Devtmpfs lets the kernel create a tmpfs instance called devtmpfs
very early at kernel initialization, before any driver-core device
is registered. Every device with a major/minor will provide a
device node in devtmpfs.
Devtmpfs can be changed and altered by userspace at any time,
and in any way needed - just like today's udev-mounted tmpfs.
Unmodified udev versions will run just fine on top of it, and will
recognize an already existing kernel-created device node and use it.
The default node permissions are root:root 0600. Proper permissions
and user/group ownership, meaningful symlinks, all other policy still
needs to be applied by userspace.
If a node is created by devtmps, devtmpfs will remove the device node
when the device goes away. If the device node was created by
userspace, or the devtmpfs created node was replaced by userspace, it
will no longer be removed by devtmpfs.
If it is requested to auto-mount it, it makes init=/bin/sh work
without any further userspace support. /dev will be fully populated
and dynamic, and always reflect the current device state of the kernel.
With the commonly used dynamic device numbers, it solves the problem
where static devices nodes may point to the wrong devices.
It is intended to make the initial bootup logic simpler and more robust,
by de-coupling the creation of the inital environment, to reliably run
userspace processes, from a complex userspace bootstrap logic to provide
a working /dev.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Tested-By: Harald Hoyer <harald@redhat.com>
Tested-By: Scott James Remnant <scott@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
No one should directly access the driver_data field, so remove the field
and make it private. We dynamically create the private field now if it
is needed, to handle drivers that call get/set before they are
registered with the driver core.
Also update the copyright notices on these files while we are there.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1271) affects when new devices get linked into their
bus's list of devices. Currently this happens after probing, and it
doesn't happen at all if probing fails. Clearly this is wrong,
because at that point quite a few symbolic links have already been
created in sysfs. We are committed to adding the device, so it should
be linked into the bus's list regardless.
In addition, this needs to happen before the uevent announcing the new
device gets issued. Otherwise user programs might try to access the
device before it has been added to the bus.
To fix both these problems, the patch moves the call to
klist_add_tail() forward from bus_attach_device() to bus_add_device().
Since bus_attach_device() now does nothing but probe for drivers, it
has been renamed to bus_probe_device(). And lastly, the kerneldoc is
updated.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes a bug introduced in commit
49b420a13f.
If a instance of bus_type doesn't have .match method,
all .probe of drivers in the bus should be called, or else
the .probe have not a chance to be called.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reported-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Nothing outside of the driver core should ever touch knode_bus, so
move it out of the public eye.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Nothing outside of the driver core should ever touch knode_driver, so
move it out of the public eye.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Nothing outside of the driver core should ever touch klist_children, or
knode_parent, so move them out of the public eye.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is to be used to move things out of struct device that no code
outside of the driver core should ever touch.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch moves bus->match out from driver_probe_device and
does not hold device lock to check the match between a device
and a driver.
The idea has been verified by the commit 6cd4958609,
which leads to a faster boot. But the commit 6cd4958609 has
the following drawbacks: 1),only does the quick check in
the path of __driver_attach->driver_probe_device, not in other
paths; 2),for a matched device and driver, check the same match
twice. It is a waste of cpu ,especially for some drivers with long
device id table (eg. usb-storage driver).
This patch adds a helper of driver_match_device to check the match
in all paths, and testes the match only once.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move the sysdev_suspend/resume from the callee to the callers, with
no real change in semantics, so that we can rework the disabling of
interrupts during suspend/hibernation.
This is based on an earlier patch from Linus.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2831fe6f9c.
Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.
Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit 11c3b5c3e0.
Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.
Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit 93e746db18.
Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.
Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit b9daa99ee5.
Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.
Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Nothing outside of the driver core should ever touch knode_bus, so
move it out of the public eye.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Nothing outside of the driver core should ever touch knode_driver, so
move it out of the public eye.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Nothing outside of the driver core should ever touch klist_children, or
knode_parent, so move them out of the public eye.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is to be used to move things out of struct device that no code
outside of the driver core should ever touch.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Iterating over entries using callback usually isn't too fun especially
when the entry being iterated over can't be manipulated freely. This
patch converts class->p->class_devices to klist and implements class
device iterator so that the users can freely build their own control
structure. The users are also free to call back into class code
without worrying about locking.
class_for_each_device() and class_find_device() are converted to use
the new iterators, so their users don't have to worry about locking
anymore either.
Note: This depends on klist-dont-iterate-over-deleted-entries patch
because class_intf->add/remove_dev() depends on proper synchronization
with device removal.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Now that the lockdep infrastructure in the class core is in place, we
should be able to properly change the internal class semaphore to be a
mutex.
David wrote the original patch, and Greg fixed it up to apply properly
due to all of the recent changes in this area.
From: Dave Young <hidave.darkstar@gmail.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Removes a field that has been deleted, and adds a description fo the
class_dirs field which was previously undocumented.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This renames the struct class "sem" field to be "class_sem" to make
things easier when struct bus_type and struct class merge in the future.
It also makes grepping for fields easier as well.
Based on an idea from Kay.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This renames the struct class "subsys" field to be "class_subsys" to
make things easier when struct bus_type and struct class merge in the
future. It also makes grepping for fields easier as well.
Based on an idea from Kay.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This renames the struct class "interfaces" field to be
"class_interfaces" to make things easier when struct bus_type and struct
class merge in the future. It also makes grepping for fields easier as
well.
Based on an idea from Kay.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This renames the struct class "devices" field to be "class_devices" to
make things easier when struct bus_type and struct class merge in the
future. It also makes grepping for fields easier as well.
Based on an idea from Kay.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This moves the portions of struct class that are dynamic (kobject and
lock and lists) out of the main structure and into a dynamic, private,
structure.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix up a number of coding style issues in the drivers/base/ directory
that have annoyed me over the years. checkpatch.pl is now very happy.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When SYSFS=n and MODULES=y, build ends with:
linux-2.6.24-rc6-mm1/drivers/base/module.c: In function 'module_add_driver':
linux-2.6.24-rc6-mm1/drivers/base/module.c:49: error: 'module_kset' undeclared (first use in this function)
make[3]: *** [drivers/base/module.o] Error 1
Below is one possible fix.
Build-tested with all 4 config combinations of SYSFS & MODULES.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
LIST_HEAD has been widely used, so switch to this simpler method.
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes the kobject, and a few other driver-core-only fields
out of struct driver and into the driver core only. Now drivers can be
safely create on the stack or statically (like they currently are.)
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The module driver specific code should belong in the driver core, not in
the kernel/ directory. So move this code. This is done in preparation
for some struct device_driver rework that should be confined to the
driver core code only.
This also lets us keep from exporting these functions, as no external
code should ever be calling it.
Thanks to Andrew Morton for the !CONFIG_MODULES fix.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
struct bus_type is static everywhere in the kernel. This moves the
kobject in the structure out of it, and a bunch of other private only to
the driver core fields are now moved to a private structure. This lets
us dynamically create the backing kobject properly and gives us the
chance to be able to document to users exactly how to use the struct
bus_type as there are no fields they can improperly access.
Thanks to Kay for the build fixes on this patch.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Dynamically create the kset instead of declaring it statically. We also
rename devices_subsys to devices_kset to catch all users of the
variable.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
get_bus() should not be globally visable as it is not used by anything
other than drivers/base/bus.c. This patch removes the visability of it,
and renames it to match all of the other *_get() functions in the
kernel.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
put_bus() should not be globally visable as it is not used by anything
other than drivers/base/bus.c. This patch removes the visability of it,
and renames it to match all of the other *_put() functions in the
kernel.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Every file should include the headers containing the prototypes for
it's global functions.
Since the GNU C compiler is now able to detect that the function
prototype of devres_release_all() in the header and the actual function
disagree regarding the return value, this patch also fixes this bug.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We need to work on cleaning up the relationship between kobjects, ksets and
ktypes. The removal of 'struct subsystem' is the first step of this,
especially as it is not really needed at all.
Thanks to Kay for fixing the bugs in this patch.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Don't fail bus_attach_device() if the device cannot be bound.
If dev->driver has been specified, reset it to NULL if device_bind_driver()
failed and add the device as an unbound device. As a result,
bus_attach_device() now cannot fail, and we can remove some checking from
device_add().
Also remove an unneeded check in bus_rescan_devices_helper().
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement device resource management, in short, devres. A device
driver can allocate arbirary size of devres data which is associated
with a release function. On driver detach, release function is
invoked on the devres data, then, devres data is freed.
devreses are typed by associated release functions. Some devreses are
better represented by single instance of the type while others need
multiple instances sharing the same release function. Both usages are
supported.
devreses can be grouped using devres group such that a device driver
can easily release acquired resources halfway through initialization
or selectively release resources (e.g. resources for port 1 out of 4
ports).
This patch adds devres core including documentation and the following
managed interfaces.
* alloc/free : devm_kzalloc(), devm_kzfree()
* IO region : devm_request_region(), devm_release_region()
* IRQ : devm_request_irq(), devm_free_irq()
* DMA : dmam_alloc_coherent(), dmam_free_coherent(),
dmam_declare_coherent_memory(), dmam_pool_create(),
dmam_pool_destroy()
* PCI : pcim_enable_device(), pcim_pin_device(), pci_is_managed()
* iomap : devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(),
devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(),
pcim_iomap(), pcim_iounmap()
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This is needed for a future patch for the device code to create the
proper symlinks for devices that are "class devices".
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
To have a home for all hypervisors, this patch creates /sys/hypervisor.
A new config option SYS_HYPERVISOR is introduced, which should to be set
by architecture dependent hypervisors (e.g. s390 or Xen).
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
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>
This patch contains the following changes:
- move prototypes to base.h
- sys.c should #include "base.h" for getting the prototype of it's
global function system_bus_init()
Note that hidden in this patch there's a bugfix:
Caller and callee disagreed regarding the return type of
sysdev_shutdown().
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are a number of sparse warnings from the latest sparse
snapshot being generated from the drivers/base build. The
main culprits are due to the initialisation functions not
being declared in a header file.
Also, the firmware.c file should include <linux/device.h>
to get the prototype of firmware_register() and
firmware_unregister().
This patch moves the init function declerations from the
init.c file to the base.h, and ensures it is included in
all the relevant c sources. It also adds <linux/device.h>
to the included headers for firmware.c.
The patch does not solve all the sparse errors generated,
but reduces the count significantly.
drivers/base/core.c:161:1: warning: symbol 'devices_subsys' was not declared. Should it be static?
drivers/base/core.c:417:12: warning: symbol 'devices_init' was not declared. Should it be static?
drivers/base/sys.c:253:6: warning: symbol 'sysdev_shutdown' was not declared. Should it be static?
drivers/base/sys.c:326:5: warning: symbol 'sysdev_suspend' was not declared. Should it be static?
drivers/base/sys.c:428:5: warning: symbol 'sysdev_resume' was not declared. Should it be static?
drivers/base/sys.c:450:12: warning: symbol 'system_bus_init' was not declared. Should it be static?
drivers/base/bus.c:133:1: warning: symbol 'bus_subsys' was not declared. Should it be static?
drivers/base/bus.c:667:12: warning: symbol 'buses_init' was not declared. Should it be static?
drivers/base/class.c:759:12: warning: symbol 'classes_init' was not declared. Should it be static?
drivers/base/platform.c:313:12: warning: symbol 'platform_bus_init' was not declared. Should it be static?
drivers/base/cpu.c:110:12: warning: symbol 'cpu_dev_init' was not declared. Should it be static?
drivers/base/firmware.c:17:5: warning: symbol 'firmware_register' was not declared. Should it be static?
drivers/base/firmware.c:23:6: warning: symbol 'firmware_unregister' was not declared. Should it be static?
drivers/base/firmware.c:28:12: warning: symbol 'firmware_init' was not declared. Should it be static?
drivers/base/init.c:28:13: warning: symbol 'driver_init' was not declared. Should it be static?
drivers/base/dmapool.c:174:10: warning: implicit cast from nocast type
drivers/base/attribute_container.c:439:1: warning: symbol 'attribute_container_init' was not declared. Should it be static?
drivers/base/power/runtime.c:76:6: warning: symbol 'dpm_set_power_state' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds a single file, "bind", to the sysfs directory of every driver
registered with the driver core. To bind a device to a driver, write
the bus id of the device you wish to bind to that specific driver to the
"bind" file (remember to not add a trailing \n). If that bus id matches
a device on that bus, and it does not currently have a driver bound to
it, the probe sequence will be initiated with that driver and device.
Note, this requires that the driver itself be willing and able to accept
that device (usually through a device id type table). This patch does
not make it possible to override the driver's id table.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This relocates the driver binding/unbinding code to drivers/base/dd.c. This is done
for two reasons: One, it's not code related to the bus_type itself; it uses some from
that, some from devices, and some from drivers. And Two, it will make it easier to do
some of the upcoming lock removal on that code..
Signed-off-by: Patrick Mochel <mochel@digitalimplant.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!
