device property: Don't use "proxy" headers

Update header inclusions to follow IWYU (Include What You Use)
principle.

Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240301180138.271590-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Let args be NULL in software_node_get_reference_args

fwnode_get_property_reference_args() may not be called with args argument
NULL and while OF already supports this. Add the missing NULL check.

The purpose is to be able to count the references.

Fixes: b06184acf751 ("software node: Add software_node_get_reference_args()")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20231109101010.1329587-3-sakari.ailus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

This is less verbose.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/c7cdc3566c783d106138698b1e1923351fabace8.1698831275.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: make kobj_type structures constant

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definitions to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20230204-kobj_type-driver-core-v1-1-b9f809419f2c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Remove unused APIs

There are no more users of software_node_register_nodes() and
software_node_unregister_nodes(). Remove them.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Daniel Scally <dan.scally@ideasonboard.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20221228094922.84119-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: fix wrong node passed to find nargs_prop

nargs_prop refers to a property located in the reference that is found
within the nargs property. Use the correct reference node in call to
property_entry_read_int_array() to retrieve the correct nargs value.

Fixes: b06184acf751 ("software node: Add software_node_get_reference_args()")
Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Daniel Scally <djrscally@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

device property: Drop redundant NULL checks

In cases when functions are called via fwnode operations,
we already know that this is software node we are dealing
with, hence no need to check if it's NULL, it can't be,

Reported-by: YE Chengfeng <cyeaa@connect.ust.hk>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211026162954.89811-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: balance refcount for managed software nodes

software_node_notify(), on KOBJ_REMOVE drops the refcount twice on managed
software nodes, thus leading to underflow errors. Balance the refcount by
bumping it in the device_create_managed_software_node() function.

The error [1] was encountered after adding a .shutdown() op to our
fsl-mc-bus driver.

[1]
pc : refcount_warn_saturate+0xf8/0x150
lr : refcount_warn_saturate+0xf8/0x150
sp : ffff80001009b920
x29: ffff80001009b920 x28: ffff1a2420318000 x27: 0000000000000000
x26: ffffccac15e7a038 x25: 0000000000000008 x24: ffffccac168e0030
x23: ffff1a2428a82000 x22: 0000000000080000 x21: ffff1a24287b5000
x20: 0000000000000001 x19: ffff1a24261f4400 x18: ffffffffffffffff
x17: 6f72645f726f7272 x16: 0000000000000000 x15: ffff80009009b607
x14: 0000000000000000 x13: ffffccac16602670 x12: 0000000000000a17
x11: 000000000000035d x10: ffffccac16602670 x9 : ffffccac16602670
x8 : 00000000ffffefff x7 : ffffccac1665a670 x6 : ffffccac1665a670
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000ffffffff
x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff1a2420318000
Call trace:
refcount_warn_saturate+0xf8/0x150
kobject_put+0x10c/0x120
software_node_notify+0xd8/0x140
device_platform_notify+0x4c/0xb4
device_del+0x188/0x424
fsl_mc_device_remove+0x2c/0x4c
rebofind sp.c__fsl_mc_device_remove+0x14/0x2c
device_for_each_child+0x5c/0xac
dprc_remove+0x9c/0xc0
fsl_mc_driver_remove+0x28/0x64
__device_release_driver+0x188/0x22c
device_release_driver+0x30/0x50
bus_remove_device+0x128/0x134
device_del+0x16c/0x424
fsl_mc_bus_remove+0x8c/0x114
fsl_mc_bus_shutdown+0x14/0x20
platform_shutdown+0x28/0x40
device_shutdown+0x15c/0x330
__do_sys_reboot+0x218/0x2a0
__arm64_sys_reboot+0x28/0x34
invoke_syscall+0x48/0x114
el0_svc_common+0x40/0xdc
do_el0_svc+0x2c/0x94
el0_svc+0x2c/0x54
el0t_64_sync_handler+0xa8/0x12c
el0t_64_sync+0x198/0x19c
---[ end trace 32eb1c71c7d86821 ]---

Fixes: 151f6ff78cdf ("software node: Provide replacement for device_add_properties()")
Reported-by: Jon Nettleton <jon@solid-run.com>
Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: 5.12+ <stable@vger.kernel.org> # 5.12+
[ rjw: Fix up the software_node_notify() invocation ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software nodes: Split software_node_notify()

Split software_node_notify_remove) out of software_node_notify()
and make device_platform_notify() call the latter on device addition
and the former on device removal.

While at it, put the headers of the above functions into base.h,
because they don't need to be present in a global header file.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

software node: Handle software node injection to an existing device properly

The function software_node_notify() - the function that creates
and removes the symlinks between the node and the device - was
called unconditionally in device_add_software_node() and
device_remove_software_node(), but it needs to be called in
those functions only in the special case where the node is
added to a device that has already been registered.

This fixes NULL pointer dereference that happens if
device_remove_software_node() is used with device that was
never registered.

Fixes: b622b24519f5 ("software node: Allow node addition to already existing device")
Reported-and-tested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Allow node addition to already existing device

If the node is added to an already exiting device, the node
needs to be also linked to the device separately.

This will make sure the reference count is kept in balance
also when the node is injected to a device afterwards.

Fixes: e68d0119e328 ("software node: Introduce device_add_software_node()")
Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210414075438.64547-1-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Imply kobj_to_swnode() to be no-op

Since we don't use structure field layout randomization
the manual shuffling can affect some macros, in particular
kobj_to_swnode(), which becomes a no-op when kobj member
is the first one in the struct swnode.

Bloat-o-meter statistics for swnode.o:

add/remove: 0/0 grow/shrink: 2/10 up/down: 9/-100 (-91)
Total: Before=7217, After=7126, chg -1.26%

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210329151207.36619-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Deduplicate code in fwnode_create_software_node()

Deduplicate conditional and assignment in fwnode_create_software_node(),
i.e. parent is checked in two out of three cases and parent software node
is assigned by to_swnode() call.

Reviewed-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210329151207.36619-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Introduce software_node_alloc()/software_node_free()

Introduce software_node_alloc() and software_node_free() helpers.
This will help with code readability and maintenance.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210329151207.36619-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Free resources explicitly when swnode_register() fails

Currently we have a slightly twisted logic in swnode_register().
It frees resources that it doesn't allocate on error path and
in once case it relies on the ->release() implementation.

Untwist the logic by freeing resources explicitly when swnode_register()
fails. Currently it happens only in fwnode_create_software_node().

Tested-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210329151207.36619-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

device property: Sync descriptions of swnode array and group APIs

After a few updates against swnode APIs the kernel documentation, i.e.
for swnode group registration and unregistration deviates from the one
for swnode array. In general, the same rules are applied to both.
Hence, synchronize descriptions of swnode array and group APIs

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210308103644.81960-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Fix device_add_software_node()

The function device_add_software_node() was meant to
register the node supplied to it, but only if that node
wasn't already registered. Right now the function attempts
to always register the node. That will cause a failure with
nodes that are already registered.

Fixing that by incrementing the reference count of the nodes
that have already been registered, and only registering the
new nodes. Also, clarifying the behaviour in the function
documentation.

Fixes: e68d0119e328 ("software node: Introduce device_add_software_node()")
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Fix node registration

Software node can not be registered before its parent.

Fixes: 80488a6b1d3c ("software node: Add support for static node descriptors")
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

media: software_node: Add support for fwnode_graph*() family of functions

This implements the remaining .graph_*() callbacks in the fwnode
operations structure for the software nodes. That makes the
fwnode_graph_*() functions available in the drivers also when software
nodes are used.

The implementation tries to mimic the "OF graph" as much as possible, but
there is no support for the "reg" device property. The ports will need to
have the index in their name which starts with "port@" (for example
"port@0", "port@1", ...) and endpoints will use the index of the software
node that is given to them during creation. The port nodes can also be
grouped under a specially named "ports" subnode, just like in DT, if
necessary.

The remote-endpoints are reference properties under the endpoint nodes
that are named "remote-endpoint".

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Co-developed-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: software_node: unregister software_nodes in reverse order

To maintain consistency with software_node_unregister_nodes(), reverse
the order in which the software_node_unregister_node_group() function
unregisters nodes.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: software_node: Enforce parent before child ordering of nodes arrays

Registering software_nodes with the .parent member set to point to a
currently unregistered software_node has the potential for problems,
so enforce parent -> child ordering in arrays passed in to
software_node_register_nodes().

Software nodes that are children of another software node should be
unregistered before their parent. To allow easy unregistering of an array
of software_nodes ordered parent to child, reverse the order in which
software_node_unregister_nodes() unregisters software_nodes.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: software_node: Fix refcounts in software_node_get_next_child()

The software_node_get_next_child() function currently does not hold
references to the child software_node that it finds or put the ref that
is held against the old child - fix that.

Fixes: 59abd83672f7 ("drivers: base: Introducing software nodes to the firmware node framework")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

software node: Provide replacement for device_add_properties()

At the moment the function device_del() is calling
device_remove_properties() unconditionally. That will result into the
reference count of the software node attached to the device being
decremented, and in most cases it will hit 0 at that point. So in
practice device_del() will unregister the software node attached to
the device, even if that was not the intention of the caller. Right
now software nodes can not be reused or shared because of that.

So device_del() can not unregister the software nodes unconditionally
like that. Unfortunately some of the users of device_add_properties()
are now relying on this behaviour. Because of that, and also in
general, we do need a function that can offer similar behaviour where
the lifetime of the software node is bound to the lifetime of the
device. But it just has to be a separate function so the behaviour is
optional. We can not remove the device_remove_properties() call from
device_del() before we have that new function, and before we have
replaced device_add_properties() calls with it in all the places that
require that behaviour.

This adds function device_create_managed_software_node() that can be
used for exactly that purpose. Software nodes created with it are
declared "managed", and separate handling for those nodes is added to
the software node code. The reference count of the "managed" nodes is
decremented when the device they are attached to is removed. This will
not affect the other nodes that are not declared "managed".

The function device_create_managed_software_node() has also one
additional feature that device_add_properties() does not have. It
allows the software nodes created with it to be part of a node
hierarchy by taking also an optional parent node as parameter.

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210204141711.53775-2-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Introduce device_add_software_node()

This helper will register a software node and then assign
it to device at the same time. The function will also make
sure that the device can't have more than one software node.

Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210115094914.88401-2-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Add fwnode_init()

There are multiple locations in the kernel where a struct fwnode_handle
is initialized. Add fwnode_init() so that we have one way of
initializing a fwnode_handle.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-8-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Use software_node_unregister() when unregistering group of nodes

After the commit
46d26819a505 ("software node: implement software_node_unregister()")
has been applied a new helper appears that may be utilised in other places.
For time being there is one such place, i.e. in
software_node_unregister_node_group() which will benefit of the clean up.

Use software_node_unregister() when unregistering group of nodes.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200622082108.25577-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: implement software_node_unregister()

Sometimes it is better to unregister individual nodes instead of trying
to do them all at once with software_node_unregister_nodes(), so create
software_node_unregister() so that you can unregister them one at a
time.

This is especially important when creating nodes in a hierarchy, with
parent -> children representations. Children always need to be removed
before a parent is, as the swnode logic assumes this is going to be the
case.

Fix up the lib/test_printf.c fwnode_pointer() test which to use this new
function as it had the problem of tearing things down in the backwards
order.

Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier")
Cc: stable <stable@vger.kernel.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: kernel test robot <rong.a.chen@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Petr Mladek <pmladek@suse.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20200524153041.2361-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software node: Allow register and unregister software node groups

Sometimes it's more convenient to register a set of individual software nodes
grouped together. Add couple of functions for that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Revert "software node: Simplify software_node_release() function"

This reverts commit 3df85a1ae51f6b256982fe9d17c2dc5bfb4cc402.

The reverted commit says "It's possible to release the node ID
immediately when fwnode_remove_software_node() is called, no need to
wait for software_node_release() with that." However, releasing the node
ID before waiting for software_node_release() to be called causes the
node ID to be released before the kobject and the underlying sysfs
entry; this means there is a period of time where a sysfs entry exists
that is associated with an unallocated node ID.

Once consequence of this is that there is a race condition where it is
possible to call fwnode_create_software_node() with no parent node
specified (NULL) and have it fail with -EEXIST because the node ID that
was assigned is still associated with a stale sysfs entry that hasn't
been cleaned up yet.

Although it is difficult to reproduce this race condition under normal
conditions, it can be deterministically reproduced with the following
minconfig on UML:

CONFIG_KUNIT_DRIVER_PE_TEST=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_OBJECTS=y
CONFIG_DEBUG_OBJECTS_TIMERS=y
CONFIG_DEBUG_KOBJECT_RELEASE=y
CONFIG_KUNIT=y

Running the tests with this configuration causes the following failure:

<snip>
kobject: 'node0' ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed 400)
ok 1 - pe_test_uints
sysfs: cannot create duplicate filename '/kernel/software_nodes/node0'
CPU: 0 PID: 28 Comm: kunit_try_catch Not tainted 5.6.0-rc3-next-20200227 #14
<snip>
kobject_add_internal failed for node0 with -EEXIST, don't try to register things with the same name in the same directory.
kobject: 'node0' ((____ptrval____)): kobject_release, parent (____ptrval____) (delayed 100)
# pe_test_uint_arrays: ASSERTION FAILED at drivers/base/test/property-entry-test.c:123
Expected node is not error, but is: -17
not ok 2 - pe_test_uint_arrays
<snip>

Reported-by: Heidi Fahim <heidifahim@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: remove separate handling of references

Now that all users of references have moved to reference properties,
we can remove separate handling of references.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: implement reference properties

It is possible to store references to software nodes in the same fashion as
other static properties, so that users do not need to define separate
structures:

static const struct software_node gpio_bank_b_node = {
.name = "B",
};

static const struct property_entry simone_key_enter_props[] = {
PROPERTY_ENTRY_U32("linux,code", KEY_ENTER),
PROPERTY_ENTRY_STRING("label", "enter"),
PROPERTY_ENTRY_REF("gpios", &gpio_bank_b_node, 123, GPIO_ACTIVE_LOW),
{ }
};

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: allow embedding of small arrays into property_entry

We should not conflate whether a property data is an array or a single
value with where it is stored (embedded into property_entry structure or
out-of-line). All single-value properties are in effect 1-element
arrays, and we can figure the amount of data stored in a property by
examining its length and the data type. And arrays can be as easily
stored in property entry instances as single values are, provided that
we have enough space (we have up to 8 bytes). We can embed:

- up to 8 bytes from U8 arrays
- up to 4 words
- up to 2 double words
- one U64 value
- one (on 64 bit architectures) or 2 (on 32 bit) strings.

This change also has an effect of switching properties with small amount
of data to embed it instead of keeping it separate when copying such
properties.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: replace is_array with is_inline

We do not need a special flag to know if we are dealing with an
array, as we can get that data from ratio between element length and
the data size, but we do need a flag to know whether or not the data
is stored directly inside property_entry.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
[ rjw: Subject & changelog, struct property_entry kerneldoc ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: simplify property_entry_read_string_array()

There is no need to treat string arrays and single strings separately, we can go
exclusively by the element length in relation to data type size.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: remove property_entry_read_uNN_array functions

There is absolutely no reason to have them as we can handle it all nicely in
property_entry_read_int_array().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: get rid of property_set_pointer()

Instead of explicitly setting values of integer types when copying
property entries lets just copy entire value union when processing
non-array values.

For value arrays we no longer use union of pointers, but rather a single
void pointer, which allows us to remove property_set_pointer().

In property_get_pointer() we do not need to handle each data type
separately, we can simply return either the pointer or pointer to values
union.

We are not losing anything from removing typed pointer union because the
upper layers do their accesses through void pointers anyway, and we
trust the "type" of the property when interpret the data. We rely on
users of property entries on using PROPERTY_ENTRY_XXX() macros to
properly initialize entries instead of poking in the instances directly.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: clean up property_copy_string_array()

Because property_copy_string_array() stores the newly allocated pointer in the
destination property, we have an awkward code in property_entry_copy_data()
where we fetch the new pointer from dst.

Let's change property_copy_string_array() to return pointer and rely on the
common path in property_entry_copy_data() to store it in destination structure.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

device property: Add a function to obtain a node's prefix

The prefix is used for printing purpose before a node, and it also works
as a separator between two nodes.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org> (for OF)
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

device property: Add fwnode_get_name for returning the name of a node

The fwnode framework did not have means to obtain the name of a node. Add
that now, in form of the fwnode_get_name() function and a corresponding
get_name fwnode op. OF and ACPI support is included.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org> (for OF)
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Make argument to to_software_node const

to_software_node() does not need to modify the fwnode_handle it operates
on; therefore make it const. This allows passing a const fwnode_handle to
to_software_node().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Get reference to parent swnode in get_parent op

The software_node_get_parent() returned a pointer to the parent swnode,
but did not take a reference to it, leading the caller to put a reference
that was not taken. Take that reference now.

Fixes: 59abd83672f7 ("drivers: base: Introducing software nodes to the firmware node framework")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Initialize the return value in software_node_find_by_name()

The software node is searched from a list that may be empty
when the function is called. This makes sure that the
function returns NULL if the list is empty.

Fixes: 1666faedb567 ("software node: Add software_node_find_by_name()")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Initialize the return value in software_node_to_swnode()

The software node is searched from a list that may be empty
when the function is called. This makes sure that the
function returns NULL even if the list is empty.

Fixes: 80488a6b1d3c ("software node: Add support for static node descriptors")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Add software_node_find_by_name()

Function that searches software nodes by node name.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Add software_node_get_reference_args()

This makes it possible to support drivers that use
fwnode_property_get_reference_args() function.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Use kobject name when finding child nodes by name

Using the kobject name of the node instead of a device
property "name" in software_node_get_named_child_node().

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Add support for static node descriptors

Until now the software nodes could only be created
dynamically with fwnode_create_software_node() function.
This introduces struct software_node data structure, which
makes it possible to describe the software nodes also
statically.

The statically described software nodes can be registered
with a new function fwnode_register_software_node(). This
also adds a helper fwnode_register_software_nodes()
which makes it possible to register an array of struct
software_nodes, i.e. multiple nodes at the same time.

There is no difference between statically described and
dynamically allocated software nodes. Even the registration
does not differ, except that during node creation the device
properties are only copied if the node is created
dynamically. With statically described nodes, the property
entries in the descriptor (struct software_node) are
assigned directly to the new software node that is being
created without any copies.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Simplify software_node_release() function

It's possible to release the node ID immediately when
fwnode_remove_software_node() is called, no need to wait for
software_node_release() with that.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Allow node creation without properties

Software nodes are not forced to have device properties.
Adding check to property_entries_dup() to make it possible
to create software nodes that don't have any properties.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers: base: swnode: Make two functions static

Fix sparse warning:

drivers/base/swnode.c:475:22: warning: symbol 'software_node_get_parent' was not declared. Should it be static?
drivers/base/swnode.c:484:22: warning: symbol 'software_node_get_next_child' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

software node: Implement get_named_child_node fwnode callback

This makes it possible to support drivers that use
fwnode_get_named_child_node() and device_get_named_child_node()
functions.

The node name is for now taken from a device property named
"name". That mimics the old style of naming of the nodes in
devicetree (though with modern flattened DT, the name is
matched against the actual node-name, it used to be done
with a property "name"). In Open Firmware DT the "name"
property is also still being used.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers: base: swnode: check if swnode is NULL before dereferencing it

The to_software_mode() macro can potentially return NULL, so also add
a NULL check on swnode before dereferencing it to avoid any NULL
pointer dereferences.

Detected by CoverityScan, CID#1476052 ("Explicit null dereferenced")

Fixes: 59abd83672f7 (drivers: base: Introducing software nodes to the firmware node framework)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers: base: swnode: check if pointer p is NULL before dereferencing it

The pointer p can be potentially NULL as macro to_software_node can
return NULL.

Add null check on p before dereferencing it to avoid any NULL pointer
dereferences.

Detected by CoverityScan, CID#1476039 ("Explicit null dereferenced")

Fixes: 59abd83672f7 (drivers: base: Introducing software nodes to the firmware node framework)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers: base: swnode: remove need for a temporary string for the node name

Currently the node name is being formatting into a temporary string
node_name, however, kobject_init_and_add allows one to format up
a node name, so use that instead. This removes the need for the
node_name string and also cleans up the following warning:

Fixes clang warning:
warning: format string is not a string literal (potentially
insecure) [-Wformat-security]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

device property: Move device_add_properties() to swnode.c

Concentrating struct property_entry processing to
drivers/base/swnode.c

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers: base: Introducing software nodes to the firmware node framework

Software node is a new struct fwnode_handle type that can be
used to describe devices in kernel (software). It is meant
to complement fwnodes representing real firmware nodes when
they are incomplete (for example missing device properties)
and to supply the primary fwnode when the firmware lacks
hardware description for a device completely.

The software node type is really meant to replace the
currently used "property_set" struct fwnode_handle type. The
handling of struct property_set is glued to the generic
device property handling code, and it is not possible to
create a struct property_set independently from the device
that it is bind to. struct property_set is only created when
device properties are added to already initialized struct
device, and control of it is only possible from the generic
property handling code.

Software nodes are instead designed to be created
independently from the device entries (struct device). It
makes them much more flexible, as then the device meant to
be bind to the node can be created at a later time, and from
another location. It is also possible to bind multiple
devices to a single software node if needed.

The software node implementation also includes support for
node hierarchy, which was the main motivation for this
commit. The node hierarchy was something that was requested
for the struct property_set, but it did not seem reasonable
to try to extend the property_set support for that purpose.
struct property_set was really meant only for device
property handling like the name suggests.

Support for struct property_set is not yet removed in this
commit, but it will be in the following one.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>