);
+ isc_unregister(IO_SCH_ISC);
+}
+
+static int __init channel_subsystem_init(void)
+{
+ int ret;
+
+ ret = css_bus_init();
+ if (ret)
+ return ret;
+ cio_work_q = create_singlethread_workqueue("cio");
+ if (!cio_work_q) {
+ ret = -ENOMEM;
+ goto out_bus;
+ }
+ ret = io_subchannel_init();
+ if (ret)
+ goto out_wq;
+
+ return ret;
+out_wq:
+ destroy_workqueue(cio_work_q);
+out_bus:
+ css_bus_cleanup();
return ret;
}
+subsys_initcall(channel_subsystem_init);
+
+static int css_settle(struct device_driver *drv, void *unused)
+{
+ struct css_driver *cssdrv = to_cssdriver(drv);
+
+ if (cssdrv->settle)
+ return cssdrv->settle();
+ return 0;
+}
+
+int css_complete_work(void)
+{
+ int ret;
+
+ /* Wait for the evaluation of subchannels to finish. */
+ ret = wait_event_interruptible(css_eval_wq,
+ atomic_read(&css_eval_scheduled) == 0);
+ if (ret)
+ return -EINTR;
+ flush_workqueue(cio_work_q);
+ /* Wait for the subchannel type specific initialization to finish */
+ return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
+}
+
/*
- * find a driver for a subchannel. They identify by the subchannel
- * type with the exception that the console subchannel driver has its own
- * subchannel type although the device is an i/o subchannel
+ * Wait for the initialization of devices to finish, to make sure we are
+ * done with our setup if the search for the root device starts.
*/
-static int
-css_bus_match (struct device *dev, struct device_driver *drv)
+static int __init channel_subsystem_init_sync(void)
+{
+ /* Start initial subchannel evaluation. */
+ css_schedule_eval_all();
+ css_complete_work();
+ return 0;
+}
+subsys_initcall_sync(channel_subsystem_init_sync);
+
+void channel_subsystem_reinit(void)
+{
+ chsc_enable_facility(CHSC_SDA_OC_MSS);
+}
+
+#ifdef CONFIG_PROC_FS
+static ssize_t cio_settle_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
{
- struct subchannel *sch = container_of (dev, struct subchannel, dev);
- struct css_driver *driver = container_of (drv, struct css_driver, drv);
+ int ret;
- if (sch->st == driver->subchannel_type)
- return 1;
+ /* Handle pending CRW's. */
+ crw_wait_for_channel_report();
+ ret = css_complete_work();
+ return ret ? ret : count;
+}
+
+static const struct file_operations cio_settle_proc_fops = {
+ .write = cio_settle_write,
+};
+
+static int __init cio_settle_init(void)
+{
+ struct proc_dir_entry *entry;
+
+ entry = proc_create("cio_settle", S_IWUSR, NULL,
+ &cio_settle_proc_fops);
+ if (!entry)
+ return -ENOMEM;
return 0;
}
+device_initcall(cio_settle_init);
+#endif /*CONFIG_PROC_FS*/
-static int
-css_probe (struct device *dev)
+int sch_is_pseudo_sch(struct subchannel *sch)
+{
+ return sch == to_css(sch->dev.parent)->pseudo_subchannel;
+}
+
+static int css_bus_match(struct device *dev, struct device_driver *drv)
+{
+ struct subchannel *sch = to_subchannel(dev);
+ struct css_driver *driver = to_cssdriver(drv);
+ struct css_device_id *id;
+
+ for (id = driver->subchannel_type; id->match_flags; id++) {
+ if (sch->st == id->type)
+ return 1;
+ }
+
+ return 0;
+}
+
+static int css_probe(struct device *dev)
{
struct subchannel *sch;
+ int ret;
sch = to_subchannel(dev);
- sch->driver = container_of (dev->driver, struct css_driver, drv);
- return (sch->driver->probe ? sch->driver->probe(sch) : 0);
+ sch->driver = to_cssdriver(dev->driver);
+ ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
+ if (ret)
+ sch->driver = NULL;
+ return ret;
}
-static int
-css_remove (struct device *dev)
+static int css_remove(struct device *dev)
{
struct subchannel *sch;
+ int ret;
sch = to_subchannel(dev);
- return (sch->driver->remove ? sch->driver->remove(sch) : 0);
+ ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
+ sch->driver = NULL;
+ return ret;
}
-static void
-css_shutdown (struct device *dev)
+static void css_shutdown(struct device *dev)
{
struct subchannel *sch;
sch = to_subchannel(dev);
- if (sch->driver->shutdown)
+ if (sch->driver && sch->driver->shutdown)
sch->driver->shutdown(sch);
}
-struct bus_type css_bus_type = {
- .name = "css",
- .match = css_bus_match,
- .probe = css_probe,
- .remove = css_remove,
- .shutdown = css_shutdown,
-};
+static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct subchannel *sch = to_subchannel(dev);
+ int ret;
-subsys_initcall(init_channel_subsystem);
+ ret = add_uevent_var(env, "ST=%01X", sch->st);
+ if (ret)
+ return ret;
+ ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
+ return ret;
+}
-int
-css_enqueue_subchannel_slow(struct subchannel_id schid)
+static int css_pm_prepare(struct device *dev)
{
- struct slow_subchannel *new_slow_sch;
- unsigned long flags;
+ struct subchannel *sch = to_subchannel(dev);
+ struct css_driver *drv;
- new_slow_sch = kzalloc(sizeof(struct slow_subchannel), GFP_ATOMIC);
- if (!new_slow_sch)
- return -ENOMEM;
- new_slow_sch->schid = schid;
- spin_lock_irqsave(&slow_subchannel_lock, flags);
- list_add_tail(&new_slow_sch->slow_list, &slow_subchannels_head);
- spin_unlock_irqrestore(&slow_subchannel_lock, flags);
- return 0;
+ if (mutex_is_locked(&sch->reg_mutex))
+ return -EAGAIN;
+ if (!sch->dev.driver)
+ return 0;
+ drv = to_cssdriver(sch->dev.driver);
+ /* Notify drivers that they may not register children. */
+ return drv->prepare ? drv->prepare(sch) : 0;
}
-void
-css_clear_subchannel_slow_list(void)
+static void css_pm_complete(struct device *dev)
{
- unsigned long flags;
+ struct subchannel *sch = to_subchannel(dev);
+ struct css_driver *drv;
- spin_lock_irqsave(&slow_subchannel_lock, flags);
- while (!list_empty(&slow_subchannels_head)) {
- struct slow_subchannel *slow_sch =
- list_entry(slow_subchannels_head.next,
- struct slow_subchannel, slow_list);
+ if (!sch->dev.driver)
+ return;
+ drv = to_cssdriver(sch->dev.driver);
+ if (drv->complete)
+ drv->complete(sch);
+}
- list_del_init(slow_subchannels_head.next);
- kfree(slow_sch);
- }
- spin_unlock_irqrestore(&slow_subchannel_lock, flags);
+static int css_pm_freeze(struct device *dev)
+{
+ struct subchannel *sch = to_subchannel(dev);
+ struct css_driver *drv;
+
+ if (!sch->dev.driver)
+ return 0;
+ drv = to_cssdriver(sch->dev.driver);
+ return drv->freeze ? drv->freeze(sch) : 0;
}
+static int css_pm_thaw(struct device *dev)
+{
+ struct subchannel *sch = to_subchannel(dev);
+ struct css_driver *drv;
+ if (!sch->dev.driver)
+ return 0;
+ drv = to_cssdriver(sch->dev.driver);
+ return drv->thaw ? drv->thaw(sch) : 0;
+}
-int
-css_slow_subchannels_exist(void)
+static int css_pm_restore(struct device *dev)
+{
+ struct subchannel *sch = to_subchannel(dev);
+ struct css_driver *drv;
+
+ if (!sch->dev.driver)
+ return 0;
+ drv = to_cssdriver(sch->dev.driver);
+ return drv->restore ? drv->restore(sch) : 0;
+}
+
+static const struct dev_pm_ops css_pm_ops = {
+ .prepare = css_pm_prepare,
+ .complete = css_pm_complete,
+ .freeze = css_pm_freeze,
+ .thaw = css_pm_thaw,
+ .restore = css_pm_restore,
+};
+
+struct bus_type css_bus_type = {
+ .name = "css",
+ .match = css_bus_match,
+ .probe = css_probe,
+ .remove = css_remove,
+ .shutdown = css_shutdown,
+ .uevent = css_uevent,
+ .pm = &css_pm_ops,
+};
+
+/**
+ * css_driver_register - register a css driver
+ * @cdrv: css driver to register
+ *
+ * This is mainly a wrapper around driver_register that sets name
+ * and bus_type in the embedded struct device_driver correctly.
+ */
+int css_driver_register(struct css_driver *cdrv)
+{
+ cdrv->drv.name = cdrv->name;
+ cdrv->drv.bus = &css_bus_type;
+ cdrv->drv.owner = cdrv->owner;
+ return driver_register(&cdrv->drv);
+}
+EXPORT_SYMBOL_GPL(css_driver_register);
+
+/**
+ * css_driver_unregister - unregister a css driver
+ * @cdrv: css driver to unregister
+ *
+ * This is a wrapper around driver_unregister.
+ */
+void css_driver_unregister(struct css_driver *cdrv)
{
- return (!list_empty(&slow_subchannels_head));
+ driver_unregister(&cdrv->drv);
}
+EXPORT_SYMBOL_GPL(css_driver_unregister);
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(css_bus_type);
-EXPORT_SYMBOL_GPL(css_characteristics_avail);