/*
- * drivers/base/dd.c - The core device/driver interactions.
+ * drivers/base/dd.c - The core device/driver interactions.
*
- * This file contains the (sometimes tricky) code that controls the
- * interactions between devices and drivers, which primarily includes
- * driver binding and unbinding.
+ * This file contains the (sometimes tricky) code that controls the
+ * interactions between devices and drivers, which primarily includes
+ * driver binding and unbinding.
*
- * All of this code used to exist in drivers/base/bus.c, but was
- * relocated to here in the name of compartmentalization (since it wasn't
- * strictly code just for the 'struct bus_type'.
+ * All of this code used to exist in drivers/base/bus.c, but was
+ * relocated to here in the name of compartmentalization (since it wasn't
+ * strictly code just for the 'struct bus_type'.
*
- * Copyright (c) 2002-5 Patrick Mochel
- * Copyright (c) 2002-3 Open Source Development Labs
+ * Copyright (c) 2002-5 Patrick Mochel
+ * Copyright (c) 2002-3 Open Source Development Labs
+ * Copyright (c) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2007-2009 Novell Inc.
*
- * This file is released under the GPLv2
+ * This file is released under the GPLv2
*/
#include <linux/device.h>
+#include <linux/delay.h>
#include <linux/module.h>
#include <linux/kthread.h>
+#include <linux/wait.h>
+#include <linux/async.h>
+#include <linux/pm_runtime.h>
#include "base.h"
#include "power/power.h"
-#define to_drv(node) container_of(node, struct device_driver, kobj.entry)
+/*
+ * Deferred Probe infrastructure.
+ *
+ * Sometimes driver probe order matters, but the kernel doesn't always have
+ * dependency information which means some drivers will get probed before a
+ * resource it depends on is available. For example, an SDHCI driver may
+ * first need a GPIO line from an i2c GPIO controller before it can be
+ * initialized. If a required resource is not available yet, a driver can
+ * request probing to be deferred by returning -EPROBE_DEFER from its probe hook
+ *
+ * Deferred probe maintains two lists of devices, a pending list and an active
+ * list. A driver returning -EPROBE_DEFER causes the device to be added to the
+ * pending list. A successful driver probe will trigger moving all devices
+ * from the pending to the active list so that the workqueue will eventually
+ * retry them.
+ *
+ * The deferred_probe_mutex must be held any time the deferred_probe_*_list
+ * of the (struct device*)->p->deferred_probe pointers are manipulated
+ */
+static DEFINE_MUTEX(deferred_probe_mutex);
+static LIST_HEAD(deferred_probe_pending_list);
+static LIST_HEAD(deferred_probe_active_list);
+static struct workqueue_struct *deferred_wq;
+/**
+ * deferred_probe_work_func() - Retry probing devices in the active list.
+ */
+static void deferred_probe_work_func(struct work_struct *work)
+{
+ struct device *dev;
+ struct device_private *private;
+ /*
+ * This block processes every device in the deferred 'active' list.
+ * Each device is removed from the active list and passed to
+ * bus_probe_device() to re-attempt the probe. The loop continues
+ * until every device in the active list is removed and retried.
+ *
+ * Note: Once the device is removed from the list and the mutex is
+ * released, it is possible for the device get freed by another thread
+ * and cause a illegal pointer dereference. This code uses
+ * get/put_device() to ensure the device structure cannot disappear
+ * from under our feet.
+ */
+ mutex_lock(&deferred_probe_mutex);
+ while (!list_empty(&deferred_probe_active_list)) {
+ private = list_first_entry(&deferred_probe_active_list,
+ typeof(*dev->p), deferred_probe);
+ dev = private->device;
+ list_del_init(&private->deferred_probe);
+ get_device(dev);
+
+ /*
+ * Drop the mutex while probing each device; the probe path may
+ * manipulate the deferred list
+ */
+ mutex_unlock(&deferred_probe_mutex);
+ dev_dbg(dev, "Retrying from deferred list\n");
+ bus_probe_device(dev);
+ mutex_lock(&deferred_probe_mutex);
+
+ put_device(dev);
+ }
+ mutex_unlock(&deferred_probe_mutex);
+}
+static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
+
+static void driver_deferred_probe_add(struct device *dev)
+{
+ mutex_lock(&deferred_probe_mutex);
+ if (list_empty(&dev->p->deferred_probe)) {
+ dev_dbg(dev, "Added to deferred list\n");
+ list_add(&dev->p->deferred_probe, &deferred_probe_pending_list);
+ }
+ mutex_unlock(&deferred_probe_mutex);
+}
+
+void driver_deferred_probe_del(struct device *dev)
+{
+ mutex_lock(&deferred_probe_mutex);
+ if (!list_empty(&dev->p->deferred_probe)) {
+ dev_dbg(dev, "Removed from deferred list\n");
+ list_del_init(&dev->p->deferred_probe);
+ }
+ mutex_unlock(&deferred_probe_mutex);
+}
+
+static bool driver_deferred_probe_enable = false;
/**
- * device_bind_driver - bind a driver to one device.
- * @dev: device.
+ * driver_deferred_probe_trigger() - Kick off re-probing deferred devices
*
- * Allow manual attachment of a driver to a device.
- * Caller must have already set @dev->driver.
- *
- * Note that this does not modify the bus reference count
- * nor take the bus's rwsem. Please verify those are accounted
- * for before calling this. (It is ok to call with no other effort
- * from a driver's probe() method.)
+ * This functions moves all devices from the pending list to the active
+ * list and schedules the deferred probe workqueue to process them. It
+ * should be called anytime a driver is successfully bound to a device.
+ */
+static void driver_deferred_probe_trigger(void)
+{
+ if (!driver_deferred_probe_enable)
+ return;
+
+ /*
+ * A successful probe means that all the devices in the pending list
+ * should be triggered to be reprobed. Move all the deferred devices
+ * into the active list so they can be retried by the workqueue
+ */
+ mutex_lock(&deferred_probe_mutex);
+ list_splice_tail_init(&deferred_probe_pending_list,
+ &deferred_probe_active_list);
+ mutex_unlock(&deferred_probe_mutex);
+
+ /*
+ * Kick the re-probe thread. It may already be scheduled, but it is
+ * safe to kick it again.
+ */
+ queue_work(deferred_wq, &deferred_probe_work);
+}
+
+/**
+ * deferred_probe_initcall() - Enable probing of deferred devices
*
- * This function must be called with @dev->sem held.
+ * We don't want to get in the way when the bulk of drivers are getting probed.
+ * Instead, this initcall makes sure that deferred probing is delayed until
+ * late_initcall time.
*/
-int device_bind_driver(struct device *dev)
+static int deferred_probe_initcall(void)
{
- int ret;
+ deferred_wq = create_singlethread_workqueue("deferwq");
+ if (WARN_ON(!deferred_wq))
+ return -ENOMEM;
+
+ driver_deferred_probe_enable = true;
+ driver_deferred_probe_trigger();
+ /* Sort as many dependencies as possible before exiting initcalls */
+ flush_workqueue(deferred_wq);
+ return 0;
+}
+late_initcall(deferred_probe_initcall);
- if (klist_node_attached(&dev->knode_driver)) {
+static void driver_bound(struct device *dev)
+{
+ if (klist_node_attached(&dev->p->knode_driver)) {
printk(KERN_WARNING "%s: device %s already bound\n",
- __FUNCTION__, kobject_name(&dev->kobj));
- return 0;
+ __func__, kobject_name(&dev->kobj));
+ return;
}
- pr_debug("bound device '%s' to driver '%s'\n",
- dev->bus_id, dev->driver->name);
- klist_add_tail(&dev->knode_driver, &dev->driver->klist_devices);
- ret = sysfs_create_link(&dev->driver->kobj, &dev->kobj,
+ pr_debug("driver: '%s': %s: bound to device '%s'\n", dev_name(dev),
+ __func__, dev->driver->name);
+
+ klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
+
+ /*
+ * Make sure the device is no longer in one of the deferred lists and
+ * kick off retrying all pending devices
+ */
+ driver_deferred_probe_del(dev);
+ driver_deferred_probe_trigger();
+
+ if (dev->bus)
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+ BUS_NOTIFY_BOUND_DRIVER, dev);
+}
+
+static int driver_sysfs_add(struct device *dev)
+{
+ int ret;
+
+ if (dev->bus)
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+ BUS_NOTIFY_BIND_DRIVER, dev);
+
+ ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
kobject_name(&dev->kobj));
if (ret == 0) {
- ret = sysfs_create_link(&dev->kobj, &dev->driver->kobj,
+ ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj,
"driver");
if (ret)
- sysfs_remove_link(&dev->driver->kobj,
+ sysfs_remove_link(&dev->driver->p->kobj,
kobject_name(&dev->kobj));
}
return ret;
}
-struct stupid_thread_structure {
- struct device_driver *drv;
- struct device *dev;
-};
+static void driver_sysfs_remove(struct device *dev)
+{
+ struct device_driver *drv = dev->driver;
+
+ if (drv) {
+ sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj));
+ sysfs_remove_link(&dev->kobj, "driver");
+ }
+}
+
+/**
+ * device_bind_driver - bind a driver to one device.
+ * @dev: device.
+ *
+ * Allow manual attachment of a driver to a device.
+ * Caller must have already set @dev->driver.
+ *
+ * Note that this does not modify the bus reference count
+ * nor take the bus's rwsem. Please verify those are accounted
+ * for before calling this. (It is ok to call with no other effort
+ * from a driver's probe() method.)
+ *
+ * This function must be called with the device lock held.
+ */
+int device_bind_driver(struct device *dev)
+{
+ int ret;
+
+ ret = driver_sysfs_add(dev);
+ if (!ret)
+ driver_bound(dev);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(device_bind_driver);
static atomic_t probe_count = ATOMIC_INIT(0);
-static int really_probe(void *void_data)
+static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
+
+static int really_probe(struct device *dev, struct device_driver *drv)
{
- struct stupid_thread_structure *data = void_data;
- struct device_driver *drv = data->drv;
- struct device *dev = data->dev;
int ret = 0;
atomic_inc(&probe_count);
- pr_debug("%s: Probing driver %s with device %s\n",
- drv->bus->name, drv->name, dev->bus_id);
+ pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
+ drv->bus->name, __func__, drv->name, dev_name(dev));
+ WARN_ON(!list_empty(&dev->devres_head));
dev->driver = drv;
+ if (driver_sysfs_add(dev)) {
+ printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
+ __func__, dev_name(dev));
+ goto probe_failed;
+ }
+
if (dev->bus->probe) {
ret = dev->bus->probe(dev);
- if (ret) {
- dev->driver = NULL;
+ if (ret)
goto probe_failed;
- }
} else if (drv->probe) {
ret = drv->probe(dev);
- if (ret) {
- dev->driver = NULL;
+ if (ret)
goto probe_failed;
- }
- }
- if (device_bind_driver(dev)) {
- printk(KERN_ERR "%s: device_bind_driver(%s) failed\n",
- __FUNCTION__, dev->bus_id);
- /* How does undo a ->probe? We're screwed. */
}
+
+ driver_bound(dev);
ret = 1;
- pr_debug("%s: Bound Device %s to Driver %s\n",
- drv->bus->name, dev->bus_id, drv->name);
+ pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
+ drv->bus->name, __func__, dev_name(dev), drv->name);
goto done;
probe_failed:
- if (ret == -ENODEV || ret == -ENXIO) {
- /* Driver matched, but didn't support device
- * or device not found.
- * Not an error; keep going.
- */
- ret = 0;
- } else {
+ devres_release_all(dev);
+ driver_sysfs_remove(dev);
+ dev->driver = NULL;
+
+ if (ret == -EPROBE_DEFER) {
+ /* Driver requested deferred probing */
+ dev_info(dev, "Driver %s requests probe deferral\n", drv->name);
+ driver_deferred_probe_add(dev);
+ } else if (ret != -ENODEV && ret != -ENXIO) {
/* driver matched but the probe failed */
printk(KERN_WARNING
"%s: probe of %s failed with error %d\n",
- drv->name, dev->bus_id, ret);
+ drv->name, dev_name(dev), ret);
+ } else {
+ pr_debug("%s: probe of %s rejects match %d\n",
+ drv->name, dev_name(dev), ret);
}
+ /*
+ * Ignore errors returned by ->probe so that the next driver can try
+ * its luck.
+ */
+ ret = 0;
done:
- kfree(data);
atomic_dec(&probe_count);
+ wake_up(&probe_waitqueue);
return ret;
}
*/
int driver_probe_done(void)
{
- pr_debug("%s: probe_count = %d\n", __FUNCTION__,
+ pr_debug("%s: probe_count = %d\n", __func__,
atomic_read(&probe_count));
if (atomic_read(&probe_count))
return -EBUSY;
return 0;
}
+/**
+ * wait_for_device_probe
+ * Wait for device probing to be completed.
+ */
+void wait_for_device_probe(void)
+{
+ /* wait for the known devices to complete their probing */
+ wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
+ async_synchronize_full();
+}
+EXPORT_SYMBOL_GPL(wait_for_device_probe);
+
/**
* driver_probe_device - attempt to bind device & driver together
* @drv: driver to bind a device to
* @dev: device to try to bind to the driver
*
- * First, we call the bus's match function, if one present, which should
- * compare the device IDs the driver supports with the device IDs of the
- * device. Note we don't do this ourselves because we don't know the
- * format of the ID structures, nor what is to be considered a match and
- * what is not.
- *
- * This function returns 1 if a match is found, an error if one occurs
- * (that is not -ENODEV or -ENXIO), and 0 otherwise.
+ * This function returns -ENODEV if the device is not registered,
+ * 1 if the device is bound successfully and 0 otherwise.
*
- * This function must be called with @dev->sem held. When called for a
- * USB interface, @dev->parent->sem must be held as well.
+ * This function must be called with @dev lock held. When called for a
+ * USB interface, @dev->parent lock must be held as well.
*/
-int driver_probe_device(struct device_driver * drv, struct device * dev)
+int driver_probe_device(struct device_driver *drv, struct device *dev)
{
- struct stupid_thread_structure *data;
- struct task_struct *probe_task;
int ret = 0;
if (!device_is_registered(dev))
return -ENODEV;
- if (drv->bus->match && !drv->bus->match(dev, drv))
- goto done;
- pr_debug("%s: Matched Device %s with Driver %s\n",
- drv->bus->name, dev->bus_id, drv->name);
+ pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
+ drv->bus->name, __func__, dev_name(dev), drv->name);
- data = kmalloc(sizeof(*data), GFP_KERNEL);
- data->drv = drv;
- data->dev = dev;
+ pm_runtime_get_noresume(dev);
+ pm_runtime_barrier(dev);
+ ret = really_probe(dev, drv);
+ pm_runtime_put_sync(dev);
- if (drv->multithread_probe) {
- probe_task = kthread_run(really_probe, data,
- "probe-%s", dev->bus_id);
- if (IS_ERR(probe_task))
- ret = really_probe(data);
- } else
- ret = really_probe(data);
-
-done:
return ret;
}
-static int __device_attach(struct device_driver * drv, void * data)
+static int __device_attach(struct device_driver *drv, void *data)
{
- struct device * dev = data;
+ struct device *dev = data;
+
+ if (!driver_match_device(drv, dev))
+ return 0;
+
return driver_probe_device(drv, dev);
}
/**
- * device_attach - try to attach device to a driver.
- * @dev: device.
+ * device_attach - try to attach device to a driver.
+ * @dev: device.
*
- * Walk the list of drivers that the bus has and call
- * driver_probe_device() for each pair. If a compatible
- * pair is found, break out and return.
+ * Walk the list of drivers that the bus has and call
+ * driver_probe_device() for each pair. If a compatible
+ * pair is found, break out and return.
*
- * Returns 1 if the device was bound to a driver;
- * 0 if no matching device was found; error code otherwise.
+ * Returns 1 if the device was bound to a driver;
+ * 0 if no matching driver was found;
+ * -ENODEV if the device is not registered.
*
- * When called for a USB interface, @dev->parent->sem must be held.
+ * When called for a USB interface, @dev->parent lock must be held.
*/
-int device_attach(struct device * dev)
+int device_attach(struct device *dev)
{
int ret = 0;
- down(&dev->sem);
+ device_lock(dev);
if (dev->driver) {
+ if (klist_node_attached(&dev->p->knode_driver)) {
+ ret = 1;
+ goto out_unlock;
+ }
ret = device_bind_driver(dev);
if (ret == 0)
ret = 1;
- } else
+ else {
+ dev->driver = NULL;
+ ret = 0;
+ }
+ } else {
+ pm_runtime_get_noresume(dev);
ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
- up(&dev->sem);
+ pm_runtime_put_sync(dev);
+ }
+out_unlock:
+ device_unlock(dev);
return ret;
}
+EXPORT_SYMBOL_GPL(device_attach);
-static int __driver_attach(struct device * dev, void * data)
+static int __driver_attach(struct device *dev, void *data)
{
- struct device_driver * drv = data;
+ struct device_driver *drv = data;
/*
* Lock device and try to bind to it. We drop the error
* is an error.
*/
+ if (!driver_match_device(drv, dev))
+ return 0;
+
if (dev->parent) /* Needed for USB */
- down(&dev->parent->sem);
- down(&dev->sem);
+ device_lock(dev->parent);
+ device_lock(dev);
if (!dev->driver)
driver_probe_device(drv, dev);
- up(&dev->sem);
+ device_unlock(dev);
if (dev->parent)
- up(&dev->parent->sem);
+ device_unlock(dev->parent);
return 0;
}
/**
- * driver_attach - try to bind driver to devices.
- * @drv: driver.
+ * driver_attach - try to bind driver to devices.
+ * @drv: driver.
*
- * Walk the list of devices that the bus has on it and try to
- * match the driver with each one. If driver_probe_device()
- * returns 0 and the @dev->driver is set, we've found a
- * compatible pair.
+ * Walk the list of devices that the bus has on it and try to
+ * match the driver with each one. If driver_probe_device()
+ * returns 0 and the @dev->driver is set, we've found a
+ * compatible pair.
*/
-int driver_attach(struct device_driver * drv)
+int driver_attach(struct device_driver *drv)
{
return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
}
+EXPORT_SYMBOL_GPL(driver_attach);
-/**
- * device_release_driver - manually detach device from driver.
- * @dev: device.
- *
- * Manually detach device from driver.
- *
- * __device_release_driver() must be called with @dev->sem held.
- * When called for a USB interface, @dev->parent->sem must be held
- * as well.
+/*
+ * __device_release_driver() must be called with @dev lock held.
+ * When called for a USB interface, @dev->parent lock must be held as well.
*/
-
-static void __device_release_driver(struct device * dev)
+static void __device_release_driver(struct device *dev)
{
- struct device_driver * drv;
+ struct device_driver *drv;
drv = dev->driver;
if (drv) {
- get_driver(drv);
- sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
- sysfs_remove_link(&dev->kobj, "driver");
- klist_remove(&dev->knode_driver);
+ pm_runtime_get_sync(dev);
+
+ driver_sysfs_remove(dev);
+
+ if (dev->bus)
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+ BUS_NOTIFY_UNBIND_DRIVER,
+ dev);
+
+ pm_runtime_put_sync(dev);
if (dev->bus && dev->bus->remove)
dev->bus->remove(dev);
else if (drv->remove)
drv->remove(dev);
+ devres_release_all(dev);
dev->driver = NULL;
- put_driver(drv);
+ klist_remove(&dev->p->knode_driver);
+ if (dev->bus)
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+ BUS_NOTIFY_UNBOUND_DRIVER,
+ dev);
+
}
}
-void device_release_driver(struct device * dev)
+/**
+ * device_release_driver - manually detach device from driver.
+ * @dev: device.
+ *
+ * Manually detach device from driver.
+ * When called for a USB interface, @dev->parent lock must be held.
+ */
+void device_release_driver(struct device *dev)
{
/*
* If anyone calls device_release_driver() recursively from
* within their ->remove callback for the same device, they
* will deadlock right here.
*/
- down(&dev->sem);
+ device_lock(dev);
__device_release_driver(dev);
- up(&dev->sem);
+ device_unlock(dev);
}
-
+EXPORT_SYMBOL_GPL(device_release_driver);
/**
* driver_detach - detach driver from all devices it controls.
* @drv: driver.
*/
-void driver_detach(struct device_driver * drv)
+void driver_detach(struct device_driver *drv)
{
- struct device * dev;
+ struct device_private *dev_prv;
+ struct device *dev;
for (;;) {
- spin_lock(&drv->klist_devices.k_lock);
- if (list_empty(&drv->klist_devices.k_list)) {
- spin_unlock(&drv->klist_devices.k_lock);
+ spin_lock(&drv->p->klist_devices.k_lock);
+ if (list_empty(&drv->p->klist_devices.k_list)) {
+ spin_unlock(&drv->p->klist_devices.k_lock);
break;
}
- dev = list_entry(drv->klist_devices.k_list.prev,
- struct device, knode_driver.n_node);
+ dev_prv = list_entry(drv->p->klist_devices.k_list.prev,
+ struct device_private,
+ knode_driver.n_node);
+ dev = dev_prv->device;
get_device(dev);
- spin_unlock(&drv->klist_devices.k_lock);
+ spin_unlock(&drv->p->klist_devices.k_lock);
if (dev->parent) /* Needed for USB */
- down(&dev->parent->sem);
- down(&dev->sem);
+ device_lock(dev->parent);
+ device_lock(dev);
if (dev->driver == drv)
__device_release_driver(dev);
- up(&dev->sem);
+ device_unlock(dev);
if (dev->parent)
- up(&dev->parent->sem);
+ device_unlock(dev->parent);
put_device(dev);
}
}
+/*
+ * These exports can't be _GPL due to .h files using this within them, and it
+ * might break something that was previously working...
+ */
+void *dev_get_drvdata(const struct device *dev)
+{
+ if (dev && dev->p)
+ return dev->p->driver_data;
+ return NULL;
+}
+EXPORT_SYMBOL(dev_get_drvdata);
-EXPORT_SYMBOL_GPL(device_bind_driver);
-EXPORT_SYMBOL_GPL(device_release_driver);
-EXPORT_SYMBOL_GPL(device_attach);
-EXPORT_SYMBOL_GPL(driver_attach);
+int dev_set_drvdata(struct device *dev, void *data)
+{
+ int error;
+ if (!dev->p) {
+ error = device_private_init(dev);
+ if (error)
+ return error;
+ }
+ dev->p->driver_data = data;
+ return 0;
+}
+EXPORT_SYMBOL(dev_set_drvdata);
Code Review / linux-2.6.git / blobdiff