driver_find_device() can be called with an unregistered driver. Need
to check driver_private to see if it's populated or not, especially
under deferrable probe.

In the case that there are 2 drivers, one depends on the other. With
-EPROBE_DEFER, two drivers can use deferred probe to ensure that their
relative probe order doesn't matter. If dependee driver is probed
first, then the dependant's driver_find_device('dependee')
succeeds. If the dependant is probed first, then the dependant's
driver_find_device('dependee') should return NULL, and the dependant
should get -EPROBE_DEFER. driver_find_device() needs to return NULL if
it's not populated.

In [PATCHv5 2/3] ARM: tegra: Add SMMU enabler in AHB:
  http://article.gmane.org/gmane.linux.ports.tegra/4658

"tegra_ahb_driver" may not be populated when it's called.

For more SMMU/AHB specific discussion, refer to the following thread:
  https://lkml.org/lkml/2012/5/10/21Signed-off-by: NHiroshi DOYU <hdoyu@nvidia.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit a15d49fd as that
patch broke the build.

Cc: Hannes Reinecke <hare@suse.de>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

klist_iter_init_node() takes a node as a start argument.
However, this node might not be valid anymore.
This patch updates the klist_iter_init_node() and
dependent functions to return an error if so.
All calling functions have been audited to check
for a return code here.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Cc: Greg Kroah-Hartmann <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Stable Kernel <stable@kernel.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The PowerPC legacy iSeries plateform is being removed along with the
"one looney iseries driver", so this code can now be removed as well.

cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Now that there are no users of get_driver() or put_driver(), this
patch (as1513) removes those routines completely.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

As part of the removal of get_driver()/put_driver(), this patch
(as1510) changes driver_find(); it now drops the reference it acquires
before returning.  The patch also adjusts all the callers of
driver_find() to remove the now unnecessary calls to put_driver().

In addition, the patch adds a warning to driver_find(): Callers must
make sure the driver they are searching for does not get unloaded
while they are using it.  This has always been the case; driver_find()
has never prevented a driver from being unregistered or unloaded.
Hence the patch will not introduce any new bugs.  The existing callers
all seem to be okay in this respect, however I don't understand the
video drivers well enough to be certain about them.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CC: Kyungmin Park <kyungmin.park@samsung.com>
CC: Andy Walls <awalls@md.metrocast.net>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Many struct driver_attribute descriptors are purely read-only
structures, and there's no need to change them. Therefore make
the promise not to, which will let those descriptors be put in
a ro section.
Signed-off-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In this patch:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=16dc42e018c2868211b4928f20a957c0c216126c
the check was added for another driver to already claim the same device
on the same bus. But the returned error code was wrong: to modprobe, the
-EEXIST means that _this_ driver is already installed. It therefore
doesn't produce the needed error message when _another_ driver is trying
to register for the same device.  Returning -EBUSY fixes the problem.
Signed-off-by: NStas Sergeev <stsp@aknet.ru>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Let attribute group vectors be declared "const".  We'd
like to let most attribute metadata live in read-only
sections... this is a start.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We also fix a problem with cleaning up properly when initializing
drivers and devices, so checks like this will work successfully.

Portions of the patch by Linus and Greg and Ingo.
Reported-by: NOzan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NGreg 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: NGreg Kroah-Hartman <gregkh@suse.de>

If the bus_type is not registerd, driver_register to that bus will cause oops.

I found this bug when test built-in usb serial drivers (ie. aircable driver)
with 'nousb' cmdline params.

In this patch:
1. set the bus->p=NULL when bus_register failed and unregisterd.
2. if bus->p is NULL, driver_register BUG_ON will be triggered.
Signed-off-by: NDave Young <hidave.darkstar@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This reverts commit 93e746db.

Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.
Reported-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg 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: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Currently an attempt to register multiple
drivers with the same name causes the
stack trace with some cryptic error message.
The attached patch adds the necessary check
and the clear error message.
Signed-off-by: NStas Sergeev <stsp@aknet.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The Coverity checker spotted that we leak the storage allocated to 'name' in
int driver_add_kobj().  The leak looks legit to me - this is the code :

int driver_add_kobj(struct device_driver *drv, struct kobject *kobj,
                    const char *fmt, ...)
{
        va_list args;
        char *name;
        int ret;

        va_start(args, fmt);
        name = kvasprintf(GFP_KERNEL, fmt, args);
        ^^^^^^^^ This dynamically allocates space...

        va_end(args);

        if (!name)
                return -ENOMEM;

        return kobject_add(kobj, &drv->p->kobj, "%s", name);
	^^^^^^^^ This neglects to free the space allocated
}

Inside kobject_add() a copy of 'name' will be made and used.  As far as I can
see, Coverity is correct in flagging this as a leak, but I'd like some
configmation before the patch is applied.

This should fix it.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix drivers/base/ missing kernel-doc parameters:
Warning(linux-2.6.24-git12//drivers/base/driver.c:133): No description found for parameter 'drv'
Warning(linux-2.6.24-git12//drivers/base/driver.c:133): No description found for parameter 'kobj'
Warning(linux-2.6.24-git12//drivers/base/driver.c:133): No description found for parameter 'fmt'
Warning(linux-2.6.24-git12//drivers/base/power/main.c:530): No description found for parameter 'state'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Driver core: Remove unneeded get_{device,driver}() calls.

Code trying to add/remove attributes must hold a reference to
the device resp. driver anyway, so let's remove those reference
count games.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: NGreg 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: NGreg Kroah-Hartman <gregkh@suse.de>

Now that the old kobject_add() function is gone, rename kobject_add_ng()
to kobject_add() to clean up the namespace.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg 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: NGreg Kroah-Hartman <gregkh@suse.de>

The iseries driver wants to hang kobjects off of its driver, so, to
preserve backwards compatibility, we need to add a call to the driver
core to allow future changes to work properly.

Hopefully no one uses this function in the future and the iseries_veth
driver authors come to their senses so I can remove this hack...

Cc: Dave Larson <larson1@us.ibm.com>
Cc: Santiago Leon <santil@us.ibm.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is lot like default attributes for devices (and indeed,
a lot of the code is lifted from there).
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGreg 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: NGreg Kroah-Hartman <gregkh@suse.de>

Dynamically create the kset instead of declaring it statically.

Having 3 static kobjects in one structure is not only foolish, but ripe
for nasty race conditions if handled improperly.  We also rename the
field to catch any potential users of it (not that there should be
outside of the driver core...)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The completion in the driver release path is due to ancient history in
the _very_ early 2.5 days when we were not tracking the module reference
count of attributes.  It is not needed at all and can be removed.

Note, we now have an empty release function for the driver structure.
This is due to the fact that drivers are statically allocated in the
system at this point in time, something which I want to change in the
future.  But remember, drivers are really code, which is reference
counted by the module, unlike devices, which are data and _must_ be
reference counted properly in order to work correctly.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Ingo reported that built-in drivers suffered bootup hangs with certain
driver unregistry sequences, due to sysfs breakage.

Do the minimal fix for v2.6.21: only wait if the driver is a module.
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch (as783) simplifies the driver core slightly by removing four
unnecessary _get and _put methods.

It is vital that when a driver is removed from its bus's klist of
registered drivers, or when a device is removed from a driver's klist
of bound devices, that the klist updates complete synchronously.
Otherwise the kernel might try binding an unregistered driver to a
newly-registered device, or adding a device to the klist for a new
driver before it has been removed from the old driver's klist.

Since the removals must be synchronous, they don't need to update any
reference counts.  Hence the _get and _put methods can be dispensed
with.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Add bus_type probe, remove and shutdown methods to replace the
corresponding methods in struct device_driver.  This matches
the way we handle the suspend/resume methods.

Since the bus methods override the device_driver methods, warn
if a device driver is registered whose methods will not be
called.

The long-term idea is to remove the device_driver methods entirely.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

driver/base: add missing function parameters; eliminate all warnings.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NGreg 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: NJames Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add bus_find_device() and driver_find_device() which allow searching for a
device in the bus's resp. the driver's klist and obtain a reference on it.
Signed-off-by: NCornelia Huck <cohuck@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Index: linux-2.6.12-rc2/drivers/base/driver.c
===================================================================

Signed-off-by: NPatrick Mochel <mochel@digitalimplant.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

diff -Nru a/drivers/base/driver.c b/drivers/base/driver.c

- 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: NPatrick Mochel <mochel@digitalimplant.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now there's an iterator for accessing each device bound to a driver.
Signed-off-by: NPatrick Mochel <mochel@digitalimplant.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Index: linux-2.6.12-rc2/drivers/base/driver.c
===================================================================

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!