Contributors: 76
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Patrick Mochel |
547 |
12.93% |
16 |
8.84% |
| Rafael J. Wysocki |
354 |
8.37% |
12 |
6.63% |
| Grant C. Likely |
311 |
7.35% |
3 |
1.66% |
| Dmitry Torokhov |
305 |
7.21% |
9 |
4.97% |
| Saravana Kannan |
274 |
6.48% |
10 |
5.52% |
| Christoph Hellwig |
261 |
6.17% |
6 |
3.31% |
| Greg Kroah-Hartman |
213 |
5.04% |
17 |
9.39% |
| Alexander Duyck |
208 |
4.92% |
3 |
1.66% |
| Alan Stern |
187 |
4.42% |
6 |
3.31% |
| Rob Herring |
151 |
3.57% |
5 |
2.76% |
| Tomeu Vizoso |
114 |
2.70% |
3 |
1.66% |
| Arend Van Spriel |
104 |
2.46% |
1 |
0.55% |
| Kay Sievers |
96 |
2.27% |
3 |
1.66% |
| Javier Martinez Canillas |
83 |
1.96% |
2 |
1.10% |
| Feng Tang |
81 |
1.91% |
1 |
0.55% |
| Grygorii Strashko |
70 |
1.65% |
1 |
0.55% |
| Andrzej Hajda |
64 |
1.51% |
1 |
0.55% |
| Todd Android Poynor |
57 |
1.35% |
2 |
1.10% |
| Andrew Morton |
46 |
1.09% |
2 |
1.10% |
| Lu Baolu |
46 |
1.09% |
3 |
1.66% |
| Cornelia Huck |
41 |
0.97% |
3 |
1.66% |
| Ahmad Fatoum |
40 |
0.95% |
2 |
1.10% |
| Linus Torvalds |
38 |
0.90% |
2 |
1.10% |
| Zhang Wensheng |
37 |
0.87% |
2 |
1.10% |
| Russell King |
32 |
0.76% |
1 |
0.55% |
| Lei Ming |
30 |
0.71% |
2 |
1.10% |
| Luis R. Rodriguez |
29 |
0.69% |
2 |
1.10% |
| Andy Shevchenko |
28 |
0.66% |
3 |
1.66% |
| Arjan van de Ven |
25 |
0.59% |
4 |
2.21% |
| Jason Gunthorpe |
22 |
0.52% |
2 |
1.10% |
| Zhen Lei |
21 |
0.50% |
1 |
0.55% |
| R Sricharan |
19 |
0.45% |
1 |
0.55% |
| Sebastian Ott |
17 |
0.40% |
1 |
0.55% |
| Tejun Heo |
14 |
0.33% |
1 |
0.55% |
| Geert Uytterhoeven |
14 |
0.33% |
2 |
1.10% |
| Mårten Lindahl |
13 |
0.31% |
1 |
0.55% |
| Lukas Wunner |
13 |
0.31% |
1 |
0.55% |
| Song Muchun |
13 |
0.31% |
1 |
0.55% |
| Martin Liu |
12 |
0.28% |
1 |
0.55% |
| Ulf Hansson |
12 |
0.28% |
2 |
1.10% |
| Bhaktipriya Shridhar |
12 |
0.28% |
1 |
0.55% |
| Benjamin Herrenschmidt |
11 |
0.26% |
1 |
0.55% |
| Jia-Ju Bai |
11 |
0.26% |
1 |
0.55% |
| Hugh Daschbach |
11 |
0.26% |
1 |
0.55% |
| Isaac Manjarres |
10 |
0.24% |
2 |
1.10% |
| Daniel Ritz |
10 |
0.24% |
1 |
0.55% |
| Linus Walleij |
10 |
0.24% |
1 |
0.55% |
| Hans de Goede |
9 |
0.21% |
1 |
0.55% |
| Mark-PK Tsai |
9 |
0.21% |
1 |
0.55% |
| John Stultz |
8 |
0.19% |
2 |
1.10% |
| Harvey Harrison |
7 |
0.17% |
1 |
0.55% |
| Christophe Jaillet |
7 |
0.17% |
1 |
0.55% |
| Magnus Damm |
6 |
0.14% |
1 |
0.55% |
| Joerg Roedel |
6 |
0.14% |
1 |
0.55% |
| David Brownell |
6 |
0.14% |
1 |
0.55% |
| Tetsuo Handa |
6 |
0.14% |
1 |
0.55% |
| Doug Anderson |
5 |
0.12% |
1 |
0.55% |
| Mark Brown |
5 |
0.12% |
1 |
0.55% |
| James Bottomley |
4 |
0.09% |
1 |
0.55% |
| Zenghui Yu |
4 |
0.09% |
1 |
0.55% |
| Adrian Hunter |
4 |
0.09% |
1 |
0.55% |
| Yogesh Lal |
3 |
0.07% |
1 |
0.55% |
| Adrian Bunk |
3 |
0.07% |
1 |
0.55% |
| Randy Dunlap |
3 |
0.07% |
2 |
1.10% |
| Uwe Kleine-König |
3 |
0.07% |
1 |
0.55% |
| Thierry Reding |
2 |
0.05% |
2 |
1.10% |
| Julian Wiedmann |
2 |
0.05% |
1 |
0.55% |
| Tom Rix |
2 |
0.05% |
1 |
0.55% |
| Nipun Gupta |
2 |
0.05% |
1 |
0.55% |
| Duncan Sands |
1 |
0.02% |
1 |
0.55% |
| Kuninori Morimoto |
1 |
0.02% |
1 |
0.55% |
| Shailendra Verma |
1 |
0.02% |
1 |
0.55% |
| Joe Perches |
1 |
0.02% |
1 |
0.55% |
| Wolfram Sang |
1 |
0.02% |
1 |
0.55% |
| David S. Miller |
1 |
0.02% |
1 |
0.55% |
| Feng Kan |
1 |
0.02% |
1 |
0.55% |
| Total |
4230 |
|
181 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* 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.
*
* 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) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de>
* Copyright (c) 2007-2009 Novell Inc.
*/
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-map-ops.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/wait.h>
#include <linux/async.h>
#include <linux/pm_runtime.h>
#include <linux/pinctrl/devinfo.h>
#include <linux/slab.h>
#include "base.h"
#include "power/power.h"
/*
* 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 atomic_t deferred_trigger_count = ATOMIC_INIT(0);
static bool initcalls_done;
/* Save the async probe drivers' name from kernel cmdline */
#define ASYNC_DRV_NAMES_MAX_LEN 256
static char async_probe_drv_names[ASYNC_DRV_NAMES_MAX_LEN];
static bool async_probe_default;
/*
* In some cases, like suspend to RAM or hibernation, It might be reasonable
* to prohibit probing of devices as it could be unsafe.
* Once defer_all_probes is true all drivers probes will be forcibly deferred.
*/
static bool defer_all_probes;
static void __device_set_deferred_probe_reason(const struct device *dev, char *reason)
{
kfree(dev->p->deferred_probe_reason);
dev->p->deferred_probe_reason = reason;
}
/*
* 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);
__device_set_deferred_probe_reason(dev, NULL);
/*
* Drop the mutex while probing each device; the probe path may
* manipulate the deferred list
*/
mutex_unlock(&deferred_probe_mutex);
/*
* Force the device to the end of the dpm_list since
* the PM code assumes that the order we add things to
* the list is a good order for suspend but deferred
* probe makes that very unsafe.
*/
device_pm_move_to_tail(dev);
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);
void driver_deferred_probe_add(struct device *dev)
{
if (!dev->can_match)
return;
mutex_lock(&deferred_probe_mutex);
if (list_empty(&dev->p->deferred_probe)) {
dev_dbg(dev, "Added to deferred list\n");
list_add_tail(&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);
__device_set_deferred_probe_reason(dev, NULL);
}
mutex_unlock(&deferred_probe_mutex);
}
static bool driver_deferred_probe_enable;
/**
* driver_deferred_probe_trigger() - Kick off re-probing deferred devices
*
* 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.
*
* Note, there is a race condition in multi-threaded probe. In the case where
* more than one device is probing at the same time, it is possible for one
* probe to complete successfully while another is about to defer. If the second
* depends on the first, then it will get put on the pending list after the
* trigger event has already occurred and will be stuck there.
*
* The atomic 'deferred_trigger_count' is used to determine if a successful
* trigger has occurred in the midst of probing a driver. If the trigger count
* changes in the midst of a probe, then deferred processing should be triggered
* again.
*/
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);
atomic_inc(&deferred_trigger_count);
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(system_unbound_wq, &deferred_probe_work);
}
/**
* device_block_probing() - Block/defer device's probes
*
* It will disable probing of devices and defer their probes instead.
*/
void device_block_probing(void)
{
defer_all_probes = true;
/* sync with probes to avoid races. */
wait_for_device_probe();
}
/**
* device_unblock_probing() - Unblock/enable device's probes
*
* It will restore normal behavior and trigger re-probing of deferred
* devices.
*/
void device_unblock_probing(void)
{
defer_all_probes = false;
driver_deferred_probe_trigger();
}
/**
* device_set_deferred_probe_reason() - Set defer probe reason message for device
* @dev: the pointer to the struct device
* @vaf: the pointer to va_format structure with message
*/
void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf)
{
const char *drv = dev_driver_string(dev);
char *reason;
mutex_lock(&deferred_probe_mutex);
reason = kasprintf(GFP_KERNEL, "%s: %pV", drv, vaf);
__device_set_deferred_probe_reason(dev, reason);
mutex_unlock(&deferred_probe_mutex);
}
/*
* deferred_devs_show() - Show the devices in the deferred probe pending list.
*/
static int deferred_devs_show(struct seq_file *s, void *data)
{
struct device_private *curr;
mutex_lock(&deferred_probe_mutex);
list_for_each_entry(curr, &deferred_probe_pending_list, deferred_probe)
seq_printf(s, "%s\t%s", dev_name(curr->device),
curr->device->p->deferred_probe_reason ?: "\n");
mutex_unlock(&deferred_probe_mutex);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(deferred_devs);
#ifdef CONFIG_MODULES
static int driver_deferred_probe_timeout = 10;
#else
static int driver_deferred_probe_timeout;
#endif
static int __init deferred_probe_timeout_setup(char *str)
{
int timeout;
if (!kstrtoint(str, 10, &timeout))
driver_deferred_probe_timeout = timeout;
return 1;
}
__setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
/**
* driver_deferred_probe_check_state() - Check deferred probe state
* @dev: device to check
*
* Return:
* * -ENODEV if initcalls have completed and modules are disabled.
* * -ETIMEDOUT if the deferred probe timeout was set and has expired
* and modules are enabled.
* * -EPROBE_DEFER in other cases.
*
* Drivers or subsystems can opt-in to calling this function instead of directly
* returning -EPROBE_DEFER.
*/
int driver_deferred_probe_check_state(struct device *dev)
{
if (!IS_ENABLED(CONFIG_MODULES) && initcalls_done) {
dev_warn(dev, "ignoring dependency for device, assuming no driver\n");
return -ENODEV;
}
if (!driver_deferred_probe_timeout && initcalls_done) {
dev_warn(dev, "deferred probe timeout, ignoring dependency\n");
return -ETIMEDOUT;
}
return -EPROBE_DEFER;
}
EXPORT_SYMBOL_GPL(driver_deferred_probe_check_state);
static void deferred_probe_timeout_work_func(struct work_struct *work)
{
struct device_private *p;
fw_devlink_drivers_done();
driver_deferred_probe_timeout = 0;
driver_deferred_probe_trigger();
flush_work(&deferred_probe_work);
mutex_lock(&deferred_probe_mutex);
list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe)
dev_info(p->device, "deferred probe pending\n");
mutex_unlock(&deferred_probe_mutex);
}
static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);
void deferred_probe_extend_timeout(void)
{
/*
* If the work hasn't been queued yet or if the work expired, don't
* start a new one.
*/
if (cancel_delayed_work(&deferred_probe_timeout_work)) {
schedule_delayed_work(&deferred_probe_timeout_work,
driver_deferred_probe_timeout * HZ);
pr_debug("Extended deferred probe timeout by %d secs\n",
driver_deferred_probe_timeout);
}
}
/**
* deferred_probe_initcall() - Enable probing of deferred devices
*
* 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.
*/
static int deferred_probe_initcall(void)
{
debugfs_create_file("devices_deferred", 0444, NULL, NULL,
&deferred_devs_fops);
driver_deferred_probe_enable = true;
driver_deferred_probe_trigger();
/* Sort as many dependencies as possible before exiting initcalls */
flush_work(&deferred_probe_work);
initcalls_done = true;
if (!IS_ENABLED(CONFIG_MODULES))
fw_devlink_drivers_done();
/*
* Trigger deferred probe again, this time we won't defer anything
* that is optional
*/
driver_deferred_probe_trigger();
flush_work(&deferred_probe_work);
if (driver_deferred_probe_timeout > 0) {
schedule_delayed_work(&deferred_probe_timeout_work,
driver_deferred_probe_timeout * HZ);
}
return 0;
}
late_initcall(deferred_probe_initcall);
static void __exit deferred_probe_exit(void)
{
debugfs_lookup_and_remove("devices_deferred", NULL);
}
__exitcall(deferred_probe_exit);
/**
* device_is_bound() - Check if device is bound to a driver
* @dev: device to check
*
* Returns true if passed device has already finished probing successfully
* against a driver.
*
* This function must be called with the device lock held.
*/
bool device_is_bound(struct device *dev)
{
return dev->p && klist_node_attached(&dev->p->knode_driver);
}
static void driver_bound(struct device *dev)
{
if (device_is_bound(dev)) {
pr_warn("%s: device %s already bound\n",
__func__, kobject_name(&dev->kobj));
return;
}
pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name,
__func__, dev_name(dev));
klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
device_links_driver_bound(dev);
device_pm_check_callbacks(dev);
/*
* 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();
bus_notify(dev, BUS_NOTIFY_BOUND_DRIVER);
kobject_uevent(&dev->kobj, KOBJ_BIND);
}
static ssize_t coredump_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
device_lock(dev);
dev->driver->coredump(dev);
device_unlock(dev);
return count;
}
static DEVICE_ATTR_WO(coredump);
static int driver_sysfs_add(struct device *dev)
{
int ret;
bus_notify(dev, BUS_NOTIFY_BIND_DRIVER);
ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
kobject_name(&dev->kobj));
if (ret)
goto fail;
ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj,
"driver");
if (ret)
goto rm_dev;
if (!IS_ENABLED(CONFIG_DEV_COREDUMP) || !dev->driver->coredump)
return 0;
ret = device_create_file(dev, &dev_attr_coredump);
if (!ret)
return 0;
sysfs_remove_link(&dev->kobj, "driver");
rm_dev:
sysfs_remove_link(&dev->driver->p->kobj,
kobject_name(&dev->kobj));
fail:
return ret;
}
static void driver_sysfs_remove(struct device *dev)
{
struct device_driver *drv = dev->driver;
if (drv) {
if (drv->coredump)
device_remove_file(dev, &dev_attr_coredump);
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.
* Please verify that is 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.
*
* Callers should prefer to use device_driver_attach() instead.
*/
int device_bind_driver(struct device *dev)
{
int ret;
ret = driver_sysfs_add(dev);
if (!ret) {
device_links_force_bind(dev);
driver_bound(dev);
}
else
bus_notify(dev, BUS_NOTIFY_DRIVER_NOT_BOUND);
return ret;
}
EXPORT_SYMBOL_GPL(device_bind_driver);
static atomic_t probe_count = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
static ssize_t state_synced_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
bool val;
device_lock(dev);
val = dev->state_synced;
device_unlock(dev);
return sysfs_emit(buf, "%u\n", val);
}
static DEVICE_ATTR_RO(state_synced);
static void device_unbind_cleanup(struct device *dev)
{
devres_release_all(dev);
arch_teardown_dma_ops(dev);
kfree(dev->dma_range_map);
dev->dma_range_map = NULL;
dev->driver = NULL;
dev_set_drvdata(dev, NULL);
if (dev->pm_domain && dev->pm_domain->dismiss)
dev->pm_domain->dismiss(dev);
pm_runtime_reinit(dev);
dev_pm_set_driver_flags(dev, 0);
}
static void device_remove(struct device *dev)
{
device_remove_file(dev, &dev_attr_state_synced);
device_remove_groups(dev, dev->driver->dev_groups);
if (dev->bus && dev->bus->remove)
dev->bus->remove(dev);
else if (dev->driver->remove)
dev->driver->remove(dev);
}
static int call_driver_probe(struct device *dev, struct device_driver *drv)
{
int ret = 0;
if (dev->bus->probe)
ret = dev->bus->probe(dev);
else if (drv->probe)
ret = drv->probe(dev);
switch (ret) {
case 0:
break;
case -EPROBE_DEFER:
/* Driver requested deferred probing */
dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
break;
case -ENODEV:
case -ENXIO:
pr_debug("%s: probe of %s rejects match %d\n",
drv->name, dev_name(dev), ret);
break;
default:
/* driver matched but the probe failed */
pr_warn("%s: probe of %s failed with error %d\n",
drv->name, dev_name(dev), ret);
break;
}
return ret;
}
static int really_probe(struct device *dev, struct device_driver *drv)
{
bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
!drv->suppress_bind_attrs;
int ret, link_ret;
if (defer_all_probes) {
/*
* Value of defer_all_probes can be set only by
* device_block_probing() which, in turn, will call
* wait_for_device_probe() right after that to avoid any races.
*/
dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);
return -EPROBE_DEFER;
}
link_ret = device_links_check_suppliers(dev);
if (link_ret == -EPROBE_DEFER)
return link_ret;
pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
drv->bus->name, __func__, drv->name, dev_name(dev));
if (!list_empty(&dev->devres_head)) {
dev_crit(dev, "Resources present before probing\n");
ret = -EBUSY;
goto done;
}
re_probe:
dev->driver = drv;
/* If using pinctrl, bind pins now before probing */
ret = pinctrl_bind_pins(dev);
if (ret)
goto pinctrl_bind_failed;
if (dev->bus->dma_configure) {
ret = dev->bus->dma_configure(dev);
if (ret)
goto pinctrl_bind_failed;
}
ret = driver_sysfs_add(dev);
if (ret) {
pr_err("%s: driver_sysfs_add(%s) failed\n",
__func__, dev_name(dev));
goto sysfs_failed;
}
if (dev->pm_domain && dev->pm_domain->activate) {
ret = dev->pm_domain->activate(dev);
if (ret)
goto probe_failed;
}
ret = call_driver_probe(dev, drv);
if (ret) {
/*
* If fw_devlink_best_effort is active (denoted by -EAGAIN), the
* device might actually probe properly once some of its missing
* suppliers have probed. So, treat this as if the driver
* returned -EPROBE_DEFER.
*/
if (link_ret == -EAGAIN)
ret = -EPROBE_DEFER;
/*
* Return probe errors as positive values so that the callers
* can distinguish them from other errors.
*/
ret = -ret;
goto probe_failed;
}
ret = device_add_groups(dev, drv->dev_groups);
if (ret) {
dev_err(dev, "device_add_groups() failed\n");
goto dev_groups_failed;
}
if (dev_has_sync_state(dev)) {
ret = device_create_file(dev, &dev_attr_state_synced);
if (ret) {
dev_err(dev, "state_synced sysfs add failed\n");
goto dev_sysfs_state_synced_failed;
}
}
if (test_remove) {
test_remove = false;
device_remove(dev);
driver_sysfs_remove(dev);
device_unbind_cleanup(dev);
goto re_probe;
}
pinctrl_init_done(dev);
if (dev->pm_domain && dev->pm_domain->sync)
dev->pm_domain->sync(dev);
driver_bound(dev);
pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
drv->bus->name, __func__, dev_name(dev), drv->name);
goto done;
dev_sysfs_state_synced_failed:
dev_groups_failed:
device_remove(dev);
probe_failed:
driver_sysfs_remove(dev);
sysfs_failed:
bus_notify(dev, BUS_NOTIFY_DRIVER_NOT_BOUND);
if (dev->bus && dev->bus->dma_cleanup)
dev->bus->dma_cleanup(dev);
pinctrl_bind_failed:
device_links_no_driver(dev);
device_unbind_cleanup(dev);
done:
return ret;
}
/*
* For initcall_debug, show the driver probe time.
*/
static int really_probe_debug(struct device *dev, struct device_driver *drv)
{
ktime_t calltime, rettime;
int ret;
calltime = ktime_get();
ret = really_probe(dev, drv);
rettime = ktime_get();
pr_debug("probe of %s returned %d after %lld usecs\n",
dev_name(dev), ret, ktime_us_delta(rettime, calltime));
return ret;
}
/**
* driver_probe_done
* Determine if the probe sequence is finished or not.
*
* Should somehow figure out how to use a semaphore, not an atomic variable...
*/
int driver_probe_done(void)
{
int local_probe_count = atomic_read(&probe_count);
pr_debug("%s: probe_count = %d\n", __func__, local_probe_count);
if (local_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 deferred probe workqueue to finish */
flush_work(&deferred_probe_work);
/* 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);
static int __driver_probe_device(struct device_driver *drv, struct device *dev)
{
int ret = 0;
if (dev->p->dead || !device_is_registered(dev))
return -ENODEV;
if (dev->driver)
return -EBUSY;
dev->can_match = true;
pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
drv->bus->name, __func__, dev_name(dev), drv->name);
pm_runtime_get_suppliers(dev);
if (dev->parent)
pm_runtime_get_sync(dev->parent);
pm_runtime_barrier(dev);
if (initcall_debug)
ret = really_probe_debug(dev, drv);
else
ret = really_probe(dev, drv);
pm_request_idle(dev);
if (dev->parent)
pm_runtime_put(dev->parent);
pm_runtime_put_suppliers(dev);
return ret;
}
/**
* 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
*
* This function returns -ENODEV if the device is not registered, -EBUSY if it
* already has a driver, 0 if the device is bound successfully and a positive
* (inverted) error code for failures from the ->probe method.
*
* This function must be called with @dev lock held. When called for a
* USB interface, @dev->parent lock must be held as well.
*
* If the device has a parent, runtime-resume the parent before driver probing.
*/
static int driver_probe_device(struct device_driver *drv, struct device *dev)
{
int trigger_count = atomic_read(&deferred_trigger_count);
int ret;
atomic_inc(&probe_count);
ret = __driver_probe_device(drv, dev);
if (ret == -EPROBE_DEFER || ret == EPROBE_DEFER) {
driver_deferred_probe_add(dev);
/*
* Did a trigger occur while probing? Need to re-trigger if yes
*/
if (trigger_count != atomic_read(&deferred_trigger_count) &&
!defer_all_probes)
driver_deferred_probe_trigger();
}
atomic_dec(&probe_count);
wake_up_all(&probe_waitqueue);
return ret;
}
static inline bool cmdline_requested_async_probing(const char *drv_name)
{
bool async_drv;
async_drv = parse_option_str(async_probe_drv_names, drv_name);
return (async_probe_default != async_drv);
}
/* The option format is "driver_async_probe=drv_name1,drv_name2,..." */
static int __init save_async_options(char *buf)
{
if (strlen(buf) >= ASYNC_DRV_NAMES_MAX_LEN)
pr_warn("Too long list of driver names for 'driver_async_probe'!\n");
strscpy(async_probe_drv_names, buf, ASYNC_DRV_NAMES_MAX_LEN);
async_probe_default = parse_option_str(async_probe_drv_names, "*");
return 1;
}
__setup("driver_async_probe=", save_async_options);
static bool driver_allows_async_probing(struct device_driver *drv)
{
switch (drv->probe_type) {
case PROBE_PREFER_ASYNCHRONOUS:
return true;
case PROBE_FORCE_SYNCHRONOUS:
return false;
default:
if (cmdline_requested_async_probing(drv->name))
return true;
if (module_requested_async_probing(drv->owner))
return true;
return false;
}
}
struct device_attach_data {
struct device *dev;
/*
* Indicates whether we are considering asynchronous probing or
* not. Only initial binding after device or driver registration
* (including deferral processing) may be done asynchronously, the
* rest is always synchronous, as we expect it is being done by
* request from userspace.
*/
bool check_async;
/*
* Indicates if we are binding synchronous or asynchronous drivers.
* When asynchronous probing is enabled we'll execute 2 passes
* over drivers: first pass doing synchronous probing and second
* doing asynchronous probing (if synchronous did not succeed -
* most likely because there was no driver requiring synchronous
* probing - and we found asynchronous driver during first pass).
* The 2 passes are done because we can't shoot asynchronous
* probe for given device and driver from bus_for_each_drv() since
* driver pointer is not guaranteed to stay valid once
* bus_for_each_drv() iterates to the next driver on the bus.
*/
bool want_async;
/*
* We'll set have_async to 'true' if, while scanning for matching
* driver, we'll encounter one that requests asynchronous probing.
*/
bool have_async;
};
static int __device_attach_driver(struct device_driver *drv, void *_data)
{
struct device_attach_data *data = _data;
struct device *dev = data->dev;
bool async_allowed;
int ret;
ret = driver_match_device(drv, dev);
if (ret == 0) {
/* no match */
return 0;
} else if (ret == -EPROBE_DEFER) {
dev_dbg(dev, "Device match requests probe deferral\n");
dev->can_match = true;
driver_deferred_probe_add(dev);
/*
* Device can't match with a driver right now, so don't attempt
* to match or bind with other drivers on the bus.
*/
return ret;
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
return ret;
} /* ret > 0 means positive match */
async_allowed = driver_allows_async_probing(drv);
if (async_allowed)
data->have_async = true;
if (data->check_async && async_allowed != data->want_async)
return 0;
/*
* Ignore errors returned by ->probe so that the next driver can try
* its luck.
*/
ret = driver_probe_device(drv, dev);
if (ret < 0)
return ret;
return ret == 0;
}
static void __device_attach_async_helper(void *_dev, async_cookie_t cookie)
{
struct device *dev = _dev;
struct device_attach_data data = {
.dev = dev,
.check_async = true,
.want_async = true,
};
device_lock(dev);
/*
* Check if device has already been removed or claimed. This may
* happen with driver loading, device discovery/registration,
* and deferred probe processing happens all at once with
* multiple threads.
*/
if (dev->p->dead || dev->driver)
goto out_unlock;
if (dev->parent)
pm_runtime_get_sync(dev->parent);
bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver);
dev_dbg(dev, "async probe completed\n");
pm_request_idle(dev);
if (dev->parent)
pm_runtime_put(dev->parent);
out_unlock:
device_unlock(dev);
put_device(dev);
}
static int __device_attach(struct device *dev, bool allow_async)
{
int ret = 0;
bool async = false;
device_lock(dev);
if (dev->p->dead) {
goto out_unlock;
} else if (dev->driver) {
if (device_is_bound(dev)) {
ret = 1;
goto out_unlock;
}
ret = device_bind_driver(dev);
if (ret == 0)
ret = 1;
else {
dev->driver = NULL;
ret = 0;
}
} else {
struct device_attach_data data = {
.dev = dev,
.check_async = allow_async,
.want_async = false,
};
if (dev->parent)
pm_runtime_get_sync(dev->parent);
ret = bus_for_each_drv(dev->bus, NULL, &data,
__device_attach_driver);
if (!ret && allow_async && data.have_async) {
/*
* If we could not find appropriate driver
* synchronously and we are allowed to do
* async probes and there are drivers that
* want to probe asynchronously, we'll
* try them.
*/
dev_dbg(dev, "scheduling asynchronous probe\n");
get_device(dev);
async = true;
} else {
pm_request_idle(dev);
}
if (dev->parent)
pm_runtime_put(dev->parent);
}
out_unlock:
device_unlock(dev);
if (async)
async_schedule_dev(__device_attach_async_helper, dev);
return ret;
}
/**
* 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.
*
* 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 lock must be held.
*/
int device_attach(struct device *dev)
{
return __device_attach(dev, false);
}
EXPORT_SYMBOL_GPL(device_attach);
void device_initial_probe(struct device *dev)
{
__device_attach(dev, true);
}
/*
* __device_driver_lock - acquire locks needed to manipulate dev->drv
* @dev: Device we will update driver info for
* @parent: Parent device. Needed if the bus requires parent lock
*
* This function will take the required locks for manipulating dev->drv.
* Normally this will just be the @dev lock, but when called for a USB
* interface, @parent lock will be held as well.
*/
static void __device_driver_lock(struct device *dev, struct device *parent)
{
if (parent && dev->bus->need_parent_lock)
device_lock(parent);
device_lock(dev);
}
/*
* __device_driver_unlock - release locks needed to manipulate dev->drv
* @dev: Device we will update driver info for
* @parent: Parent device. Needed if the bus requires parent lock
*
* This function will release the required locks for manipulating dev->drv.
* Normally this will just be the @dev lock, but when called for a
* USB interface, @parent lock will be released as well.
*/
static void __device_driver_unlock(struct device *dev, struct device *parent)
{
device_unlock(dev);
if (parent && dev->bus->need_parent_lock)
device_unlock(parent);
}
/**
* device_driver_attach - attach a specific driver to a specific device
* @drv: Driver to attach
* @dev: Device to attach it to
*
* Manually attach driver to a device. Will acquire both @dev lock and
* @dev->parent lock if needed. Returns 0 on success, -ERR on failure.
*/
int device_driver_attach(struct device_driver *drv, struct device *dev)
{
int ret;
__device_driver_lock(dev, dev->parent);
ret = __driver_probe_device(drv, dev);
__device_driver_unlock(dev, dev->parent);
/* also return probe errors as normal negative errnos */
if (ret > 0)
ret = -ret;
if (ret == -EPROBE_DEFER)
return -EAGAIN;
return ret;
}
EXPORT_SYMBOL_GPL(device_driver_attach);
static void __driver_attach_async_helper(void *_dev, async_cookie_t cookie)
{
struct device *dev = _dev;
struct device_driver *drv;
int ret;
__device_driver_lock(dev, dev->parent);
drv = dev->p->async_driver;
dev->p->async_driver = NULL;
ret = driver_probe_device(drv, dev);
__device_driver_unlock(dev, dev->parent);
dev_dbg(dev, "driver %s async attach completed: %d\n", drv->name, ret);
put_device(dev);
}
static int __driver_attach(struct device *dev, void *data)
{
struct device_driver *drv = data;
bool async = false;
int ret;
/*
* Lock device and try to bind to it. We drop the error
* here and always return 0, because we need to keep trying
* to bind to devices and some drivers will return an error
* simply if it didn't support the device.
*
* driver_probe_device() will spit a warning if there
* is an error.
*/
ret = driver_match_device(drv, dev);
if (ret == 0) {
/* no match */
return 0;
} else if (ret == -EPROBE_DEFER) {
dev_dbg(dev, "Device match requests probe deferral\n");
dev->can_match = true;
driver_deferred_probe_add(dev);
/*
* Driver could not match with device, but may match with
* another device on the bus.
*/
return 0;
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
/*
* Driver could not match with device, but may match with
* another device on the bus.
*/
return 0;
} /* ret > 0 means positive match */
if (driver_allows_async_probing(drv)) {
/*
* Instead of probing the device synchronously we will
* probe it asynchronously to allow for more parallelism.
*
* We only take the device lock here in order to guarantee
* that the dev->driver and async_driver fields are protected
*/
dev_dbg(dev, "probing driver %s asynchronously\n", drv->name);
device_lock(dev);
if (!dev->driver && !dev->p->async_driver) {
get_device(dev);
dev->p->async_driver = drv;
async = true;
}
device_unlock(dev);
if (async)
async_schedule_dev(__driver_attach_async_helper, dev);
return 0;
}
__device_driver_lock(dev, dev->parent);
driver_probe_device(drv, dev);
__device_driver_unlock(dev, dev->parent);
return 0;
}
/**
* 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.
*/
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() 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, struct device *parent)
{
struct device_driver *drv;
drv = dev->driver;
if (drv) {
pm_runtime_get_sync(dev);
while (device_links_busy(dev)) {
__device_driver_unlock(dev, parent);
device_links_unbind_consumers(dev);
__device_driver_lock(dev, parent);
/*
* A concurrent invocation of the same function might
* have released the driver successfully while this one
* was waiting, so check for that.
*/
if (dev->driver != drv) {
pm_runtime_put(dev);
return;
}
}
driver_sysfs_remove(dev);
bus_notify(dev, BUS_NOTIFY_UNBIND_DRIVER);
pm_runtime_put_sync(dev);
device_remove(dev);
if (dev->bus && dev->bus->dma_cleanup)
dev->bus->dma_cleanup(dev);
device_links_driver_cleanup(dev);
device_unbind_cleanup(dev);
klist_remove(&dev->p->knode_driver);
device_pm_check_callbacks(dev);
bus_notify(dev, BUS_NOTIFY_UNBOUND_DRIVER);
kobject_uevent(&dev->kobj, KOBJ_UNBIND);
}
}
void device_release_driver_internal(struct device *dev,
struct device_driver *drv,
struct device *parent)
{
__device_driver_lock(dev, parent);
if (!drv || drv == dev->driver)
__device_release_driver(dev, parent);
__device_driver_unlock(dev, parent);
}
/**
* 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.
*
* If this function is to be called with @dev->parent lock held, ensure that
* the device's consumers are unbound in advance or that their locks can be
* acquired under the @dev->parent lock.
*/
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.
*/
device_release_driver_internal(dev, NULL, NULL);
}
EXPORT_SYMBOL_GPL(device_release_driver);
/**
* device_driver_detach - detach driver from a specific device
* @dev: device to detach driver from
*
* Detach driver from device. Will acquire both @dev lock and @dev->parent
* lock if needed.
*/
void device_driver_detach(struct device *dev)
{
device_release_driver_internal(dev, NULL, dev->parent);
}
/**
* driver_detach - detach driver from all devices it controls.
* @drv: driver.
*/
void driver_detach(struct device_driver *drv)
{
struct device_private *dev_prv;
struct device *dev;
if (driver_allows_async_probing(drv))
async_synchronize_full();
for (;;) {
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_prv = list_last_entry(&drv->p->klist_devices.k_list,
struct device_private,
knode_driver.n_node);
dev = dev_prv->device;
get_device(dev);
spin_unlock(&drv->p->klist_devices.k_lock);
device_release_driver_internal(dev, drv, dev->parent);
put_device(dev);
}
}