I finally did as you suggested and added the notifier to the struct
bus_type itself. There are still problems to be expected is something
attaches to a bus type where the code can hook in different struct
device sub-classes (which is imho a big bogosity but I won't even try to
argue that case now) but it will solve nicely a number of issues I've
had so far.
That also means that clients interested in registering for such
notifications have to do it before devices are added and after bus types
are registered. Fortunately, most bus types that matter for the various
usage scenarios I have in mind are registerd at postcore_initcall time,
which means I have a really nice spot at arch_initcall time to add my
notifiers.
There are 4 notifications provided. Device being added (before hooked to
the bus) and removed (failure of previous case or after being unhooked
from the bus), along with driver being bound to a device and about to be
unbound.
The usage I have for these are:
- The 2 first ones are used to maintain a struct device_ext that is
hooked to struct device.firmware_data. This structure contains for now a
pointer to the Open Firmware node related to the device (if any), the
NUMA node ID (for quick access to it) and the DMA operations pointers &
iommu table instance for DMA to/from this device. For bus types I own
(like IBM VIO or EBUS), I just maintain that structure directly from the
bus code when creating the devices. But for bus types managed by generic
code like PCI or platform (actually, of_platform which is a variation of
platform linked to Open Firmware device-tree), I need this notifier.
- The other two ones have a completely different usage scenario. I have
cases where multiple devices and their drivers depend on each other. For
example, the IBM EMAC network driver needs to attach to a MAL DMA engine
which is a separate device, and a PHY interface which is also a separate
device. They are all of_platform_device's (well, about to be with my
upcoming patches) but there is no say in what precise order the core
will "probe" them and instanciate the various modules. The solution I
found for that is to have the drivers for emac to use multithread_probe,
and wait for a driver to be bound to the target MAL and PHY control
devices (the device-tree contains reference to the MAL and PHY interface
nodes, which I can then match to of_platform_devices). Right now, I've
been polling, but with that notifier, I can more cleanly wait (with a
timeout of course).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
dev->devt_attr is allocated in device_add() but it is never freed in
device_del() in the drivers/base/core.c file (reported by kmemleak).
Signed-off-by: Catalin Marinas <catalin.marinas@gmail.com>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch (as797) fixes device_add() in the driver core. It needs to
pay attention when the driver for a new device reports an error.
At the same time, since bus_remove_device() undoes the effects of both
bus_add_device() and bus_attach_device(), it needs to check whether
the bus_attach_device step failed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If kmalloc() fails to allocate space for 'old_symlink_name' in
drivers/base/core.c::device_rename(), then we'll leak 'old_class_name'.
Spotted by the Coverity checker.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Check for return code of device_create_file() and correct cleanup in
the error case in device_add().
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make dev_printk usable from non-GPL modules again
dev_printk now calls dev_driver_string. We want even proprietary modules
to be calling dev_printk, so the export of dev_driver_string needs to be
non-GPL-only.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The platform_notify call for Arm and PPC architectures needs to be called
before the driver attaches to the device. The problem only presents itself
when hotplugging certain devices while the driver is already loaded.
Signed-off-by: Brian Walsh <brian@walsh.ws>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Makes it easier for devices to create and remove binary attribute files
so they don't have to call directly into sysfs. This is needed to help
with the conversion from struct class_device to struct device.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When moving class_device usage over to device, we need to handle
class_interfaces properly with devices. This patch adds that support.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This change creates a devices/virtual/CLASS_NAME tree for struct devices
that belong to a class, yet do not have a "real" struct device for a
parent. It automatically creates the directories on the fly as needed.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds two new callbacks to the class structure:
int (*dev_uevent)(struct device *dev, char **envp, int num_envp,
char *buffer, int buffer_size);
void (*dev_release)(struct device *dev);
And one pointer:
struct device_attribute * dev_attrs;
which all corrispond with the same thing as the "normal" class devices
do, yet this is for when a struct device is bound to a class.
Someday soon, struct class_device will go away, and then the other
fields in this structure can be removed too. But this is necessary in
order to get the transition to work properly.
Tested out on a network core patch that converted it to use struct
device instead of struct class_device.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes an oops when a device is attached to a class, yet has no
"parent" device. An example of this would be the "lo" device in the
network core.
We should create a "virtual" subdirectory under /sys/devices/ for these,
but no one seems to agree on a proper name for it yet...
Oh, and update my copyright on the driver core.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is needed for the network class devices in order to be able to
convert over to use struct device.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
deprecate PHYSDEV* values in the uevent environment
These values are no longer needed and inconsistent with the
stacking of class devices. The event environment should not
carry properties of a parent device. The key PHYSDEVDRIVER is
available as DRIVER, PHYDEVBUS is indentical SUBSYSTEM. Class
devices should not carry any of these values.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Corrects the kerneldocs for device_create() and device_destroy()
with an eye on coding style, grammar and readability.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Warning(/var/linsrc/linux-2617-g4//drivers/base/core.c:574): No description found for parameter 'class'
Warning(/var/linsrc/linux-2617-g4//drivers/base/core.c:574): No description found for parameter 'devt'
Warning(/var/linsrc/linux-2617-g4//drivers/base/core.c:626): No description found for parameter 'devt'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as721) makes dev_info and related macros print the device's
bus name if the device doesn't have a driver, instead of printing just a
blank. If the device isn't on a bus either... well, then it does leave
a blank space. But it will be easier for someone else to change if they
want.
Cc: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We need to create the "compatible" symlinks that class_devices used to
create when they were in the class directories so that userspace does
not know anything changed at all.
Yeah, we have a lot of symlinks now, but we should be able to get rid of
them in a year or two... (wishful thinking...)
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Like the SUBSYTEM= key we find in the environment of the uevent, this
creates a generic "subsystem" link in sysfs for every device. Userspace
usually doesn't care at all if its a "class" or a "bus" device. This
provides an unified way to determine the subsytem of a device, regardless
of the way the driver core has created it.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is the first step in moving class_device to being replaced by
struct device. It allows struct device to export a dev_t and makes it
easy to dynamically create and destroy struct device as long as they are
associated with a specific class.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
split bus_add_device() and send device uevents after sysfs population
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix typos in comments to remove kernel-doc warnings.
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Leave the overloaded "hotplug" word to susbsystems which are handling
real devices. The driver core does not "plug" anything, it just exports
the state to userspace and generates events.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A "coldplug + udevstart" can be simple like this:
for i in /sys/block/*/*/uevent; do echo 1 > $i; done
for i in /sys/class/*/*/uevent; do echo 1 > $i; done
for i in /sys/bus/*/devices/*/uevent; do echo 1 > $i; done
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is a refresh of an earlier patch to add "wakeup" support to the
PM core model. This provides per-device bus-neutral control of the
use of wakeup events.
* "struct device_pm_info" has two bits that are initialized as
part of setting up the enclosing struct device:
- "can_wakeup", reflecting hardware capabilities
- "may_wakeup", the policy setting (when CONFIG_PM)
* There's a writeable sysfs "wakeup" file, with one of two values:
- "enabled", when the policy is to allow wakeup
- "disabled", when the policy is not to allow it
- "" if the device can't currently issue wakeups
By default, wakeup is enabled on all devices that support it. If its
driver doesn't support it ... treat it as a bug. :)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The problem is that klists claim to provide semantics for safe traversal of
lists which are being modified. The failure case is when traversal of a
list causes element removal (a fairly common case). The issue is that
although the list node is refcounted, if it is embedded in an object (which
is universally the case), then the object will be freed regardless of the
klist refcount leading to slab corruption because the klist iterator refers
to the prior element to get the next.
The solution is to make the klist take and release references to the
embedding object meaning that the embedding object won't be released until
the list relinquishes the reference to it.
(akpm: fast-track this because it's needed for the 2.6.13 scsi merge)
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
at the moment, the list_head semantics are
list_add(node, head)
whereas current klist semantics are
klist_add(head, node)
This is bound to cause confusion, and since klist is the newcomer, it
should follow the list_head semantics.
I also added missing include guards to klist.h
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use klist_del() instead of klist_remove() when unregistering devices.
This will prevent a deadlock when executing a recursive unregister using
device_for_each_child().
Signed-off-by Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds the device_attribute paramerter to the
device_attribute store and show sysfs callback functions, and passes a
reference to the attribute when the callbacks are called.
Signed-off-by: Yani Ioannou <yani.ioannou@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Use klist iterator in device_for_each_child(), making it safe to use for
removing devices.
- Remove unused list_to_dev() function.
- Kills all usage of devices_subsys.rwsem.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Use it in driver_for_each_device() instead of the regular list_head and stop using
the bus's rwsem for protection.
- Use driver_for_each_device() in driver_detach() so we don't deadlock on the
bus's rwsem.
- Remove ->devices.
- Move klist access and sysfs link access out from under device's semaphore, since
they're synchronized through other means.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds a per-device semaphore that is taken before every call from the core to a
driver method. This prevents e.g. simultaneous calls to the ->suspend() or ->resume()
and ->probe() or ->release(), potentially saving a whole lot of headaches.
It also moves us a step closer to removing the bus rwsem, since it protects the fields
in struct device that are modified by the core.
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: fix drivers/base so if an attribute doesn't implement
show or store method read/write will return -EIO
instead of 0.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As a result of the split of the kobject-registration and the
corresponding hotplug event, the order of events for device_add() has
changed. This restores the old order, cause it confused some userspace
applications.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The driver model has a "detach_state" mechanism that:
- Has never been used by any in-kernel drive;
- Is superfluous, since driver remove() methods can do the same thing;
- Became buggy when the suspend() parameter changed semantics and type;
- Could self-deadlock when called from certain suspend contexts;
- Is effectively wasted documentation, object code, and headspace.
This removes that "detach_state" mechanism; net code shrink, as well
as a per-device saving in the driver model and sysfs.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Earlier in the same function dev->bus is checked before dereferenced,
make consistent although I honestly don't know if dev->bus could
ever be NULL
Found by the Coverity tool
Signed-off-by: Alexander Nyberg <alexn@dsv.su.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobject_add() and kobject_del() don't emit hotplug events anymore. Do it
ourselves if we are finished populating the device directory.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
